Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:

- a few misc things

- ocfs2 updates

- most of MM

* emailed patches from Andrew Morton <[e-mail]>: (159 commits)
tools/testing/selftests/proc/proc-self-syscall.c: remove duplicate include
proc: more robust bulk read test
proc: test /proc/*/maps, smaps, smaps_rollup, statm
proc: use seq_puts() everywhere
proc: read kernel cpu stat pointer once
proc: remove unused argument in proc_pid_lookup()
fs/proc/thread_self.c: code cleanup for proc_setup_thread_self()
fs/proc/self.c: code cleanup for proc_setup_self()
proc: return exit code 4 for skipped tests
mm,mremap: bail out earlier in mremap_to under map pressure
mm/sparse: fix a bad comparison
mm/memory.c: do_fault: avoid usage of stale vm_area_struct
writeback: fix inode cgroup switching comment
mm/huge_memory.c: fix "orig_pud" set but not used
mm/hotplug: fix an imbalance with DEBUG_PAGEALLOC
mm/memcontrol.c: fix bad line in comment
mm/cma.c: cma_declare_contiguous: correct err handling
mm/page_ext.c: fix an imbalance with kmemleak
mm/compaction: pass pgdat to too_many_isolated() instead of zone
mm: remove zone_lru_lock() function, access ->lru_lock directly
...

Documentation/admin-guide/cgroup-v2.rst

···
 		Amount of cached filesystem data that was modified and
 		is currently being written back to disk
 
+	  anon_thp
+		Amount of memory used in anonymous mappings backed by
+		transparent hugepages
+
 	  inactive_anon, active_anon, inactive_file, active_file, unevictable
 		Amount of memory, swap-backed and filesystem-backed,
 		on the internal memory management lists used by the
···
 	  pglazyfreed
 
 		Amount of reclaimed lazyfree pages
+
+	  thp_fault_alloc
+
+		Number of transparent hugepages which were allocated to satisfy
+		a page fault, including COW faults. This counter is not present
+		when CONFIG_TRANSPARENT_HUGEPAGE is not set.
+
+	  thp_collapse_alloc
+
+		Number of transparent hugepages which were allocated to allow
+		collapsing an existing range of pages. This counter is not
+		present when CONFIG_TRANSPARENT_HUGEPAGE is not set.
 
   memory.swap.current
 	A read-only single value file which exists on non-root

Documentation/admin-guide/mm/pagemap.rst

···
     20. NOPAGE
     21. KSM
     22. THP
-    23. BALLOON
+    23. OFFLINE
     24. ZERO_PAGE
     25. IDLE
+    26. PGTABLE
 
  * ``/proc/kpagecgroup``.  This file contains a 64-bit inode number of the
    memory cgroup each page is charged to, indexed by PFN. Only available when
···
     identical memory pages dynamically shared between one or more processes
 22 - THP
     contiguous pages which construct transparent hugepages
-23 - BALLOON
-    balloon compaction page
+23 - OFFLINE
+    page is logically offline
 24 - ZERO_PAGE
     zero page for pfn_zero or huge_zero page
 25 - IDLE
···
     Note that this flag may be stale in case the page was accessed via
     a PTE. To make sure the flag is up-to-date one has to read
     ``/sys/kernel/mm/page_idle/bitmap`` first.
+26 - PGTABLE
+    page is in use as a page table
 
 IO related page flags
 ---------------------

Documentation/cgroup-v1/memcg_test.txt

···
 
 8. LRU
         Each memcg has its own private LRU. Now, its handling is under global
-	VM's control (means that it's handled under global zone_lru_lock).
+	VM's control (means that it's handled under global pgdat->lru_lock).
 	Almost all routines around memcg's LRU is called by global LRU's
-	list management functions under zone_lru_lock().
+	list management functions under pgdat->lru_lock.
 
 	A special function is mem_cgroup_isolate_pages(). This scans
 	memcg's private LRU and call __isolate_lru_page() to extract a page

Documentation/cgroup-v1/memory.txt

···
    Other lock order is following:
    PG_locked.
    mm->page_table_lock
-       zone_lru_lock
+       pgdat->lru_lock
 	  lock_page_cgroup.
   In many cases, just lock_page_cgroup() is called.
   per-zone-per-cgroup LRU (cgroup's private LRU) is just guarded by
-  zone_lru_lock, it has no lock of its own.
+  pgdat->lru_lock, it has no lock of its own.
 
 2.7 Kernel Memory Extension (CONFIG_MEMCG_KMEM)
 

MAINTAINERS

···
 F:	include/uapi/linux/membarrier.h
 F:	arch/powerpc/include/asm/membarrier.h
 
+MEMBLOCK
+M:	Mike Rapoport <[e-mail]>
+L:	[e-mail]
+S:	Maintained
+F:	include/linux/memblock.h
+F:	mm/memblock.c
+F:	Documentation/core-api/boot-time-mm.rst
+
 MEMORY MANAGEMENT
 L:	[e-mail]
 W:	http://www.linux-mm.org

arch/alpha/include/asm/topology.h

···
 
 #include <linux/smp.h>
 #include <linux/threads.h>
+#include <linux/numa.h>
 #include <asm/machvec.h>
 
 #ifdef CONFIG_NUMA
···
 {
 	int cpu;
 
-	if (node == -1)
+	if (node == NUMA_NO_NODE)
 		return cpu_all_mask;
 
 	cpumask_clear(&node_to_cpumask_map[node]);

arch/arm64/Kconfig

···
 	def_bool y
 	depends on COMPAT && SYSVIPC
 
+config ARCH_ENABLE_HUGEPAGE_MIGRATION
+	def_bool y
+	depends on HUGETLB_PAGE && MIGRATION
+
 menu "Power management options"
 
 source "kernel/power/Kconfig"

arch/arm64/include/asm/hugetlb.h

···
 
 #include <asm/page.h>
 
+#ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
+#define arch_hugetlb_migration_supported arch_hugetlb_migration_supported
+extern bool arch_hugetlb_migration_supported(struct hstate *h);
+#endif
+
 #define __HAVE_ARCH_HUGE_PTEP_GET
 static inline pte_t huge_ptep_get(pte_t *ptep)
 {

arch/arm64/include/asm/memory.h

···
  */
 #ifdef CONFIG_KASAN
 #define KASAN_SHADOW_SIZE	(UL(1) << (VA_BITS - KASAN_SHADOW_SCALE_SHIFT))
-#ifdef CONFIG_KASAN_EXTRA
-#define KASAN_THREAD_SHIFT	2
-#else
 #define KASAN_THREAD_SHIFT	1
-#endif /* CONFIG_KASAN_EXTRA */
 #else
 #define KASAN_SHADOW_SIZE	(0)
 #define KASAN_THREAD_SHIFT	0

arch/arm64/kernel/machine_kexec.c

···
  * but does not hold any data of loaded kernel image.
  *
  * Note that all the pages in crash dump kernel memory have been initially
- * marked as Reserved in kexec_reserve_crashkres_pages().
+ * marked as Reserved as memory was allocated via memblock_reserve().
  *
  * In hibernation, the pages which are Reserved and yet "nosave" are excluded
  * from the hibernation iamge. crash_is_nosave() does thich check for crash
···
 
 	for (addr = begin; addr < end; addr += PAGE_SIZE) {
 		page = phys_to_page(addr);
-		ClearPageReserved(page);
 		free_reserved_page(page);
 	}
 }

arch/arm64/mm/hugetlbpage.c

···
 #include <asm/tlbflush.h>
 #include <asm/pgalloc.h>
 
+#ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
+bool arch_hugetlb_migration_supported(struct hstate *h)
+{
+	size_t pagesize = huge_page_size(h);
+
+	switch (pagesize) {
+#ifdef CONFIG_ARM64_4K_PAGES
+	case PUD_SIZE:
+#endif
+	case PMD_SIZE:
+	case CONT_PMD_SIZE:
+	case CONT_PTE_SIZE:
+		return true;
+	}
+	pr_warn("%s: unrecognized huge page size 0x%lx\n",
+			__func__, pagesize);
+	return false;
+}
+#endif
+
 int pmd_huge(pmd_t pmd)
 {
 	return pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT);

arch/arm64/mm/init.c

···
 	crashk_res.start = crash_base;
 	crashk_res.end = crash_base + crash_size - 1;
 }
-
-static void __init kexec_reserve_crashkres_pages(void)
-{
-#ifdef CONFIG_HIBERNATION
-	phys_addr_t addr;
-	struct page *page;
-
-	if (!crashk_res.end)
-		return;
-
-	/*
-	 * To reduce the size of hibernation image, all the pages are
-	 * marked as Reserved initially.
-	 */
-	for (addr = crashk_res.start; addr < (crashk_res.end + 1);
-			addr += PAGE_SIZE) {
-		page = phys_to_page(addr);
-		SetPageReserved(page);
-	}
-#endif
-}
 #else
 static void __init reserve_crashkernel(void)
-{
-}
-
-static void __init kexec_reserve_crashkres_pages(void)
 {
 }
 #endif /* CONFIG_KEXEC_CORE */
···
 #endif
 	/* this will put all unused low memory onto the freelists */
 	memblock_free_all();
-
-	kexec_reserve_crashkres_pages();
 
 	mem_init_print_info(NULL);
 

arch/arm64/mm/numa.c

···
 	}
 
 	/* cpumask_of_node() will now work */
-	pr_debug("Node to cpumask map for %d nodes\n", nr_node_ids);
+	pr_debug("Node to cpumask map for %u nodes\n", nr_node_ids);
 }
 
 /*

arch/ia64/kernel/numa.c

···
 		cpumask_clear(&node_to_cpu_mask[node]);
 
 	for_each_possible_early_cpu(cpu) {
-		node = -1;
+		node = NUMA_NO_NODE;
 		for (i = 0; i < NR_CPUS; ++i)
 			if (cpu_physical_id(cpu) == node_cpuid[i].phys_id) {
 				node = node_cpuid[i].nid;

arch/ia64/kernel/perfmon.c

···
 	if (task != current) put_task_struct(task);
 }
 
-static inline void
-pfm_reserve_page(unsigned long a)
-{
-	SetPageReserved(vmalloc_to_page((void *)a));
-}
-static inline void
-pfm_unreserve_page(unsigned long a)
-{
-	ClearPageReserved(vmalloc_to_page((void*)a));
-}
-
 static inline unsigned long
 pfm_protect_ctx_ctxsw(pfm_context_t *x)
 {
···
 {
 	ctx->ctx_msgq_head = ctx->ctx_msgq_tail = 0;
 	DPRINT(("ctx=%p msgq reset\n", ctx));
-}
-
-static void *
-pfm_rvmalloc(unsigned long size)
-{
-	void *mem;
-	unsigned long addr;
-
-	size = PAGE_ALIGN(size);
-	mem  = vzalloc(size);
-	if (mem) {
-		//printk("perfmon: CPU%d pfm_rvmalloc(%ld)=%p\n", smp_processor_id(), size, mem);
-		addr = (unsigned long)mem;
-		while (size > 0) {
-			pfm_reserve_page(addr);
-			addr+=PAGE_SIZE;
-			size-=PAGE_SIZE;
-		}
-	}
-	return mem;
-}
-
-static void
-pfm_rvfree(void *mem, unsigned long size)
-{
-	unsigned long addr;
-
-	if (mem) {
-		DPRINT(("freeing physical buffer @%p size=%lu\n", mem, size));
-		addr = (unsigned long) mem;
-		while ((long) size > 0) {
-			pfm_unreserve_page(addr);
-			addr+=PAGE_SIZE;
-			size-=PAGE_SIZE;
-		}
-		vfree(mem);
-	}
-	return;
 }
 
 static pfm_context_t *
···
 	/*
 	 * free the buffer
 	 */
-	pfm_rvfree(ctx->ctx_smpl_hdr, ctx->ctx_smpl_size);
+	vfree(ctx->ctx_smpl_hdr);
 
 	ctx->ctx_smpl_hdr  = NULL;
 	ctx->ctx_smpl_size = 0UL;
···
 	 * All memory free operations (especially for vmalloc'ed memory)
 	 * MUST be done with interrupts ENABLED.
 	 */
-	if (smpl_buf_addr)  pfm_rvfree(smpl_buf_addr, smpl_buf_size);
+	vfree(smpl_buf_addr);
 
 	/*
 	 * return the memory used by the context
···
 
 	/*
 	 * We do the easy to undo allocations first.
- 	 *
-	 * pfm_rvmalloc(), clears the buffer, so there is no leak
 	 */
-	smpl_buf = pfm_rvmalloc(size);
+	smpl_buf = vzalloc(size);
 	if (smpl_buf == NULL) {
 		DPRINT(("Can't allocate sampling buffer\n"));
 		return -ENOMEM;
···
 error:
 	vm_area_free(vma);
 error_kmem:
-	pfm_rvfree(smpl_buf, size);
+	vfree(smpl_buf);
 
 	return -ENOMEM;
 }

arch/ia64/mm/discontig.c

···
 	 * CPUs are put into groups according to node.  Walk cpu_map
 	 * and create new groups at node boundaries.
 	 */
-	prev_node = -1;
+	prev_node = NUMA_NO_NODE;
 	ai->nr_groups = 0;
 	for (unit = 0; unit < nr_units; unit++) {
 		cpu = cpu_map[unit];
···
 {
 	void *ptr = NULL;
 	u8 best = 0xff;
-	int bestnode = -1, node, anynode = 0;
+	int bestnode = NUMA_NO_NODE, node, anynode = 0;
 
 	for_each_online_node(node) {
 		if (node_isset(node, memory_less_mask))
···
 		anynode = node;
 	}
 
-	if (bestnode == -1)
+	if (bestnode == NUMA_NO_NODE)
 		bestnode = anynode;
 
 	ptr = memblock_alloc_try_nid(pernodesize, PERCPU_PAGE_SIZE,

arch/m68k/mm/memory.c

···
 	pr_debug("init_pointer_table: %lx, %x\n", ptable, PD_MARKBITS(dp));
 
 	/* unreserve the page so it's possible to free that page */
-	PD_PAGE(dp)->flags &= ~(1 << PG_reserved);
+	__ClearPageReserved(PD_PAGE(dp));
 	init_page_count(PD_PAGE(dp));
 
 	return;

arch/powerpc/include/asm/book3s/64/hugetlb.h

···
 				unsigned long len, unsigned long pgoff,
 				unsigned long flags);
 
+extern void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
+						unsigned long addr, pte_t *ptep,
+						pte_t old_pte, pte_t pte);
+
 static inline int hstate_get_psize(struct hstate *hstate)
 {
 	unsigned long shift;
···
 /* hugepd entry valid bit */
 #define HUGEPD_VAL_BITS		(0x8000000000000000UL)
 
+#define huge_ptep_modify_prot_start huge_ptep_modify_prot_start
+extern pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
+					 unsigned long addr, pte_t *ptep);
+
+#define huge_ptep_modify_prot_commit huge_ptep_modify_prot_commit
+extern void huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
+					 unsigned long addr, pte_t *ptep,
+					 pte_t old_pte, pte_t new_pte);
 #endif

arch/powerpc/include/asm/book3s/64/pgtable.h

···
 	BUILD_BUG();
 	return 0;
 }
+#define __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
+pte_t ptep_modify_prot_start(struct vm_area_struct *, unsigned long, pte_t *);
+void ptep_modify_prot_commit(struct vm_area_struct *, unsigned long,
+			     pte_t *, pte_t, pte_t);
+
+/*
+ * Returns true for a R -> RW upgrade of pte
+ */
+static inline bool is_pte_rw_upgrade(unsigned long old_val, unsigned long new_val)
+{
+	if (!(old_val & _PAGE_READ))
+		return false;
+
+	if ((!(old_val & _PAGE_WRITE)) && (new_val & _PAGE_WRITE))
+		return true;
+
+	return false;
+}
 
 #endif /* __ASSEMBLY__ */
 #endif /* _ASM_POWERPC_BOOK3S_64_PGTABLE_H_ */

arch/powerpc/include/asm/book3s/64/radix.h

···
 					 pte_t entry, unsigned long address,
 					 int psize);
 
+extern void radix__ptep_modify_prot_commit(struct vm_area_struct *vma,
+					   unsigned long addr, pte_t *ptep,
+					   pte_t old_pte, pte_t pte);
+
 static inline unsigned long __radix_pte_update(pte_t *ptep, unsigned long clr,
 					       unsigned long set)
 {

arch/powerpc/include/asm/pci-bridge.h

···
 #include <linux/pci.h>
 #include <linux/list.h>
 #include <linux/ioport.h>
+#include <linux/numa.h>
 
 struct device_node;
 
···
 #ifdef CONFIG_NUMA
 #define PHB_SET_NODE(PHB, NODE)		((PHB)->node = (NODE))
 #else
-#define PHB_SET_NODE(PHB, NODE)		((PHB)->node = -1)
+#define PHB_SET_NODE(PHB, NODE)		((PHB)->node = NUMA_NO_NODE)
 #endif
 
 #endif	/* CONFIG_PPC64 */

arch/powerpc/kernel/paca.c

···
 #include <linux/export.h>
 #include <linux/memblock.h>
 #include <linux/sched/task.h>
+#include <linux/numa.h>
 
 #include <asm/lppaca.h>
 #include <asm/paca.h>
···
 	 * which will put its paca in the right place.
 	 */
 	if (cpu == boot_cpuid) {
-		nid = -1;
+		nid = NUMA_NO_NODE;
 		memblock_set_bottom_up(true);
 	} else {
 		nid = early_cpu_to_node(cpu);

arch/powerpc/kernel/pci-common.c

···
 #include <linux/vmalloc.h>
 #include <linux/slab.h>
 #include <linux/vgaarb.h>
+#include <linux/numa.h>
 
 #include <asm/processor.h>
 #include <asm/io.h>
···
 		int nid = of_node_to_nid(dev);
 
 		if (nid < 0 || !node_online(nid))
-			nid = -1;
+			nid = NUMA_NO_NODE;
 
 		PHB_SET_NODE(phb, nid);
 	}

arch/powerpc/kernel/vdso.c

···
 	BUG_ON(vdso32_pagelist == NULL);
 	for (i = 0; i < vdso32_pages; i++) {
 		struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
-		ClearPageReserved(pg);
 		get_page(pg);
 		vdso32_pagelist[i] = pg;
 	}
···
 	BUG_ON(vdso64_pagelist == NULL);
 	for (i = 0; i < vdso64_pages; i++) {
 		struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
-		ClearPageReserved(pg);
 		get_page(pg);
 		vdso64_pagelist[i] = pg;
 	}

arch/powerpc/mm/hugetlbpage-hash64.c

···
 	*ptep = __pte(new_pte & ~H_PAGE_BUSY);
 	return 0;
 }
+
+pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
+				  unsigned long addr, pte_t *ptep)
+{
+	unsigned long pte_val;
+	/*
+	 * Clear the _PAGE_PRESENT so that no hardware parallel update is
+	 * possible. Also keep the pte_present true so that we don't take
+	 * wrong fault.
+	 */
+	pte_val = pte_update(vma->vm_mm, addr, ptep,
+			     _PAGE_PRESENT, _PAGE_INVALID, 1);
+
+	return __pte(pte_val);
+}
+
+void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
+				  pte_t *ptep, pte_t old_pte, pte_t pte)
+{
+
+	if (radix_enabled())
+		return radix__huge_ptep_modify_prot_commit(vma, addr, ptep,
+							   old_pte, pte);
+	set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
+}

arch/powerpc/mm/hugetlbpage-radix.c

···
 
 	return vm_unmapped_area(&info);
 }
+
+void radix__huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
+					 unsigned long addr, pte_t *ptep,
+					 pte_t old_pte, pte_t pte)
+{
+	struct mm_struct *mm = vma->vm_mm;
+
+	/*
+	 * To avoid NMMU hang while relaxing access we need to flush the tlb before
+	 * we set the new value.
+	 */
+	if (is_pte_rw_upgrade(pte_val(old_pte), pte_val(pte)) &&
+	    (atomic_read(&mm->context.copros) > 0))
+		radix__flush_hugetlb_page(vma, addr);
+
+	set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
+}

arch/powerpc/mm/mmu_context_iommu.c

···
 #include <linux/sizes.h>
 #include <asm/mmu_context.h>
 #include <asm/pte-walk.h>
+#include <linux/mm_inline.h>
 
 static DEFINE_MUTEX(mem_list_mutex);
 
···
 	atomic64_t mapped;
 	unsigned int pageshift;
 	u64 ua;			/* userspace address */
-	u64 entries;		/* number of entries in hpas[] */
-	u64 *hpas;		/* vmalloc'ed */
+	u64 entries;		/* number of entries in hpas/hpages[] */
+	/*
+	 * in mm_iommu_get we temporarily use this to store
+	 * struct page address.
+	 *
+	 * We need to convert ua to hpa in real mode. Make it
+	 * simpler by storing physical address.
+	 */
+	union {
+		struct page **hpages;	/* vmalloc'ed */
+		phys_addr_t *hpas;
+	};
 #define MM_IOMMU_TABLE_INVALID_HPA	((uint64_t)-1)
 	u64 dev_hpa;		/* Device memory base address */
 };
···
 }
 EXPORT_SYMBOL_GPL(mm_iommu_preregistered);
 
-/*
- * Taken from alloc_migrate_target with changes to remove CMA allocations
- */
-struct page *new_iommu_non_cma_page(struct page *page, unsigned long private)
-{
-	gfp_t gfp_mask = GFP_USER;
-	struct page *new_page;
-
-	if (PageCompound(page))
-		return NULL;
-
-	if (PageHighMem(page))
-		gfp_mask |= __GFP_HIGHMEM;
-
-	/*
-	 * We don't want the allocation to force an OOM if possibe
-	 */
-	new_page = alloc_page(gfp_mask | __GFP_NORETRY | __GFP_NOWARN);
-	return new_page;
-}
-
-static int mm_iommu_move_page_from_cma(struct page *page)
-{
-	int ret = 0;
-	LIST_HEAD(cma_migrate_pages);
-
-	/* Ignore huge pages for now */
-	if (PageCompound(page))
-		return -EBUSY;
-
-	lru_add_drain();
-	ret = isolate_lru_page(page);
-	if (ret)
-		return ret;
-
-	list_add(&page->lru, &cma_migrate_pages);
-	put_page(page); /* Drop the gup reference */
-
-	ret = migrate_pages(&cma_migrate_pages, new_iommu_non_cma_page,
-				NULL, 0, MIGRATE_SYNC, MR_CONTIG_RANGE);
-	if (ret) {
-		if (!list_empty(&cma_migrate_pages))
-			putback_movable_pages(&cma_migrate_pages);
-	}
-
-	return 0;
-}
-
 static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua,
-		unsigned long entries, unsigned long dev_hpa,
-		struct mm_iommu_table_group_mem_t **pmem)
+			      unsigned long entries, unsigned long dev_hpa,
+			      struct mm_iommu_table_group_mem_t **pmem)
 {
 	struct mm_iommu_table_group_mem_t *mem;
-	long i, j, ret = 0, locked_entries = 0;
+	long i, ret, locked_entries = 0;
 	unsigned int pageshift;
-	unsigned long flags;
-	unsigned long cur_ua;
-	struct page *page = NULL;
 
 	mutex_lock(&mem_list_mutex);
 
···
 		goto unlock_exit;
 	}
 
+	down_read(&mm->mmap_sem);
+	ret = get_user_pages_longterm(ua, entries, FOLL_WRITE, mem->hpages, NULL);
+	up_read(&mm->mmap_sem);
+	if (ret != entries) {
+		/* free the reference taken */
+		for (i = 0; i < ret; i++)
+			put_page(mem->hpages[i]);
+
+		vfree(mem->hpas);
+		kfree(mem);
+		ret = -EFAULT;
+		goto unlock_exit;
+	}
+
+	pageshift = PAGE_SHIFT;
 	for (i = 0; i < entries; ++i) {
-		cur_ua = ua + (i << PAGE_SHIFT);
-		if (1 != get_user_pages_fast(cur_ua,
-					1/* pages */, 1/* iswrite */, &page)) {
-			ret = -EFAULT;
-			for (j = 0; j < i; ++j)
-				put_page(pfn_to_page(mem->hpas[j] >>
-						PAGE_SHIFT));
-			vfree(mem->hpas);
-			kfree(mem);
-			goto unlock_exit;
-		}
+		struct page *page = mem->hpages[i];
+
 		/*
-		 * If we get a page from the CMA zone, since we are going to
-		 * be pinning these entries, we might as well move them out
-		 * of the CMA zone if possible. NOTE: faulting in + migration
-		 * can be expensive. Batching can be considered later
+		 * Allow to use larger than 64k IOMMU pages. Only do that
+		 * if we are backed by hugetlb.
 		 */
-		if (is_migrate_cma_page(page)) {
-			if (mm_iommu_move_page_from_cma(page))
-				goto populate;
-			if (1 != get_user_pages_fast(cur_ua,
-						1/* pages */, 1/* iswrite */,
-						&page)) {
-				ret = -EFAULT;
-				for (j = 0; j < i; ++j)
-					put_page(pfn_to_page(mem->hpas[j] >>
-								PAGE_SHIFT));
-				vfree(mem->hpas);
-				kfree(mem);
-				goto unlock_exit;
-			}
-		}
-populate:
-		pageshift = PAGE_SHIFT;
-		if (mem->pageshift > PAGE_SHIFT && PageCompound(page)) {
-			pte_t *pte;
+		if ((mem->pageshift > PAGE_SHIFT) && PageHuge(page)) {
 			struct page *head = compound_head(page);
-			unsigned int compshift = compound_order(head);
-			unsigned int pteshift;
 
-			local_irq_save(flags); /* disables as well */
-			pte = find_linux_pte(mm->pgd, cur_ua, NULL, &pteshift);
-
-			/* Double check it is still the same pinned page */
-			if (pte && pte_page(*pte) == head &&
-			    pteshift == compshift + PAGE_SHIFT)
-				pageshift = max_t(unsigned int, pteshift,
-						PAGE_SHIFT);
-			local_irq_restore(flags);
+			pageshift = compound_order(head) + PAGE_SHIFT;
 		}
 		mem->pageshift = min(mem->pageshift, pageshift);
+		/*
+		 * We don't need struct page reference any more, switch
+		 * to physical address.
+		 */
 		mem->hpas[i] = page_to_pfn(page) << PAGE_SHIFT;
 	}
 
 good_exit:
+	ret = 0;
 	atomic64_set(&mem->mapped, 1);
 	mem->used = 1;
 	mem->ua = ua;

arch/powerpc/mm/numa.c

···
 		alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
 
 	/* cpumask_of_node() will now work */
-	dbg("Node to cpumask map for %d nodes\n", nr_node_ids);
+	dbg("Node to cpumask map for %u nodes\n", nr_node_ids);
 }
 
 static int __init fake_numa_create_new_node(unsigned long end_pfn,
···
  */
 static int associativity_to_nid(const __be32 *associativity)
 {
-	int nid = -1;
+	int nid = NUMA_NO_NODE;
 
 	if (min_common_depth == -1)
 		goto out;
···
 
 	/* POWER4 LPAR uses 0xffff as invalid node */
 	if (nid == 0xffff || nid >= MAX_NUMNODES)
-		nid = -1;
+		nid = NUMA_NO_NODE;
 
 	if (nid > 0 &&
 		of_read_number(associativity, 1) >= distance_ref_points_depth) {
···
  */
 static int of_node_to_nid_single(struct device_node *device)
 {
-	int nid = -1;
+	int nid = NUMA_NO_NODE;
 	const __be32 *tmp;
 
 	tmp = of_get_associativity(device);
···
 /* Walk the device tree upwards, looking for an associativity id */
 int of_node_to_nid(struct device_node *device)
 {
-	int nid = -1;
+	int nid = NUMA_NO_NODE;
 
 	of_node_get(device);
 	while (device) {
···
  */
 static int numa_setup_cpu(unsigned long lcpu)
 {
-	int nid = -1;
+	int nid = NUMA_NO_NODE;
 	struct device_node *cpu;
 
 	/*
···
 {
 	struct drmem_lmb *lmb;
 	unsigned long lmb_size;
-	int nid = -1;
+	int nid = NUMA_NO_NODE;
 
 	lmb_size = drmem_lmb_size();
 
···
 static int hot_add_node_scn_to_nid(unsigned long scn_addr)
 {
 	struct device_node *memory;
-	int nid = -1;
+	int nid = NUMA_NO_NODE;
 
 	for_each_node_by_type(memory, "memory") {
 		unsigned long start, size;

arch/powerpc/mm/pgtable-book3s64.c

···
 }
 #endif /* CONFIG_PROC_FS */
 
+pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr,
+			     pte_t *ptep)
+{
+	unsigned long pte_val;
+
+	/*
+	 * Clear the _PAGE_PRESENT so that no hardware parallel update is
+	 * possible. Also keep the pte_present true so that we don't take
+	 * wrong fault.
+	 */
+	pte_val = pte_update(vma->vm_mm, addr, ptep, _PAGE_PRESENT, _PAGE_INVALID, 0);
+
+	return __pte(pte_val);
+
+}
+
+void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
+			     pte_t *ptep, pte_t old_pte, pte_t pte)
+{
+	if (radix_enabled())
+		return radix__ptep_modify_prot_commit(vma, addr,
+						      ptep, old_pte, pte);
+	set_pte_at(vma->vm_mm, addr, ptep, pte);
+}
+
 /*
  * For hash translation mode, we use the deposited table to store hash slot
  * information and they are stored at PTRS_PER_PMD offset from related pmd

arch/powerpc/mm/pgtable-radix.c

···
 	}
 	/* See ptesync comment in radix__set_pte_at */
 }
+
+void radix__ptep_modify_prot_commit(struct vm_area_struct *vma,
+				    unsigned long addr, pte_t *ptep,
+				    pte_t old_pte, pte_t pte)
+{
+	struct mm_struct *mm = vma->vm_mm;
+
+	/*
+	 * To avoid NMMU hang while relaxing access we need to flush the tlb before
+	 * we set the new value. We need to do this only for radix, because hash
+	 * translation does flush when updating the linux pte.
+	 */
+	if (is_pte_rw_upgrade(pte_val(old_pte), pte_val(pte)) &&
+	    (atomic_read(&mm->context.copros) > 0))
+		radix__flush_tlb_page(vma, addr);
+
+	set_pte_at(mm, addr, ptep, pte);
+}

arch/powerpc/platforms/powernv/memtrace.c

···
 #include <linux/slab.h>
 #include <linux/memory.h>
 #include <linux/memory_hotplug.h>
+#include <linux/numa.h>
 #include <asm/machdep.h>
 #include <asm/debugfs.h>
 
···
 		ent = &memtrace_array[i];
 
 		/* We have onlined this chunk previously */
-		if (ent->nid == -1)
+		if (ent->nid == NUMA_NO_NODE)
 			continue;
 
 		/* Remove from io mappings */
···
 		 */
 		debugfs_remove_recursive(ent->dir);
 		pr_info("Added trace memory back to node %d\n", ent->nid);
-		ent->size = ent->start = ent->nid = -1;
+		ent->size = ent->start = ent->nid = NUMA_NO_NODE;
 	}
 	if (ret)
 		return ret;

arch/riscv/kernel/vdso.c

···
 		struct page *pg;
 
 		pg = virt_to_page(vdso_start + (i << PAGE_SHIFT));
-		ClearPageReserved(pg);
 		vdso_pagelist[i] = pg;
 	}
 	vdso_pagelist[i] = virt_to_page(vdso_data);

arch/s390/include/asm/pgtable.h

···
 }
 
 #define __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
-pte_t ptep_modify_prot_start(struct mm_struct *, unsigned long, pte_t *);
-void ptep_modify_prot_commit(struct mm_struct *, unsigned long, pte_t *, pte_t);
+pte_t ptep_modify_prot_start(struct vm_area_struct *, unsigned long, pte_t *);
+void ptep_modify_prot_commit(struct vm_area_struct *, unsigned long,
+			     pte_t *, pte_t, pte_t);
 
 #define __HAVE_ARCH_PTEP_CLEAR_FLUSH
 static inline pte_t ptep_clear_flush(struct vm_area_struct *vma,

arch/s390/kernel/vdso.c

···
 	BUG_ON(vdso32_pagelist == NULL);
 	for (i = 0; i < vdso32_pages - 1; i++) {
 		struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
-		ClearPageReserved(pg);
 		get_page(pg);
 		vdso32_pagelist[i] = pg;
 	}
···
 	BUG_ON(vdso64_pagelist == NULL);
 	for (i = 0; i < vdso64_pages - 1; i++) {
 		struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
-		ClearPageReserved(pg);
 		get_page(pg);
 		vdso64_pagelist[i] = pg;
 	}

arch/s390/mm/pgtable.c

···
 }
 EXPORT_SYMBOL(ptep_xchg_lazy);
 
-pte_t ptep_modify_prot_start(struct mm_struct *mm, unsigned long addr,
+pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr,
 			     pte_t *ptep)
 {
 	pgste_t pgste;
 	pte_t old;
 	int nodat;
+	struct mm_struct *mm = vma->vm_mm;
 
 	preempt_disable();
 	pgste = ptep_xchg_start(mm, addr, ptep);
···
 	return old;
 }
 
-void ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
-			     pte_t *ptep, pte_t pte)
+void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
+			     pte_t *ptep, pte_t old_pte, pte_t pte)
 {
 	pgste_t pgste;
+	struct mm_struct *mm = vma->vm_mm;
 
 	if (!MACHINE_HAS_NX)
 		pte_val(pte) &= ~_PAGE_NOEXEC;

arch/sh/kernel/syscalls/syscalltbl.sh

···
 	t_entry="$3"
 
 	while [ $t_nxt -lt $t_nr ]; do
-		printf "__SYSCALL(%s, sys_ni_syscall, )\n" "${t_nxt}"
+		printf "__SYSCALL(%s,sys_ni_syscall)\n" "${t_nxt}"
 		t_nxt=$((t_nxt+1))
 	done
-	printf "__SYSCALL(%s, %s, )\n" "${t_nxt}" "${t_entry}"
+	printf "__SYSCALL(%s,%s)\n" "${t_nxt}" "${t_entry}"
 }
 
 grep -E "^[0-9A-Fa-fXx]+[[:space:]]+${my_abis}" "$in" | sort -n | (

arch/sh/kernel/syscalls_32.S

···
 #include <linux/sys.h>
 #include <linux/linkage.h>
 
-#define __SYSCALL(nr, entry, nargs) .long entry
+#define __SYSCALL(nr, entry)	.long entry
 	.data
 ENTRY(sys_call_table)
 #include <asm/syscall_table.h>

arch/sparc/kernel/pci_fire.c

···
 #include <linux/export.h>
 #include <linux/irq.h>
 #include <linux/of_device.h>
+#include <linux/numa.h>
 
 #include <asm/prom.h>
 #include <asm/irq.h>
···
 	struct device_node *dp = op->dev.of_node;
 	int err;
 
-	pbm->numa_node = -1;
+	pbm->numa_node = NUMA_NO_NODE;
 
 	pbm->pci_ops = &sun4u_pci_ops;
 	pbm->config_space_reg_bits = 12;

arch/sparc/kernel/pci_schizo.c

···
 #include <linux/export.h>
 #include <linux/interrupt.h>
 #include <linux/of_device.h>
+#include <linux/numa.h>
 
 #include <asm/iommu.h>
 #include <asm/irq.h>
···
 	pbm->next = pci_pbm_root;
 	pci_pbm_root = pbm;
 
-	pbm->numa_node = -1;
+	pbm->numa_node = NUMA_NO_NODE;
 
 	pbm->pci_ops = &sun4u_pci_ops;
 	pbm->config_space_reg_bits = 8;

arch/sparc/kernel/psycho_common.c

···
  */
 #include <linux/kernel.h>
 #include <linux/interrupt.h>
+#include <linux/numa.h>
 
 #include <asm/upa.h>
 
···
 	struct device_node *dp = op->dev.of_node;
 
 	pbm->name = dp->full_name;
-	pbm->numa_node = -1;
+	pbm->numa_node = NUMA_NO_NODE;
 	pbm->chip_type = chip_type;
 	pbm->chip_version = of_getintprop_default(dp, "version#", 0);
 	pbm->chip_revision = of_getintprop_default(dp, "module-revision#", 0);

arch/sparc/kernel/sbus.c

···
 #include <linux/interrupt.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/numa.h>
 
 #include <asm/page.h>
 #include <asm/io.h>
···
 
 	op->dev.archdata.iommu = iommu;
 	op->dev.archdata.stc = strbuf;
-	op->dev.archdata.numa_node = -1;
+	op->dev.archdata.numa_node = NUMA_NO_NODE;
 
 	reg_base = regs + SYSIO_IOMMUREG_BASE;
 	iommu->iommu_control = reg_base + IOMMU_CONTROL;

arch/sparc/mm/init_64.c

···
 {
 	int prev_nid, new_nid;
 
-	prev_nid = -1;
+	prev_nid = NUMA_NO_NODE;
 	for ( ; start < end; start += PAGE_SIZE) {
 		for (new_nid = 0; new_nid < num_node_masks; new_nid++) {
 			struct node_mem_mask *p = &node_masks[new_nid];
 
 			if ((start & p->mask) == p->match) {
-				if (prev_nid == -1)
+				if (prev_nid == NUMA_NO_NODE)
 					prev_nid = new_nid;
 				break;
 			}
···
 	md = mdesc_grab();
 
 	count = 0;
-	nid = -1;
+	nid = NUMA_NO_NODE;
 	mdesc_for_each_node_by_name(md, grp, "group") {
 		if (!scan_arcs_for_cfg_handle(md, grp, cfg_handle)) {
 			nid = count;

arch/x86/include/asm/paravirt.h

···
 }
 
 #define  __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
-static inline pte_t ptep_modify_prot_start(struct mm_struct *mm, unsigned long addr,
+static inline pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr,
 					   pte_t *ptep)
 {
 	pteval_t ret;
 
-	ret = PVOP_CALL3(pteval_t, mmu.ptep_modify_prot_start, mm, addr, ptep);
+	ret = PVOP_CALL3(pteval_t, mmu.ptep_modify_prot_start, vma, addr, ptep);
 
 	return (pte_t) { .pte = ret };
 }
 
-static inline void ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
-					   pte_t *ptep, pte_t pte)
+static inline void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
+					   pte_t *ptep, pte_t old_pte, pte_t pte)
 {
+
 	if (sizeof(pteval_t) > sizeof(long))
 		/* 5 arg words */
-		pv_ops.mmu.ptep_modify_prot_commit(mm, addr, ptep, pte);
+		pv_ops.mmu.ptep_modify_prot_commit(vma, addr, ptep, pte);
 	else
 		PVOP_VCALL4(mmu.ptep_modify_prot_commit,
-			    mm, addr, ptep, pte.pte);
+			    vma, addr, ptep, pte.pte);
 }
 
 static inline void set_pte(pte_t *ptep, pte_t pte)

arch/x86/include/asm/paravirt_types.h

···
 struct cpumask;
 struct flush_tlb_info;
 struct mmu_gather;
+struct vm_area_struct;
 
 /*
  * Wrapper type for pointers to code which uses the non-standard
···
 			   pte_t *ptep, pte_t pteval);
 	void (*set_pmd)(pmd_t *pmdp, pmd_t pmdval);
 
-	pte_t (*ptep_modify_prot_start)(struct mm_struct *mm, unsigned long addr,
+	pte_t (*ptep_modify_prot_start)(struct vm_area_struct *vma, unsigned long addr,
 					pte_t *ptep);
-	void (*ptep_modify_prot_commit)(struct mm_struct *mm, unsigned long addr,
+	void (*ptep_modify_prot_commit)(struct vm_area_struct *vma, unsigned long addr,
 					pte_t *ptep, pte_t pte);
 
 	struct paravirt_callee_save pte_val;

arch/x86/include/asm/pci.h

···
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/scatterlist.h>
+#include <linux/numa.h>
 #include <asm/io.h>
 #include <asm/pat.h>
 #include <asm/x86_init.h>
···
 	int node;
 
 	node = __pcibus_to_node(bus);
-	return (node == -1) ? cpu_online_mask :
+	return (node == NUMA_NO_NODE) ? cpu_online_mask :
 			      cpumask_of_node(node);
 }
 #endif

arch/x86/include/asm/uaccess.h

···
 #endif
 
 /**
- * access_ok: - Checks if a user space pointer is valid
+ * access_ok - Checks if a user space pointer is valid
  * @addr: User space pointer to start of block to check
  * @size: Size of block to check
  *
···
  *
  * Checks if a pointer to a block of memory in user space is valid.
  *
- * Returns true (nonzero) if the memory block may be valid, false (zero)
- * if it is definitely invalid.
- *
  * Note that, depending on architecture, this function probably just
  * checks that the pointer is in the user space range - after calling
  * this function, memory access functions may still return -EFAULT.
+ *
+ * Return: true (nonzero) if the memory block may be valid, false (zero)
+ * if it is definitely invalid.
  */
 #define access_ok(addr, size)					\
 ({									\
···
 __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
 
 /**
- * get_user: - Get a simple variable from user space.
+ * get_user - Get a simple variable from user space.
  * @x:   Variable to store result.
  * @ptr: Source address, in user space.
  *
···
  * @ptr must have pointer-to-simple-variable type, and the result of
  * dereferencing @ptr must be assignable to @x without a cast.
  *
- * Returns zero on success, or -EFAULT on error.
+ * Return: zero on success, or -EFAULT on error.
  * On error, the variable @x is set to zero.
  */
 /*
···
 extern void __put_user_8(void);
 
 /**
- * put_user: - Write a simple value into user space.
+ * put_user - Write a simple value into user space.
  * @x:   Value to copy to user space.
  * @ptr: Destination address, in user space.
  *
···
  * @ptr must have pointer-to-simple-variable type, and @x must be assignable
  * to the result of dereferencing @ptr.
  *
- * Returns zero on success, or -EFAULT on error.
+ * Return: zero on success, or -EFAULT on error.
  */
 #define put_user(x, ptr)					\
 ({								\
···
 } while (0)
 
 /**
- * __get_user: - Get a simple variable from user space, with less checking.
+ * __get_user - Get a simple variable from user space, with less checking.
  * @x:   Variable to store result.
  * @ptr: Source address, in user space.
  *
···
  * Caller must check the pointer with access_ok() before calling this
  * function.
  *
- * Returns zero on success, or -EFAULT on error.
+ * Return: zero on success, or -EFAULT on error.
  * On error, the variable @x is set to zero.
  */
 
···
 	__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
 
 /**
- * __put_user: - Write a simple value into user space, with less checking.
+ * __put_user - Write a simple value into user space, with less checking.
  * @x:   Value to copy to user space.
  * @ptr: Destination address, in user space.
  *
···
  * Caller must check the pointer with access_ok() before calling this
  * function.
  *
- * Returns zero on success, or -EFAULT on error.
+ * Return: zero on success, or -EFAULT on error.
  */
 
 #define __put_user(x, ptr)						\

arch/x86/kernel/apic/x2apic_uv_x.c

···
 #include <linux/crash_dump.h>
 #include <linux/reboot.h>
 #include <linux/memory.h>
+#include <linux/numa.h>
 
 #include <asm/uv/uv_mmrs.h>
 #include <asm/uv/uv_hub.h>
···
 	}
 
 	/* Set socket -> node values: */
-	lnid = -1;
+	lnid = NUMA_NO_NODE;
 	for_each_present_cpu(cpu) {
 		int nid = cpu_to_node(cpu);
 		int apicid, sockid;
···
 			new_hub->pnode = 0xffff;
 
 		new_hub->numa_blade_id = uv_node_to_blade_id(nodeid);
-		new_hub->memory_nid = -1;
+		new_hub->memory_nid = NUMA_NO_NODE;
 		new_hub->nr_possible_cpus = 0;
 		new_hub->nr_online_cpus = 0;
 	}
···
 
 		uv_cpu_info_per(cpu)->p_uv_hub_info = uv_hub_info_list(nodeid);
 		uv_cpu_info_per(cpu)->blade_cpu_id = uv_cpu_hub_info(cpu)->nr_possible_cpus++;
-		if (uv_cpu_hub_info(cpu)->memory_nid == -1)
+		if (uv_cpu_hub_info(cpu)->memory_nid == NUMA_NO_NODE)
 			uv_cpu_hub_info(cpu)->memory_nid = cpu_to_node(cpu);
 
 		/* Init memoryless node: */

arch/x86/kernel/setup_percpu.c

···
 	unsigned long delta;
 	int rc;
 
-	pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%u nr_node_ids:%d\n",
+	pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%u nr_node_ids:%u\n",
 		NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids);
 
 	/*

arch/x86/kernel/smpboot.c

···
 #include <linux/stackprotector.h>
 #include <linux/gfp.h>
 #include <linux/cpuidle.h>
+#include <linux/numa.h>
 
 #include <asm/acpi.h>
 #include <asm/desc.h>
···
 /* reduce the number of lines printed when booting a large cpu count system */
 static void announce_cpu(int cpu, int apicid)
 {
-	static int current_node = -1;
+	static int current_node = NUMA_NO_NODE;
 	int node = early_cpu_to_node(cpu);
 	static int width, node_width;
 

arch/x86/lib/usercopy_32.c

···
 } while (0)
 
 /**
- * clear_user: - Zero a block of memory in user space.
+ * clear_user - Zero a block of memory in user space.
  * @to:   Destination address, in user space.
  * @n:    Number of bytes to zero.
  *
  * Zero a block of memory in user space.
  *
- * Returns number of bytes that could not be cleared.
+ * Return: number of bytes that could not be cleared.
  * On success, this will be zero.
  */
 unsigned long
···
 EXPORT_SYMBOL(clear_user);
 
 /**
- * __clear_user: - Zero a block of memory in user space, with less checking.
+ * __clear_user - Zero a block of memory in user space, with less checking.
  * @to:   Destination address, in user space.
  * @n:    Number of bytes to zero.
  *
  * Zero a block of memory in user space.  Caller must check
  * the specified block with access_ok() before calling this function.
  *
- * Returns number of bytes that could not be cleared.
+ * Return: number of bytes that could not be cleared.
  * On success, this will be zero.
  */
 unsigned long

arch/x86/mm/numa.c

···
 		alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
 
 	/* cpumask_of_node() will now work */
-	pr_debug("Node to cpumask map for %d nodes\n", nr_node_ids);
+	pr_debug("Node to cpumask map for %u nodes\n", nr_node_ids);
 }
 
 static int __init numa_add_memblk_to(int nid, u64 start, u64 end,
···
 {
 	if (node >= nr_node_ids) {
 		printk(KERN_WARNING
-			"cpumask_of_node(%d): node > nr_node_ids(%d)\n",
+			"cpumask_of_node(%d): node > nr_node_ids(%u)\n",
 			node, nr_node_ids);
 		dump_stack();
 		return cpu_none_mask;

arch/x86/xen/mmu.h

···
 
 void set_pte_mfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags);
 
-pte_t xen_ptep_modify_prot_start(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
-void  xen_ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
+pte_t xen_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep);
+void  xen_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
 				  pte_t *ptep, pte_t pte);
 
 unsigned long xen_read_cr2_direct(void);

arch/x86/xen/mmu_pv.c

···
 	__xen_set_pte(ptep, pteval);
 }
 
-pte_t xen_ptep_modify_prot_start(struct mm_struct *mm,
+pte_t xen_ptep_modify_prot_start(struct vm_area_struct *vma,
 				 unsigned long addr, pte_t *ptep)
 {
 	/* Just return the pte as-is.  We preserve the bits on commit */
-	trace_xen_mmu_ptep_modify_prot_start(mm, addr, ptep, *ptep);
+	trace_xen_mmu_ptep_modify_prot_start(vma->vm_mm, addr, ptep, *ptep);
 	return *ptep;
 }
 
-void xen_ptep_modify_prot_commit(struct mm_struct *mm, unsigned long addr,
+void xen_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
 				 pte_t *ptep, pte_t pte)
 {
 	struct mmu_update u;
 
-	trace_xen_mmu_ptep_modify_prot_commit(mm, addr, ptep, pte);
+	trace_xen_mmu_ptep_modify_prot_commit(vma->vm_mm, addr, ptep, pte);
 	xen_mc_batch();
 
 	u.ptr = virt_to_machine(ptep).maddr | MMU_PT_UPDATE_PRESERVE_AD;

drivers/block/mtip32xx/mtip32xx.c

···
 #include <linux/export.h>
 #include <linux/debugfs.h>
 #include <linux/prefetch.h>
+#include <linux/numa.h>
 #include "mtip32xx.h"
 
 #define HW_CMD_SLOT_SZ		(MTIP_MAX_COMMAND_SLOTS * 32)
···
 /* Helper for selecting a node in round robin mode */
 static inline int mtip_get_next_rr_node(void)
 {
-	static int next_node = -1;
+	static int next_node = NUMA_NO_NODE;
 
-	if (next_node == -1) {
+	if (next_node == NUMA_NO_NODE) {
 		next_node = first_online_node;
 		return next_node;
 	}

drivers/char/agp/efficeon-agp.c

···
 		unsigned long page = efficeon_private.l1_table[index];
 		if (page) {
 			efficeon_private.l1_table[index] = 0;
-			ClearPageReserved(virt_to_page((char *)page));
 			free_page(page);
 			freed++;
 		}
···
 			efficeon_free_gatt_table(agp_bridge);
 			return -ENOMEM;
 		}
-		SetPageReserved(virt_to_page((char *)page));
 
 		for (offset = 0; offset < PAGE_SIZE; offset += clflush_chunk)
 			clflush((char *)page+offset);

drivers/dma/dmaengine.c

···
 #include <linux/acpi_dma.h>
 #include <linux/of_dma.h>
 #include <linux/mempool.h>
+#include <linux/numa.h>
 
 static DEFINE_MUTEX(dma_list_mutex);
 static DEFINE_IDA(dma_ida);
···
 static bool dma_chan_is_local(struct dma_chan *chan, int cpu)
 {
 	int node = dev_to_node(chan->device->dev);
-	return node == -1 || cpumask_test_cpu(cpu, cpumask_of_node(node));
+	return node == NUMA_NO_NODE ||
+		cpumask_test_cpu(cpu, cpumask_of_node(node));
 }
 
 /**

drivers/gpu/drm/i915/i915_utils.h

···
 
 #include <linux/list.h>
 
-static inline int list_is_first(const struct list_head *list,
-				const struct list_head *head)
-{
-	return head->next == list;
-}
-
 static inline void __list_del_many(struct list_head *head,
 				   struct list_head *first)
 {

drivers/hv/hv_balloon.c

···
 /* Check if the particular page is backed and can be onlined and online it. */
 static void hv_page_online_one(struct hv_hotadd_state *has, struct page *pg)
 {
-	if (!has_pfn_is_backed(has, page_to_pfn(pg)))
+	if (!has_pfn_is_backed(has, page_to_pfn(pg))) {
+		if (!PageOffline(pg))
+			__SetPageOffline(pg);
 		return;
+	}
+	if (PageOffline(pg))
+		__ClearPageOffline(pg);
 
 	/* This frame is currently backed; online the page. */
 	__online_page_set_limits(pg);
···
 	}
 }
 
-static void hv_online_page(struct page *pg)
+static void hv_online_page(struct page *pg, unsigned int order)
 {
 	struct hv_hotadd_state *has;
 	unsigned long flags;
···
 	spin_lock_irqsave(&dm_device.ha_lock, flags);
 	list_for_each_entry(has, &dm_device.ha_region_list, list) {
 		/* The page belongs to a different HAS. */
-		if ((pfn < has->start_pfn) || (pfn >= has->end_pfn))
+		if ((pfn < has->start_pfn) ||
+				(pfn + (1UL << order) > has->end_pfn))
 			continue;
 
-		hv_page_online_one(has, pg);
+		hv_bring_pgs_online(has, pfn, 1UL << order);
 		break;
 	}
 	spin_unlock_irqrestore(&dm_device.ha_lock, flags);
···
 
 	for (i = 0; i < num_pages; i++) {
 		pg = pfn_to_page(i + start_frame);
+		__ClearPageOffline(pg);
 		__free_page(pg);
 		dm->num_pages_ballooned--;
 	}
···
 					struct dm_balloon_response *bl_resp,
 					int alloc_unit)
 {
-	unsigned int i = 0;
+	unsigned int i, j;
 	struct page *pg;
 
 	if (num_pages < alloc_unit)
···
 
 		if (alloc_unit != 1)
 			split_page(pg, get_order(alloc_unit << PAGE_SHIFT));
+
+		/* mark all pages offline */
+		for (j = 0; j < (1 << get_order(alloc_unit << PAGE_SHIFT)); j++)
+			__SetPageOffline(pg + j);
 
 		bl_resp->range_count++;
 		bl_resp->range_array[i].finfo.start_page =

drivers/infiniband/hw/hfi1/affinity.c

···
 #include <linux/cpumask.h>
 #include <linux/module.h>
 #include <linux/interrupt.h>
+#include <linux/numa.h>
 
 #include "hfi.h"
 #include "affinity.h"
···
 	_dev_comp_vect_cpu_mask_clean_up(dd, entry);
 unlock:
 	mutex_unlock(&node_affinity.lock);
-	dd->node = -1;
+	dd->node = NUMA_NO_NODE;
 }
 
 /*

drivers/infiniband/hw/hfi1/init.c

···
 #include <linux/printk.h>
 #include <linux/hrtimer.h>
 #include <linux/bitmap.h>
+#include <linux/numa.h>
 #include <rdma/rdma_vt.h>
 
 #include "hfi.h"
···
 		dd->unit = ret;
 		list_add(&dd->list, &hfi1_dev_list);
 	}
-	dd->node = -1;
+	dd->node = NUMA_NO_NODE;
 
 	spin_unlock_irqrestore(&hfi1_devs_lock, flags);
 	idr_preload_end();

drivers/iommu/dmar.c

···
 #include <linux/dmi.h>
 #include <linux/slab.h>
 #include <linux/iommu.h>
+#include <linux/numa.h>
 #include <asm/irq_remapping.h>
 #include <asm/iommu_table.h>
 
···
 			int node = acpi_map_pxm_to_node(rhsa->proximity_domain);
 
 			if (!node_online(node))
-				node = -1;
+				node = NUMA_NO_NODE;
 			drhd->iommu->node = node;
 			return 0;
 		}
···
 	iommu->msagaw = msagaw;
 	iommu->segment = drhd->segment;
 
-	iommu->node = -1;
+	iommu->node = NUMA_NO_NODE;
 
 	ver = readl(iommu->reg + DMAR_VER_REG);
 	pr_info("%s: reg_base_addr %llx ver %d:%d cap %llx ecap %llx\n",

drivers/iommu/intel-iommu.c

···
 #include <linux/dma-contiguous.h>
 #include <linux/dma-direct.h>
 #include <linux/crash_dump.h>
+#include <linux/numa.h>
 #include <asm/irq_remapping.h>
 #include <asm/cacheflush.h>
 #include <asm/iommu.h>
···
 		return NULL;
 
 	memset(domain, 0, sizeof(*domain));
-	domain->nid = -1;
+	domain->nid = NUMA_NO_NODE;
 	domain->flags = flags;
 	domain->has_iotlb_device = false;
 	INIT_LIST_HEAD(&domain->devices);

drivers/misc/sgi-xp/xpc_uv.c

···
 #include <linux/module.h>
 #include <linux/err.h>
 #include <linux/slab.h>
+#include <linux/numa.h>
 #include <asm/uv/uv_hub.h>
 #if defined CONFIG_X86_64
 #include <asm/uv/bios.h>
···
 					 XPC_NOTIFY_MSG_SIZE_UV)
 #define XPC_NOTIFY_IRQ_NAME		"xpc_notify"
 
-static int xpc_mq_node = -1;
+static int xpc_mq_node = NUMA_NO_NODE;
 
 static struct xpc_gru_mq_uv *xpc_activate_mq_uv;
 static struct xpc_gru_mq_uv *xpc_notify_mq_uv;

drivers/misc/vmw_balloon.c

···
 }
 
 /**
+ * vmballoon_mark_page_offline() - mark a page as offline
+ * @page: pointer for the page.
+ * @page_size: the size of the page.
+ */
+static void
+vmballoon_mark_page_offline(struct page *page,
+			    enum vmballoon_page_size_type page_size)
+{
+	int i;
+
+	for (i = 0; i < vmballoon_page_in_frames(page_size); i++)
+		__SetPageOffline(page + i);
+}
+
+/**
+ * vmballoon_mark_page_online() - mark a page as online
+ * @page: pointer for the page.
+ * @page_size: the size of the page.
+ */
+static void
+vmballoon_mark_page_online(struct page *page,
+			   enum vmballoon_page_size_type page_size)
+{
+	int i;
+
+	for (i = 0; i < vmballoon_page_in_frames(page_size); i++)
+		__ClearPageOffline(page + i);
+}
+
+/**
  * vmballoon_send_get_target() - Retrieve desired balloon size from the host.
  *
  * @b: pointer to the balloon.
···
 					 ctl->page_size);
 
 		if (page) {
+			vmballoon_mark_page_offline(page, ctl->page_size);
 			/* Success. Add the page to the list and continue. */
 			list_add(&page->lru, &ctl->pages);
 			continue;
···
 
 	list_for_each_entry_safe(page, tmp, page_list, lru) {
 		list_del(&page->lru);
+		vmballoon_mark_page_online(page, page_size);
 		__free_pages(page, vmballoon_page_order(page_size));
 	}
 

drivers/net/ethernet/intel/ixgbe/ixgbe_main.c

···
 #include <linux/bpf.h>
 #include <linux/bpf_trace.h>
 #include <linux/atomic.h>
+#include <linux/numa.h>
 #include <scsi/fc/fc_fcoe.h>
 #include <net/udp_tunnel.h>
 #include <net/pkt_cls.h>
···
 {
 	struct device *dev = tx_ring->dev;
 	int orig_node = dev_to_node(dev);
-	int ring_node = -1;
+	int ring_node = NUMA_NO_NODE;
 	int size;
 
 	size = sizeof(struct ixgbe_tx_buffer) * tx_ring->count;
···
 {
 	struct device *dev = rx_ring->dev;
 	int orig_node = dev_to_node(dev);
-	int ring_node = -1;
+	int ring_node = NUMA_NO_NODE;
 	int size;
 
 	size = sizeof(struct ixgbe_rx_buffer) * rx_ring->count;

drivers/xen/balloon.c

···
 	return BP_ECANCELED;
 }
 
-static void xen_online_page(struct page *page)
+static void xen_online_page(struct page *page, unsigned int order)
 {
-	__online_page_set_limits(page);
+	unsigned long i, size = (1 << order);
+	unsigned long start_pfn = page_to_pfn(page);
+	struct page *p;
 
+	pr_debug("Online %lu pages starting at pfn 0x%lx\n", size, start_pfn);
 	mutex_lock(&balloon_mutex);
-
-	__balloon_append(page);
-
+	for (i = 0; i < size; i++) {
+		p = pfn_to_page(start_pfn + i);
+		__online_page_set_limits(p);
+		__SetPageOffline(p);
+		__balloon_append(p);
+	}
 	mutex_unlock(&balloon_mutex);
 }
 
···
 		xenmem_reservation_va_mapping_update(1, &page, &frame_list[i]);
 
 		/* Relinquish the page back to the allocator. */
+		__ClearPageOffline(page);
 		free_reserved_page(page);
 	}
 
···
 			state = BP_EAGAIN;
 			break;
 		}
+		__SetPageOffline(page);
 		adjust_managed_page_count(page, -1);
 		xenmem_reservation_scrub_page(page);
 		list_add(&page->lru, &pages);

fs/file.c

···
 		.full_fds_bits	= init_files.full_fds_bits_init,
 	},
 	.file_lock	= __SPIN_LOCK_UNLOCKED(init_files.file_lock),
+	.resize_wait	= __WAIT_QUEUE_HEAD_INITIALIZER(init_files.resize_wait),
 };
 
 static unsigned int find_next_fd(struct fdtable *fdt, unsigned int start)

fs/hugetlbfs/inode.c

···
 		inode_lock(inode);
 
 		/* protected by i_mutex */
-		if (info->seals & F_SEAL_WRITE) {
+		if (info->seals & (F_SEAL_WRITE | F_SEAL_FUTURE_WRITE)) {
 			inode_unlock(inode);
 			return -EPERM;
 		}

fs/inode.c

···
 void inode_set_flags(struct inode *inode, unsigned int flags,
 		     unsigned int mask)
 {
-	unsigned int old_flags, new_flags;
-
 	WARN_ON_ONCE(flags & ~mask);
-	do {
-		old_flags = READ_ONCE(inode->i_flags);
-		new_flags = (old_flags & ~mask) | flags;
-	} while (unlikely(cmpxchg(&inode->i_flags, old_flags,
-				  new_flags) != old_flags));
+	set_mask_bits(&inode->i_flags, mask, flags);
 }
 EXPORT_SYMBOL(inode_set_flags);
 

fs/kernfs/file.c

···
  * to see if it supports poll (Neither 'poll' nor 'select' return
  * an appropriate error code).  When in doubt, set a suitable timeout value.
  */
+__poll_t kernfs_generic_poll(struct kernfs_open_file *of, poll_table *wait)
+{
+	struct kernfs_node *kn = kernfs_dentry_node(of->file->f_path.dentry);
+	struct kernfs_open_node *on = kn->attr.open;
+
+	poll_wait(of->file, &on->poll, wait);
+
+	if (of->event != atomic_read(&on->event))
+		return DEFAULT_POLLMASK|EPOLLERR|EPOLLPRI;
+
+	return DEFAULT_POLLMASK;
+}
+
 static __poll_t kernfs_fop_poll(struct file *filp, poll_table *wait)
 {
 	struct kernfs_open_file *of = kernfs_of(filp);
 	struct kernfs_node *kn = kernfs_dentry_node(filp->f_path.dentry);
-	struct kernfs_open_node *on = kn->attr.open;
+	__poll_t ret;
 
 	if (!kernfs_get_active(kn))
-		goto trigger;
+		return DEFAULT_POLLMASK|EPOLLERR|EPOLLPRI;
 
-	poll_wait(filp, &on->poll, wait);
+	if (kn->attr.ops->poll)
+		ret = kn->attr.ops->poll(of, wait);
+	else
+		ret = kernfs_generic_poll(of, wait);
 
 	kernfs_put_active(kn);
-
-	if (of->event != atomic_read(&on->event))
-		goto trigger;
-
-	return DEFAULT_POLLMASK;
-
- trigger:
-	return DEFAULT_POLLMASK|EPOLLERR|EPOLLPRI;
+	return ret;
 }
 
 static void kernfs_notify_workfn(struct work_struct *work)

fs/ocfs2/alloc.c

···
 	return count;
 }
 
-int ocfs2_trim_fs(struct super_block *sb, struct fstrim_range *range)
+static
+int ocfs2_trim_mainbm(struct super_block *sb, struct fstrim_range *range)
 {
 	struct ocfs2_super *osb = OCFS2_SB(sb);
-	u64 start, len, trimmed, first_group, last_group, group;
+	u64 start, len, trimmed = 0, first_group, last_group = 0, group = 0;
 	int ret, cnt;
 	u32 first_bit, last_bit, minlen;
 	struct buffer_head *main_bm_bh = NULL;
···
 	struct buffer_head *gd_bh = NULL;
 	struct ocfs2_dinode *main_bm;
 	struct ocfs2_group_desc *gd = NULL;
-	struct ocfs2_trim_fs_info info, *pinfo = NULL;
 
 	start = range->start >> osb->s_clustersize_bits;
 	len = range->len >> osb->s_clustersize_bits;
···
 	if (minlen >= osb->bitmap_cpg || range->len < sb->s_blocksize)
 		return -EINVAL;
 
+	trace_ocfs2_trim_mainbm(start, len, minlen);
+
+next_group:
 	main_bm_inode = ocfs2_get_system_file_inode(osb,
 						    GLOBAL_BITMAP_SYSTEM_INODE,
 						    OCFS2_INVALID_SLOT);
···
 	}
 	main_bm = (struct ocfs2_dinode *)main_bm_bh->b_data;
 
-	if (start >= le32_to_cpu(main_bm->i_clusters)) {
-		ret = -EINVAL;
-		goto out_unlock;
-	}
-
-	len = range->len >> osb->s_clustersize_bits;
-	if (start + len > le32_to_cpu(main_bm->i_clusters))
-		len = le32_to_cpu(main_bm->i_clusters) - start;
-
-	trace_ocfs2_trim_fs(start, len, minlen);
-
-	ocfs2_trim_fs_lock_res_init(osb);
-	ret = ocfs2_trim_fs_lock(osb, NULL, 1);
-	if (ret < 0) {
-		if (ret != -EAGAIN) {
-			mlog_errno(ret);
-			ocfs2_trim_fs_lock_res_uninit(osb);
+	/*
+	 * Do some check before trim the first group.
+	 */
+	if (!group) {
+		if (start >= le32_to_cpu(main_bm->i_clusters)) {
+			ret = -EINVAL;
 			goto out_unlock;
 		}
 
-		mlog(ML_NOTICE, "Wait for trim on device (%s) to "
-		     "finish, which is running from another node.\n",
-		     osb->dev_str);
-		ret = ocfs2_trim_fs_lock(osb, &info, 0);
-		if (ret < 0) {
-			mlog_errno(ret);
-			ocfs2_trim_fs_lock_res_uninit(osb);
-			goto out_unlock;
-		}
+		if (start + len > le32_to_cpu(main_bm->i_clusters))
+			len = le32_to_cpu(main_bm->i_clusters) - start;
 
-		if (info.tf_valid && info.tf_success &&
-		    info.tf_start == start && info.tf_len == len &&
-		    info.tf_minlen == minlen) {
-			/* Avoid sending duplicated trim to a shared device */
-			mlog(ML_NOTICE, "The same trim on device (%s) was "
-			     "just done from node (%u), return.\n",
-			     osb->dev_str, info.tf_nodenum);
-			range->len = info.tf_trimlen;
-			goto out_trimunlock;
-		}
+		/*
+		 * Determine first and last group to examine based on
+		 * start and len
+		 */
+		first_group = ocfs2_which_cluster_group(main_bm_inode, start);
+		if (first_group == osb->first_cluster_group_blkno)
+			first_bit = start;
+		else
+			first_bit = start - ocfs2_blocks_to_clusters(sb,
+								first_group);
+		last_group = ocfs2_which_cluster_group(main_bm_inode,
+						       start + len - 1);
+		group = first_group;
 	}
 
-	info.tf_nodenum = osb->node_num;
-	info.tf_start = start;
-	info.tf_len = len;
-	info.tf_minlen = minlen;
-
-	/* Determine first and last group to examine based on start and len */
-	first_group = ocfs2_which_cluster_group(main_bm_inode, start);
-	if (first_group == osb->first_cluster_group_blkno)
-		first_bit = start;
-	else
-		first_bit = start - ocfs2_blocks_to_clusters(sb, first_group);
-	last_group = ocfs2_which_cluster_group(main_bm_inode, start + len - 1);
-	last_bit = osb->bitmap_cpg;
-
-	trimmed = 0;
-	for (group = first_group; group <= last_group;) {
+	do {
 		if (first_bit + len >= osb->bitmap_cpg)
 			last_bit = osb->bitmap_cpg;
 		else
···
 			group = ocfs2_clusters_to_blocks(sb, osb->bitmap_cpg);
 		else
 			group += ocfs2_clusters_to_blocks(sb, osb->bitmap_cpg);
-	}
-	range->len = trimmed * sb->s_blocksize;
+	} while (0);
 
-	info.tf_trimlen = range->len;
-	info.tf_success = (ret ? 0 : 1);
-	pinfo = &info;
-out_trimunlock:
-	ocfs2_trim_fs_unlock(osb, pinfo);
-	ocfs2_trim_fs_lock_res_uninit(osb);
 out_unlock:
 	ocfs2_inode_unlock(main_bm_inode, 0);
 	brelse(main_bm_bh);
+	main_bm_bh = NULL;
 out_mutex:
 	inode_unlock(main_bm_inode);
 	iput(main_bm_inode);
+
+	/*
+	 * If all the groups trim are not done or failed, but we should release
+	 * main_bm related locks for avoiding the current IO starve, then go to
+	 * trim the next group
+	 */
+	if (ret >= 0 && group <= last_group)
+		goto next_group;
 out:
+	range->len = trimmed * sb->s_blocksize;
+	return ret;
+}
+
+int ocfs2_trim_fs(struct super_block *sb, struct fstrim_range *range)
+{
+	int ret;
+	struct ocfs2_super *osb = OCFS2_SB(sb);
+	struct ocfs2_trim_fs_info info, *pinfo = NULL;
+
+	ocfs2_trim_fs_lock_res_init(osb);
+
+	trace_ocfs2_trim_fs(range->start, range->len, range->minlen);
+
+	ret = ocfs2_trim_fs_lock(osb, NULL, 1);
+	if (ret < 0) {
+		if (ret != -EAGAIN) {
+			mlog_errno(ret);
+			ocfs2_trim_fs_lock_res_uninit(osb);
+			return ret;
+		}
+
+		mlog(ML_NOTICE, "Wait for trim on device (%s) to "
+		     "finish, which is running from another node.\n",
+		     osb->dev_str);
+		ret = ocfs2_trim_fs_lock(osb, &info, 0);
+		if (ret < 0) {
+			mlog_errno(ret);
+			ocfs2_trim_fs_lock_res_uninit(osb);
+			return ret;
+		}
+
+		if (info.tf_valid && info.tf_success &&
+		    info.tf_start == range->start &&
+		    info.tf_len == range->len &&
+		    info.tf_minlen == range->minlen) {
+			/* Avoid sending duplicated trim to a shared device */
+			mlog(ML_NOTICE, "The same trim on device (%s) was "
+			     "just done from node (%u), return.\n",
+			     osb->dev_str, info.tf_nodenum);
+			range->len = info.tf_trimlen;
+			goto out;
+		}
+	}
+
+	info.tf_nodenum = osb->node_num;
+	info.tf_start = range->start;
+	info.tf_len = range->len;
+	info.tf_minlen = range->minlen;
+
+	ret = ocfs2_trim_mainbm(sb, range);
+
+	info.tf_trimlen = range->len;
+	info.tf_success = (ret < 0 ? 0 : 1);
+	pinfo = &info;
+out:
+	ocfs2_trim_fs_unlock(osb, pinfo);
+	ocfs2_trim_fs_lock_res_uninit(osb);
 	return ret;
 }

fs/ocfs2/cluster/nodemanager.c

···
 	struct o2nm_node *node = to_o2nm_node(item);
 	struct o2nm_cluster *cluster = to_o2nm_cluster(group->cg_item.ci_parent);
 
-	o2net_disconnect_node(node);
+	if (cluster->cl_nodes[node->nd_num] == node) {
+		o2net_disconnect_node(node);
 
-	if (cluster->cl_has_local &&
-	    (cluster->cl_local_node == node->nd_num)) {
-		cluster->cl_has_local = 0;
-		cluster->cl_local_node = O2NM_INVALID_NODE_NUM;
-		o2net_stop_listening(node);
+		if (cluster->cl_has_local &&
+		    (cluster->cl_local_node == node->nd_num)) {
+			cluster->cl_has_local = 0;
+			cluster->cl_local_node = O2NM_INVALID_NODE_NUM;
+			o2net_stop_listening(node);
+		}
 	}
 
 	/* XXX call into net to stop this node from trading messages */

fs/ocfs2/dlmglue.c

···
 {
 	struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
 
+	/* Only one trimfs thread are allowed to work at the same time. */
+	mutex_lock(&osb->obs_trim_fs_mutex);
+
 	ocfs2_lock_res_init_once(lockres);
 	ocfs2_build_lock_name(OCFS2_LOCK_TYPE_TRIM_FS, 0, 0, lockres->l_name);
 	ocfs2_lock_res_init_common(osb, lockres, OCFS2_LOCK_TYPE_TRIM_FS,
···
 
 	ocfs2_simple_drop_lockres(osb, lockres);
 	ocfs2_lock_res_free(lockres);
+
+	mutex_unlock(&osb->obs_trim_fs_mutex);
 }
 
 static void ocfs2_orphan_scan_lock_res_init(struct ocfs2_lock_res *res,

fs/ocfs2/ocfs2.h

···
 	struct ocfs2_lock_res osb_rename_lockres;
 	struct ocfs2_lock_res osb_nfs_sync_lockres;
 	struct ocfs2_lock_res osb_trim_fs_lockres;
+	struct mutex obs_trim_fs_mutex;
 	struct ocfs2_dlm_debug *osb_dlm_debug;
 
 	struct dentry *osb_debug_root;

fs/ocfs2/ocfs2_trace.h

···
 
 DEFINE_OCFS2_ULL_UINT_UINT_UINT_EVENT(ocfs2_trim_group);
 
+DEFINE_OCFS2_ULL_ULL_ULL_EVENT(ocfs2_trim_mainbm);
+
 DEFINE_OCFS2_ULL_ULL_ULL_EVENT(ocfs2_trim_fs);
 
 /* End of trace events for fs/ocfs2/alloc.c. */

fs/ocfs2/slot_map.c

···
 	unsigned int si_blocks;
 	struct buffer_head **si_bh;
 	unsigned int si_num_slots;
-	struct ocfs2_slot *si_slots;
+	struct ocfs2_slot si_slots[];
 };
 
 
···
 	struct inode *inode = NULL;
 	struct ocfs2_slot_info *si;
 
-	si = kzalloc(sizeof(struct ocfs2_slot_info) +
-		     (sizeof(struct ocfs2_slot) * osb->max_slots),
-		     GFP_KERNEL);
+	si = kzalloc(struct_size(si, si_slots, osb->max_slots), GFP_KERNEL);
 	if (!si) {
 		status = -ENOMEM;
 		mlog_errno(status);
···
 
 	si->si_extended = ocfs2_uses_extended_slot_map(osb);
 	si->si_num_slots = osb->max_slots;
-	si->si_slots = (struct ocfs2_slot *)((char *)si +
-					     sizeof(struct ocfs2_slot_info));
 
 	inode = ocfs2_get_system_file_inode(osb, SLOT_MAP_SYSTEM_INODE,
 					    OCFS2_INVALID_SLOT);

fs/ocfs2/super.c

···
 	if (ocfs2_is_hard_readonly(osb))
 		goto leave;
 
+	mutex_init(&osb->obs_trim_fs_mutex);
+
 	status = ocfs2_dlm_init(osb);
 	if (status < 0) {
 		mlog_errno(status);

fs/pipe.c

···
 	struct page *page = buf->page;
 
 	if (page_count(page) == 1) {
-		if (memcg_kmem_enabled())
-			memcg_kmem_uncharge(page, 0);
+		memcg_kmem_uncharge(page, 0);
 		__SetPageLocked(page);
 		return 0;
 	}

fs/proc/array.c

···
 #ifdef CONFIG_SECCOMP
 	seq_put_decimal_ull(m, "\nSeccomp:\t", p->seccomp.mode);
 #endif
-	seq_printf(m, "\nSpeculation_Store_Bypass:\t");
+	seq_puts(m, "\nSpeculation_Store_Bypass:\t");
 	switch (arch_prctl_spec_ctrl_get(p, PR_SPEC_STORE_BYPASS)) {
 	case -EINVAL:
-		seq_printf(m, "unknown");
+		seq_puts(m, "unknown");
 		break;
 	case PR_SPEC_NOT_AFFECTED:
-		seq_printf(m, "not vulnerable");
+		seq_puts(m, "not vulnerable");
 		break;
 	case PR_SPEC_PRCTL | PR_SPEC_FORCE_DISABLE:
-		seq_printf(m, "thread force mitigated");
+		seq_puts(m, "thread force mitigated");
 		break;
 	case PR_SPEC_PRCTL | PR_SPEC_DISABLE:
-		seq_printf(m, "thread mitigated");
+		seq_puts(m, "thread mitigated");
 		break;
 	case PR_SPEC_PRCTL | PR_SPEC_ENABLE:
-		seq_printf(m, "thread vulnerable");
+		seq_puts(m, "thread vulnerable");
 		break;
 	case PR_SPEC_DISABLE:
-		seq_printf(m, "globally mitigated");
+		seq_puts(m, "globally mitigated");
 		break;
 	default:
-		seq_printf(m, "vulnerable");
+		seq_puts(m, "vulnerable");
 		break;
 	}
 	seq_putc(m, '\n');

fs/proc/base.c

···
 			      struct pid *pid, struct task_struct *task)
 {
 	if (unlikely(!sched_info_on()))
-		seq_printf(m, "0 0 0\n");
+		seq_puts(m, "0 0 0\n");
 	else
 		seq_printf(m, "%llu %llu %lu\n",
 		   (unsigned long long)task->se.sum_exec_runtime,
···
 	return d_splice_alias(inode, dentry);
 }
 
-struct dentry *proc_pid_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
+struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags)
 {
 	struct task_struct *task;
 	unsigned tgid;

fs/proc/internal.h

···
 extern void pid_update_inode(struct task_struct *, struct inode *);
 extern int pid_delete_dentry(const struct dentry *);
 extern int proc_pid_readdir(struct file *, struct dir_context *);
-extern struct dentry *proc_pid_lookup(struct inode *, struct dentry *, unsigned int);
+struct dentry *proc_pid_lookup(struct dentry *, unsigned int);
 extern loff_t mem_lseek(struct file *, loff_t, int);
 
 /* Lookups */

fs/proc/page.c

···
 	else if (page_count(page) == 0 && is_free_buddy_page(page))
 		u |= 1 << KPF_BUDDY;
 
-	if (PageBalloon(page))
-		u |= 1 << KPF_BALLOON;
+	if (PageOffline(page))
+		u |= 1 << KPF_OFFLINE;
 	if (PageTable(page))
 		u |= 1 << KPF_PGTABLE;
 

fs/proc/root.c

···
 
 static struct dentry *proc_root_lookup(struct inode * dir, struct dentry * dentry, unsigned int flags)
 {
-	if (!proc_pid_lookup(dir, dentry, flags))
+	if (!proc_pid_lookup(dentry, flags))
 		return NULL;
 	
 	return proc_lookup(dir, dentry, flags);

fs/proc/self.c

···
 	struct inode *root_inode = d_inode(s->s_root);
 	struct pid_namespace *ns = proc_pid_ns(root_inode);
 	struct dentry *self;
+	int ret = -ENOMEM;
 	
 	inode_lock(root_inode);
 	self = d_alloc_name(s->s_root, "self");
···
 			inode->i_gid = GLOBAL_ROOT_GID;
 			inode->i_op = &proc_self_inode_operations;
 			d_add(self, inode);
+			ret = 0;
 		} else {
 			dput(self);
-			self = ERR_PTR(-ENOMEM);
 		}
-	} else {
-		self = ERR_PTR(-ENOMEM);
 	}
 	inode_unlock(root_inode);
-	if (IS_ERR(self)) {
+
+	if (ret)
 		pr_err("proc_fill_super: can't allocate /proc/self\n");
-		return PTR_ERR(self);
-	}
-	ns->proc_self = self;
-	return 0;
+	else
+		ns->proc_self = self;
+
+	return ret;
 }
 
 void __init proc_self_init(void)

fs/proc/stat.c

···
 
 #ifdef arch_idle_time
 
-static u64 get_idle_time(int cpu)
+static u64 get_idle_time(struct kernel_cpustat *kcs, int cpu)
 {
 	u64 idle;
 
-	idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
+	idle = kcs->cpustat[CPUTIME_IDLE];
 	if (cpu_online(cpu) && !nr_iowait_cpu(cpu))
 		idle += arch_idle_time(cpu);
 	return idle;
 }
 
-static u64 get_iowait_time(int cpu)
+static u64 get_iowait_time(struct kernel_cpustat *kcs, int cpu)
 {
 	u64 iowait;
 
-	iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
+	iowait = kcs->cpustat[CPUTIME_IOWAIT];
 	if (cpu_online(cpu) && nr_iowait_cpu(cpu))
 		iowait += arch_idle_time(cpu);
 	return iowait;
···
 
 #else
 
-static u64 get_idle_time(int cpu)
+static u64 get_idle_time(struct kernel_cpustat *kcs, int cpu)
 {
 	u64 idle, idle_usecs = -1ULL;
 
···
 
 	if (idle_usecs == -1ULL)
 		/* !NO_HZ or cpu offline so we can rely on cpustat.idle */
-		idle = kcpustat_cpu(cpu).cpustat[CPUTIME_IDLE];
+		idle = kcs->cpustat[CPUTIME_IDLE];
 	else
 		idle = idle_usecs * NSEC_PER_USEC;
 
 	return idle;
 }
 
-static u64 get_iowait_time(int cpu)
+static u64 get_iowait_time(struct kernel_cpustat *kcs, int cpu)
 {
 	u64 iowait, iowait_usecs = -1ULL;
 
···
 
 	if (iowait_usecs == -1ULL)
 		/* !NO_HZ or cpu offline so we can rely on cpustat.iowait */
-		iowait = kcpustat_cpu(cpu).cpustat[CPUTIME_IOWAIT];
+		iowait = kcs->cpustat[CPUTIME_IOWAIT];
 	else
 		iowait = iowait_usecs * NSEC_PER_USEC;
 
···
 	getboottime64(&boottime);
 
 	for_each_possible_cpu(i) {
-		user += kcpustat_cpu(i).cpustat[CPUTIME_USER];
-		nice += kcpustat_cpu(i).cpustat[CPUTIME_NICE];
-		system += kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
-		idle += get_idle_time(i);
-		iowait += get_iowait_time(i);
-		irq += kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
-		softirq += kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ];
-		steal += kcpustat_cpu(i).cpustat[CPUTIME_STEAL];
-		guest += kcpustat_cpu(i).cpustat[CPUTIME_GUEST];
-		guest_nice += kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE];
+		struct kernel_cpustat *kcs = &kcpustat_cpu(i);
+
+		user += kcs->cpustat[CPUTIME_USER];
+		nice += kcs->cpustat[CPUTIME_NICE];
+		system += kcs->cpustat[CPUTIME_SYSTEM];
+		idle += get_idle_time(kcs, i);
+		iowait += get_iowait_time(kcs, i);
+		irq += kcs->cpustat[CPUTIME_IRQ];
+		softirq += kcs->cpustat[CPUTIME_SOFTIRQ];
+		steal += kcs->cpustat[CPUTIME_STEAL];
+		guest += kcs->cpustat[CPUTIME_GUEST];
+		guest_nice += kcs->cpustat[CPUTIME_GUEST_NICE];
 		sum += kstat_cpu_irqs_sum(i);
 		sum += arch_irq_stat_cpu(i);
 
···
 	seq_putc(p, '\n');
 
 	for_each_online_cpu(i) {
+		struct kernel_cpustat *kcs = &kcpustat_cpu(i);
+
 		/* Copy values here to work around gcc-2.95.3, gcc-2.96 */
-		user = kcpustat_cpu(i).cpustat[CPUTIME_USER];
-		nice = kcpustat_cpu(i).cpustat[CPUTIME_NICE];
-		system = kcpustat_cpu(i).cpustat[CPUTIME_SYSTEM];
-		idle = get_idle_time(i);
-		iowait = get_iowait_time(i);
-		irq = kcpustat_cpu(i).cpustat[CPUTIME_IRQ];
-		softirq = kcpustat_cpu(i).cpustat[CPUTIME_SOFTIRQ];
-		steal = kcpustat_cpu(i).cpustat[CPUTIME_STEAL];
-		guest = kcpustat_cpu(i).cpustat[CPUTIME_GUEST];
-		guest_nice = kcpustat_cpu(i).cpustat[CPUTIME_GUEST_NICE];
+		user = kcs->cpustat[CPUTIME_USER];
+		nice = kcs->cpustat[CPUTIME_NICE];
+		system = kcs->cpustat[CPUTIME_SYSTEM];
+		idle = get_idle_time(kcs, i);
+		iowait = get_iowait_time(kcs, i);
+		irq = kcs->cpustat[CPUTIME_IRQ];
+		softirq = kcs->cpustat[CPUTIME_SOFTIRQ];
+		steal = kcs->cpustat[CPUTIME_STEAL];
+		guest = kcs->cpustat[CPUTIME_GUEST];
+		guest_nice = kcs->cpustat[CPUTIME_GUEST_NICE];
 		seq_printf(p, "cpu%d", i);
 		seq_put_decimal_ull(p, " ", nsec_to_clock_t(user));
 		seq_put_decimal_ull(p, " ", nsec_to_clock_t(nice));

fs/proc/task_mmu.c

···
 	pte_t ptent = *pte;
 
 	if (pte_present(ptent)) {
-		ptent = ptep_modify_prot_start(vma->vm_mm, addr, pte);
-		ptent = pte_wrprotect(ptent);
+		pte_t old_pte;
+
+		old_pte = ptep_modify_prot_start(vma, addr, pte);
+		ptent = pte_wrprotect(old_pte);
 		ptent = pte_clear_soft_dirty(ptent);
-		ptep_modify_prot_commit(vma->vm_mm, addr, pte, ptent);
+		ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
 	} else if (is_swap_pte(ptent)) {
 		ptent = pte_swp_clear_soft_dirty(ptent);
 		set_pte_at(vma->vm_mm, addr, pte, ptent);

fs/proc/task_nommu.c

···
 		seq_file_path(m, file, "");
 	} else if (mm && is_stack(vma)) {
 		seq_pad(m, ' ');
-		seq_printf(m, "[stack]");
+		seq_puts(m, "[stack]");
 	}
 
 	seq_putc(m, '\n');

fs/proc/thread_self.c

···
 	struct inode *root_inode = d_inode(s->s_root);
 	struct pid_namespace *ns = proc_pid_ns(root_inode);
 	struct dentry *thread_self;
+	int ret = -ENOMEM;
 
 	inode_lock(root_inode);
 	thread_self = d_alloc_name(s->s_root, "thread-self");
···
 			inode->i_gid = GLOBAL_ROOT_GID;
 			inode->i_op = &proc_thread_self_inode_operations;
 			d_add(thread_self, inode);
+			ret = 0;
 		} else {
 			dput(thread_self);
-			thread_self = ERR_PTR(-ENOMEM);
 		}
-	} else {
-		thread_self = ERR_PTR(-ENOMEM);
 	}
 	inode_unlock(root_inode);
-	if (IS_ERR(thread_self)) {
+
+	if (ret)
 		pr_err("proc_fill_super: can't allocate /proc/thread_self\n");
-		return PTR_ERR(thread_self);
-	}
-	ns->proc_thread_self = thread_self;
-	return 0;
+	else
+		ns->proc_thread_self = thread_self;
+
+	return ret;
 }
 
 void __init proc_thread_self_init(void)

include/asm-generic/pgtable.h

···
 	return 0;
 }
 
-static inline pte_t __ptep_modify_prot_start(struct mm_struct *mm,
+static inline pte_t __ptep_modify_prot_start(struct vm_area_struct *vma,
 					     unsigned long addr,
 					     pte_t *ptep)
 {
···
 	 * non-present, preventing the hardware from asynchronously
 	 * updating it.
 	 */
-	return ptep_get_and_clear(mm, addr, ptep);
+	return ptep_get_and_clear(vma->vm_mm, addr, ptep);
 }
 
-static inline void __ptep_modify_prot_commit(struct mm_struct *mm,
+static inline void __ptep_modify_prot_commit(struct vm_area_struct *vma,
 					     unsigned long addr,
 					     pte_t *ptep, pte_t pte)
 {
···
 	 * The pte is non-present, so there's no hardware state to
 	 * preserve.
 	 */
-	set_pte_at(mm, addr, ptep, pte);
+	set_pte_at(vma->vm_mm, addr, ptep, pte);
 }
 
 #ifndef __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
···
  * queue the update to be done at some later time.  The update must be
  * actually committed before the pte lock is released, however.
  */
-static inline pte_t ptep_modify_prot_start(struct mm_struct *mm,
+static inline pte_t ptep_modify_prot_start(struct vm_area_struct *vma,
 					   unsigned long addr,
 					   pte_t *ptep)
 {
-	return __ptep_modify_prot_start(mm, addr, ptep);
+	return __ptep_modify_prot_start(vma, addr, ptep);
 }
 
 /*
  * Commit an update to a pte, leaving any hardware-controlled bits in
  * the PTE unmodified.
  */
-static inline void ptep_modify_prot_commit(struct mm_struct *mm,
+static inline void ptep_modify_prot_commit(struct vm_area_struct *vma,
 					   unsigned long addr,
-					   pte_t *ptep, pte_t pte)
+					   pte_t *ptep, pte_t old_pte, pte_t pte)
 {
-	__ptep_modify_prot_commit(mm, addr, ptep, pte);
+	__ptep_modify_prot_commit(vma, addr, ptep, pte);
 }
 #endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
 #endif /* CONFIG_MMU */

include/linux/backing-dev.h

···
 	rcu_read_lock();
 
 	/*
-	 * Paired with store_release in inode_switch_wb_work_fn() and
+	 * Paired with store_release in inode_switch_wbs_work_fn() and
 	 * ensures that we see the new wb if we see cleared I_WB_SWITCH.
 	 */
 	cookie->locked = smp_load_acquire(&inode->i_state) & I_WB_SWITCH;

include/linux/balloon_compaction.h

···
  *
  * Common interface definitions for making balloon pages movable by compaction.
  *
- * Despite being perfectly possible to perform ballooned pages migration, they
- * make a special corner case to compaction scans because balloon pages are not
- * enlisted at any LRU list like the other pages we do compact / migrate.
+ * Balloon page migration makes use of the general non-lru movable page
+ * feature.
+ *
+ * page->private is used to reference the responsible balloon device.
+ * page->mapping is used in context of non-lru page migration to reference
+ * the address space operations for page isolation/migration/compaction.
  *
  * As the page isolation scanning step a compaction thread does is a lockless
  * procedure (from a page standpoint), it might bring some racy situations while
  * performing balloon page compaction. In order to sort out these racy scenarios
  * and safely perform balloon's page compaction and migration we must, always,
- * ensure following these three simple rules:
+ * ensure following these simple rules:
  *
  *   i. when updating a balloon's page ->mapping element, strictly do it under
  *      the following lock order, independently of the far superior
···
  *	      +--spin_lock_irq(&b_dev_info->pages_lock);
  *	            ... page->mapping updates here ...
  *
- *  ii. before isolating or dequeueing a balloon page from the balloon device
- *      pages list, the page reference counter must be raised by one and the
- *      extra refcount must be dropped when the page is enqueued back into
- *      the balloon device page list, thus a balloon page keeps its reference
- *      counter raised only while it is under our special handling;
- *
- * iii. after the lockless scan step have selected a potential balloon page for
- *      isolation, re-test the PageBalloon mark and the PagePrivate flag
- *      under the proper page lock, to ensure isolating a valid balloon page
- *      (not yet isolated, nor under release procedure)
- *
- *  iv. isolation or dequeueing procedure must clear PagePrivate flag under
- *      page lock together with removing page from balloon device page list.
+ *  ii. isolation or dequeueing procedure must remove the page from balloon
+ *      device page list under b_dev_info->pages_lock.
  *
  * The functions provided by this interface are placed to help on coping with
  * the aforementioned balloon page corner case, as well as to ensure the simple
···
 static inline void balloon_page_insert(struct balloon_dev_info *balloon,
 				       struct page *page)
 {
-	__SetPageBalloon(page);
+	__SetPageOffline(page);
 	__SetPageMovable(page, balloon->inode->i_mapping);
 	set_page_private(page, (unsigned long)balloon);
 	list_add(&page->lru, &balloon->pages);
···
  */
 static inline void balloon_page_delete(struct page *page)
 {
-	__ClearPageBalloon(page);
+	__ClearPageOffline(page);
 	__ClearPageMovable(page);
 	set_page_private(page, 0);
 	/*
···
 static inline void balloon_page_insert(struct balloon_dev_info *balloon,
 				       struct page *page)
 {
-	__SetPageBalloon(page);
+	__SetPageOffline(page);
 	list_add(&page->lru, &balloon->pages);
 }
 
 static inline void balloon_page_delete(struct page *page)
 {
-	__ClearPageBalloon(page);
+	__ClearPageOffline(page);
 	list_del(&page->lru);
 }
 

include/linux/cgroup-defs.h

···
 struct kernfs_ops;
 struct kernfs_open_file;
 struct seq_file;
+struct poll_table_struct;
 
 #define MAX_CGROUP_TYPE_NAMELEN 32
 #define MAX_CGROUP_ROOT_NAMELEN 64
···
 	 */
 	ssize_t (*write)(struct kernfs_open_file *of,
 			 char *buf, size_t nbytes, loff_t off);
+
+	__poll_t (*poll)(struct kernfs_open_file *of,
+			 struct poll_table_struct *pt);
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 	struct lock_class_key	lockdep_key;

include/linux/compaction.h

···
 extern int sysctl_compaction_handler(struct ctl_table *table, int write,
 			void __user *buffer, size_t *length, loff_t *ppos);
 extern int sysctl_extfrag_threshold;
-extern int sysctl_extfrag_handler(struct ctl_table *table, int write,
-			void __user *buffer, size_t *length, loff_t *ppos);
 extern int sysctl_compact_unevictable_allowed;
 
 extern int fragmentation_index(struct zone *zone, unsigned int order);
 extern enum compact_result try_to_compact_pages(gfp_t gfp_mask,
 		unsigned int order, unsigned int alloc_flags,
-		const struct alloc_context *ac, enum compact_priority prio);
+		const struct alloc_context *ac, enum compact_priority prio,
+		struct page **page);
 extern void reset_isolation_suitable(pg_data_t *pgdat);
 extern enum compact_result compaction_suitable(struct zone *zone, int order,
 		unsigned int alloc_flags, int classzone_idx);
···
 
 #endif /* CONFIG_COMPACTION */
 
-#if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
 struct node;
+#if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
 extern int compaction_register_node(struct node *node);
 extern void compaction_unregister_node(struct node *node);
 

include/linux/device.h

···
 #else
 static inline int dev_to_node(struct device *dev)
 {
-	return -1;
+	return NUMA_NO_NODE;
 }
 static inline void set_dev_node(struct device *dev, int node)
 {

include/linux/frontswap.h

···
 #include <linux/bitops.h>
 #include <linux/jump_label.h>
 
+/*
+ * Return code to denote that requested number of
+ * frontswap pages are unused(moved to page cache).
+ * Used in in shmem_unuse and try_to_unuse.
+ */
+#define FRONTSWAP_PAGES_UNUSED	2
+
 struct frontswap_ops {
 	void (*init)(unsigned); /* this swap type was just swapon'ed */
 	int (*store)(unsigned, pgoff_t, struct page *); /* store a page */

include/linux/fs.h

···
  * I_WB_SWITCH		Cgroup bdi_writeback switching in progress.  Used to
  *			synchronize competing switching instances and to tell
  *			wb stat updates to grab the i_pages lock.  See
- *			inode_switch_wb_work_fn() for details.
+ *			inode_switch_wbs_work_fn() for details.
  *
  * I_OVL_INUSE		Used by overlayfs to get exclusive ownership on upper
  *			and work dirs among overlayfs mounts.

include/linux/gfp.h

···
 #define ___GFP_HIGH		0x20u
 #define ___GFP_IO		0x40u
 #define ___GFP_FS		0x80u
-#define ___GFP_WRITE		0x100u
-#define ___GFP_NOWARN		0x200u
-#define ___GFP_RETRY_MAYFAIL	0x400u
-#define ___GFP_NOFAIL		0x800u
-#define ___GFP_NORETRY		0x1000u
-#define ___GFP_MEMALLOC		0x2000u
-#define ___GFP_COMP		0x4000u
-#define ___GFP_ZERO		0x8000u
-#define ___GFP_NOMEMALLOC	0x10000u
-#define ___GFP_HARDWALL		0x20000u
-#define ___GFP_THISNODE		0x40000u
-#define ___GFP_ATOMIC		0x80000u
-#define ___GFP_ACCOUNT		0x100000u
-#define ___GFP_DIRECT_RECLAIM	0x200000u
-#define ___GFP_KSWAPD_RECLAIM	0x400000u
+#define ___GFP_ZERO		0x100u
+#define ___GFP_ATOMIC		0x200u
+#define ___GFP_DIRECT_RECLAIM	0x400u
+#define ___GFP_KSWAPD_RECLAIM	0x800u
+#define ___GFP_WRITE		0x1000u
+#define ___GFP_NOWARN		0x2000u
+#define ___GFP_RETRY_MAYFAIL	0x4000u
+#define ___GFP_NOFAIL		0x8000u
+#define ___GFP_NORETRY		0x10000u
+#define ___GFP_MEMALLOC		0x20000u
+#define ___GFP_COMP		0x40000u
+#define ___GFP_NOMEMALLOC	0x80000u
+#define ___GFP_HARDWALL		0x100000u
+#define ___GFP_THISNODE		0x200000u
+#define ___GFP_ACCOUNT		0x400000u
 #ifdef CONFIG_LOCKDEP
 #define ___GFP_NOLOCKDEP	0x800000u
 #else

include/linux/hugetlb.h

···
 				nodemask_t *nmask);
 struct page *alloc_huge_page_vma(struct hstate *h, struct vm_area_struct *vma,
 				unsigned long address);
+struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask,
+				     int nid, nodemask_t *nmask);
 int huge_add_to_page_cache(struct page *page, struct address_space *mapping,
 			pgoff_t idx);
 
···
 extern int dissolve_free_huge_page(struct page *page);
 extern int dissolve_free_huge_pages(unsigned long start_pfn,
 				    unsigned long end_pfn);
-static inline bool hugepage_migration_supported(struct hstate *h)
-{
+
 #ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
+#ifndef arch_hugetlb_migration_supported
+static inline bool arch_hugetlb_migration_supported(struct hstate *h)
+{
 	if ((huge_page_shift(h) == PMD_SHIFT) ||
-		(huge_page_shift(h) == PGDIR_SHIFT))
+		(huge_page_shift(h) == PUD_SHIFT) ||
+			(huge_page_shift(h) == PGDIR_SHIFT))
 		return true;
 	else
 		return false;
-#else
-	return false;
+}
 #endif
+#else
+static inline bool arch_hugetlb_migration_supported(struct hstate *h)
+{
+	return false;
+}
+#endif
+
+static inline bool hugepage_migration_supported(struct hstate *h)
+{
+	return arch_hugetlb_migration_supported(h);
+}
+
+/*
+ * Movability check is different as compared to migration check.
+ * It determines whether or not a huge page should be placed on
+ * movable zone or not. Movability of any huge page should be
+ * required only if huge page size is supported for migration.
+ * There wont be any reason for the huge page to be movable if
+ * it is not migratable to start with. Also the size of the huge
+ * page should be large enough to be placed under a movable zone
+ * and still feasible enough to be migratable. Just the presence
+ * in movable zone does not make the migration feasible.
+ *
+ * So even though large huge page sizes like the gigantic ones
+ * are migratable they should not be movable because its not
+ * feasible to migrate them from movable zone.
+ */
+static inline bool hugepage_movable_supported(struct hstate *h)
+{
+	if (!hugepage_migration_supported(h))
+		return false;
+
+	if (hstate_is_gigantic(h))
+		return false;
+	return true;
 }
 
 static inline spinlock_t *huge_pte_lockptr(struct hstate *h,
···
 	set_huge_pte_at(mm, addr, ptep, pte);
 }
 #endif
+
+#ifndef huge_ptep_modify_prot_start
+#define huge_ptep_modify_prot_start huge_ptep_modify_prot_start
+static inline pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
+						unsigned long addr, pte_t *ptep)
+{
+	return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
+}
+#endif
+
+#ifndef huge_ptep_modify_prot_commit
+#define huge_ptep_modify_prot_commit huge_ptep_modify_prot_commit
+static inline void huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
+						unsigned long addr, pte_t *ptep,
+						pte_t old_pte, pte_t pte)
+{
+	set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
+}
+#endif
+
 #else	/* CONFIG_HUGETLB_PAGE */
 struct hstate {};
 #define alloc_huge_page(v, a, r) NULL
···
 }
 
 static inline bool hugepage_migration_supported(struct hstate *h)
+{
+	return false;
+}
+
+static inline bool hugepage_movable_supported(struct hstate *h)
 {
 	return false;
 }

include/linux/kasan-checks.h

···
 #ifndef _LINUX_KASAN_CHECKS_H
 #define _LINUX_KASAN_CHECKS_H
 
-#ifdef CONFIG_KASAN
+#if defined(__SANITIZE_ADDRESS__) || defined(__KASAN_INTERNAL)
 void kasan_check_read(const volatile void *p, unsigned int size);
 void kasan_check_write(const volatile void *p, unsigned int size);
 #else

include/linux/kernfs.h

···
 struct vm_area_struct;
 struct super_block;
 struct file_system_type;
+struct poll_table_struct;
 
 struct kernfs_open_node;
 struct kernfs_iattrs;
···
 	ssize_t (*write)(struct kernfs_open_file *of, char *buf, size_t bytes,
 			 loff_t off);
 
+	__poll_t (*poll)(struct kernfs_open_file *of,
+			 struct poll_table_struct *pt);
+
 	int (*mmap)(struct kernfs_open_file *of, struct vm_area_struct *vma);
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
···
 int kernfs_rename_ns(struct kernfs_node *kn, struct kernfs_node *new_parent,
 		     const char *new_name, const void *new_ns);
 int kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr);
+__poll_t kernfs_generic_poll(struct kernfs_open_file *of,
+			     struct poll_table_struct *pt);
 void kernfs_notify(struct kernfs_node *kn);
 
 const void *kernfs_super_ns(struct super_block *sb);

include/linux/ksm.h

···
 
 void rmap_walk_ksm(struct page *page, struct rmap_walk_control *rwc);
 void ksm_migrate_page(struct page *newpage, struct page *oldpage);
+bool reuse_ksm_page(struct page *page,
+			struct vm_area_struct *vma, unsigned long address);
 
 #else  /* !CONFIG_KSM */
 
···
 
 static inline void ksm_migrate_page(struct page *newpage, struct page *oldpage)
 {
+}
+static inline bool reuse_ksm_page(struct page *page,
+			struct vm_area_struct *vma, unsigned long address)
+{
+	return false;
 }
 #endif /* CONFIG_MMU */
 #endif /* !CONFIG_KSM */

include/linux/list.h

···
 }
 
 /**
+ * list_is_first -- tests whether @ list is the first entry in list @head
+ * @list: the entry to test
+ * @head: the head of the list
+ */
+static inline int list_is_first(const struct list_head *list,
+					const struct list_head *head)
+{
+	return list->prev == head;
+}
+
+/**
  * list_is_last - tests whether @list is the last entry in list @head
  * @list: the entry to test
  * @head: the head of the list

include/linux/memcontrol.h

···
 }
 struct mem_cgroup *mem_cgroup_from_id(unsigned short id);
 
+static inline struct mem_cgroup *mem_cgroup_from_seq(struct seq_file *m)
+{
+	return mem_cgroup_from_css(seq_css(m));
+}
+
 static inline struct mem_cgroup *lruvec_memcg(struct lruvec *lruvec)
 {
 	struct mem_cgroup_per_node *mz;
···
 	return NULL;
 }
 
+static inline struct mem_cgroup *mem_cgroup_from_seq(struct seq_file *m)
+{
+	return NULL;
+}
+
 static inline struct mem_cgroup *lruvec_memcg(struct lruvec *lruvec)
 {
 	return NULL;
···
 
 struct kmem_cache *memcg_kmem_get_cache(struct kmem_cache *cachep);
 void memcg_kmem_put_cache(struct kmem_cache *cachep);
-int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
-			    struct mem_cgroup *memcg);
 
 #ifdef CONFIG_MEMCG_KMEM
-int memcg_kmem_charge(struct page *page, gfp_t gfp, int order);
-void memcg_kmem_uncharge(struct page *page, int order);
+int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order);
+void __memcg_kmem_uncharge(struct page *page, int order);
+int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
+			      struct mem_cgroup *memcg);
 
 extern struct static_key_false memcg_kmem_enabled_key;
 extern struct workqueue_struct *memcg_kmem_cache_wq;
···
 	return static_branch_unlikely(&memcg_kmem_enabled_key);
 }
 
+static inline int memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
+{
+	if (memcg_kmem_enabled())
+		return __memcg_kmem_charge(page, gfp, order);
+	return 0;
+}
+
+static inline void memcg_kmem_uncharge(struct page *page, int order)
+{
+	if (memcg_kmem_enabled())
+		__memcg_kmem_uncharge(page, order);
+}
+
+static inline int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp,
+					  int order, struct mem_cgroup *memcg)
+{
+	if (memcg_kmem_enabled())
+		return __memcg_kmem_charge_memcg(page, gfp, order, memcg);
+	return 0;
+}
 /*
  * helper for accessing a memcg's index. It will be used as an index in the
  * child cache array in kmem_cache, and also to derive its name. This function
···
 }
 
 static inline void memcg_kmem_uncharge(struct page *page, int order)
+{
+}
+
+static inline int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
+{
+	return 0;
+}
+
+static inline void __memcg_kmem_uncharge(struct page *page, int order)
 {
 }
 

include/linux/memory_hotplug.h

···
 	unsigned long *valid_start, unsigned long *valid_end);
 extern void __offline_isolated_pages(unsigned long, unsigned long);
 
-typedef void (*online_page_callback_t)(struct page *page);
+typedef void (*online_page_callback_t)(struct page *page, unsigned int order);
 
 extern int set_online_page_callback(online_page_callback_t callback);
 extern int restore_online_page_callback(online_page_callback_t callback);

include/linux/mm.h

···
 		    unsigned int gup_flags, struct page **pages, int *locked);
 long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
 		    struct page **pages, unsigned int gup_flags);
-#ifdef CONFIG_FS_DAX
+
+#if defined(CONFIG_FS_DAX) || defined(CONFIG_CMA)
 long get_user_pages_longterm(unsigned long start, unsigned long nr_pages,
 			    unsigned int gup_flags, struct page **pages,
 			    struct vm_area_struct **vmas);

include/linux/mm_types.h

···
 		struct {	/* Page cache and anonymous pages */
 			/**
 			 * @lru: Pageout list, eg. active_list protected by
-			 * zone_lru_lock.  Sometimes used as a generic list
+			 * pgdat->lru_lock.  Sometimes used as a generic list
 			 * by the page owner.
 			 */
 			struct list_head lru;

include/linux/mmzone.h

···
 	unsigned long		compact_cached_free_pfn;
 	/* pfn where async and sync compaction migration scanner should start */
 	unsigned long		compact_cached_migrate_pfn[2];
+	unsigned long		compact_init_migrate_pfn;
+	unsigned long		compact_init_free_pfn;
 #endif
 
 #ifdef CONFIG_COMPACTION
···
 
 #define node_start_pfn(nid)	(NODE_DATA(nid)->node_start_pfn)
 #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid))
-static inline spinlock_t *zone_lru_lock(struct zone *zone)
-{
-	return &zone->zone_pgdat->lru_lock;
-}
 
 static inline struct lruvec *node_lruvec(struct pglist_data *pgdat)
 {
···
 
 /*
  * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
- * need to check pfn validility within that MAX_ORDER_NR_PAGES block.
+ * need to check pfn validity within that MAX_ORDER_NR_PAGES block.
  * pfn_valid_within() should be used in this case; we optimise this away
  * when we have no holes within a MAX_ORDER_NR_PAGES block.
  */

include/linux/nodemask.h

···
 	return next_node(nid, node_states[N_MEMORY]);
 }
 
-extern int nr_node_ids;
-extern int nr_online_nodes;
+extern unsigned int nr_node_ids;
+extern unsigned int nr_online_nodes;
 
 static inline void node_set_online(int nid)
 {
···
 #define first_online_node	0
 #define first_memory_node	0
 #define next_online_node(nid)	(MAX_NUMNODES)
-#define nr_node_ids		1
-#define nr_online_nodes		1
+#define nr_node_ids		1U
+#define nr_online_nodes		1U
 
 #define node_set_online(node)	   node_set_state((node), N_ONLINE)
 #define node_set_offline(node)	   node_clear_state((node), N_ONLINE)

include/linux/page-flags.h

···
 /*
  * Various page->flags bits:
  *
- * PG_reserved is set for special pages, which can never be swapped out. Some
- * of them might not even exist...
+ * PG_reserved is set for special pages. The "struct page" of such a page
+ * should in general not be touched (e.g. set dirty) except by its owner.
+ * Pages marked as PG_reserved include:
+ * - Pages part of the kernel image (including vDSO) and similar (e.g. BIOS,
+ *   initrd, HW tables)
+ * - Pages reserved or allocated early during boot (before the page allocator
+ *   was initialized). This includes (depending on the architecture) the
+ *   initial vmemmap, initial page tables, crashkernel, elfcorehdr, and much
+ *   much more. Once (if ever) freed, PG_reserved is cleared and they will
+ *   be given to the page allocator.
+ * - Pages falling into physical memory gaps - not IORESOURCE_SYSRAM. Trying
+ *   to read/write these pages might end badly. Don't touch!
+ * - The zero page(s)
+ * - Pages not added to the page allocator when onlining a section because
+ *   they were excluded via the online_page_callback() or because they are
+ *   PG_hwpoison.
+ * - Pages allocated in the context of kexec/kdump (loaded kernel image,
+ *   control pages, vmcoreinfo)
+ * - MMIO/DMA pages. Some architectures don't allow to ioremap pages that are
+ *   not marked PG_reserved (as they might be in use by somebody else who does
+ *   not respect the caching strategy).
+ * - Pages part of an offline section (struct pages of offline sections should
+ *   not be trusted as they will be initialized when first onlined).
+ * - MCA pages on ia64
+ * - Pages holding CPU notes for POWER Firmware Assisted Dump
+ * - Device memory (e.g. PMEM, DAX, HMM)
+ * Some PG_reserved pages will be excluded from the hibernation image.
+ * PG_reserved does in general not hinder anybody from dumping or swapping
+ * and is no longer required for remap_pfn_range(). ioremap might require it.
+ * Consequently, PG_reserved for a page mapped into user space can indicate
+ * the zero page, the vDSO, MMIO pages or device memory.
  *
  * The PG_private bitflag is set on pagecache pages if they contain filesystem
  * specific data (which is normally at page->private). It can be used by
···
 /* Reserve		0x0000007f to catch underflows of page_mapcount */
 #define PAGE_MAPCOUNT_RESERVE	-128
 #define PG_buddy	0x00000080
-#define PG_balloon	0x00000100
+#define PG_offline	0x00000100
 #define PG_kmemcg	0x00000200
 #define PG_table	0x00000400
 
···
 PAGE_TYPE_OPS(Buddy, buddy)
 
 /*
- * PageBalloon() is true for pages that are on the balloon page list
- * (see mm/balloon_compaction.c).
+ * PageOffline() indicates that the page is logically offline although the
+ * containing section is online. (e.g. inflated in a balloon driver or
+ * not onlined when onlining the section).
+ * The content of these pages is effectively stale. Such pages should not
+ * be touched (read/write/dump/save) except by their owner.
  */
-PAGE_TYPE_OPS(Balloon, balloon)
+PAGE_TYPE_OPS(Offline, offline)
 
 /*
  * If kmemcg is enabled, the buddy allocator will set PageKmemcg() on

include/linux/pagemap.h

···
  * will find the page or it will not. Likewise, the old find_get_page could run
  * either before the insertion or afterwards, depending on timing.
  */
-static inline int page_cache_get_speculative(struct page *page)
+static inline int __page_cache_add_speculative(struct page *page, int count)
 {
 #ifdef CONFIG_TINY_RCU
 # ifdef CONFIG_PREEMPT_COUNT
···
 	 * SMP requires.
 	 */
 	VM_BUG_ON_PAGE(page_count(page) == 0, page);
-	page_ref_inc(page);
+	page_ref_add(page, count);
 
 #else
-	if (unlikely(!get_page_unless_zero(page))) {
+	if (unlikely(!page_ref_add_unless(page, count, 0))) {
 		/*
 		 * Either the page has been freed, or will be freed.
 		 * In either case, retry here and the caller should
···
 	return 1;
 }
 
-/*
- * Same as above, but add instead of inc (could just be merged)
- */
+static inline int page_cache_get_speculative(struct page *page)
+{
+	return __page_cache_add_speculative(page, 1);
+}
+
 static inline int page_cache_add_speculative(struct page *page, int count)
 {
-	VM_BUG_ON(in_interrupt());
-
-#if !defined(CONFIG_SMP) && defined(CONFIG_TREE_RCU)
-# ifdef CONFIG_PREEMPT_COUNT
-	VM_BUG_ON(!in_atomic() && !irqs_disabled());
-# endif
-	VM_BUG_ON_PAGE(page_count(page) == 0, page);
-	page_ref_add(page, count);
-
-#else
-	if (unlikely(!page_ref_add_unless(page, count, 0)))
-		return 0;
-#endif
-	VM_BUG_ON_PAGE(PageCompound(page) && page != compound_head(page), page);
-
-	return 1;
+	return __page_cache_add_speculative(page, count);
 }
 
 #ifdef CONFIG_NUMA

include/linux/poison.h

···
  */
 #define TIMER_ENTRY_STATIC	((void *) 0x300 + POISON_POINTER_DELTA)
 
-/********** mm/debug-pagealloc.c **********/
+/********** mm/page_poison.c **********/
 #ifdef CONFIG_PAGE_POISONING_ZERO
 #define PAGE_POISON 0x00
 #else

include/linux/sched.h

···
 struct pipe_inode_info;
 struct rcu_node;
 struct reclaim_state;
+struct capture_control;
 struct robust_list_head;
 struct sched_attr;
 struct sched_param;
···
 
 	struct io_context		*io_context;
 
+#ifdef CONFIG_COMPACTION
+	struct capture_control		*capture_control;
+#endif
 	/* Ptrace state: */
 	unsigned long			ptrace_message;
 	kernel_siginfo_t		*last_siginfo;
···
 #define PF_UMH			0x02000000	/* I'm an Usermodehelper process */
 #define PF_NO_SETAFFINITY	0x04000000	/* Userland is not allowed to meddle with cpus_allowed */
 #define PF_MCE_EARLY		0x08000000      /* Early kill for mce process policy */
+#define PF_MEMALLOC_NOCMA	0x10000000	/* All allocation request will have _GFP_MOVABLE cleared */
 #define PF_FREEZER_SKIP		0x40000000	/* Freezer should not count it as freezable */
 #define PF_SUSPEND_TASK		0x80000000      /* This thread called freeze_processes() and should not be frozen */
 

include/linux/sched/mm.h

···
  * Applies per-task gfp context to the given allocation flags.
  * PF_MEMALLOC_NOIO implies GFP_NOIO
  * PF_MEMALLOC_NOFS implies GFP_NOFS
+ * PF_MEMALLOC_NOCMA implies no allocation from CMA region.
  */
 static inline gfp_t current_gfp_context(gfp_t flags)
 {
-	/*
-	 * NOIO implies both NOIO and NOFS and it is a weaker context
-	 * so always make sure it makes precedence
-	 */
-	if (unlikely(current->flags & PF_MEMALLOC_NOIO))
-		flags &= ~(__GFP_IO | __GFP_FS);
-	else if (unlikely(current->flags & PF_MEMALLOC_NOFS))
-		flags &= ~__GFP_FS;
+	if (unlikely(current->flags &
+		     (PF_MEMALLOC_NOIO | PF_MEMALLOC_NOFS | PF_MEMALLOC_NOCMA))) {
+		/*
+		 * NOIO implies both NOIO and NOFS and it is a weaker context
+		 * so always make sure it makes precedence
+		 */
+		if (current->flags & PF_MEMALLOC_NOIO)
+			flags &= ~(__GFP_IO | __GFP_FS);
+		else if (current->flags & PF_MEMALLOC_NOFS)
+			flags &= ~__GFP_FS;
+#ifdef CONFIG_CMA
+		if (current->flags & PF_MEMALLOC_NOCMA)
+			flags &= ~__GFP_MOVABLE;
+#endif
+	}
 	return flags;
 }
 
···
 {
 	current->flags = (current->flags & ~PF_MEMALLOC) | flags;
 }
+
+#ifdef CONFIG_CMA
+static inline unsigned int memalloc_nocma_save(void)
+{
+	unsigned int flags = current->flags & PF_MEMALLOC_NOCMA;
+
+	current->flags |= PF_MEMALLOC_NOCMA;
+	return flags;
+}
+
+static inline void memalloc_nocma_restore(unsigned int flags)
+{
+	current->flags = (current->flags & ~PF_MEMALLOC_NOCMA) | flags;
+}
+#else
+static inline unsigned int memalloc_nocma_save(void)
+{
+	return 0;
+}
+
+static inline void memalloc_nocma_restore(unsigned int flags)
+{
+}
+#endif
 
 #ifdef CONFIG_MEMCG
 /**

include/linux/shmem_fs.h

···
 extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
 					pgoff_t index, gfp_t gfp_mask);
 extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
-extern int shmem_unuse(swp_entry_t entry, struct page *page);
+extern int shmem_unuse(unsigned int type, bool frontswap,
+		       unsigned long *fs_pages_to_unuse);
 
 extern unsigned long shmem_swap_usage(struct vm_area_struct *vma);
 extern unsigned long shmem_partial_swap_usage(struct address_space *mapping,

include/linux/slub_def.h

···
  */
 struct kmem_cache {
 	struct kmem_cache_cpu __percpu *cpu_slab;
-	/* Used for retriving partial slabs etc */
+	/* Used for retrieving partial slabs, etc. */
 	slab_flags_t flags;
 	unsigned long min_partial;
-	unsigned int size;	/* The size of an object including meta data */
-	unsigned int object_size;/* The size of an object without meta data */
-	unsigned int offset;	/* Free pointer offset. */
+	unsigned int size;	/* The size of an object including metadata */
+	unsigned int object_size;/* The size of an object without metadata */
+	unsigned int offset;	/* Free pointer offset */
 #ifdef CONFIG_SLUB_CPU_PARTIAL
 	/* Number of per cpu partial objects to keep around */
 	unsigned int cpu_partial;
···
 #endif
 #ifdef CONFIG_MEMCG
 	struct memcg_cache_params memcg_params;
-	/* for propagation, maximum size of a stored attr */
+	/* For propagation, maximum size of a stored attr */
 	unsigned int max_attr_size;
 #ifdef CONFIG_SYSFS
 	struct kset *memcg_kset;
···
 #else
 #define slub_cpu_partial(s)		(0)
 #define slub_set_cpu_partial(s, n)
-#endif // CONFIG_SLUB_CPU_PARTIAL
+#endif /* CONFIG_SLUB_CPU_PARTIAL */
 
 #ifdef CONFIG_SYSFS
 #define SLAB_SUPPORTS_SYSFS

include/linux/swap.h

···
 };
 
 /* linux/mm/workingset.c */
-void *workingset_eviction(struct address_space *mapping, struct page *page);
+void *workingset_eviction(struct page *page);
 void workingset_refault(struct page *page, void *shadow);
 void workingset_activation(struct page *page);
 
···
 		return vm_swappiness;
 
 	/* root ? */
-	if (mem_cgroup_disabled() || !memcg->css.parent)
+	if (mem_cgroup_disabled() || mem_cgroup_is_root(memcg))
 		return vm_swappiness;
 
 	return memcg->swappiness;

include/uapi/linux/fcntl.h

···
 #define F_SEAL_SHRINK	0x0002	/* prevent file from shrinking */
 #define F_SEAL_GROW	0x0004	/* prevent file from growing */
 #define F_SEAL_WRITE	0x0008	/* prevent writes */
+#define F_SEAL_FUTURE_WRITE	0x0010  /* prevent future writes while mapped */
 /* (1U << 31) is reserved for signed error codes */
 
 /*

include/uapi/linux/kernel-page-flags.h

···
 
 #define KPF_KSM			21
 #define KPF_THP			22
-#define KPF_BALLOON		23
+#define KPF_OFFLINE		23
 #define KPF_ZERO_PAGE		24
 #define KPF_IDLE		25
 #define KPF_PGTABLE		26

init/init_task.c

···
 #include <linux/fs.h>
 #include <linux/mm.h>
 #include <linux/audit.h>
+#include <linux/numa.h>
 
 #include <asm/pgtable.h>
 #include <linux/uaccess.h>
···
 	.vtime.state	= VTIME_SYS,
 #endif
 #ifdef CONFIG_NUMA_BALANCING
-	.numa_preferred_nid = -1,
+	.numa_preferred_nid = NUMA_NO_NODE,
 	.numa_group	= NULL,
 	.numa_faults	= NULL,
 #endif

kernel/cgroup/cgroup.c

···
 	return ret ?: nbytes;
 }
 
+static __poll_t cgroup_file_poll(struct kernfs_open_file *of, poll_table *pt)
+{
+	struct cftype *cft = of->kn->priv;
+
+	if (cft->poll)
+		return cft->poll(of, pt);
+
+	return kernfs_generic_poll(of, pt);
+}
+
 static void *cgroup_seqfile_start(struct seq_file *seq, loff_t *ppos)
 {
 	return seq_cft(seq)->seq_start(seq, ppos);
···
 	.open			= cgroup_file_open,
 	.release		= cgroup_file_release,
 	.write			= cgroup_file_write,
+	.poll			= cgroup_file_poll,
 	.seq_show		= cgroup_seqfile_show,
 };
 
···
 	.open			= cgroup_file_open,
 	.release		= cgroup_file_release,
 	.write			= cgroup_file_write,
+	.poll			= cgroup_file_poll,
 	.seq_start		= cgroup_seqfile_start,
 	.seq_next		= cgroup_seqfile_next,
 	.seq_stop		= cgroup_seqfile_stop,

kernel/crash_core.c

···
 	VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
 #ifdef CONFIG_HUGETLB_PAGE
 	VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
+#define PAGE_OFFLINE_MAPCOUNT_VALUE	(~PG_offline)
+	VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE);
 #endif
 
 	arch_crash_save_vmcoreinfo();

kernel/kthread.c

···
 #include <linux/freezer.h>
 #include <linux/ptrace.h>
 #include <linux/uaccess.h>
+#include <linux/numa.h>
 #include <trace/events/sched.h>
 
 static DEFINE_SPINLOCK(kthread_create_lock);
···
 {
 	struct kthread_worker *worker;
 	struct task_struct *task;
-	int node = -1;
+	int node = NUMA_NO_NODE;
 
 	worker = kzalloc(sizeof(*worker), GFP_KERNEL);
 	if (!worker)

kernel/power/snapshot.c

···
 	if (!pfn_valid(pfn))
 		return NULL;
 
-	page = pfn_to_page(pfn);
-	if (page_zone(page) != zone)
+	page = pfn_to_online_page(pfn);
+	if (!page || page_zone(page) != zone)
 		return NULL;
 
 	BUG_ON(!PageHighMem(page));
 
-	if (swsusp_page_is_forbidden(page) ||  swsusp_page_is_free(page) ||
-	    PageReserved(page))
+	if (swsusp_page_is_forbidden(page) ||  swsusp_page_is_free(page))
+		return NULL;
+
+	if (PageReserved(page) || PageOffline(page))
 		return NULL;
 
 	if (page_is_guard(page))
···
 	if (!pfn_valid(pfn))
 		return NULL;
 
-	page = pfn_to_page(pfn);
-	if (page_zone(page) != zone)
+	page = pfn_to_online_page(pfn);
+	if (!page || page_zone(page) != zone)
 		return NULL;
 
 	BUG_ON(PageHighMem(page));
 
 	if (swsusp_page_is_forbidden(page) || swsusp_page_is_free(page))
+		return NULL;
+
+	if (PageOffline(page))
 		return NULL;
 
 	if (PageReserved(page)

kernel/sched/core.c

···
 	INIT_HLIST_HEAD(&p->preempt_notifiers);
 #endif
 
+#ifdef CONFIG_COMPACTION
+	p->capture_control = NULL;
+#endif
 	init_numa_balancing(clone_flags, p);
 }
 

kernel/sched/fair.c

···
 
 	/* New address space, reset the preferred nid */
 	if (!(clone_flags & CLONE_VM)) {
-		p->numa_preferred_nid = -1;
+		p->numa_preferred_nid = NUMA_NO_NODE;
 		return;
 	}
 
···
 
 static void account_numa_enqueue(struct rq *rq, struct task_struct *p)
 {
-	rq->nr_numa_running += (p->numa_preferred_nid != -1);
+	rq->nr_numa_running += (p->numa_preferred_nid != NUMA_NO_NODE);
 	rq->nr_preferred_running += (p->numa_preferred_nid == task_node(p));
 }
 
 static void account_numa_dequeue(struct rq *rq, struct task_struct *p)
 {
-	rq->nr_numa_running -= (p->numa_preferred_nid != -1);
+	rq->nr_numa_running -= (p->numa_preferred_nid != NUMA_NO_NODE);
 	rq->nr_preferred_running -= (p->numa_preferred_nid == task_node(p));
 }
 
···
 	 * two full passes of the "multi-stage node selection" test that is
 	 * executed below.
 	 */
-	if ((p->numa_preferred_nid == -1 || p->numa_scan_seq <= 4) &&
+	if ((p->numa_preferred_nid == NUMA_NO_NODE || p->numa_scan_seq <= 4) &&
 	    (cpupid_pid_unset(last_cpupid) || cpupid_match_pid(p, last_cpupid)))
 		return true;
 
···
 	unsigned long interval = HZ;
 
 	/* This task has no NUMA fault statistics yet */
-	if (unlikely(p->numa_preferred_nid == -1 || !p->numa_faults))
+	if (unlikely(p->numa_preferred_nid == NUMA_NO_NODE || !p->numa_faults))
 		return;
 
 	/* Periodically retry migrating the task to the preferred node */
···
 
 static void task_numa_placement(struct task_struct *p)
 {
-	int seq, nid, max_nid = -1;
+	int seq, nid, max_nid = NUMA_NO_NODE;
 	unsigned long max_faults = 0;
 	unsigned long fault_types[2] = { 0, 0 };
 	unsigned long total_faults;
···
 		 * the preferred node.
 		 */
 		if (dst_nid == p->numa_preferred_nid ||
-		    (p->numa_preferred_nid != -1 && src_nid != p->numa_preferred_nid))
+		    (p->numa_preferred_nid != NUMA_NO_NODE &&
+			src_nid != p->numa_preferred_nid))
 			return;
 	}
 

kernel/sysctl.c

···
 		.data		= &sysctl_extfrag_threshold,
 		.maxlen		= sizeof(int),
 		.mode		= 0644,
-		.proc_handler	= sysctl_extfrag_handler,
+		.proc_handler	= proc_dointvec_minmax,
 		.extra1		= &min_extfrag_threshold,
 		.extra2		= &max_extfrag_threshold,
 	},

lib/Kconfig.debug

···
 config FRAME_WARN
 	int "Warn for stack frames larger than (needs gcc 4.4)"
 	range 0 8192
-	default 3072 if KASAN_EXTRA
 	default 2048 if GCC_PLUGIN_LATENT_ENTROPY
 	default 1280 if (!64BIT && PARISC)
 	default 1024 if (!64BIT && !PARISC)
···
 	  mail to the linux kernel mailing list mentioning the symbol and why
 	  you really need it, and what the merge plan to the mainline kernel for
 	  your module is.
-
-config PAGE_OWNER
-	bool "Track page owner"
-	depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
-	select DEBUG_FS
-	select STACKTRACE
-	select STACKDEPOT
-	select PAGE_EXTENSION
-	help
-	  This keeps track of what call chain is the owner of a page, may
-	  help to find bare alloc_page(s) leaks. Even if you include this
-	  feature on your build, it is disabled in default. You should pass
-	  "page_owner=on" to boot parameter in order to enable it. Eats
-	  a fair amount of memory if enabled. See tools/vm/page_owner_sort.c
-	  for user-space helper.
-
-	  If unsure, say N.
 
 config DEBUG_FS
 	bool "Debug Filesystem"
···
 	  validating module verification). It lacks any extra dependencies,
 	  and will not normally be loaded by the system unless explicitly
 	  requested by name.
+
+	  If unsure, say N.
+
+config TEST_VMALLOC
+	tristate "Test module for stress/performance analysis of vmalloc allocator"
+	default n
+       depends on MMU
+	depends on m
+	help
+	  This builds the "test_vmalloc" module that should be used for
+	  stress and performance analysis. So, any new change for vmalloc
+	  subsystem can be evaluated from performance and stability point
+	  of view.
 
 	  If unsure, say N.
 

lib/Kconfig.kasan

···
 
 endchoice
 
-config KASAN_EXTRA
-	bool "KASAN: extra checks"
-	depends on KASAN_GENERIC && DEBUG_KERNEL && !COMPILE_TEST
-	help
-	  This enables further checks in generic KASAN, for now it only
-	  includes the address-use-after-scope check that can lead to
-	  excessive kernel stack usage, frame size warnings and longer
-	  compile time.
-	  See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715
-
 choice
 	prompt "Instrumentation type"
 	depends on KASAN

lib/Makefile

···
 obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o
 obj-$(CONFIG_TEST_LIST_SORT) += test_list_sort.o
 obj-$(CONFIG_TEST_LKM) += test_module.o
+obj-$(CONFIG_TEST_VMALLOC) += test_vmalloc.o
 obj-$(CONFIG_TEST_OVERFLOW) += test_overflow.o
 obj-$(CONFIG_TEST_RHASHTABLE) += test_rhashtable.o
 obj-$(CONFIG_TEST_SORT) += test_sort.o

lib/cpumask.c

···
 #include <linux/cpumask.h>
 #include <linux/export.h>
 #include <linux/memblock.h>
+#include <linux/numa.h>
 
 /**
  * cpumask_next - get the next cpu in a cpumask
···
 	/* Wrap: we always want a cpu. */
 	i %= num_online_cpus();
 
-	if (node == -1) {
+	if (node == NUMA_NO_NODE) {
 		for_each_cpu(cpu, cpu_online_mask)
 			if (i-- == 0)
 				return cpu;

lib/test_kasan.c

···
 	kfree(kmem);
 }
 
-static noinline void __init use_after_scope_test(void)
-{
-	volatile char *volatile p;
-
-	pr_info("use-after-scope on int\n");
-	{
-		int local = 0;
-
-		p = (char *)&local;
-	}
-	p[0] = 1;
-	p[3] = 1;
-
-	pr_info("use-after-scope on array\n");
-	{
-		char local[1024] = {0};
-
-		p = local;
-	}
-	p[0] = 1;
-	p[1023] = 1;
-}
-
 static noinline void __init kasan_alloca_oob_left(void)
 {
 	volatile int i = 10;
···
 	kasan_alloca_oob_right();
 	ksize_unpoisons_memory();
 	copy_user_test();
-	use_after_scope_test();
 	kmem_cache_double_free();
 	kmem_cache_invalid_free();
 	kasan_memchr();

lib/test_vmalloc.c

···
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Test module for stress and analyze performance of vmalloc allocator.
+ * (C) 2018 Uladzislau Rezki (Sony) <[e-mail]>
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/random.h>
+#include <linux/kthread.h>
+#include <linux/moduleparam.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/rwsem.h>
+#include <linux/mm.h>
+
+#define __param(type, name, init, msg)		\
+	static type name = init;				\
+	module_param(name, type, 0444);			\
+	MODULE_PARM_DESC(name, msg)				\
+
+__param(bool, single_cpu_test, false,
+	"Use single first online CPU to run tests");
+
+__param(bool, sequential_test_order, false,
+	"Use sequential stress tests order");
+
+__param(int, test_repeat_count, 1,
+	"Set test repeat counter");
+
+__param(int, test_loop_count, 1000000,
+	"Set test loop counter");
+
+__param(int, run_test_mask, INT_MAX,
+	"Set tests specified in the mask.\n\n"
+		"\t\tid: 1,   name: fix_size_alloc_test\n"
+		"\t\tid: 2,   name: full_fit_alloc_test\n"
+		"\t\tid: 4,   name: long_busy_list_alloc_test\n"
+		"\t\tid: 8,   name: random_size_alloc_test\n"
+		"\t\tid: 16,  name: fix_align_alloc_test\n"
+		"\t\tid: 32,  name: random_size_align_alloc_test\n"
+		"\t\tid: 64,  name: align_shift_alloc_test\n"
+		"\t\tid: 128, name: pcpu_alloc_test\n"
+		/* Add a new test case description here. */
+);
+
+/*
+ * Depends on single_cpu_test parameter. If it is true, then
+ * use first online CPU to trigger a test on, otherwise go with
+ * all online CPUs.
+ */
+static cpumask_t cpus_run_test_mask = CPU_MASK_NONE;
+
+/*
+ * Read write semaphore for synchronization of setup
+ * phase that is done in main thread and workers.
+ */
+static DECLARE_RWSEM(prepare_for_test_rwsem);
+
+/*
+ * Completion tracking for worker threads.
+ */
+static DECLARE_COMPLETION(test_all_done_comp);
+static atomic_t test_n_undone = ATOMIC_INIT(0);
+
+static inline void
+test_report_one_done(void)
+{
+	if (atomic_dec_and_test(&test_n_undone))
+		complete(&test_all_done_comp);
+}
+
+static int random_size_align_alloc_test(void)
+{
+	unsigned long size, align, rnd;
+	void *ptr;
+	int i;
+
+	for (i = 0; i < test_loop_count; i++) {
+		get_random_bytes(&rnd, sizeof(rnd));
+
+		/*
+		 * Maximum 1024 pages, if PAGE_SIZE is 4096.
+		 */
+		align = 1 << (rnd % 23);
+
+		/*
+		 * Maximum 10 pages.
+		 */
+		size = ((rnd % 10) + 1) * PAGE_SIZE;
+
+		ptr = __vmalloc_node_range(size, align,
+		   VMALLOC_START, VMALLOC_END,
+		   GFP_KERNEL | __GFP_ZERO,
+		   PAGE_KERNEL,
+		   0, 0, __builtin_return_address(0));
+
+		if (!ptr)
+			return -1;
+
+		vfree(ptr);
+	}
+
+	return 0;
+}
+
+/*
+ * This test case is supposed to be failed.
+ */
+static int align_shift_alloc_test(void)
+{
+	unsigned long align;
+	void *ptr;
+	int i;
+
+	for (i = 0; i < BITS_PER_LONG; i++) {
+		align = ((unsigned long) 1) << i;
+
+		ptr = __vmalloc_node_range(PAGE_SIZE, align,
+			VMALLOC_START, VMALLOC_END,
+			GFP_KERNEL | __GFP_ZERO,
+			PAGE_KERNEL,
+			0, 0, __builtin_return_address(0));
+
+		if (!ptr)
+			return -1;
+
+		vfree(ptr);
+	}
+
+	return 0;
+}
+
+static int fix_align_alloc_test(void)
+{
+	void *ptr;
+	int i;
+
+	for (i = 0; i < test_loop_count; i++) {
+		ptr = __vmalloc_node_range(5 * PAGE_SIZE,
+			THREAD_ALIGN << 1,
+			VMALLOC_START, VMALLOC_END,
+			GFP_KERNEL | __GFP_ZERO,
+			PAGE_KERNEL,
+			0, 0, __builtin_return_address(0));
+
+		if (!ptr)
+			return -1;
+
+		vfree(ptr);
+	}
+
+	return 0;
+}
+
+static int random_size_alloc_test(void)
+{
+	unsigned int n;
+	void *p;
+	int i;
+
+	for (i = 0; i < test_loop_count; i++) {
+		get_random_bytes(&n, sizeof(i));
+		n = (n % 100) + 1;
+
+		p = vmalloc(n * PAGE_SIZE);
+
+		if (!p)
+			return -1;
+
+		*((__u8 *)p) = 1;
+		vfree(p);
+	}
+
+	return 0;
+}
+
+static int long_busy_list_alloc_test(void)
+{
+	void *ptr_1, *ptr_2;
+	void **ptr;
+	int rv = -1;
+	int i;
+
+	ptr = vmalloc(sizeof(void *) * 15000);
+	if (!ptr)
+		return rv;
+
+	for (i = 0; i < 15000; i++)
+		ptr[i] = vmalloc(1 * PAGE_SIZE);
+
+	for (i = 0; i < test_loop_count; i++) {
+		ptr_1 = vmalloc(100 * PAGE_SIZE);
+		if (!ptr_1)
+			goto leave;
+
+		ptr_2 = vmalloc(1 * PAGE_SIZE);
+		if (!ptr_2) {
+			vfree(ptr_1);
+			goto leave;
+		}
+
+		*((__u8 *)ptr_1) = 0;
+		*((__u8 *)ptr_2) = 1;
+
+		vfree(ptr_1);
+		vfree(ptr_2);
+	}
+
+	/*  Success */
+	rv = 0;
+
+leave:
+	for (i = 0; i < 15000; i++)
+		vfree(ptr[i]);
+
+	vfree(ptr);
+	return rv;
+}
+
+static int full_fit_alloc_test(void)
+{
+	void **ptr, **junk_ptr, *tmp;
+	int junk_length;
+	int rv = -1;
+	int i;
+
+	junk_length = fls(num_online_cpus());
+	junk_length *= (32 * 1024 * 1024 / PAGE_SIZE);
+
+	ptr = vmalloc(sizeof(void *) * junk_length);
+	if (!ptr)
+		return rv;
+
+	junk_ptr = vmalloc(sizeof(void *) * junk_length);
+	if (!junk_ptr) {
+		vfree(ptr);
+		return rv;
+	}
+
+	for (i = 0; i < junk_length; i++) {
+		ptr[i] = vmalloc(1 * PAGE_SIZE);
+		junk_ptr[i] = vmalloc(1 * PAGE_SIZE);
+	}
+
+	for (i = 0; i < junk_length; i++)
+		vfree(junk_ptr[i]);
+
+	for (i = 0; i < test_loop_count; i++) {
+		tmp = vmalloc(1 * PAGE_SIZE);
+
+		if (!tmp)
+			goto error;
+
+		*((__u8 *)tmp) = 1;
+		vfree(tmp);
+	}
+
+	/* Success */
+	rv = 0;
+
+error:
+	for (i = 0; i < junk_length; i++)
+		vfree(ptr[i]);
+
+	vfree(ptr);
+	vfree(junk_ptr);
+
+	return rv;
+}
+
+static int fix_size_alloc_test(void)
+{
+	void *ptr;
+	int i;
+
+	for (i = 0; i < test_loop_count; i++) {
+		ptr = vmalloc(3 * PAGE_SIZE);
+
+		if (!ptr)
+			return -1;
+
+		*((__u8 *)ptr) = 0;
+
+		vfree(ptr);
+	}
+
+	return 0;
+}
+
+static int
+pcpu_alloc_test(void)
+{
+	int rv = 0;
+#ifndef CONFIG_NEED_PER_CPU_KM
+	void __percpu **pcpu;
+	size_t size, align;
+	int i;
+
+	pcpu = vmalloc(sizeof(void __percpu *) * 35000);
+	if (!pcpu)
+		return -1;
+
+	for (i = 0; i < 35000; i++) {
+		unsigned int r;
+
+		get_random_bytes(&r, sizeof(i));
+		size = (r % (PAGE_SIZE / 4)) + 1;
+
+		/*
+		 * Maximum PAGE_SIZE
+		 */
+		get_random_bytes(&r, sizeof(i));
+		align = 1 << ((i % 11) + 1);
+
+		pcpu[i] = __alloc_percpu(size, align);
+		if (!pcpu[i])
+			rv = -1;
+	}
+
+	for (i = 0; i < 35000; i++)
+		free_percpu(pcpu[i]);
+
+	vfree(pcpu);
+#endif
+	return rv;
+}
+
+struct test_case_desc {
+	const char *test_name;
+	int (*test_func)(void);
+};
+
+static struct test_case_desc test_case_array[] = {
+	{ "fix_size_alloc_test", fix_size_alloc_test },
+	{ "full_fit_alloc_test", full_fit_alloc_test },
+	{ "long_busy_list_alloc_test", long_busy_list_alloc_test },
+	{ "random_size_alloc_test", random_size_alloc_test },
+	{ "fix_align_alloc_test", fix_align_alloc_test },
+	{ "random_size_align_alloc_test", random_size_align_alloc_test },
+	{ "align_shift_alloc_test", align_shift_alloc_test },
+	{ "pcpu_alloc_test", pcpu_alloc_test },
+	/* Add a new test case here. */
+};
+
+struct test_case_data {
+	int test_failed;
+	int test_passed;
+	u64 time;
+};
+
+/* Split it to get rid of: WARNING: line over 80 characters */
+static struct test_case_data
+	per_cpu_test_data[NR_CPUS][ARRAY_SIZE(test_case_array)];
+
+static struct test_driver {
+	struct task_struct *task;
+	unsigned long start;
+	unsigned long stop;
+	int cpu;
+} per_cpu_test_driver[NR_CPUS];
+
+static void shuffle_array(int *arr, int n)
+{
+	unsigned int rnd;
+	int i, j, x;
+
+	for (i = n - 1; i > 0; i--)  {
+		get_random_bytes(&rnd, sizeof(rnd));
+
+		/* Cut the range. */
+		j = rnd % i;
+
+		/* Swap indexes. */
+		x = arr[i];
+		arr[i] = arr[j];
+		arr[j] = x;
+	}
+}
+
+static int test_func(void *private)
+{
+	struct test_driver *t = private;
+	cpumask_t newmask = CPU_MASK_NONE;
+	int random_array[ARRAY_SIZE(test_case_array)];
+	int index, i, j, ret;
+	ktime_t kt;
+	u64 delta;
+
+	cpumask_set_cpu(t->cpu, &newmask);
+	set_cpus_allowed_ptr(current, &newmask);
+
+	for (i = 0; i < ARRAY_SIZE(test_case_array); i++)
+		random_array[i] = i;
+
+	if (!sequential_test_order)
+		shuffle_array(random_array, ARRAY_SIZE(test_case_array));
+
+	/*
+	 * Block until initialization is done.
+	 */
+	down_read(&prepare_for_test_rwsem);
+
+	t->start = get_cycles();
+	for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
+		index = random_array[i];
+
+		/*
+		 * Skip tests if run_test_mask has been specified.
+		 */
+		if (!((run_test_mask & (1 << index)) >> index))
+			continue;
+
+		kt = ktime_get();
+		for (j = 0; j < test_repeat_count; j++) {
+			ret = test_case_array[index].test_func();
+			if (!ret)
+				per_cpu_test_data[t->cpu][index].test_passed++;
+			else
+				per_cpu_test_data[t->cpu][index].test_failed++;
+		}
+
+		/*
+		 * Take an average time that test took.
+		 */
+		delta = (u64) ktime_us_delta(ktime_get(), kt);
+		do_div(delta, (u32) test_repeat_count);
+
+		per_cpu_test_data[t->cpu][index].time = delta;
+	}
+	t->stop = get_cycles();
+
+	up_read(&prepare_for_test_rwsem);
+	test_report_one_done();
+
+	/*
+	 * Wait for the kthread_stop() call.
+	 */
+	while (!kthread_should_stop())
+		msleep(10);
+
+	return 0;
+}
+
+static void
+init_test_configurtion(void)
+{
+	/*
+	 * Reset all data of all CPUs.
+	 */
+	memset(per_cpu_test_data, 0, sizeof(per_cpu_test_data));
+
+	if (single_cpu_test)
+		cpumask_set_cpu(cpumask_first(cpu_online_mask),
+			&cpus_run_test_mask);
+	else
+		cpumask_and(&cpus_run_test_mask, cpu_online_mask,
+			cpu_online_mask);
+
+	if (test_repeat_count <= 0)
+		test_repeat_count = 1;
+
+	if (test_loop_count <= 0)
+		test_loop_count = 1;
+}
+
+static void do_concurrent_test(void)
+{
+	int cpu, ret;
+
+	/*
+	 * Set some basic configurations plus sanity check.
+	 */
+	init_test_configurtion();
+
+	/*
+	 * Put on hold all workers.
+	 */
+	down_write(&prepare_for_test_rwsem);
+
+	for_each_cpu(cpu, &cpus_run_test_mask) {
+		struct test_driver *t = &per_cpu_test_driver[cpu];
+
+		t->cpu = cpu;
+		t->task = kthread_run(test_func, t, "vmalloc_test/%d", cpu);
+
+		if (!IS_ERR(t->task))
+			/* Success. */
+			atomic_inc(&test_n_undone);
+		else
+			pr_err("Failed to start kthread for %d CPU\n", cpu);
+	}
+
+	/*
+	 * Now let the workers do their job.
+	 */
+	up_write(&prepare_for_test_rwsem);
+
+	/*
+	 * Sleep quiet until all workers are done with 1 second
+	 * interval. Since the test can take a lot of time we
+	 * can run into a stack trace of the hung task. That is
+	 * why we go with completion_timeout and HZ value.
+	 */
+	do {
+		ret = wait_for_completion_timeout(&test_all_done_comp, HZ);
+	} while (!ret);
+
+	for_each_cpu(cpu, &cpus_run_test_mask) {
+		struct test_driver *t = &per_cpu_test_driver[cpu];
+		int i;
+
+		if (!IS_ERR(t->task))
+			kthread_stop(t->task);
+
+		for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
+			if (!((run_test_mask & (1 << i)) >> i))
+				continue;
+
+			pr_info(
+				"Summary: %s passed: %d failed: %d repeat: %d loops: %d avg: %llu usec\n",
+				test_case_array[i].test_name,
+				per_cpu_test_data[cpu][i].test_passed,
+				per_cpu_test_data[cpu][i].test_failed,
+				test_repeat_count, test_loop_count,
+				per_cpu_test_data[cpu][i].time);
+		}
+
+		pr_info("All test took CPU%d=%lu cycles\n",
+			cpu, t->stop - t->start);
+	}
+}
+
+static int vmalloc_test_init(void)
+{
+	do_concurrent_test();
+	return -EAGAIN; /* Fail will directly unload the module */
+}
+
+static void vmalloc_test_exit(void)
+{
+}
+
+module_init(vmalloc_test_init)
+module_exit(vmalloc_test_exit)
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Uladzislau Rezki");
+MODULE_DESCRIPTION("vmalloc test module");

mm/Kconfig.debug

···
 	  Enable debug page memory allocations by default? This value
 	  can be overridden by debug_pagealloc=off|on.
 
+config PAGE_OWNER
+	bool "Track page owner"
+	depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
+	select DEBUG_FS
+	select STACKTRACE
+	select STACKDEPOT
+	select PAGE_EXTENSION
+	help
+	  This keeps track of what call chain is the owner of a page, may
+	  help to find bare alloc_page(s) leaks. Even if you include this
+	  feature on your build, it is disabled in default. You should pass
+	  "page_owner=on" to boot parameter in order to enable it. Eats
+	  a fair amount of memory if enabled. See tools/vm/page_owner_sort.c
+	  for user-space helper.
+
+	  If unsure, say N.
+
 config PAGE_POISONING
 	bool "Poison pages after freeing"
 	select PAGE_POISONING_NO_SANITY if HIBERNATION

mm/cma.c

···
 
 	ret = cma_init_reserved_mem(base, size, order_per_bit, name, res_cma);
 	if (ret)
-		goto err;
+		goto free_mem;
 
 	pr_info("Reserved %ld MiB at %pa\n", (unsigned long)size / SZ_1M,
 		&base);
 	return 0;
 
+free_mem:
+	memblock_free(base, size);
 err:
 	pr_err("Failed to reserve %ld MiB\n", (unsigned long)size / SZ_1M);
 	return ret;

mm/cma_debug.c

···
 	unsigned long n;
 };
 
-static struct dentry *cma_debugfs_root;
-
 static int cma_debugfs_get(void *data, u64 *val)
 {
 	unsigned long *p = data;
···
 }
 DEFINE_SIMPLE_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n");
 
-static void cma_debugfs_add_one(struct cma *cma, int idx)
+static void cma_debugfs_add_one(struct cma *cma, struct dentry *root_dentry)
 {
 	struct dentry *tmp;
 	char name[16];
···
 
 	scnprintf(name, sizeof(name), "cma-%s", cma->name);
 
-	tmp = debugfs_create_dir(name, cma_debugfs_root);
+	tmp = debugfs_create_dir(name, root_dentry);
 
 	debugfs_create_file("alloc", 0200, tmp, cma, &cma_alloc_fops);
 	debugfs_create_file("free", 0200, tmp, cma, &cma_free_fops);
···
 
 static int __init cma_debugfs_init(void)
 {
+	struct dentry *cma_debugfs_root;
 	int i;
 
 	cma_debugfs_root = debugfs_create_dir("cma", NULL);
-	if (!cma_debugfs_root)
-		return -ENOMEM;
 
 	for (i = 0; i < cma_area_count; i++)
-		cma_debugfs_add_one(&cma_areas[i], i);
+		cma_debugfs_add_one(&cma_areas[i], cma_debugfs_root);
 
 	return 0;
 }

mm/compaction.c

···
 	return high_pfn;
 }
 
-static void map_pages(struct list_head *list)
+static void split_map_pages(struct list_head *list)
 {
 	unsigned int i, order, nr_pages;
 	struct page *page, *next;
···
 	return false;
 }
 
+static bool
+__reset_isolation_pfn(struct zone *zone, unsigned long pfn, bool check_source,
+							bool check_target)
+{
+	struct page *page = pfn_to_online_page(pfn);
+	struct page *end_page;
+	unsigned long block_pfn;
+
+	if (!page)
+		return false;
+	if (zone != page_zone(page))
+		return false;
+	if (pageblock_skip_persistent(page))
+		return false;
+
+	/*
+	 * If skip is already cleared do no further checking once the
+	 * restart points have been set.
+	 */
+	if (check_source && check_target && !get_pageblock_skip(page))
+		return true;
+
+	/*
+	 * If clearing skip for the target scanner, do not select a
+	 * non-movable pageblock as the starting point.
+	 */
+	if (!check_source && check_target &&
+	    get_pageblock_migratetype(page) != MIGRATE_MOVABLE)
+		return false;
+
+	/*
+	 * Only clear the hint if a sample indicates there is either a
+	 * free page or an LRU page in the block. One or other condition
+	 * is necessary for the block to be a migration source/target.
+	 */
+	block_pfn = pageblock_start_pfn(pfn);
+	pfn = max(block_pfn, zone->zone_start_pfn);
+	page = pfn_to_page(pfn);
+	if (zone != page_zone(page))
+		return false;
+	pfn = block_pfn + pageblock_nr_pages;
+	pfn = min(pfn, zone_end_pfn(zone));
+	end_page = pfn_to_page(pfn);
+
+	do {
+		if (pfn_valid_within(pfn)) {
+			if (check_source && PageLRU(page)) {
+				clear_pageblock_skip(page);
+				return true;
+			}
+
+			if (check_target && PageBuddy(page)) {
+				clear_pageblock_skip(page);
+				return true;
+			}
+		}
+
+		page += (1 << PAGE_ALLOC_COSTLY_ORDER);
+		pfn += (1 << PAGE_ALLOC_COSTLY_ORDER);
+	} while (page < end_page);
+
+	return false;
+}
+
 /*
  * This function is called to clear all cached information on pageblocks that
  * should be skipped for page isolation when the migrate and free page scanner
···
  */
 static void __reset_isolation_suitable(struct zone *zone)
 {
-	unsigned long start_pfn = zone->zone_start_pfn;
-	unsigned long end_pfn = zone_end_pfn(zone);
-	unsigned long pfn;
+	unsigned long migrate_pfn = zone->zone_start_pfn;
+	unsigned long free_pfn = zone_end_pfn(zone);
+	unsigned long reset_migrate = free_pfn;
+	unsigned long reset_free = migrate_pfn;
+	bool source_set = false;
+	bool free_set = false;
+
+	if (!zone->compact_blockskip_flush)
+		return;
 
 	zone->compact_blockskip_flush = false;
 
-	/* Walk the zone and mark every pageblock as suitable for isolation */
-	for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) {
-		struct page *page;
-
+	/*
+	 * Walk the zone and update pageblock skip information. Source looks
+	 * for PageLRU while target looks for PageBuddy. When the scanner
+	 * is found, both PageBuddy and PageLRU are checked as the pageblock
+	 * is suitable as both source and target.
+	 */
+	for (; migrate_pfn < free_pfn; migrate_pfn += pageblock_nr_pages,
+					free_pfn -= pageblock_nr_pages) {
 		cond_resched();
 
-		page = pfn_to_online_page(pfn);
-		if (!page)
-			continue;
-		if (zone != page_zone(page))
-			continue;
-		if (pageblock_skip_persistent(page))
-			continue;
+		/* Update the migrate PFN */
+		if (__reset_isolation_pfn(zone, migrate_pfn, true, source_set) &&
+		    migrate_pfn < reset_migrate) {
+			source_set = true;
+			reset_migrate = migrate_pfn;
+			zone->compact_init_migrate_pfn = reset_migrate;
+			zone->compact_cached_migrate_pfn[0] = reset_migrate;
+			zone->compact_cached_migrate_pfn[1] = reset_migrate;
+		}
 
-		clear_pageblock_skip(page);
+		/* Update the free PFN */
+		if (__reset_isolation_pfn(zone, free_pfn, free_set, true) &&
+		    free_pfn > reset_free) {
+			free_set = true;
+			reset_free = free_pfn;
+			zone->compact_init_free_pfn = reset_free;
+			zone->compact_cached_free_pfn = reset_free;
+		}
 	}
 
-	reset_cached_positions(zone);
+	/* Leave no distance if no suitable block was reset */
+	if (reset_migrate >= reset_free) {
+		zone->compact_cached_migrate_pfn[0] = migrate_pfn;
+		zone->compact_cached_migrate_pfn[1] = migrate_pfn;
+		zone->compact_cached_free_pfn = free_pfn;
+	}
 }
 
 void reset_isolation_suitable(pg_data_t *pgdat)
···
 }
 
 /*
+ * Sets the pageblock skip bit if it was clear. Note that this is a hint as
+ * locks are not required for read/writers. Returns true if it was already set.
+ */
+static bool test_and_set_skip(struct compact_control *cc, struct page *page,
+							unsigned long pfn)
+{
+	bool skip;
+
+	/* Do no update if skip hint is being ignored */
+	if (cc->ignore_skip_hint)
+		return false;
+
+	if (!IS_ALIGNED(pfn, pageblock_nr_pages))
+		return false;
+
+	skip = get_pageblock_skip(page);
+	if (!skip && !cc->no_set_skip_hint)
+		set_pageblock_skip(page);
+
+	return skip;
+}
+
+static void update_cached_migrate(struct compact_control *cc, unsigned long pfn)
+{
+	struct zone *zone = cc->zone;
+
+	pfn = pageblock_end_pfn(pfn);
+
+	/* Set for isolation rather than compaction */
+	if (cc->no_set_skip_hint)
+		return;
+
+	if (pfn > zone->compact_cached_migrate_pfn[0])
+		zone->compact_cached_migrate_pfn[0] = pfn;
+	if (cc->mode != MIGRATE_ASYNC &&
+	    pfn > zone->compact_cached_migrate_pfn[1])
+		zone->compact_cached_migrate_pfn[1] = pfn;
+}
+
+/*
  * If no pages were isolated then mark this pageblock to be skipped in the
  * future. The information is later cleared by __reset_isolation_suitable().
  */
 static void update_pageblock_skip(struct compact_control *cc,
-			struct page *page, unsigned long nr_isolated,
-			bool migrate_scanner)
+			struct page *page, unsigned long pfn)
 {
 	struct zone *zone = cc->zone;
-	unsigned long pfn;
 
 	if (cc->no_set_skip_hint)
 		return;
···
 	if (!page)
 		return;
 
-	if (nr_isolated)
-		return;
-
 	set_pageblock_skip(page);
 
-	pfn = page_to_pfn(page);
-
 	/* Update where async and sync compaction should restart */
-	if (migrate_scanner) {
-		if (pfn > zone->compact_cached_migrate_pfn[0])
-			zone->compact_cached_migrate_pfn[0] = pfn;
-		if (cc->mode != MIGRATE_ASYNC &&
-		    pfn > zone->compact_cached_migrate_pfn[1])
-			zone->compact_cached_migrate_pfn[1] = pfn;
-	} else {
-		if (pfn < zone->compact_cached_free_pfn)
-			zone->compact_cached_free_pfn = pfn;
-	}
+	if (pfn < zone->compact_cached_free_pfn)
+		zone->compact_cached_free_pfn = pfn;
 }
 #else
 static inline bool isolation_suitable(struct compact_control *cc,
···
 }
 
 static inline void update_pageblock_skip(struct compact_control *cc,
-			struct page *page, unsigned long nr_isolated,
-			bool migrate_scanner)
+			struct page *page, unsigned long pfn)
 {
+}
+
+static void update_cached_migrate(struct compact_control *cc, unsigned long pfn)
+{
+}
+
+static bool test_and_set_skip(struct compact_control *cc, struct page *page,
+							unsigned long pfn)
+{
+	return false;
 }
 #endif /* CONFIG_COMPACTION */
 
 /*
  * Compaction requires the taking of some coarse locks that are potentially
- * very heavily contended. For async compaction, back out if the lock cannot
- * be taken immediately. For sync compaction, spin on the lock if needed.
+ * very heavily contended. For async compaction, trylock and record if the
+ * lock is contended. The lock will still be acquired but compaction will
+ * abort when the current block is finished regardless of success rate.
+ * Sync compaction acquires the lock.
  *
- * Returns true if the lock is held
- * Returns false if the lock is not held and compaction should abort
+ * Always returns true which makes it easier to track lock state in callers.
  */
-static bool compact_trylock_irqsave(spinlock_t *lock, unsigned long *flags,
+static bool compact_lock_irqsave(spinlock_t *lock, unsigned long *flags,
 						struct compact_control *cc)
 {
-	if (cc->mode == MIGRATE_ASYNC) {
-		if (!spin_trylock_irqsave(lock, *flags)) {
-			cc->contended = true;
-			return false;
-		}
-	} else {
-		spin_lock_irqsave(lock, *flags);
+	/* Track if the lock is contended in async mode */
+	if (cc->mode == MIGRATE_ASYNC && !cc->contended) {
+		if (spin_trylock_irqsave(lock, *flags))
+			return true;
+
+		cc->contended = true;
 	}
 
+	spin_lock_irqsave(lock, *flags);
 	return true;
 }
 
···
 		return true;
 	}
 
-	if (need_resched()) {
-		if (cc->mode == MIGRATE_ASYNC) {
-			cc->contended = true;
-			return true;
-		}
-		cond_resched();
-	}
-
-	return false;
-}
-
-/*
- * Aside from avoiding lock contention, compaction also periodically checks
- * need_resched() and either schedules in sync compaction or aborts async
- * compaction. This is similar to what compact_unlock_should_abort() does, but
- * is used where no lock is concerned.
- *
- * Returns false when no scheduling was needed, or sync compaction scheduled.
- * Returns true when async compaction should abort.
- */
-static inline bool compact_should_abort(struct compact_control *cc)
-{
-	/* async compaction aborts if contended */
-	if (need_resched()) {
-		if (cc->mode == MIGRATE_ASYNC) {
-			cc->contended = true;
-			return true;
-		}
-
-		cond_resched();
-	}
+	cond_resched();
 
 	return false;
 }
···
 				unsigned long *start_pfn,
 				unsigned long end_pfn,
 				struct list_head *freelist,
+				unsigned int stride,
 				bool strict)
 {
 	int nr_scanned = 0, total_isolated = 0;
-	struct page *cursor, *valid_page = NULL;
+	struct page *cursor;
 	unsigned long flags = 0;
 	bool locked = false;
 	unsigned long blockpfn = *start_pfn;
 	unsigned int order;
 
+	/* Strict mode is for isolation, speed is secondary */
+	if (strict)
+		stride = 1;
+
 	cursor = pfn_to_page(blockpfn);
 
 	/* Isolate free pages. */
-	for (; blockpfn < end_pfn; blockpfn++, cursor++) {
+	for (; blockpfn < end_pfn; blockpfn += stride, cursor += stride) {
 		int isolated;
 		struct page *page = cursor;
 
···
 		nr_scanned++;
 		if (!pfn_valid_within(blockpfn))
 			goto isolate_fail;
-
-		if (!valid_page)
-			valid_page = page;
 
 		/*
 		 * For compound pages such as THP and hugetlbfs, we can save
···
 		 * recheck as well.
 		 */
 		if (!locked) {
-			/*
-			 * The zone lock must be held to isolate freepages.
-			 * Unfortunately this is a very coarse lock and can be
-			 * heavily contended if there are parallel allocations
-			 * or parallel compactions. For async compaction do not
-			 * spin on the lock and we acquire the lock as late as
-			 * possible.
-			 */
-			locked = compact_trylock_irqsave(&cc->zone->lock,
+			locked = compact_lock_irqsave(&cc->zone->lock,
 								&flags, cc);
-			if (!locked)
-				break;
 
 			/* Recheck this is a buddy page under lock */
 			if (!PageBuddy(page))
···
 	if (strict && blockpfn < end_pfn)
 		total_isolated = 0;
 
-	/* Update the pageblock-skip if the whole pageblock was scanned */
-	if (blockpfn == end_pfn)
-		update_pageblock_skip(cc, valid_page, total_isolated, false);
-
 	cc->total_free_scanned += nr_scanned;
 	if (total_isolated)
 		count_compact_events(COMPACTISOLATED, total_isolated);
···
 			break;
 
 		isolated = isolate_freepages_block(cc, &isolate_start_pfn,
-						block_end_pfn, &freelist, true);
+					block_end_pfn, &freelist, 0, true);
 
 		/*
 		 * In strict mode, isolate_freepages_block() returns 0 if
···
 	}
 
 	/* __isolate_free_page() does not map the pages */
-	map_pages(&freelist);
+	split_map_pages(&freelist);
 
 	if (pfn < end_pfn) {
 		/* Loop terminated early, cleanup. */
···
 }
 
 /* Similar to reclaim, but different enough that they don't share logic */
-static bool too_many_isolated(struct zone *zone)
+static bool too_many_isolated(pg_data_t *pgdat)
 {
 	unsigned long active, inactive, isolated;
 
-	inactive = node_page_state(zone->zone_pgdat, NR_INACTIVE_FILE) +
-			node_page_state(zone->zone_pgdat, NR_INACTIVE_ANON);
-	active = node_page_state(zone->zone_pgdat, NR_ACTIVE_FILE) +
-			node_page_state(zone->zone_pgdat, NR_ACTIVE_ANON);
-	isolated = node_page_state(zone->zone_pgdat, NR_ISOLATED_FILE) +
-			node_page_state(zone->zone_pgdat, NR_ISOLATED_ANON);
+	inactive = node_page_state(pgdat, NR_INACTIVE_FILE) +
+			node_page_state(pgdat, NR_INACTIVE_ANON);
+	active = node_page_state(pgdat, NR_ACTIVE_FILE) +
+			node_page_state(pgdat, NR_ACTIVE_ANON);
+	isolated = node_page_state(pgdat, NR_ISOLATED_FILE) +
+			node_page_state(pgdat, NR_ISOLATED_ANON);
 
 	return isolated > (inactive + active) / 2;
 }
···
 isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
 			unsigned long end_pfn, isolate_mode_t isolate_mode)
 {
-	struct zone *zone = cc->zone;
+	pg_data_t *pgdat = cc->zone->zone_pgdat;
 	unsigned long nr_scanned = 0, nr_isolated = 0;
 	struct lruvec *lruvec;
 	unsigned long flags = 0;
···
 	unsigned long start_pfn = low_pfn;
 	bool skip_on_failure = false;
 	unsigned long next_skip_pfn = 0;
+	bool skip_updated = false;
 
 	/*
 	 * Ensure that there are not too many pages isolated from the LRU
 	 * list by either parallel reclaimers or compaction. If there are,
 	 * delay for some time until fewer pages are isolated
 	 */
-	while (unlikely(too_many_isolated(zone))) {
+	while (unlikely(too_many_isolated(pgdat))) {
 		/* async migration should just abort */
 		if (cc->mode == MIGRATE_ASYNC)
 			return 0;
···
 			return 0;
 	}
 
-	if (compact_should_abort(cc))
-		return 0;
+	cond_resched();
 
 	if (cc->direct_compaction && (cc->mode == MIGRATE_ASYNC)) {
 		skip_on_failure = true;
···
 		 * if contended.
 		 */
 		if (!(low_pfn % SWAP_CLUSTER_MAX)
-		    && compact_unlock_should_abort(zone_lru_lock(zone), flags,
-								&locked, cc))
+		    && compact_unlock_should_abort(&pgdat->lru_lock,
+					    flags, &locked, cc))
 			break;
 
 		if (!pfn_valid_within(low_pfn))
···
 
 		page = pfn_to_page(low_pfn);
 
-		if (!valid_page)
+		/*
+		 * Check if the pageblock has already been marked skipped.
+		 * Only the aligned PFN is checked as the caller isolates
+		 * COMPACT_CLUSTER_MAX at a time so the second call must
+		 * not falsely conclude that the block should be skipped.
+		 */
+		if (!valid_page && IS_ALIGNED(low_pfn, pageblock_nr_pages)) {
+			if (!cc->ignore_skip_hint && get_pageblock_skip(page)) {
+				low_pfn = end_pfn;
+				goto isolate_abort;
+			}
 			valid_page = page;
+		}
 
 		/*
 		 * Skip if free. We read page order here without zone lock
···
 			if (unlikely(__PageMovable(page)) &&
 					!PageIsolated(page)) {
 				if (locked) {
-					spin_unlock_irqrestore(zone_lru_lock(zone),
+					spin_unlock_irqrestore(&pgdat->lru_lock,
 									flags);
 					locked = false;
 				}
···
 
 		/* If we already hold the lock, we can skip some rechecking */
 		if (!locked) {
-			locked = compact_trylock_irqsave(zone_lru_lock(zone),
+			locked = compact_lock_irqsave(&pgdat->lru_lock,
 								&flags, cc);
-			if (!locked)
-				break;
+
+			/* Try get exclusive access under lock */
+			if (!skip_updated) {
+				skip_updated = true;
+				if (test_and_set_skip(cc, page, low_pfn))
+					goto isolate_abort;
+			}
 
 			/* Recheck PageLRU and PageCompound under lock */
 			if (!PageLRU(page))
···
 			}
 		}
 
-		lruvec = mem_cgroup_page_lruvec(page, zone->zone_pgdat);
+		lruvec = mem_cgroup_page_lruvec(page, pgdat);
 
 		/* Try isolate the page */
 		if (__isolate_lru_page(page, isolate_mode) != 0)
···
 		nr_isolated++;
 
 		/*
-		 * Record where we could have freed pages by migration and not
-		 * yet flushed them to buddy allocator.
-		 * - this is the lowest page that was isolated and likely be
-		 * then freed by migration.
+		 * Avoid isolating too much unless this block is being
+		 * rescanned (e.g. dirty/writeback pages, parallel allocation)
+		 * or a lock is contended. For contention, isolate quickly to
+		 * potentially remove one source of contention.
 		 */
-		if (!cc->last_migrated_pfn)
-			cc->last_migrated_pfn = low_pfn;
-
-		/* Avoid isolating too much */
-		if (cc->nr_migratepages == COMPACT_CLUSTER_MAX) {
+		if (cc->nr_migratepages == COMPACT_CLUSTER_MAX &&
+		    !cc->rescan && !cc->contended) {
 			++low_pfn;
 			break;
 		}
···
 		 */
 		if (nr_isolated) {
 			if (locked) {
-				spin_unlock_irqrestore(zone_lru_lock(zone), flags);
+				spin_unlock_irqrestore(&pgdat->lru_lock, flags);
 				locked = false;
 			}
 			putback_movable_pages(&cc->migratepages);
 			cc->nr_migratepages = 0;
-			cc->last_migrated_pfn = 0;
 			nr_isolated = 0;
 		}
 
···
 	if (unlikely(low_pfn > end_pfn))
 		low_pfn = end_pfn;
 
+isolate_abort:
 	if (locked)
-		spin_unlock_irqrestore(zone_lru_lock(zone), flags);
+		spin_unlock_irqrestore(&pgdat->lru_lock, flags);
 
 	/*
-	 * Update the pageblock-skip information and cached scanner pfn,
-	 * if the whole pageblock was scanned without isolating any page.
+	 * Updated the cached scanner pfn once the pageblock has been scanned
+	 * Pages will either be migrated in which case there is no point
+	 * scanning in the near future or migration failed in which case the
+	 * failure reason may persist. The block is marked for skipping if
+	 * there were no pages isolated in the block or if the block is
+	 * rescanned twice in a row.
 	 */
-	if (low_pfn == end_pfn)
-		update_pageblock_skip(cc, valid_page, nr_isolated, true);
+	if (low_pfn == end_pfn && (!nr_isolated || cc->rescan)) {
+		if (valid_page && !skip_updated)
+			set_pageblock_skip(valid_page);
+		update_cached_migrate(cc, low_pfn);
+	}
 
 	trace_mm_compaction_isolate_migratepages(start_pfn, low_pfn,
 						nr_scanned, nr_isolated);
···
 {
 	int block_mt;
 
+	if (pageblock_skip_persistent(page))
+		return false;
+
 	if ((cc->mode != MIGRATE_ASYNC) || !cc->direct_compaction)
 		return true;
 
···
 	return false;
 }
 
+static inline unsigned int
+freelist_scan_limit(struct compact_control *cc)
+{
+	return (COMPACT_CLUSTER_MAX >> cc->fast_search_fail) + 1;
+}
+
 /*
  * Test whether the free scanner has reached the same or lower pageblock than
  * the migration scanner, and compaction should thus terminate.
···
 {
 	return (cc->free_pfn >> pageblock_order)
 		<= (cc->migrate_pfn >> pageblock_order);
+}
+
+/*
+ * Used when scanning for a suitable migration target which scans freelists
+ * in reverse. Reorders the list such as the unscanned pages are scanned
+ * first on the next iteration of the free scanner
+ */
+static void
+move_freelist_head(struct list_head *freelist, struct page *freepage)
+{
+	LIST_HEAD(sublist);
+
+	if (!list_is_last(freelist, &freepage->lru)) {
+		list_cut_before(&sublist, freelist, &freepage->lru);
+		if (!list_empty(&sublist))
+			list_splice_tail(&sublist, freelist);
+	}
+}
+
+/*
+ * Similar to move_freelist_head except used by the migration scanner
+ * when scanning forward. It's possible for these list operations to
+ * move against each other if they search the free list exactly in
+ * lockstep.
+ */
+static void
+move_freelist_tail(struct list_head *freelist, struct page *freepage)
+{
+	LIST_HEAD(sublist);
+
+	if (!list_is_first(freelist, &freepage->lru)) {
+		list_cut_position(&sublist, freelist, &freepage->lru);
+		if (!list_empty(&sublist))
+			list_splice_tail(&sublist, freelist);
+	}
+}
+
+static void
+fast_isolate_around(struct compact_control *cc, unsigned long pfn, unsigned long nr_isolated)
+{
+	unsigned long start_pfn, end_pfn;
+	struct page *page = pfn_to_page(pfn);
+
+	/* Do not search around if there are enough pages already */
+	if (cc->nr_freepages >= cc->nr_migratepages)
+		return;
+
+	/* Minimise scanning during async compaction */
+	if (cc->direct_compaction && cc->mode == MIGRATE_ASYNC)
+		return;
+
+	/* Pageblock boundaries */
+	start_pfn = pageblock_start_pfn(pfn);
+	end_pfn = min(start_pfn + pageblock_nr_pages, zone_end_pfn(cc->zone));
+
+	/* Scan before */
+	if (start_pfn != pfn) {
+		isolate_freepages_block(cc, &start_pfn, pfn, &cc->freepages, 1, false);
+		if (cc->nr_freepages >= cc->nr_migratepages)
+			return;
+	}
+
+	/* Scan after */
+	start_pfn = pfn + nr_isolated;
+	if (start_pfn != end_pfn)
+		isolate_freepages_block(cc, &start_pfn, end_pfn, &cc->freepages, 1, false);
+
+	/* Skip this pageblock in the future as it's full or nearly full */
+	if (cc->nr_freepages < cc->nr_migratepages)
+		set_pageblock_skip(page);
+}
+
+/* Search orders in round-robin fashion */
+static int next_search_order(struct compact_control *cc, int order)
+{
+	order--;
+	if (order < 0)
+		order = cc->order - 1;
+
+	/* Search wrapped around? */
+	if (order == cc->search_order) {
+		cc->search_order--;
+		if (cc->search_order < 0)
+			cc->search_order = cc->order - 1;
+		return -1;
+	}
+
+	return order;
+}
+
+static unsigned long
+fast_isolate_freepages(struct compact_control *cc)
+{
+	unsigned int limit = min(1U, freelist_scan_limit(cc) >> 1);
+	unsigned int nr_scanned = 0;
+	unsigned long low_pfn, min_pfn, high_pfn = 0, highest = 0;
+	unsigned long nr_isolated = 0;
+	unsigned long distance;
+	struct page *page = NULL;
+	bool scan_start = false;
+	int order;
+
+	/* Full compaction passes in a negative order */
+	if (cc->order <= 0)
+		return cc->free_pfn;
+
+	/*
+	 * If starting the scan, use a deeper search and use the highest
+	 * PFN found if a suitable one is not found.
+	 */
+	if (cc->free_pfn >= cc->zone->compact_init_free_pfn) {
+		limit = pageblock_nr_pages >> 1;
+		scan_start = true;
+	}
+
+	/*
+	 * Preferred point is in the top quarter of the scan space but take
+	 * a pfn from the top half if the search is problematic.
+	 */
+	distance = (cc->free_pfn - cc->migrate_pfn);
+	low_pfn = pageblock_start_pfn(cc->free_pfn - (distance >> 2));
+	min_pfn = pageblock_start_pfn(cc->free_pfn - (distance >> 1));
+
+	if (WARN_ON_ONCE(min_pfn > low_pfn))
+		low_pfn = min_pfn;
+
+	/*
+	 * Search starts from the last successful isolation order or the next
+	 * order to search after a previous failure
+	 */
+	cc->search_order = min_t(unsigned int, cc->order - 1, cc->search_order);
+
+	for (order = cc->search_order;
+	     !page && order >= 0;
+	     order = next_search_order(cc, order)) {
+		struct free_area *area = &cc->zone->free_area[order];
+		struct list_head *freelist;
+		struct page *freepage;
+		unsigned long flags;
+		unsigned int order_scanned = 0;
+
+		if (!area->nr_free)
+			continue;
+
+		spin_lock_irqsave(&cc->zone->lock, flags);
+		freelist = &area->free_list[MIGRATE_MOVABLE];
+		list_for_each_entry_reverse(freepage, freelist, lru) {
+			unsigned long pfn;
+
+			order_scanned++;
+			nr_scanned++;
+			pfn = page_to_pfn(freepage);
+
+			if (pfn >= highest)
+				highest = pageblock_start_pfn(pfn);
+
+			if (pfn >= low_pfn) {
+				cc->fast_search_fail = 0;
+				cc->search_order = order;
+				page = freepage;
+				break;
+			}
+
+			if (pfn >= min_pfn && pfn > high_pfn) {
+				high_pfn = pfn;
+
+				/* Shorten the scan if a candidate is found */
+				limit >>= 1;
+			}
+
+			if (order_scanned >= limit)
+				break;
+		}
+
+		/* Use a minimum pfn if a preferred one was not found */
+		if (!page && high_pfn) {
+			page = pfn_to_page(high_pfn);
+
+			/* Update freepage for the list reorder below */
+			freepage = page;
+		}
+
+		/* Reorder to so a future search skips recent pages */
+		move_freelist_head(freelist, freepage);
+
+		/* Isolate the page if available */
+		if (page) {
+			if (__isolate_free_page(page, order)) {
+				set_page_private(page, order);
+				nr_isolated = 1 << order;
+				cc->nr_freepages += nr_isolated;
+				list_add_tail(&page->lru, &cc->freepages);
+				count_compact_events(COMPACTISOLATED, nr_isolated);
+			} else {
+				/* If isolation fails, abort the search */
+				order = -1;
+				page = NULL;
+			}
+		}
+
+		spin_unlock_irqrestore(&cc->zone->lock, flags);
+
+		/*
+		 * Smaller scan on next order so the total scan ig related
+		 * to freelist_scan_limit.
+		 */
+		if (order_scanned >= limit)
+			limit = min(1U, limit >> 1);
+	}
+
+	if (!page) {
+		cc->fast_search_fail++;
+		if (scan_start) {
+			/*
+			 * Use the highest PFN found above min. If one was
+			 * not found, be pessemistic for direct compaction
+			 * and use the min mark.
+			 */
+			if (highest) {
+				page = pfn_to_page(highest);
+				cc->free_pfn = highest;
+			} else {
+				if (cc->direct_compaction) {
+					page = pfn_to_page(min_pfn);
+					cc->free_pfn = min_pfn;
+				}
+			}
+		}
+	}
+
+	if (highest && highest >= cc->zone->compact_cached_free_pfn) {
+		highest -= pageblock_nr_pages;
+		cc->zone->compact_cached_free_pfn = highest;
+	}
+
+	cc->total_free_scanned += nr_scanned;
+	if (!page)
+		return cc->free_pfn;
+
+	low_pfn = page_to_pfn(page);
+	fast_isolate_around(cc, low_pfn, nr_isolated);
+	return low_pfn;
 }
 
 /*
···
 	unsigned long block_end_pfn;	/* end of current pageblock */
 	unsigned long low_pfn;	     /* lowest pfn scanner is able to scan */
 	struct list_head *freelist = &cc->freepages;
+	unsigned int stride;
+
+	/* Try a small search of the free lists for a candidate */
+	isolate_start_pfn = fast_isolate_freepages(cc);
+	if (cc->nr_freepages)
+		goto splitmap;
 
 	/*
 	 * Initialise the free scanner. The starting point is where we last
···
 	 * is using.
 	 */
 	isolate_start_pfn = cc->free_pfn;
-	block_start_pfn = pageblock_start_pfn(cc->free_pfn);
+	block_start_pfn = pageblock_start_pfn(isolate_start_pfn);
 	block_end_pfn = min(block_start_pfn + pageblock_nr_pages,
 						zone_end_pfn(zone));
 	low_pfn = pageblock_end_pfn(cc->migrate_pfn);
+	stride = cc->mode == MIGRATE_ASYNC ? COMPACT_CLUSTER_MAX : 1;
 
 	/*
 	 * Isolate free pages until enough are available to migrate the
···
 				block_end_pfn = block_start_pfn,
 				block_start_pfn -= pageblock_nr_pages,
 				isolate_start_pfn = block_start_pfn) {
+		unsigned long nr_isolated;
+
 		/*
 		 * This can iterate a massively long zone without finding any
-		 * suitable migration targets, so periodically check if we need
-		 * to schedule, or even abort async compaction.
+		 * suitable migration targets, so periodically check resched.
 		 */
-		if (!(block_start_pfn % (SWAP_CLUSTER_MAX * pageblock_nr_pages))
-						&& compact_should_abort(cc))
-			break;
+		if (!(block_start_pfn % (SWAP_CLUSTER_MAX * pageblock_nr_pages)))
+			cond_resched();
 
 		page = pageblock_pfn_to_page(block_start_pfn, block_end_pfn,
 									zone);
···
 			continue;
 
 		/* Found a block suitable for isolating free pages from. */
-		isolate_freepages_block(cc, &isolate_start_pfn, block_end_pfn,
-					freelist, false);
+		nr_isolated = isolate_freepages_block(cc, &isolate_start_pfn,
+					block_end_pfn, freelist, stride, false);
 
-		/*
-		 * If we isolated enough freepages, or aborted due to lock
-		 * contention, terminate.
-		 */
-		if ((cc->nr_freepages >= cc->nr_migratepages)
-							|| cc->contended) {
+		/* Update the skip hint if the full pageblock was scanned */
+		if (isolate_start_pfn == block_end_pfn)
+			update_pageblock_skip(cc, page, block_start_pfn);
+
+		/* Are enough freepages isolated? */
+		if (cc->nr_freepages >= cc->nr_migratepages) {
 			if (isolate_start_pfn >= block_end_pfn) {
 				/*
 				 * Restart at previous pageblock if more
···
 			 */
 			break;
 		}
-	}
 
-	/* __isolate_free_page() does not map the pages */
-	map_pages(freelist);
+		/* Adjust stride depending on isolation */
+		if (nr_isolated) {
+			stride = 1;
+			continue;
+		}
+		stride = min_t(unsigned int, COMPACT_CLUSTER_MAX, stride << 1);
+	}
 
 	/*
 	 * Record where the free scanner will restart next time. Either we
···
 	 * and the loop terminated due to isolate_start_pfn < low_pfn
 	 */
 	cc->free_pfn = isolate_start_pfn;
+
+splitmap:
+	/* __isolate_free_page() does not map the pages */
+	split_map_pages(freelist);
 }
 
 /*
···
 	struct compact_control *cc = (struct compact_control *)data;
 	struct page *freepage;
 
-	/*
-	 * Isolate free pages if necessary, and if we are not aborting due to
-	 * contention.
-	 */
 	if (list_empty(&cc->freepages)) {
-		if (!cc->contended)
-			isolate_freepages(cc);
+		isolate_freepages(cc);
 
 		if (list_empty(&cc->freepages))
 			return NULL;
···
  */
 int sysctl_compact_unevictable_allowed __read_mostly = 1;
 
+static inline void
+update_fast_start_pfn(struct compact_control *cc, unsigned long pfn)
+{
+	if (cc->fast_start_pfn == ULONG_MAX)
+		return;
+
+	if (!cc->fast_start_pfn)
+		cc->fast_start_pfn = pfn;
+
+	cc->fast_start_pfn = min(cc->fast_start_pfn, pfn);
+}
+
+static inline unsigned long
+reinit_migrate_pfn(struct compact_control *cc)
+{
+	if (!cc->fast_start_pfn || cc->fast_start_pfn == ULONG_MAX)
+		return cc->migrate_pfn;
+
+	cc->migrate_pfn = cc->fast_start_pfn;
+	cc->fast_start_pfn = ULONG_MAX;
+
+	return cc->migrate_pfn;
+}
+
+/*
+ * Briefly search the free lists for a migration source that already has
+ * some free pages to reduce the number of pages that need migration
+ * before a pageblock is free.
+ */
+static unsigned long fast_find_migrateblock(struct compact_control *cc)
+{
+	unsigned int limit = freelist_scan_limit(cc);
+	unsigned int nr_scanned = 0;
+	unsigned long distance;
+	unsigned long pfn = cc->migrate_pfn;
+	unsigned long high_pfn;
+	int order;
+
+	/* Skip hints are relied on to avoid repeats on the fast search */
+	if (cc->ignore_skip_hint)
+		return pfn;
+
+	/*
+	 * If the migrate_pfn is not at the start of a zone or the start
+	 * of a pageblock then assume this is a continuation of a previous
+	 * scan restarted due to COMPACT_CLUSTER_MAX.
+	 */
+	if (pfn != cc->zone->zone_start_pfn && pfn != pageblock_start_pfn(pfn))
+		return pfn;
+
+	/*
+	 * For smaller orders, just linearly scan as the number of pages
+	 * to migrate should be relatively small and does not necessarily
+	 * justify freeing up a large block for a small allocation.
+	 */
+	if (cc->order <= PAGE_ALLOC_COSTLY_ORDER)
+		return pfn;
+
+	/*
+	 * Only allow kcompactd and direct requests for movable pages to
+	 * quickly clear out a MOVABLE pageblock for allocation. This
+	 * reduces the risk that a large movable pageblock is freed for
+	 * an unmovable/reclaimable small allocation.
+	 */
+	if (cc->direct_compaction && cc->migratetype != MIGRATE_MOVABLE)
+		return pfn;
+
+	/*
+	 * When starting the migration scanner, pick any pageblock within the
+	 * first half of the search space. Otherwise try and pick a pageblock
+	 * within the first eighth to reduce the chances that a migration
+	 * target later becomes a source.
+	 */
+	distance = (cc->free_pfn - cc->migrate_pfn) >> 1;
+	if (cc->migrate_pfn != cc->zone->zone_start_pfn)
+		distance >>= 2;
+	high_pfn = pageblock_start_pfn(cc->migrate_pfn + distance);
+
+	for (order = cc->order - 1;
+	     order >= PAGE_ALLOC_COSTLY_ORDER && pfn == cc->migrate_pfn && nr_scanned < limit;
+	     order--) {
+		struct free_area *area = &cc->zone->free_area[order];
+		struct list_head *freelist;
+		unsigned long flags;
+		struct page *freepage;
+
+		if (!area->nr_free)
+			continue;
+
+		spin_lock_irqsave(&cc->zone->lock, flags);
+		freelist = &area->free_list[MIGRATE_MOVABLE];
+		list_for_each_entry(freepage, freelist, lru) {
+			unsigned long free_pfn;
+
+			nr_scanned++;
+			free_pfn = page_to_pfn(freepage);
+			if (free_pfn < high_pfn) {
+				/*
+				 * Avoid if skipped recently. Ideally it would
+				 * move to the tail but even safe iteration of
+				 * the list assumes an entry is deleted, not
+				 * reordered.
+				 */
+				if (get_pageblock_skip(freepage)) {
+					if (list_is_last(freelist, &freepage->lru))
+						break;
+
+					continue;
+				}
+
+				/* Reorder to so a future search skips recent pages */
+				move_freelist_tail(freelist, freepage);
+
+				update_fast_start_pfn(cc, free_pfn);
+				pfn = pageblock_start_pfn(free_pfn);
+				cc->fast_search_fail = 0;
+				set_pageblock_skip(freepage);
+				break;
+			}
+
+			if (nr_scanned >= limit) {
+				cc->fast_search_fail++;
+				move_freelist_tail(freelist, freepage);
+				break;
+			}
+		}
+		spin_unlock_irqrestore(&cc->zone->lock, flags);
+	}
+
+	cc->total_migrate_scanned += nr_scanned;
+
+	/*
+	 * If fast scanning failed then use a cached entry for a page block
+	 * that had free pages as the basis for starting a linear scan.
+	 */
+	if (pfn == cc->migrate_pfn)
+		pfn = reinit_migrate_pfn(cc);
+
+	return pfn;
+}
+
 /*
  * Isolate all pages that can be migrated from the first suitable block,
  * starting at the block pointed to by the migrate scanner pfn within
···
 	const isolate_mode_t isolate_mode =
 		(sysctl_compact_unevictable_allowed ? ISOLATE_UNEVICTABLE : 0) |
 		(cc->mode != MIGRATE_SYNC ? ISOLATE_ASYNC_MIGRATE : 0);
+	bool fast_find_block;
 
 	/*
 	 * Start at where we last stopped, or beginning of the zone as
-	 * initialized by compact_zone()
+	 * initialized by compact_zone(). The first failure will use
+	 * the lowest PFN as the starting point for linear scanning.
 	 */
-	low_pfn = cc->migrate_pfn;
+	low_pfn = fast_find_migrateblock(cc);
 	block_start_pfn = pageblock_start_pfn(low_pfn);
 	if (block_start_pfn < zone->zone_start_pfn)
 		block_start_pfn = zone->zone_start_pfn;
+
+	/*
+	 * fast_find_migrateblock marks a pageblock skipped so to avoid
+	 * the isolation_suitable check below, check whether the fast
+	 * search was successful.
+	 */
+	fast_find_block = low_pfn != cc->migrate_pfn && !cc->fast_search_fail;
 
 	/* Only scan within a pageblock boundary */
 	block_end_pfn = pageblock_end_pfn(low_pfn);
···
 	 * Do not cross the free scanner.
 	 */
 	for (; block_end_pfn <= cc->free_pfn;
+			fast_find_block = false,
 			low_pfn = block_end_pfn,
 			block_start_pfn = block_end_pfn,
 			block_end_pfn += pageblock_nr_pages) {
···
 		/*
 		 * This can potentially iterate a massively long zone with
 		 * many pageblocks unsuitable, so periodically check if we
-		 * need to schedule, or even abort async compaction.
+		 * need to schedule.
 		 */
-		if (!(low_pfn % (SWAP_CLUSTER_MAX * pageblock_nr_pages))
-						&& compact_should_abort(cc))
-			break;
+		if (!(low_pfn % (SWAP_CLUSTER_MAX * pageblock_nr_pages)))
+			cond_resched();
 
 		page = pageblock_pfn_to_page(block_start_pfn, block_end_pfn,
 									zone);
 		if (!page)
 			continue;
 
-		/* If isolation recently failed, do not retry */
-		if (!isolation_suitable(cc, page))
+		/*
+		 * If isolation recently failed, do not retry. Only check the
+		 * pageblock once. COMPACT_CLUSTER_MAX causes a pageblock
+		 * to be visited multiple times. Assume skip was checked
+		 * before making it "skip" so other compaction instances do
+		 * not scan the same block.
+		 */
+		if (IS_ALIGNED(low_pfn, pageblock_nr_pages) &&
+		    !fast_find_block && !isolation_suitable(cc, page))
 			continue;
 
 		/*
-		 * For async compaction, also only scan in MOVABLE blocks.
-		 * Async compaction is optimistic to see if the minimum amount
-		 * of work satisfies the allocation.
+		 * For async compaction, also only scan in MOVABLE blocks
+		 * without huge pages. Async compaction is optimistic to see
+		 * if the minimum amount of work satisfies the allocation.
+		 * The cached PFN is updated as it's possible that all
+		 * remaining blocks between source and target are unsuitable
+		 * and the compaction scanners fail to meet.
 		 */
-		if (!suitable_migration_source(cc, page))
+		if (!suitable_migration_source(cc, page)) {
+			update_cached_migrate(cc, block_end_pfn);
 			continue;
+		}
 
 		/* Perform the isolation */
 		low_pfn = isolate_migratepages_block(cc, low_pfn,
 						block_end_pfn, isolate_mode);
 
-		if (!low_pfn || cc->contended)
+		if (!low_pfn)
 			return ISOLATE_ABORT;
 
 		/*
···
 	return order == -1;
 }
 
-static enum compact_result __compact_finished(struct zone *zone,
-						struct compact_control *cc)
+static enum compact_result __compact_finished(struct compact_control *cc)
 {
 	unsigned int order;
 	const int migratetype = cc->migratetype;
-
-	if (cc->contended || fatal_signal_pending(current))
-		return COMPACT_CONTENDED;
+	int ret;
 
 	/* Compaction run completes if the migrate and free scanner meet */
 	if (compact_scanners_met(cc)) {
 		/* Let the next compaction start anew. */
-		reset_cached_positions(zone);
+		reset_cached_positions(cc->zone);
 
 		/*
 		 * Mark that the PG_migrate_skip information should be cleared
···
 		 * based on an allocation request.
 		 */
 		if (cc->direct_compaction)
-			zone->compact_blockskip_flush = true;
+			cc->zone->compact_blockskip_flush = true;
 
 		if (cc->whole_zone)
 			return COMPACT_COMPLETE;
···
 	if (is_via_compact_memory(cc->order))
 		return COMPACT_CONTINUE;
 
-	if (cc->finishing_block) {
-		/*
-		 * We have finished the pageblock, but better check again that
-		 * we really succeeded.
-		 */
-		if (IS_ALIGNED(cc->migrate_pfn, pageblock_nr_pages))
-			cc->finishing_block = false;
-		else
-			return COMPACT_CONTINUE;
-	}
+	/*
+	 * Always finish scanning a pageblock to reduce the possibility of
+	 * fallbacks in the future. This is particularly important when
+	 * migration source is unmovable/reclaimable but it's not worth
+	 * special casing.
+	 */
+	if (!IS_ALIGNED(cc->migrate_pfn, pageblock_nr_pages))
+		return COMPACT_CONTINUE;
 
 	/* Direct compactor: Is a suitable page free? */
+	ret = COMPACT_NO_SUITABLE_PAGE;
 	for (order = cc->order; order < MAX_ORDER; order++) {
-		struct free_area *area = &zone->free_area[order];
+		struct free_area *area = &cc->zone->free_area[order];
 		bool can_steal;
 
 		/* Job done if page is free of the right migratetype */
···
 				return COMPACT_SUCCESS;
 			}
 
-			cc->finishing_block = true;
-			return COMPACT_CONTINUE;
+			ret = COMPACT_CONTINUE;
+			break;
 		}
 	}
 
-	return COMPACT_NO_SUITABLE_PAGE;
+	if (cc->contended || fatal_signal_pending(current))
+		ret = COMPACT_CONTENDED;
+
+	return ret;
 }
 
-static enum compact_result compact_finished(struct zone *zone,
-			struct compact_control *cc)
+static enum compact_result compact_finished(struct compact_control *cc)
 {
 	int ret;
 
-	ret = __compact_finished(zone, cc);
-	trace_mm_compaction_finished(zone, cc->order, ret);
+	ret = __compact_finished(cc);
+	trace_mm_compaction_finished(cc->zone, cc->order, ret);
 	if (ret == COMPACT_NO_SUITABLE_PAGE)
 		ret = COMPACT_CONTINUE;
 
···
 	return false;
 }
 
-static enum compact_result compact_zone(struct zone *zone, struct compact_control *cc)
+static enum compact_result
+compact_zone(struct compact_control *cc, struct capture_control *capc)
 {
 	enum compact_result ret;
-	unsigned long start_pfn = zone->zone_start_pfn;
-	unsigned long end_pfn = zone_end_pfn(zone);
+	unsigned long start_pfn = cc->zone->zone_start_pfn;
+	unsigned long end_pfn = zone_end_pfn(cc->zone);
+	unsigned long last_migrated_pfn;
 	const bool sync = cc->mode != MIGRATE_ASYNC;
+	bool update_cached;
 
 	cc->migratetype = gfpflags_to_migratetype(cc->gfp_mask);
-	ret = compaction_suitable(zone, cc->order, cc->alloc_flags,
+	ret = compaction_suitable(cc->zone, cc->order, cc->alloc_flags,
 							cc->classzone_idx);
 	/* Compaction is likely to fail */
 	if (ret == COMPACT_SUCCESS || ret == COMPACT_SKIPPED)
···
 	 * Clear pageblock skip if there were failures recently and compaction
 	 * is about to be retried after being deferred.
 	 */
-	if (compaction_restarting(zone, cc->order))
-		__reset_isolation_suitable(zone);
+	if (compaction_restarting(cc->zone, cc->order))
+		__reset_isolation_suitable(cc->zone);
 
 	/*
 	 * Setup to move all movable pages to the end of the zone. Used cached
···
 	 * want to compact the whole zone), but check that it is initialised
 	 * by ensuring the values are within zone boundaries.
 	 */
+	cc->fast_start_pfn = 0;
 	if (cc->whole_zone) {
 		cc->migrate_pfn = start_pfn;
 		cc->free_pfn = pageblock_start_pfn(end_pfn - 1);
 	} else {
-		cc->migrate_pfn = zone->compact_cached_migrate_pfn[sync];
-		cc->free_pfn = zone->compact_cached_free_pfn;
+		cc->migrate_pfn = cc->zone->compact_cached_migrate_pfn[sync];
+		cc->free_pfn = cc->zone->compact_cached_free_pfn;
 		if (cc->free_pfn < start_pfn || cc->free_pfn >= end_pfn) {
 			cc->free_pfn = pageblock_start_pfn(end_pfn - 1);
-			zone->compact_cached_free_pfn = cc->free_pfn;
+			cc->zone->compact_cached_free_pfn = cc->free_pfn;
 		}
 		if (cc->migrate_pfn < start_pfn || cc->migrate_pfn >= end_pfn) {
 			cc->migrate_pfn = start_pfn;
-			zone->compact_cached_migrate_pfn[0] = cc->migrate_pfn;
-			zone->compact_cached_migrate_pfn[1] = cc->migrate_pfn;
+			cc->zone->compact_cached_migrate_pfn[0] = cc->migrate_pfn;
+			cc->zone->compact_cached_migrate_pfn[1] = cc->migrate_pfn;
 		}
 
-		if (cc->migrate_pfn == start_pfn)
+		if (cc->migrate_pfn <= cc->zone->compact_init_migrate_pfn)
 			cc->whole_zone = true;
 	}
 
-	cc->last_migrated_pfn = 0;
+	last_migrated_pfn = 0;
+
+	/*
+	 * Migrate has separate cached PFNs for ASYNC and SYNC* migration on
+	 * the basis that some migrations will fail in ASYNC mode. However,
+	 * if the cached PFNs match and pageblocks are skipped due to having
+	 * no isolation candidates, then the sync state does not matter.
+	 * Until a pageblock with isolation candidates is found, keep the
+	 * cached PFNs in sync to avoid revisiting the same blocks.
+	 */
+	update_cached = !sync &&
+		cc->zone->compact_cached_migrate_pfn[0] == cc->zone->compact_cached_migrate_pfn[1];
 
 	trace_mm_compaction_begin(start_pfn, cc->migrate_pfn,
 				cc->free_pfn, end_pfn, sync);
 
 	migrate_prep_local();
 
-	while ((ret = compact_finished(zone, cc)) == COMPACT_CONTINUE) {
+	while ((ret = compact_finished(cc)) == COMPACT_CONTINUE) {
 		int err;
+		unsigned long start_pfn = cc->migrate_pfn;
 
-		switch (isolate_migratepages(zone, cc)) {
+		/*
+		 * Avoid multiple rescans which can happen if a page cannot be
+		 * isolated (dirty/writeback in async mode) or if the migrated
+		 * pages are being allocated before the pageblock is cleared.
+		 * The first rescan will capture the entire pageblock for
+		 * migration. If it fails, it'll be marked skip and scanning
+		 * will proceed as normal.
+		 */
+		cc->rescan = false;
+		if (pageblock_start_pfn(last_migrated_pfn) ==
+		    pageblock_start_pfn(start_pfn)) {
+			cc->rescan = true;
+		}
+
+		switch (isolate_migratepages(cc->zone, cc)) {
 		case ISOLATE_ABORT:
 			ret = COMPACT_CONTENDED;
 			putback_movable_pages(&cc->migratepages);
 			cc->nr_migratepages = 0;
+			last_migrated_pfn = 0;
 			goto out;
 		case ISOLATE_NONE:
+			if (update_cached) {
+				cc->zone->compact_cached_migrate_pfn[1] =
+					cc->zone->compact_cached_migrate_pfn[0];
+			}
+
 			/*
 			 * We haven't isolated and migrated anything, but
 			 * there might still be unflushed migrations from
···
 			 */
 			goto check_drain;
 		case ISOLATE_SUCCESS:
+			update_cached = false;
+			last_migrated_pfn = start_pfn;
 			;
 		}
 
···
 				cc->migrate_pfn = block_end_pfn(
 						cc->migrate_pfn - 1, cc->order);
 				/* Draining pcplists is useless in this case */
-				cc->last_migrated_pfn = 0;
-
+				last_migrated_pfn = 0;
 			}
 		}
 
···
 		 * compact_finished() can detect immediately if allocation
 		 * would succeed.
 		 */
-		if (cc->order > 0 && cc->last_migrated_pfn) {
+		if (cc->order > 0 && last_migrated_pfn) {
 			int cpu;
 			unsigned long current_block_start =
 				block_start_pfn(cc->migrate_pfn, cc->order);
 
-			if (cc->last_migrated_pfn < current_block_start) {
+			if (last_migrated_pfn < current_block_start) {
 				cpu = get_cpu();
 				lru_add_drain_cpu(cpu);
-				drain_local_pages(zone);
+				drain_local_pages(cc->zone);
 				put_cpu();
 				/* No more flushing until we migrate again */
-				cc->last_migrated_pfn = 0;
+				last_migrated_pfn = 0;
 			}
 		}
 
+		/* Stop if a page has been captured */
+		if (capc && capc->page) {
+			ret = COMPACT_SUCCESS;
+			break;
+		}
 	}
 
 out:
···
 		 * Only go back, not forward. The cached pfn might have been
 		 * already reset to zone end in compact_finished()
 		 */
-		if (free_pfn > zone->compact_cached_free_pfn)
-			zone->compact_cached_free_pfn = free_pfn;
+		if (free_pfn > cc->zone->compact_cached_free_pfn)
+			cc->zone->compact_cached_free_pfn = free_pfn;
 	}
 
 	count_compact_events(COMPACTMIGRATE_SCANNED, cc->total_migrate_scanned);
···
 
 static enum compact_result compact_zone_order(struct zone *zone, int order,
 		gfp_t gfp_mask, enum compact_priority prio,
-		unsigned int alloc_flags, int classzone_idx)
+		unsigned int alloc_flags, int classzone_idx,
+		struct page **capture)
 {
 	enum compact_result ret;
 	struct compact_control cc = {
···
 		.total_migrate_scanned = 0,
 		.total_free_scanned = 0,
 		.order = order,
+		.search_order = order,
 		.gfp_mask = gfp_mask,
 		.zone = zone,
 		.mode = (prio == COMPACT_PRIO_ASYNC) ?
···
 		.ignore_skip_hint = (prio == MIN_COMPACT_PRIORITY),
 		.ignore_block_suitable = (prio == MIN_COMPACT_PRIORITY)
 	};
+	struct capture_control capc = {
+		.cc = &cc,
+		.page = NULL,
+	};
+
+	if (capture)
+		current->capture_control = &capc;
 	INIT_LIST_HEAD(&cc.freepages);
 	INIT_LIST_HEAD(&cc.migratepages);
 
-	ret = compact_zone(zone, &cc);
+	ret = compact_zone(&cc, &capc);
 
 	VM_BUG_ON(!list_empty(&cc.freepages));
 	VM_BUG_ON(!list_empty(&cc.migratepages));
+
+	*capture = capc.page;
+	current->capture_control = NULL;
 
 	return ret;
 }
···
  */
 enum compact_result try_to_compact_pages(gfp_t gfp_mask, unsigned int order,
 		unsigned int alloc_flags, const struct alloc_context *ac,
-		enum compact_priority prio)
+		enum compact_priority prio, struct page **capture)
 {
 	int may_perform_io = gfp_mask & __GFP_IO;
 	struct zoneref *z;
···
 		}
 
 		status = compact_zone_order(zone, order, gfp_mask, prio,
-					alloc_flags, ac_classzone_idx(ac));
+				alloc_flags, ac_classzone_idx(ac), capture);
 		rc = max(status, rc);
 
 		/* The allocation should succeed, stop compacting */
···
 		INIT_LIST_HEAD(&cc.freepages);
 		INIT_LIST_HEAD(&cc.migratepages);
 
-		compact_zone(zone, &cc);
+		compact_zone(&cc, NULL);
 
 		VM_BUG_ON(!list_empty(&cc.freepages));
 		VM_BUG_ON(!list_empty(&cc.migratepages));
···
 {
 	if (write)
 		compact_nodes();
-
-	return 0;
-}
-
-int sysctl_extfrag_handler(struct ctl_table *table, int write,
-			void __user *buffer, size_t *length, loff_t *ppos)
-{
-	proc_dointvec_minmax(table, write, buffer, length, ppos);
 
 	return 0;
 }
···
 	struct zone *zone;
 	struct compact_control cc = {
 		.order = pgdat->kcompactd_max_order,
+		.search_order = pgdat->kcompactd_max_order,
 		.total_migrate_scanned = 0,
 		.total_free_scanned = 0,
 		.classzone_idx = pgdat->kcompactd_classzone_idx,
···
 
 		if (kthread_should_stop())
 			return;
-		status = compact_zone(zone, &cc);
+		status = compact_zone(&cc, NULL);
 
 		if (status == COMPACT_SUCCESS) {
 			compaction_defer_reset(zone, cc.order, false);

mm/dmapool.c

···
  * @size: size of the blocks in this pool.
  * @align: alignment requirement for blocks; must be a power of two
  * @boundary: returned blocks won't cross this power of two boundary
- * Context: !in_interrupt()
+ * Context: not in_interrupt()
  *
- * Returns a dma allocation pool with the requested characteristics, or
- * null if one can't be created.  Given one of these pools, dma_pool_alloc()
+ * Given one of these pools, dma_pool_alloc()
  * may be used to allocate memory.  Such memory will all have "consistent"
  * DMA mappings, accessible by the device and its driver without using
  * cache flushing primitives.  The actual size of blocks allocated may be
···
  * cross that size boundary.  This is useful for devices which have
  * addressing restrictions on individual DMA transfers, such as not crossing
  * boundaries of 4KBytes.
+ *
+ * Return: a dma allocation pool with the requested characteristics, or
+ * %NULL if one can't be created.
  */
 struct dma_pool *dma_pool_create(const char *name, struct device *dev,
 				 size_t size, size_t align, size_t boundary)
···
  * @mem_flags: GFP_* bitmask
  * @handle: pointer to dma address of block
  *
- * This returns the kernel virtual address of a currently unused block,
+ * Return: the kernel virtual address of a currently unused block,
  * and reports its dma address through the handle.
  * If such a memory block can't be allocated, %NULL is returned.
  */
···
  *
  * Managed dma_pool_create().  DMA pool created with this function is
  * automatically destroyed on driver detach.
+ *
+ * Return: a managed dma allocation pool with the requested
+ * characteristics, or %NULL if one can't be created.
  */
 struct dma_pool *dmam_pool_create(const char *name, struct device *dev,
 				  size_t size, size_t align, size_t allocation)

mm/failslab.c

···
 	if (IS_ERR(dir))
 		return PTR_ERR(dir);
 
-	if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
-				&failslab.ignore_gfp_reclaim))
-		goto fail;
-	if (!debugfs_create_bool("cache-filter", mode, dir,
-				&failslab.cache_filter))
-		goto fail;
+	debugfs_create_bool("ignore-gfp-wait", mode, dir,
+			    &failslab.ignore_gfp_reclaim);
+	debugfs_create_bool("cache-filter", mode, dir,
+			    &failslab.cache_filter);
 
 	return 0;
-fail:
-	debugfs_remove_recursive(dir);
-
-	return -ENOMEM;
 }
 
 late_initcall(failslab_debugfs_init);

mm/filemap.c

···
  *    ->swap_lock		(try_to_unmap_one)
  *    ->private_lock		(try_to_unmap_one)
  *    ->i_pages lock		(try_to_unmap_one)
- *    ->zone_lru_lock(zone)	(follow_page->mark_page_accessed)
- *    ->zone_lru_lock(zone)	(check_pte_range->isolate_lru_page)
+ *    ->pgdat->lru_lock		(follow_page->mark_page_accessed)
+ *    ->pgdat->lru_lock		(check_pte_range->isolate_lru_page)
  *    ->private_lock		(page_remove_rmap->set_page_dirty)
  *    ->i_pages lock		(page_remove_rmap->set_page_dirty)
  *    bdi.wb->list_lock		(page_remove_rmap->set_page_dirty)
···
  * opposed to a regular memory cleansing writeback.  The difference between
  * these two operations is that if a dirty page/buffer is encountered, it must
  * be waited upon, and not just skipped over.
+ *
+ * Return: %0 on success, negative error code otherwise.
  */
 int __filemap_fdatawrite_range(struct address_space *mapping, loff_t start,
 				loff_t end, int sync_mode)
···
  *
  * This is a mostly non-blocking flush.  Not suitable for data-integrity
  * purposes - I/O may not be started against all dirty pages.
+ *
+ * Return: %0 on success, negative error code otherwise.
  */
 int filemap_flush(struct address_space *mapping)
 {
···
  *
  * Find at least one page in the range supplied, usually used to check if
  * direct writing in this range will trigger a writeback.
+ *
+ * Return: %true if at least one page exists in the specified range,
+ * %false otherwise.
  */
 bool filemap_range_has_page(struct address_space *mapping,
 			   loff_t start_byte, loff_t end_byte)
···
  * Since the error status of the address space is cleared by this function,
  * callers are responsible for checking the return value and handling and/or
  * reporting the error.
+ *
+ * Return: error status of the address space.
  */
 int filemap_fdatawait_range(struct address_space *mapping, loff_t start_byte,
 			    loff_t end_byte)
···
  * Since the error status of the file is advanced by this function,
  * callers are responsible for checking the return value and handling and/or
  * reporting the error.
+ *
+ * Return: error status of the address space vs. the file->f_wb_err cursor.
  */
 int file_fdatawait_range(struct file *file, loff_t start_byte, loff_t end_byte)
 {
···
  * Use this function if callers don't handle errors themselves.  Expected
  * call sites are system-wide / filesystem-wide data flushers: e.g. sync(2),
  * fsfreeze(8)
+ *
+ * Return: error status of the address space.
  */
 int filemap_fdatawait_keep_errors(struct address_space *mapping)
 {
···
  *
  * Note that @lend is inclusive (describes the last byte to be written) so
  * that this function can be used to write to the very end-of-file (end = -1).
+ *
+ * Return: error status of the address space.
  */
 int filemap_write_and_wait_range(struct address_space *mapping,
 				 loff_t lstart, loff_t lend)
···
  * While we handle mapping->wb_err with atomic operations, the f_wb_err
  * value is protected by the f_lock since we must ensure that it reflects
  * the latest value swapped in for this file descriptor.
+ *
+ * Return: %0 on success, negative error code otherwise.
  */
 int file_check_and_advance_wb_err(struct file *file)
 {
···
  *
  * After writing out and waiting on the data, we check and advance the
  * f_wb_err cursor to the latest value, and return any errors detected there.
+ *
+ * Return: %0 on success, negative error code otherwise.
  */
 int file_write_and_wait_range(struct file *file, loff_t lstart, loff_t lend)
 {
···
  * caller must do that.
  *
  * The remove + add is atomic.  This function cannot fail.
+ *
+ * Return: %0
  */
 int replace_page_cache_page(struct page *old, struct page *new, gfp_t gfp_mask)
 {
···
  *
  * This function is used to add a page to the pagecache. It must be locked.
  * This function does not add the page to the LRU.  The caller must do that.
+ *
+ * Return: %0 on success, negative error code otherwise.
  */
 int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
 		pgoff_t offset, gfp_t gfp_mask)
···
  * If the slot holds a shadow entry of a previously evicted page, or a
  * swap entry from shmem/tmpfs, it is returned.
  *
- * Otherwise, %NULL is returned.
+ * Return: the found page or shadow entry, %NULL if nothing is found.
  */
 struct page *find_get_entry(struct address_space *mapping, pgoff_t offset)
 {
···
  * If the slot holds a shadow entry of a previously evicted page, or a
  * swap entry from shmem/tmpfs, it is returned.
  *
- * Otherwise, %NULL is returned.
- *
  * find_lock_entry() may sleep.
+ *
+ * Return: the found page or shadow entry, %NULL if nothing is found.
  */
 struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset)
 {
···
  * - FGP_CREAT: If page is not present then a new page is allocated using
  *   @gfp_mask and added to the page cache and the VM's LRU
  *   list. The page is returned locked and with an increased
- *   refcount. Otherwise, NULL is returned.
+ *   refcount.
  *
  * If FGP_LOCK or FGP_CREAT are specified then the function may sleep even
  * if the GFP flags specified for FGP_CREAT are atomic.
  *
  * If there is a page cache page, it is returned with an increased refcount.
+ *
+ * Return: the found page or %NULL otherwise.
  */
 struct page *pagecache_get_page(struct address_space *mapping, pgoff_t offset,
 	int fgp_flags, gfp_t gfp_mask)
···
  * Any shadow entries of evicted pages, or swap entries from
  * shmem/tmpfs, are included in the returned array.
  *
- * find_get_entries() returns the number of pages and shadow entries
- * which were found.
+ * Return: the number of pages and shadow entries which were found.
  */
 unsigned find_get_entries(struct address_space *mapping,
 			  pgoff_t start, unsigned int nr_entries,
···
  * indexes.  There may be holes in the indices due to not-present pages.
  * We also update @start to index the next page for the traversal.
  *
- * find_get_pages_range() returns the number of pages which were found. If this
- * number is smaller than @nr_pages, the end of specified range has been
+ * Return: the number of pages which were found. If this number is
+ * smaller than @nr_pages, the end of specified range has been
  * reached.
  */
 unsigned find_get_pages_range(struct address_space *mapping, pgoff_t *start,
···
 
 		pages[ret] = page;
 		if (++ret == nr_pages) {
-			*start = page->index + 1;
+			*start = xas.xa_index + 1;
 			goto out;
 		}
 		continue;
···
  * find_get_pages_contig() works exactly like find_get_pages(), except
  * that the returned number of pages are guaranteed to be contiguous.
  *
- * find_get_pages_contig() returns the number of pages which were found.
+ * Return: the number of pages which were found.
  */
 unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t index,
 			       unsigned int nr_pages, struct page **pages)
···
 		if (unlikely(page != xas_reload(&xas)))
 			goto put_page;
 
-		/*
-		 * must check mapping and index after taking the ref.
-		 * otherwise we can get both false positives and false
-		 * negatives, which is just confusing to the caller.
-		 */
-		if (!page->mapping || page_to_pgoff(page) != xas.xa_index) {
-			put_page(page);
-			break;
-		}
-
 		pages[ret] = page;
 		if (++ret == nr_pages)
 			break;
···
  *
  * Like find_get_pages, except we only return pages which are tagged with
  * @tag.   We update @index to index the next page for the traversal.
+ *
+ * Return: the number of pages which were found.
  */
 unsigned find_get_pages_range_tag(struct address_space *mapping, pgoff_t *index,
 			pgoff_t end, xa_mark_t tag, unsigned int nr_pages,
···
 
 		pages[ret] = page;
 		if (++ret == nr_pages) {
-			*index = page->index + 1;
+			*index = xas.xa_index + 1;
 			goto out;
 		}
 		continue;
···
  *
  * Like find_get_entries, except we only return entries which are tagged with
  * @tag.
+ *
+ * Return: the number of entries which were found.
  */
 unsigned find_get_entries_tag(struct address_space *mapping, pgoff_t start,
 			xa_mark_t tag, unsigned int nr_entries,
···
  *
  * This is really ugly. But the goto's actually try to clarify some
  * of the logic when it comes to error handling etc.
+ *
+ * Return:
+ * * total number of bytes copied, including those the were already @written
+ * * negative error code if nothing was copied
  */
 static ssize_t generic_file_buffered_read(struct kiocb *iocb,
 		struct iov_iter *iter, ssize_t written)
···
  *
  * This is the "read_iter()" routine for all filesystems
  * that can use the page cache directly.
+ * Return:
+ * * number of bytes copied, even for partial reads
+ * * negative error code if nothing was read
  */
 ssize_t
 generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
···
  *
  * This adds the requested page to the page cache if it isn't already there,
  * and schedules an I/O to read in its contents from disk.
+ *
+ * Return: %0 on success, negative error code otherwise.
  */
 static int page_cache_read(struct file *file, pgoff_t offset, gfp_t gfp_mask)
 {
···
  * has not been released.
  *
  * We never return with VM_FAULT_RETRY and a bit from VM_FAULT_ERROR set.
+ *
+ * Return: bitwise-OR of %VM_FAULT_ codes.
  */
 vm_fault_t filemap_fault(struct vm_fault *vmf)
 {
···
  * not set, try to fill the page and wait for it to become unlocked.
  *
  * If the page does not get brought uptodate, return -EIO.
+ *
+ * Return: up to date page on success, ERR_PTR() on failure.
  */
 struct page *read_cache_page(struct address_space *mapping,
 				pgoff_t index,
···
  * any new page allocations done using the specified allocation flags.
  *
  * If the page does not get brought uptodate, return -EIO.
+ *
+ * Return: up to date page on success, ERR_PTR() on failure.
  */
 struct page *read_cache_page_gfp(struct address_space *mapping,
 				pgoff_t index,
···
 	if (iocb->ki_flags & IOCB_NOWAIT) {
 		/* If there are pages to writeback, return */
 		if (filemap_range_has_page(inode->i_mapping, pos,
-					   pos + write_len))
+					   pos + write_len - 1))
 			return -EAGAIN;
 	} else {
 		written = filemap_write_and_wait_range(mapping, pos,
···
  * This function does *not* take care of syncing data in case of O_SYNC write.
  * A caller has to handle it. This is mainly due to the fact that we want to
  * avoid syncing under i_mutex.
+ *
+ * Return:
+ * * number of bytes written, even for truncated writes
+ * * negative error code if no data has been written at all
  */
 ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
···
  * This is a wrapper around __generic_file_write_iter() to be used by most
  * filesystems. It takes care of syncing the file in case of O_SYNC file
  * and acquires i_mutex as needed.
+ * Return:
+ * * negative error code if no data has been written at all of
+ *   vfs_fsync_range() failed for a synchronous write
+ * * number of bytes written, even for truncated writes
  */
 ssize_t generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 {
···
  * @gfp_mask: memory allocation flags (and I/O mode)
  *
  * The address_space is to try to release any data against the page
- * (presumably at page->private).  If the release was successful, return '1'.
- * Otherwise return zero.
+ * (presumably at page->private).
  *
  * This may also be called if PG_fscache is set on a page, indicating that the
  * page is known to the local caching routines.
···
  * The @gfp_mask argument specifies whether I/O may be performed to release
  * this page (__GFP_IO), and whether the call may block (__GFP_RECLAIM & __GFP_FS).
  *
+ * Return: %1 if the release was successful, otherwise return zero.
  */
 int try_to_release_page(struct page *page, gfp_t gfp_mask)
 {

mm/gup.c

···
 #include <linux/sched/signal.h>
 #include <linux/rwsem.h>
 #include <linux/hugetlb.h>
+#include <linux/migrate.h>
+#include <linux/mm_inline.h>
+#include <linux/sched/mm.h>
 
 #include <asm/mmu_context.h>
 #include <asm/pgtable.h>
···
 }
 EXPORT_SYMBOL(get_user_pages);
 
+#if defined(CONFIG_FS_DAX) || defined (CONFIG_CMA)
+
 #ifdef CONFIG_FS_DAX
+static bool check_dax_vmas(struct vm_area_struct **vmas, long nr_pages)
+{
+	long i;
+	struct vm_area_struct *vma_prev = NULL;
+
+	for (i = 0; i < nr_pages; i++) {
+		struct vm_area_struct *vma = vmas[i];
+
+		if (vma == vma_prev)
+			continue;
+
+		vma_prev = vma;
+
+		if (vma_is_fsdax(vma))
+			return true;
+	}
+	return false;
+}
+#else
+static inline bool check_dax_vmas(struct vm_area_struct **vmas, long nr_pages)
+{
+	return false;
+}
+#endif
+
+#ifdef CONFIG_CMA
+static struct page *new_non_cma_page(struct page *page, unsigned long private)
+{
+	/*
+	 * We want to make sure we allocate the new page from the same node
+	 * as the source page.
+	 */
+	int nid = page_to_nid(page);
+	/*
+	 * Trying to allocate a page for migration. Ignore allocation
+	 * failure warnings. We don't force __GFP_THISNODE here because
+	 * this node here is the node where we have CMA reservation and
+	 * in some case these nodes will have really less non movable
+	 * allocation memory.
+	 */
+	gfp_t gfp_mask = GFP_USER | __GFP_NOWARN;
+
+	if (PageHighMem(page))
+		gfp_mask |= __GFP_HIGHMEM;
+
+#ifdef CONFIG_HUGETLB_PAGE
+	if (PageHuge(page)) {
+		struct hstate *h = page_hstate(page);
+		/*
+		 * We don't want to dequeue from the pool because pool pages will
+		 * mostly be from the CMA region.
+		 */
+		return alloc_migrate_huge_page(h, gfp_mask, nid, NULL);
+	}
+#endif
+	if (PageTransHuge(page)) {
+		struct page *thp;
+		/*
+		 * ignore allocation failure warnings
+		 */
+		gfp_t thp_gfpmask = GFP_TRANSHUGE | __GFP_NOWARN;
+
+		/*
+		 * Remove the movable mask so that we don't allocate from
+		 * CMA area again.
+		 */
+		thp_gfpmask &= ~__GFP_MOVABLE;
+		thp = __alloc_pages_node(nid, thp_gfpmask, HPAGE_PMD_ORDER);
+		if (!thp)
+			return NULL;
+		prep_transhuge_page(thp);
+		return thp;
+	}
+
+	return __alloc_pages_node(nid, gfp_mask, 0);
+}
+
+static long check_and_migrate_cma_pages(unsigned long start, long nr_pages,
+					unsigned int gup_flags,
+					struct page **pages,
+					struct vm_area_struct **vmas)
+{
+	long i;
+	bool drain_allow = true;
+	bool migrate_allow = true;
+	LIST_HEAD(cma_page_list);
+
+check_again:
+	for (i = 0; i < nr_pages; i++) {
+		/*
+		 * If we get a page from the CMA zone, since we are going to
+		 * be pinning these entries, we might as well move them out
+		 * of the CMA zone if possible.
+		 */
+		if (is_migrate_cma_page(pages[i])) {
+
+			struct page *head = compound_head(pages[i]);
+
+			if (PageHuge(head)) {
+				isolate_huge_page(head, &cma_page_list);
+			} else {
+				if (!PageLRU(head) && drain_allow) {
+					lru_add_drain_all();
+					drain_allow = false;
+				}
+
+				if (!isolate_lru_page(head)) {
+					list_add_tail(&head->lru, &cma_page_list);
+					mod_node_page_state(page_pgdat(head),
+							    NR_ISOLATED_ANON +
+							    page_is_file_cache(head),
+							    hpage_nr_pages(head));
+				}
+			}
+		}
+	}
+
+	if (!list_empty(&cma_page_list)) {
+		/*
+		 * drop the above get_user_pages reference.
+		 */
+		for (i = 0; i < nr_pages; i++)
+			put_page(pages[i]);
+
+		if (migrate_pages(&cma_page_list, new_non_cma_page,
+				  NULL, 0, MIGRATE_SYNC, MR_CONTIG_RANGE)) {
+			/*
+			 * some of the pages failed migration. Do get_user_pages
+			 * without migration.
+			 */
+			migrate_allow = false;
+
+			if (!list_empty(&cma_page_list))
+				putback_movable_pages(&cma_page_list);
+		}
+		/*
+		 * We did migrate all the pages, Try to get the page references again
+		 * migrating any new CMA pages which we failed to isolate earlier.
+		 */
+		nr_pages = get_user_pages(start, nr_pages, gup_flags, pages, vmas);
+		if ((nr_pages > 0) && migrate_allow) {
+			drain_allow = true;
+			goto check_again;
+		}
+	}
+
+	return nr_pages;
+}
+#else
+static inline long check_and_migrate_cma_pages(unsigned long start, long nr_pages,
+					       unsigned int gup_flags,
+					       struct page **pages,
+					       struct vm_area_struct **vmas)
+{
+	return nr_pages;
+}
+#endif
+
 /*
  * This is the same as get_user_pages() in that it assumes we are
  * operating on the current task's mm, but it goes further to validate
···
  * Contrast this to iov_iter_get_pages() usages which are transient.
  */
 long get_user_pages_longterm(unsigned long start, unsigned long nr_pages,
-		unsigned int gup_flags, struct page **pages,
-		struct vm_area_struct **vmas_arg)
+			     unsigned int gup_flags, struct page **pages,
+			     struct vm_area_struct **vmas_arg)
 {
 	struct vm_area_struct **vmas = vmas_arg;
-	struct vm_area_struct *vma_prev = NULL;
+	unsigned long flags;
 	long rc, i;
 
 	if (!pages)
···
 			return -ENOMEM;
 	}
 
+	flags = memalloc_nocma_save();
 	rc = get_user_pages(start, nr_pages, gup_flags, pages, vmas);
-
-	for (i = 0; i < rc; i++) {
-		struct vm_area_struct *vma = vmas[i];
-
-		if (vma == vma_prev)
-			continue;
-
-		vma_prev = vma;
-
-		if (vma_is_fsdax(vma))
-			break;
-	}
-
-	/*
-	 * Either get_user_pages() failed, or the vma validation
-	 * succeeded, in either case we don't need to put_page() before
-	 * returning.
-	 */
-	if (i >= rc)
+	memalloc_nocma_restore(flags);
+	if (rc < 0)
 		goto out;
 
-	for (i = 0; i < rc; i++)
-		put_page(pages[i]);
-	rc = -EOPNOTSUPP;
+	if (check_dax_vmas(vmas, rc)) {
+		for (i = 0; i < rc; i++)
+			put_page(pages[i]);
+		rc = -EOPNOTSUPP;
+		goto out;
+	}
+
+	rc = check_and_migrate_cma_pages(start, rc, gup_flags, pages, vmas);
 out:
 	if (vmas != vmas_arg)
 		kfree(vmas);

mm/gup_benchmark.c

···
 
 static int gup_benchmark_init(void)
 {
-	void *ret;
-
-	ret = debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
-			&gup_benchmark_fops);
-	if (!ret)
-		pr_warn("Failed to create gup_benchmark in debugfs");
+	debugfs_create_file_unsafe("gup_benchmark", 0600, NULL, NULL,
+				   &gup_benchmark_fops);
 
 	return 0;
 }

mm/huge_memory.c

···
 #include <linux/page_idle.h>
 #include <linux/shmem_fs.h>
 #include <linux/oom.h>
+#include <linux/numa.h>
 
 #include <asm/tlb.h>
 #include <asm/pgalloc.h>
···
 		mm_inc_nr_ptes(vma->vm_mm);
 		spin_unlock(vmf->ptl);
 		count_vm_event(THP_FAULT_ALLOC);
+		count_memcg_events(memcg, THP_FAULT_ALLOC, 1);
 	}
 
 	return 0;
···
 	}
 
 	count_vm_event(THP_FAULT_ALLOC);
+	count_memcg_events(memcg, THP_FAULT_ALLOC, 1);
 
 	if (!page)
 		clear_huge_page(new_page, vmf->address, HPAGE_PMD_NR);
···
 	struct anon_vma *anon_vma = NULL;
 	struct page *page;
 	unsigned long haddr = vmf->address & HPAGE_PMD_MASK;
-	int page_nid = -1, this_nid = numa_node_id();
+	int page_nid = NUMA_NO_NODE, this_nid = numa_node_id();
 	int target_nid, last_cpupid = -1;
 	bool page_locked;
 	bool migrated = false;
···
 	 */
 	page_locked = trylock_page(page);
 	target_nid = mpol_misplaced(page, vma, haddr);
-	if (target_nid == -1) {
+	if (target_nid == NUMA_NO_NODE) {
 		/* If the page was locked, there are no parallel migrations */
 		if (page_locked)
 			goto clear_pmdnuma;
···
 
 	/* Migration could have started since the pmd_trans_migrating check */
 	if (!page_locked) {
-		page_nid = -1;
+		page_nid = NUMA_NO_NODE;
 		if (!get_page_unless_zero(page))
 			goto out_unlock;
 		spin_unlock(vmf->ptl);
···
 	if (unlikely(!pmd_same(pmd, *vmf->pmd))) {
 		unlock_page(page);
 		put_page(page);
-		page_nid = -1;
+		page_nid = NUMA_NO_NODE;
 		goto out_unlock;
 	}
 
 	/* Bail if we fail to protect against THP splits for any reason */
 	if (unlikely(!anon_vma)) {
 		put_page(page);
-		page_nid = -1;
+		page_nid = NUMA_NO_NODE;
 		goto clear_pmdnuma;
 	}
 
···
 	if (anon_vma)
 		page_unlock_anon_vma_read(anon_vma);
 
-	if (page_nid != -1)
+	if (page_nid != NUMA_NO_NODE)
 		task_numa_fault(last_cpupid, page_nid, HPAGE_PMD_NR,
 				flags);
 
···
 int zap_huge_pud(struct mmu_gather *tlb, struct vm_area_struct *vma,
 		 pud_t *pud, unsigned long addr)
 {
-	pud_t orig_pud;
 	spinlock_t *ptl;
 
 	ptl = __pud_trans_huge_lock(pud, vma);
···
 	 * pgtable_trans_huge_withdraw after finishing pudp related
 	 * operations.
 	 */
-	orig_pud = pudp_huge_get_and_clear_full(tlb->mm, addr, pud,
-			tlb->fullmm);
+	pudp_huge_get_and_clear_full(tlb->mm, addr, pud, tlb->fullmm);
 	tlb_remove_pud_tlb_entry(tlb, pud, addr);
 	if (vma_is_dax(vma)) {
 		spin_unlock(ptl);
···
 		pgoff_t end, unsigned long flags)
 {
 	struct page *head = compound_head(page);
-	struct zone *zone = page_zone(head);
+	pg_data_t *pgdat = page_pgdat(head);
 	struct lruvec *lruvec;
 	int i;
 
-	lruvec = mem_cgroup_page_lruvec(head, zone->zone_pgdat);
+	lruvec = mem_cgroup_page_lruvec(head, pgdat);
 
 	/* complete memcg works before add pages to LRU */
 	mem_cgroup_split_huge_fixup(head);
···
 		xa_unlock(&head->mapping->i_pages);
 	}
 
-	spin_unlock_irqrestore(zone_lru_lock(page_zone(head)), flags);
+	spin_unlock_irqrestore(&pgdat->lru_lock, flags);
 
 	remap_page(head);
 
···
 		lru_add_drain();
 
 	/* prevent PageLRU to go away from under us, and freeze lru stats */
-	spin_lock_irqsave(zone_lru_lock(page_zone(head)), flags);
+	spin_lock_irqsave(&pgdata->lru_lock, flags);
 
 	if (mapping) {
 		XA_STATE(xas, &mapping->i_pages, page_index(head));
···
 		spin_unlock(&pgdata->split_queue_lock);
 fail:		if (mapping)
 			xa_unlock(&mapping->i_pages);
-		spin_unlock_irqrestore(zone_lru_lock(page_zone(head)), flags);
+		spin_unlock_irqrestore(&pgdata->lru_lock, flags);
 		remap_page(head);
 		ret = -EBUSY;
 	}
···
 
 static int __init split_huge_pages_debugfs(void)
 {
-	void *ret;
-
-	ret = debugfs_create_file("split_huge_pages", 0200, NULL, NULL,
-			&split_huge_pages_fops);
-	if (!ret)
-		pr_warn("Failed to create split_huge_pages in debugfs");
+	debugfs_create_file("split_huge_pages", 0200, NULL, NULL,
+			    &split_huge_pages_fops);
 	return 0;
 }
 late_initcall(split_huge_pages_debugfs);

mm/hugetlb.c

···
 #include <linux/swap.h>
 #include <linux/swapops.h>
 #include <linux/jhash.h>
+#include <linux/numa.h>
 
 #include <asm/page.h>
 #include <asm/pgtable.h>
···
 	struct zonelist *zonelist;
 	struct zone *zone;
 	struct zoneref *z;
-	int node = -1;
+	int node = NUMA_NO_NODE;
 
 	zonelist = node_zonelist(nid, gfp_mask);
 
···
 /* Movability of hugepages depends on migration support. */
 static inline gfp_t htlb_alloc_mask(struct hstate *h)
 {
-	if (hugepage_migration_supported(h))
+	if (hugepage_movable_supported(h))
 		return GFP_HIGHUSER_MOVABLE;
 	else
 		return GFP_HIGHUSER;
···
 	return page;
 }
 
-static struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask,
-		int nid, nodemask_t *nmask)
+struct page *alloc_migrate_huge_page(struct hstate *h, gfp_t gfp_mask,
+				     int nid, nodemask_t *nmask)
 {
 	struct page *page;
 
···
 			continue;
 		}
 		if (!huge_pte_none(pte)) {
-			pte = huge_ptep_get_and_clear(mm, address, ptep);
-			pte = pte_mkhuge(huge_pte_modify(pte, newprot));
+			pte_t old_pte;
+
+			old_pte = huge_ptep_modify_prot_start(vma, address, ptep);
+			pte = pte_mkhuge(huge_pte_modify(old_pte, newprot));
 			pte = arch_make_huge_pte(pte, vma, NULL, 0);
-			set_huge_pte_at(mm, address, ptep, pte);
+			huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte);
 			pages++;
 		}
 		spin_unlock(ptl);

mm/internal.h

···
 extern int __isolate_free_page(struct page *page, unsigned int order);
 extern void memblock_free_pages(struct page *page, unsigned long pfn,
 					unsigned int order);
+extern void __free_pages_core(struct page *page, unsigned int order);
 extern void prep_compound_page(struct page *page, unsigned int order);
 extern void post_alloc_hook(struct page *page, unsigned int order,
 					gfp_t gfp_flags);
···
 struct compact_control {
 	struct list_head freepages;	/* List of free pages to migrate to */
 	struct list_head migratepages;	/* List of pages being migrated */
-	struct zone *zone;
-	unsigned long nr_freepages;	/* Number of isolated free pages */
-	unsigned long nr_migratepages;	/* Number of pages to migrate */
-	unsigned long total_migrate_scanned;
-	unsigned long total_free_scanned;
+	unsigned int nr_freepages;	/* Number of isolated free pages */
+	unsigned int nr_migratepages;	/* Number of pages to migrate */
 	unsigned long free_pfn;		/* isolate_freepages search base */
 	unsigned long migrate_pfn;	/* isolate_migratepages search base */
-	unsigned long last_migrated_pfn;/* Not yet flushed page being freed */
+	unsigned long fast_start_pfn;	/* a pfn to start linear scan from */
+	struct zone *zone;
+	unsigned long total_migrate_scanned;
+	unsigned long total_free_scanned;
+	unsigned short fast_search_fail;/* failures to use free list searches */
+	short search_order;		/* order to start a fast search at */
 	const gfp_t gfp_mask;		/* gfp mask of a direct compactor */
 	int order;			/* order a direct compactor needs */
 	int migratetype;		/* migratetype of direct compactor */
···
 	bool direct_compaction;		/* False from kcompactd or /proc/... */
 	bool whole_zone;		/* Whole zone should/has been scanned */
 	bool contended;			/* Signal lock or sched contention */
-	bool finishing_block;		/* Finishing current pageblock */
+	bool rescan;			/* Rescanning the same pageblock */
+};
+
+/*
+ * Used in direct compaction when a page should be taken from the freelists
+ * immediately when one is created during the free path.
+ */
+struct capture_control {
+	struct compact_control *cc;
+	struct page *page;
 };
 
 unsigned long

mm/kasan/common.c

···
  *
  */
 
+#define __KASAN_INTERNAL
+
 #include <linux/export.h>
 #include <linux/interrupt.h>
 #include <linux/init.h>

mm/kasan/generic.c

···
 void __asan_handle_no_return(void) {}
 EXPORT_SYMBOL(__asan_handle_no_return);
 
-/* Emitted by compiler to poison large objects when they go out of scope. */
-void __asan_poison_stack_memory(const void *addr, size_t size)
-{
-	/*
-	 * Addr is KASAN_SHADOW_SCALE_SIZE-aligned and the object is surrounded
-	 * by redzones, so we simply round up size to simplify logic.
-	 */
-	kasan_poison_shadow(addr, round_up(size, KASAN_SHADOW_SCALE_SIZE),
-			    KASAN_USE_AFTER_SCOPE);
-}
-EXPORT_SYMBOL(__asan_poison_stack_memory);
-
-/* Emitted by compiler to unpoison large objects when they go into scope. */
-void __asan_unpoison_stack_memory(const void *addr, size_t size)
-{
-	kasan_unpoison_shadow(addr, size);
-}
-EXPORT_SYMBOL(__asan_unpoison_stack_memory);
-
 /* Emitted by compiler to poison alloca()ed objects. */
 void __asan_alloca_poison(unsigned long addr, size_t size)
 {

mm/kasan/generic_report.c

···
 	case KASAN_KMALLOC_FREE:
 		bug_type = "use-after-free";
 		break;
-	case KASAN_USE_AFTER_SCOPE:
-		bug_type = "use-after-scope";
-		break;
 	case KASAN_ALLOCA_LEFT:
 	case KASAN_ALLOCA_RIGHT:
 		bug_type = "alloca-out-of-bounds";

mm/kasan/init.c

···
 #else
 static inline bool kasan_p4d_table(pgd_t pgd)
 {
-	return 0;
+	return false;
 }
 #endif
 #if CONFIG_PGTABLE_LEVELS > 3
···
 #else
 static inline bool kasan_pud_table(p4d_t p4d)
 {
-	return 0;
+	return false;
 }
 #endif
 #if CONFIG_PGTABLE_LEVELS > 2
···
 #else
 static inline bool kasan_pmd_table(pud_t pud)
 {
-	return 0;
+	return false;
 }
 #endif
 pte_t kasan_early_shadow_pte[PTRS_PER_PTE] __page_aligned_bss;

mm/kasan/kasan.h

···
 #define KASAN_STACK_MID         0xF2
 #define KASAN_STACK_RIGHT       0xF3
 #define KASAN_STACK_PARTIAL     0xF4
-#define KASAN_USE_AFTER_SCOPE   0xF8
 
 /*
  * alloca redzone shadow values
···
 void __asan_loadN(unsigned long addr, size_t size);
 void __asan_storeN(unsigned long addr, size_t size);
 void __asan_handle_no_return(void);
-void __asan_poison_stack_memory(const void *addr, size_t size);
-void __asan_unpoison_stack_memory(const void *addr, size_t size);
 void __asan_alloca_poison(unsigned long addr, size_t size);
 void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom);
 

mm/khugepaged.c

···
 	BUG_ON(!pmd_none(*pmd));
 	page_add_new_anon_rmap(new_page, vma, address, true);
 	mem_cgroup_commit_charge(new_page, memcg, false, true);
+	count_memcg_events(memcg, THP_COLLAPSE_ALLOC, 1);
 	lru_cache_add_active_or_unevictable(new_page, vma);
 	pgtable_trans_huge_deposit(mm, pmd, pgtable);
 	set_pmd_at(mm, address, pmd, _pmd);
···
 		page_ref_add(new_page, HPAGE_PMD_NR - 1);
 		set_page_dirty(new_page);
 		mem_cgroup_commit_charge(new_page, memcg, false, true);
+		count_memcg_events(memcg, THP_COLLAPSE_ALLOC, 1);
 		lru_cache_add_anon(new_page);
 
 		/*

mm/ksm.c

···
 		chain->chain_prune_time = jiffies;
 		chain->rmap_hlist_len = STABLE_NODE_CHAIN;
 #if defined (CONFIG_DEBUG_VM) && defined(CONFIG_NUMA)
-		chain->nid = -1; /* debug */
+		chain->nid = NUMA_NO_NODE; /* debug */
 #endif
 		ksm_stable_node_chains++;
 
···
 	free_stable_node(stable_node);
 }
 
+enum get_ksm_page_flags {
+	GET_KSM_PAGE_NOLOCK,
+	GET_KSM_PAGE_LOCK,
+	GET_KSM_PAGE_TRYLOCK
+};
+
 /*
  * get_ksm_page: checks if the page indicated by the stable node
  * is still its ksm page, despite having held no reference to it.
···
  * a page to put something that might look like our key in page->mapping.
  * is on its way to being freed; but it is an anomaly to bear in mind.
  */
-static struct page *get_ksm_page(struct stable_node *stable_node, bool lock_it)
+static struct page *get_ksm_page(struct stable_node *stable_node,
+				 enum get_ksm_page_flags flags)
 {
 	struct page *page;
 	void *expected_mapping;
···
 	 * case this node is no longer referenced, and should be freed;
 	 * however, it might mean that the page is under page_ref_freeze().
 	 * The __remove_mapping() case is easy, again the node is now stale;
-	 * but if page is swapcache in migrate_page_move_mapping(), it might
-	 * still be our page, in which case it's essential to keep the node.
+	 * the same is in reuse_ksm_page() case; but if page is swapcache
+	 * in migrate_page_move_mapping(), it might still be our page,
+	 * in which case it's essential to keep the node.
 	 */
 	while (!get_page_unless_zero(page)) {
 		/*
···
 		goto stale;
 	}
 
-	if (lock_it) {
+	if (flags == GET_KSM_PAGE_TRYLOCK) {
+		if (!trylock_page(page)) {
+			put_page(page);
+			return ERR_PTR(-EBUSY);
+		}
+	} else if (flags == GET_KSM_PAGE_LOCK)
 		lock_page(page);
+
+	if (flags != GET_KSM_PAGE_NOLOCK) {
 		if (READ_ONCE(page->mapping) != expected_mapping) {
 			unlock_page(page);
 			put_page(page);
···
 		struct page *page;
 
 		stable_node = rmap_item->head;
-		page = get_ksm_page(stable_node, true);
+		page = get_ksm_page(stable_node, GET_KSM_PAGE_LOCK);
 		if (!page)
 			goto out;
 
···
 	struct page *page;
 	int err;
 
-	page = get_ksm_page(stable_node, true);
+	page = get_ksm_page(stable_node, GET_KSM_PAGE_LOCK);
 	if (!page) {
 		/*
 		 * get_ksm_page did remove_node_from_stable_tree itself.
···
 		 * stable_node parameter itself will be freed from
 		 * under us if it returns NULL.
 		 */
-		_tree_page = get_ksm_page(dup, false);
+		_tree_page = get_ksm_page(dup, GET_KSM_PAGE_NOLOCK);
 		if (!_tree_page)
 			continue;
 		nr += 1;
···
 	if (!is_stable_node_chain(stable_node)) {
 		if (is_page_sharing_candidate(stable_node)) {
 			*_stable_node_dup = stable_node;
-			return get_ksm_page(stable_node, false);
+			return get_ksm_page(stable_node, GET_KSM_PAGE_NOLOCK);
 		}
 		/*
 		 * _stable_node_dup set to NULL means the stable_node
···
 			 * wrprotected at all times. Any will work
 			 * fine to continue the walk.
 			 */
-			tree_page = get_ksm_page(stable_node_any, false);
+			tree_page = get_ksm_page(stable_node_any,
+						 GET_KSM_PAGE_NOLOCK);
 		}
 		VM_BUG_ON(!stable_node_dup ^ !!stable_node_any);
 		if (!tree_page) {
···
 			 * It would be more elegant to return stable_node
 			 * than kpage, but that involves more changes.
 			 */
-			tree_page = get_ksm_page(stable_node_dup, true);
+			tree_page = get_ksm_page(stable_node_dup,
+						 GET_KSM_PAGE_TRYLOCK);
+
+			if (PTR_ERR(tree_page) == -EBUSY)
+				return ERR_PTR(-EBUSY);
+
 			if (unlikely(!tree_page))
 				/*
 				 * The tree may have been rebalanced,
···
 			 * wrprotected at all times. Any will work
 			 * fine to continue the walk.
 			 */
-			tree_page = get_ksm_page(stable_node_any, false);
+			tree_page = get_ksm_page(stable_node_any,
+						 GET_KSM_PAGE_NOLOCK);
 		}
 		VM_BUG_ON(!stable_node_dup ^ !!stable_node_any);
 		if (!tree_page) {
···
 	remove_rmap_item_from_tree(rmap_item);
 
 	if (kpage) {
+		if (PTR_ERR(kpage) == -EBUSY)
+			return;
+
 		err = try_to_merge_with_ksm_page(rmap_item, page, kpage);
 		if (!err) {
 			/*
···
 
 			list_for_each_entry_safe(stable_node, next,
 						 &migrate_nodes, list) {
-				page = get_ksm_page(stable_node, false);
+				page = get_ksm_page(stable_node,
+						    GET_KSM_PAGE_NOLOCK);
 				if (page)
 					put_page(page);
 				cond_resched();
···
 		goto again;
 }
 
+bool reuse_ksm_page(struct page *page,
+		    struct vm_area_struct *vma,
+		    unsigned long address)
+{
+#ifdef CONFIG_DEBUG_VM
+	if (WARN_ON(is_zero_pfn(page_to_pfn(page))) ||
+			WARN_ON(!page_mapped(page)) ||
+			WARN_ON(!PageLocked(page))) {
+		dump_page(page, "reuse_ksm_page");
+		return false;
+	}
+#endif
+
+	if (PageSwapCache(page) || !page_stable_node(page))
+		return false;
+	/* Prohibit parallel get_ksm_page() */
+	if (!page_ref_freeze(page, 1))
+		return false;
+
+	page_move_anon_rmap(page, vma);
+	page->index = linear_page_index(vma, address);
+	page_ref_unfreeze(page, 1);
+
+	return true;
+}
 #ifdef CONFIG_MIGRATION
 void ksm_migrate_page(struct page *newpage, struct page *oldpage)
 {

mm/list_lru.c

···
 		    struct lock_class_key *key, struct shrinker *shrinker)
 {
 	int i;
-	size_t size = sizeof(*lru->node) * nr_node_ids;
 	int err = -ENOMEM;
 
 #ifdef CONFIG_MEMCG_KMEM
···
 #endif
 	memcg_get_cache_ids();
 
-	lru->node = kzalloc(size, GFP_KERNEL);
+	lru->node = kcalloc(nr_node_ids, sizeof(*lru->node), GFP_KERNEL);
 	if (!lru->node)
 		goto out;
 

mm/memblock.c

···
 static int __init memblock_init_debugfs(void)
 {
 	struct dentry *root = debugfs_create_dir("memblock", NULL);
-	if (!root)
-		return -ENXIO;
+
 	debugfs_create_file("memory", 0444, root,
 			    &memblock.memory, &memblock_debug_fops);
 	debugfs_create_file("reserved", 0444, root,

mm/memcontrol.c

···
 #include <linux/shmem_fs.h>
 #include <linux/hugetlb.h>
 #include <linux/pagemap.h>
+#include <linux/vm_event_item.h>
 #include <linux/smp.h>
 #include <linux/page-flags.h>
 #include <linux/backing-dev.h>
···
 	for (iter = mem_cgroup_iter(NULL, NULL, NULL);	\
 	     iter != NULL;				\
 	     iter = mem_cgroup_iter(NULL, iter, NULL))
+
+static inline bool should_force_charge(void)
+{
+	return tsk_is_oom_victim(current) || fatal_signal_pending(current) ||
+		(current->flags & PF_EXITING);
+}
 
 /* Some nice accessors for the vmpressure. */
 struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg)
···
 	};
 	bool ret;
 
-	mutex_lock(&oom_lock);
-	ret = out_of_memory(&oc);
+	if (mutex_lock_killable(&oom_lock))
+		return true;
+	/*
+	 * A few threads which were not waiting at mutex_lock_killable() can
+	 * fail to bail out. Therefore, check again after holding oom_lock.
+	 */
+	ret = should_force_charge() || out_of_memory(&oc);
 	mutex_unlock(&oom_lock);
 	return ret;
 }
···
 	 * bypass the last charges so that they can exit quickly and
 	 * free their memory.
 	 */
-	if (unlikely(tsk_is_oom_victim(current) ||
-		     fatal_signal_pending(current) ||
-		     current->flags & PF_EXITING))
+	if (unlikely(should_force_charge()))
 		goto force;
 
 	/*
···
 
 static void lock_page_lru(struct page *page, int *isolated)
 {
-	struct zone *zone = page_zone(page);
+	pg_data_t *pgdat = page_pgdat(page);
 
-	spin_lock_irq(zone_lru_lock(zone));
+	spin_lock_irq(&pgdat->lru_lock);
 	if (PageLRU(page)) {
 		struct lruvec *lruvec;
 
-		lruvec = mem_cgroup_page_lruvec(page, zone->zone_pgdat);
+		lruvec = mem_cgroup_page_lruvec(page, pgdat);
 		ClearPageLRU(page);
 		del_page_from_lru_list(page, lruvec, page_lru(page));
 		*isolated = 1;
···
 
 static void unlock_page_lru(struct page *page, int isolated)
 {
-	struct zone *zone = page_zone(page);
+	pg_data_t *pgdat = page_pgdat(page);
 
 	if (isolated) {
 		struct lruvec *lruvec;
 
-		lruvec = mem_cgroup_page_lruvec(page, zone->zone_pgdat);
+		lruvec = mem_cgroup_page_lruvec(page, pgdat);
 		VM_BUG_ON_PAGE(PageLRU(page), page);
 		SetPageLRU(page);
 		add_page_to_lru_list(page, lruvec, page_lru(page));
 	}
-	spin_unlock_irq(zone_lru_lock(zone));
+	spin_unlock_irq(&pgdat->lru_lock);
 }
 
 static void commit_charge(struct page *page, struct mem_cgroup *memcg,
···
 }
 
 /**
- * memcg_kmem_charge_memcg: charge a kmem page
+ * __memcg_kmem_charge_memcg: charge a kmem page
  * @page: page to charge
  * @gfp: reclaim mode
  * @order: allocation order
···
  *
  * Returns 0 on success, an error code on failure.
  */
-int memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
+int __memcg_kmem_charge_memcg(struct page *page, gfp_t gfp, int order,
 			    struct mem_cgroup *memcg)
 {
 	unsigned int nr_pages = 1 << order;
···
 }
 
 /**
- * memcg_kmem_charge: charge a kmem page to the current memory cgroup
+ * __memcg_kmem_charge: charge a kmem page to the current memory cgroup
  * @page: page to charge
  * @gfp: reclaim mode
  * @order: allocation order
  *
  * Returns 0 on success, an error code on failure.
  */
-int memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
+int __memcg_kmem_charge(struct page *page, gfp_t gfp, int order)
 {
 	struct mem_cgroup *memcg;
 	int ret = 0;
 
-	if (mem_cgroup_disabled() || memcg_kmem_bypass())
+	if (memcg_kmem_bypass())
 		return 0;
 
 	memcg = get_mem_cgroup_from_current();
 	if (!mem_cgroup_is_root(memcg)) {
-		ret = memcg_kmem_charge_memcg(page, gfp, order, memcg);
+		ret = __memcg_kmem_charge_memcg(page, gfp, order, memcg);
 		if (!ret)
 			__SetPageKmemcg(page);
 	}
···
 	return ret;
 }
 /**
- * memcg_kmem_uncharge: uncharge a kmem page
+ * __memcg_kmem_uncharge: uncharge a kmem page
  * @page: page to uncharge
  * @order: allocation order
  */
-void memcg_kmem_uncharge(struct page *page, int order)
+void __memcg_kmem_uncharge(struct page *page, int order)
 {
 	struct mem_cgroup *memcg = page->mem_cgroup;
 	unsigned int nr_pages = 1 << order;
···
 
 /*
  * Because tail pages are not marked as "used", set it. We're under
- * zone_lru_lock and migration entries setup in all page mappings.
+ * pgdat->lru_lock and migration entries setup in all page mappings.
  */
 void mem_cgroup_split_huge_fixup(struct page *head)
 {
···
 	const struct numa_stat *stat;
 	int nid;
 	unsigned long nr;
-	struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+	struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
 
 	for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) {
 		nr = mem_cgroup_nr_lru_pages(memcg, stat->lru_mask);
···
 
 static int memcg_stat_show(struct seq_file *m, void *v)
 {
-	struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+	struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
 	unsigned long memory, memsw;
 	struct mem_cgroup *mi;
 	unsigned int i;
···
 	size = thresholds->primary ? thresholds->primary->size + 1 : 1;
 
 	/* Allocate memory for new array of thresholds */
-	new = kmalloc(sizeof(*new) + size * sizeof(struct mem_cgroup_threshold),
-			GFP_KERNEL);
+	new = kmalloc(struct_size(new, entries, size), GFP_KERNEL);
 	if (!new) {
 		ret = -ENOMEM;
 		goto unlock;
···
 
 static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v)
 {
-	struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(sf));
+	struct mem_cgroup *memcg = mem_cgroup_from_seq(sf);
 
 	seq_printf(sf, "oom_kill_disable %d\n", memcg->oom_kill_disable);
 	seq_printf(sf, "under_oom %d\n", (bool)memcg->under_oom);
···
 static struct mem_cgroup *mem_cgroup_alloc(void)
 {
 	struct mem_cgroup *memcg;
-	size_t size;
+	unsigned int size;
 	int node;
 
 	size = sizeof(struct mem_cgroup);
···
 		root_mem_cgroup->use_hierarchy = false;
 }
 
+static int seq_puts_memcg_tunable(struct seq_file *m, unsigned long value)
+{
+	if (value == PAGE_COUNTER_MAX)
+		seq_puts(m, "max\n");
+	else
+		seq_printf(m, "%llu\n", (u64)value * PAGE_SIZE);
+
+	return 0;
+}
+
 static u64 memory_current_read(struct cgroup_subsys_state *css,
 			       struct cftype *cft)
 {
···
 
 static int memory_min_show(struct seq_file *m, void *v)
 {
-	struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
-	unsigned long min = READ_ONCE(memcg->memory.min);
-
-	if (min == PAGE_COUNTER_MAX)
-		seq_puts(m, "max\n");
-	else
-		seq_printf(m, "%llu\n", (u64)min * PAGE_SIZE);
-
-	return 0;
+	return seq_puts_memcg_tunable(m,
+		READ_ONCE(mem_cgroup_from_seq(m)->memory.min));
 }
 
 static ssize_t memory_min_write(struct kernfs_open_file *of,
···
 
 static int memory_low_show(struct seq_file *m, void *v)
 {
-	struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
-	unsigned long low = READ_ONCE(memcg->memory.low);
-
-	if (low == PAGE_COUNTER_MAX)
-		seq_puts(m, "max\n");
-	else
-		seq_printf(m, "%llu\n", (u64)low * PAGE_SIZE);
-
-	return 0;
+	return seq_puts_memcg_tunable(m,
+		READ_ONCE(mem_cgroup_from_seq(m)->memory.low));
 }
 
 static ssize_t memory_low_write(struct kernfs_open_file *of,
···
 
 static int memory_high_show(struct seq_file *m, void *v)
 {
-	struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
-	unsigned long high = READ_ONCE(memcg->high);
-
-	if (high == PAGE_COUNTER_MAX)
-		seq_puts(m, "max\n");
-	else
-		seq_printf(m, "%llu\n", (u64)high * PAGE_SIZE);
-
-	return 0;
+	return seq_puts_memcg_tunable(m, READ_ONCE(mem_cgroup_from_seq(m)->high));
 }
 
 static ssize_t memory_high_write(struct kernfs_open_file *of,
···
 
 static int memory_max_show(struct seq_file *m, void *v)
 {
-	struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
-	unsigned long max = READ_ONCE(memcg->memory.max);
-
-	if (max == PAGE_COUNTER_MAX)
-		seq_puts(m, "max\n");
-	else
-		seq_printf(m, "%llu\n", (u64)max * PAGE_SIZE);
-
-	return 0;
+	return seq_puts_memcg_tunable(m,
+		READ_ONCE(mem_cgroup_from_seq(m)->memory.max));
 }
 
 static ssize_t memory_max_write(struct kernfs_open_file *of,
···
 
 static int memory_events_show(struct seq_file *m, void *v)
 {
-	struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+	struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
 
 	seq_printf(m, "low %lu\n",
 		   atomic_long_read(&memcg->memory_events[MEMCG_LOW]));
···
 
 static int memory_stat_show(struct seq_file *m, void *v)
 {
-	struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+	struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
 	struct accumulated_stats acc;
 	int i;
 
···
 	seq_printf(m, "file_writeback %llu\n",
 		   (u64)acc.stat[NR_WRITEBACK] * PAGE_SIZE);
 
+	/*
+	 * TODO: We should eventually replace our own MEMCG_RSS_HUGE counter
+	 * with the NR_ANON_THP vm counter, but right now it's a pain in the
+	 * arse because it requires migrating the work out of rmap to a place
+	 * where the page->mem_cgroup is set up and stable.
+	 */
+	seq_printf(m, "anon_thp %llu\n",
+		   (u64)acc.stat[MEMCG_RSS_HUGE] * PAGE_SIZE);
+
 	for (i = 0; i < NR_LRU_LISTS; i++)
 		seq_printf(m, "%s %llu\n", mem_cgroup_lru_names[i],
 			   (u64)acc.lru_pages[i] * PAGE_SIZE);
···
 	seq_printf(m, "pglazyfree %lu\n", acc.events[PGLAZYFREE]);
 	seq_printf(m, "pglazyfreed %lu\n", acc.events[PGLAZYFREED]);
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	seq_printf(m, "thp_fault_alloc %lu\n", acc.events[THP_FAULT_ALLOC]);
+	seq_printf(m, "thp_collapse_alloc %lu\n",
+		   acc.events[THP_COLLAPSE_ALLOC]);
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
 	return 0;
 }
 
 static int memory_oom_group_show(struct seq_file *m, void *v)
 {
-	struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+	struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
 
 	seq_printf(m, "%d\n", memcg->oom_group);
 
···
  *
  *             | memory.current, if memory.current < memory.low
  * low_usage = |
-	       | 0, otherwise.
+ *	       | 0, otherwise.
  *
  *
  * Such definition of the effective memory.low provides the expected
···
 
 static int swap_max_show(struct seq_file *m, void *v)
 {
-	struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
-	unsigned long max = READ_ONCE(memcg->swap.max);
-
-	if (max == PAGE_COUNTER_MAX)
-		seq_puts(m, "max\n");
-	else
-		seq_printf(m, "%llu\n", (u64)max * PAGE_SIZE);
-
-	return 0;
+	return seq_puts_memcg_tunable(m,
+		READ_ONCE(mem_cgroup_from_seq(m)->swap.max));
 }
 
 static ssize_t swap_max_write(struct kernfs_open_file *of,
···
 
 static int swap_events_show(struct seq_file *m, void *v)
 {
-	struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+	struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
 
 	seq_printf(m, "max %lu\n",
 		   atomic_long_read(&memcg->memory_events[MEMCG_SWAP_MAX]));

mm/memfd.c

···
 #define F_ALL_SEALS (F_SEAL_SEAL | \
 		     F_SEAL_SHRINK | \
 		     F_SEAL_GROW | \
-		     F_SEAL_WRITE)
+		     F_SEAL_WRITE | \
+		     F_SEAL_FUTURE_WRITE)
 
 static int memfd_add_seals(struct file *file, unsigned int seals)
 {

mm/memory-failure.c

···
 	struct page *hpage = compound_head(page);
 
 	if (!PageHuge(page) && PageTransHuge(hpage)) {
-		lock_page(hpage);
-		if (!PageAnon(hpage) || unlikely(split_huge_page(hpage))) {
-			unlock_page(hpage);
-			if (!PageAnon(hpage))
+		lock_page(page);
+		if (!PageAnon(page) || unlikely(split_huge_page(page))) {
+			unlock_page(page);
+			if (!PageAnon(page))
 				pr_info("soft offline: %#lx: non anonymous thp\n", page_to_pfn(page));
 			else
 				pr_info("soft offline: %#lx: thp split failed\n", page_to_pfn(page));
-			put_hwpoison_page(hpage);
+			put_hwpoison_page(page);
 			return -EBUSY;
 		}
-		unlock_page(hpage);
-		get_hwpoison_page(page);
-		put_hwpoison_page(hpage);
+		unlock_page(page);
 	}
 
 	/*

mm/memory.c

···
 #include <linux/userfaultfd_k.h>
 #include <linux/dax.h>
 #include <linux/oom.h>
+#include <linux/numa.h>
 
 #include <asm/io.h>
 #include <asm/mmu_context.h>
···
 	spinlock_t *ptl;
 
 	retval = -EINVAL;
-	if (PageAnon(page))
+	if (PageAnon(page) || PageSlab(page) || page_has_type(page))
 		goto out;
 	retval = -ENOMEM;
 	flush_dcache_page(page);
···
  * under mm->mmap_sem write-lock, so it can change vma->vm_flags.
  * Caller must set VM_MIXEDMAP on vma if it wants to call this
  * function from other places, for example from page-fault handler.
+ *
+ * Return: %0 on success, negative error code otherwise.
  */
 int vm_insert_page(struct vm_area_struct *vma, unsigned long addr,
 			struct page *page)
···
  * @size: size of map area
  * @prot: page protection flags for this mapping
  *
- *  Note: this is only safe if the mm semaphore is held when called.
+ * Note: this is only safe if the mm semaphore is held when called.
+ *
+ * Return: %0 on success, negative error code otherwise.
  */
 int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
 		    unsigned long pfn, unsigned long size, pgprot_t prot)
···
  *
  * NOTE! Some drivers might want to tweak vma->vm_page_prot first to get
  * whatever write-combining details or similar.
+ *
+ * Return: %0 on success, negative error code otherwise.
  */
 int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len)
 {
···
  *
  * This function handles all that is needed to finish a write page fault in a
  * shared mapping due to PTE being read-only once the mapped page is prepared.
- * It handles locking of PTE and modifying it. The function returns
- * VM_FAULT_WRITE on success, 0 when PTE got changed before we acquired PTE
- * lock.
+ * It handles locking of PTE and modifying it.
  *
  * The function expects the page to be locked or other protection against
  * concurrent faults / writeback (such as DAX radix tree locks).
+ *
+ * Return: %VM_FAULT_WRITE on success, %0 when PTE got changed before
+ * we acquired PTE lock.
  */
 vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf)
 {
···
 	 * Take out anonymous pages first, anonymous shared vmas are
 	 * not dirty accountable.
 	 */
-	if (PageAnon(vmf->page) && !PageKsm(vmf->page)) {
+	if (PageAnon(vmf->page)) {
 		int total_map_swapcount;
+		if (PageKsm(vmf->page) && (PageSwapCache(vmf->page) ||
+					   page_count(vmf->page) != 1))
+			goto copy;
 		if (!trylock_page(vmf->page)) {
 			get_page(vmf->page);
 			pte_unmap_unlock(vmf->pte, vmf->ptl);
···
 				return 0;
 			}
 			put_page(vmf->page);
+		}
+		if (PageKsm(vmf->page)) {
+			bool reused = reuse_ksm_page(vmf->page, vmf->vma,
+						     vmf->address);
+			unlock_page(vmf->page);
+			if (!reused)
+				goto copy;
+			wp_page_reuse(vmf);
+			return VM_FAULT_WRITE;
 		}
 		if (reuse_swap_page(vmf->page, &total_map_swapcount)) {
 			if (total_map_swapcount == 1) {
···
 					(VM_WRITE|VM_SHARED))) {
 		return wp_page_shared(vmf);
 	}
-
+copy:
 	/*
 	 * Ok, we need to copy. Oh, well..
 	 */
···
  *
  * Target users are page handler itself and implementations of
  * vm_ops->map_pages.
+ *
+ * Return: %0 on success, %VM_FAULT_ code in case of error.
  */
 vm_fault_t alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg,
 		struct page *page)
···
  * This function handles all that is needed to finish a page fault once the
  * page to fault in is prepared. It handles locking of PTEs, inserts PTE for
  * given page, adds reverse page mapping, handles memcg charges and LRU
- * addition. The function returns 0 on success, VM_FAULT_ code in case of
- * error.
+ * addition.
  *
  * The function expects the page to be locked and on success it consumes a
  * reference of a page being mapped (for the PTE which maps it).
+ *
+ * Return: %0 on success, %VM_FAULT_ code in case of error.
  */
 vm_fault_t finish_fault(struct vm_fault *vmf)
 {
···
 
 static int __init fault_around_debugfs(void)
 {
-	void *ret;
-
-	ret = debugfs_create_file_unsafe("fault_around_bytes", 0644, NULL, NULL,
-			&fault_around_bytes_fops);
-	if (!ret)
-		pr_warn("Failed to create fault_around_bytes in debugfs");
+	debugfs_create_file_unsafe("fault_around_bytes", 0644, NULL, NULL,
+				   &fault_around_bytes_fops);
 	return 0;
 }
 late_initcall(fault_around_debugfs);
···
  * but allow concurrent faults).
  * The mmap_sem may have been released depending on flags and our
  * return value.  See filemap_fault() and __lock_page_or_retry().
+ * If mmap_sem is released, vma may become invalid (for example
+ * by other thread calling munmap()).
  */
 static vm_fault_t do_fault(struct vm_fault *vmf)
 {
 	struct vm_area_struct *vma = vmf->vma;
+	struct mm_struct *vm_mm = vma->vm_mm;
 	vm_fault_t ret;
 
 	/*
···
 
 	/* preallocated pagetable is unused: free it */
 	if (vmf->prealloc_pte) {
-		pte_free(vma->vm_mm, vmf->prealloc_pte);
+		pte_free(vm_mm, vmf->prealloc_pte);
 		vmf->prealloc_pte = NULL;
 	}
 	return ret;
···
 {
 	struct vm_area_struct *vma = vmf->vma;
 	struct page *page = NULL;
-	int page_nid = -1;
+	int page_nid = NUMA_NO_NODE;
 	int last_cpupid;
 	int target_nid;
 	bool migrated = false;
-	pte_t pte;
+	pte_t pte, old_pte;
 	bool was_writable = pte_savedwrite(vmf->orig_pte);
 	int flags = 0;
 
···
 	 * Make it present again, Depending on how arch implementes non
 	 * accessible ptes, some can allow access by kernel mode.
 	 */
-	pte = ptep_modify_prot_start(vma->vm_mm, vmf->address, vmf->pte);
-	pte = pte_modify(pte, vma->vm_page_prot);
+	old_pte = ptep_modify_prot_start(vma, vmf->address, vmf->pte);
+	pte = pte_modify(old_pte, vma->vm_page_prot);
 	pte = pte_mkyoung(pte);
 	if (was_writable)
 		pte = pte_mkwrite(pte);
-	ptep_modify_prot_commit(vma->vm_mm, vmf->address, vmf->pte, pte);
+	ptep_modify_prot_commit(vma, vmf->address, vmf->pte, old_pte, pte);
 	update_mmu_cache(vma, vmf->address, vmf->pte);
 
 	page = vm_normal_page(vma, vmf->address, pte);
···
 	target_nid = numa_migrate_prep(page, vma, vmf->address, page_nid,
 			&flags);
 	pte_unmap_unlock(vmf->pte, vmf->ptl);
-	if (target_nid == -1) {
+	if (target_nid == NUMA_NO_NODE) {
 		put_page(page);
 		goto out;
 	}
···
 		flags |= TNF_MIGRATE_FAIL;
 
 out:
-	if (page_nid != -1)
+	if (page_nid != NUMA_NO_NODE)
 		task_numa_fault(last_cpupid, page_nid, 1, flags);
 	return 0;
 }
···
  *
  * Only IO mappings and raw PFN mappings are allowed.
  *
- * Returns zero and the pfn at @pfn on success, -ve otherwise.
+ * Return: zero and the pfn at @pfn on success, -ve otherwise.
  */
 int follow_pfn(struct vm_area_struct *vma, unsigned long address,
 	unsigned long *pfn)
···
  * @gup_flags:	flags modifying lookup behaviour
  *
  * The caller must hold a reference on @mm.
+ *
+ * Return: number of bytes copied from source to destination.
  */
 int access_remote_vm(struct mm_struct *mm, unsigned long addr,
 		void *buf, int len, unsigned int gup_flags)

mm/memory_hotplug.c

···
  * and restore_online_page_callback() for generic callback restore.
  */
 
-static void generic_online_page(struct page *page);
+static void generic_online_page(struct page *page, unsigned int order);
 
 static online_page_callback_t online_page_callback = generic_online_page;
 static DEFINE_MUTEX(online_page_callback_lock);
···
 }
 EXPORT_SYMBOL_GPL(__online_page_free);
 
-static void generic_online_page(struct page *page)
+static void generic_online_page(struct page *page, unsigned int order)
 {
-	__online_page_set_limits(page);
-	__online_page_increment_counters(page);
-	__online_page_free(page);
+	kernel_map_pages(page, 1 << order, 1);
+	__free_pages_core(page, order);
+	totalram_pages_add(1UL << order);
+#ifdef CONFIG_HIGHMEM
+	if (PageHighMem(page))
+		totalhigh_pages_add(1UL << order);
+#endif
+}
+
+static int online_pages_blocks(unsigned long start, unsigned long nr_pages)
+{
+	unsigned long end = start + nr_pages;
+	int order, onlined_pages = 0;
+
+	while (start < end) {
+		order = min(MAX_ORDER - 1,
+			get_order(PFN_PHYS(end) - PFN_PHYS(start)));
+		(*online_page_callback)(pfn_to_page(start), order);
+
+		onlined_pages += (1UL << order);
+		start += (1UL << order);
+	}
+	return onlined_pages;
 }
 
 static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages,
 			void *arg)
 {
-	unsigned long i;
 	unsigned long onlined_pages = *(unsigned long *)arg;
-	struct page *page;
 
 	if (PageReserved(pfn_to_page(start_pfn)))
-		for (i = 0; i < nr_pages; i++) {
-			page = pfn_to_page(start_pfn + i);
-			(*online_page_callback)(page);
-			onlined_pages++;
-		}
+		onlined_pages += online_pages_blocks(start_pfn, nr_pages);
 
 	online_mem_sections(start_pfn, start_pfn + nr_pages);
 
···
 {
 	int nid = zone_to_nid(zone);
 
-	arg->status_change_nid = -1;
-	arg->status_change_nid_normal = -1;
-	arg->status_change_nid_high = -1;
+	arg->status_change_nid = NUMA_NO_NODE;
+	arg->status_change_nid_normal = NUMA_NO_NODE;
+	arg->status_change_nid_high = NUMA_NO_NODE;
 
 	if (!node_state(nid, N_MEMORY))
 		arg->status_change_nid = nid;
···
 
 		if (PageHuge(page)) {
 			struct page *head = compound_head(page);
-			pfn = page_to_pfn(head) + (1<<compound_order(head)) - 1;
 			if (compound_order(head) > PFN_SECTION_SHIFT) {
 				ret = -EBUSY;
 				break;
 			}
-			isolate_huge_page(page, &source);
+			pfn = page_to_pfn(head) + (1<<compound_order(head)) - 1;
+			isolate_huge_page(head, &source);
 			continue;
 		} else if (PageTransHuge(page))
 			pfn = page_to_pfn(compound_head(page))
···
 	unsigned long present_pages = 0;
 	enum zone_type zt;
 
-	arg->status_change_nid = -1;
-	arg->status_change_nid_normal = -1;
-	arg->status_change_nid_high = -1;
+	arg->status_change_nid = NUMA_NO_NODE;
+	arg->status_change_nid_normal = NUMA_NO_NODE;
+	arg->status_change_nid_high = NUMA_NO_NODE;
 
 	/*
 	 * Check whether node_states[N_NORMAL_MEMORY] will be changed.
···
 
 			cond_resched();
 			lru_add_drain_all();
-			drain_all_pages(zone);
 
 			pfn = scan_movable_pages(pfn, end_pfn);
 			if (pfn) {

mm/mempolicy.c

···
 {
 	if (!pol)
 		return;
-	if (!mpol_store_user_nodemask(pol) &&
+	if (!mpol_store_user_nodemask(pol) && !(pol->flags & MPOL_F_LOCAL) &&
 	    nodes_equal(pol->w.cpuset_mems_allowed, *newmask))
 		return;
 
···
 	unsigned long pgoff;
 	int thiscpu = raw_smp_processor_id();
 	int thisnid = cpu_to_node(thiscpu);
-	int polnid = -1;
+	int polnid = NUMA_NO_NODE;
 	int ret = -1;
 
 	pol = get_vma_policy(vma, addr);

mm/mempool.c

···
  *
  * Like mempool_create(), but initializes the pool in (i.e. embedded in another
  * structure).
+ *
+ * Return: %0 on success, negative error code otherwise.
  */
 int mempool_init(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn,
 		 mempool_free_t *free_fn, void *pool_data)
···
  * functions. This function might sleep. Both the alloc_fn() and the free_fn()
  * functions might sleep - as long as the mempool_alloc() function is not called
  * from IRQ contexts.
+ *
+ * Return: pointer to the created memory pool object or %NULL on error.
  */
 mempool_t *mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
 				mempool_free_t *free_fn, void *pool_data)
···
  * Note, the caller must guarantee that no mempool_destroy is called
  * while this function is running. mempool_alloc() & mempool_free()
  * might be called (eg. from IRQ contexts) while this function executes.
+ *
+ * Return: %0 on success, negative error code otherwise.
  */
 int mempool_resize(mempool_t *pool, int new_min_nr)
 {
···
  * *never* fails when called from process contexts. (it might
  * fail if called from an IRQ context.)
  * Note: using __GFP_ZERO is not supported.
+ *
+ * Return: pointer to the allocated element or %NULL on error.
  */
 void *mempool_alloc(mempool_t *pool, gfp_t gfp_mask)
 {

mm/migrate.c

···
 	/*
 	 * Check PageMovable before holding a PG_lock because page's owner
 	 * assumes anybody doesn't touch PG_lock of newly allocated page
-	 * so unconditionally grapping the lock ruins page's owner side.
+	 * so unconditionally grabbing the lock ruins page's owner side.
 	 */
 	if (unlikely(!__PageMovable(page)))
 		goto out_putpage;
···
 }
 #endif
 
-static int expected_page_refs(struct page *page)
+static int expected_page_refs(struct address_space *mapping, struct page *page)
 {
 	int expected_count = 1;
 
···
 	 */
 	expected_count += is_device_private_page(page);
 	expected_count += is_device_public_page(page);
-	if (page_mapping(page))
+	if (mapping)
 		expected_count += hpage_nr_pages(page) + page_has_private(page);
 
 	return expected_count;
···
 	XA_STATE(xas, &mapping->i_pages, page_index(page));
 	struct zone *oldzone, *newzone;
 	int dirty;
-	int expected_count = expected_page_refs(page) + extra_count;
+	int expected_count = expected_page_refs(mapping, page) + extra_count;
 
 	if (!mapping) {
 		/* Anonymous page without mapping */
···
 		return migrate_page(mapping, newpage, page, mode);
 
 	/* Check whether page does not have extra refs before we do more work */
-	expected_count = expected_page_refs(page);
+	expected_count = expected_page_refs(mapping, page);
 	if (page_count(page) != expected_count)
 		return -EAGAIN;
 
···
 	 */
 	if (page_has_private(page) &&
 	    !try_to_release_page(page, GFP_KERNEL))
-		return -EAGAIN;
+		return mode == MIGRATE_SYNC ? -EAGAIN : -EBUSY;
 
 	return migrate_page(mapping, newpage, page, mode);
 }
···
 	struct anon_vma *anon_vma = NULL;
 
 	/*
-	 * Movability of hugepages depends on architectures and hugepage size.
+	 * Migratability of hugepages depends on architectures and their size.
 	 * This check is necessary because some callers of hugepage migration
 	 * like soft offline and memory hotremove don't walk through page
 	 * tables or check whether the hugepage is pmd-based or not before

mm/mlock.c

···
 unsigned int munlock_vma_page(struct page *page)
 {
 	int nr_pages;
-	struct zone *zone = page_zone(page);
+	pg_data_t *pgdat = page_pgdat(page);
 
 	/* For try_to_munlock() and to serialize with page migration */
 	BUG_ON(!PageLocked(page));
···
 	 * might otherwise copy PageMlocked to part of the tail pages before
 	 * we clear it in the head page. It also stabilizes hpage_nr_pages().
 	 */
-	spin_lock_irq(zone_lru_lock(zone));
+	spin_lock_irq(&pgdat->lru_lock);
 
 	if (!TestClearPageMlocked(page)) {
 		/* Potentially, PTE-mapped THP: do not skip the rest PTEs */
···
 	}
 
 	nr_pages = hpage_nr_pages(page);
-	__mod_zone_page_state(zone, NR_MLOCK, -nr_pages);
+	__mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages);
 
 	if (__munlock_isolate_lru_page(page, true)) {
-		spin_unlock_irq(zone_lru_lock(zone));
+		spin_unlock_irq(&pgdat->lru_lock);
 		__munlock_isolated_page(page);
 		goto out;
 	}
 	__munlock_isolation_failed(page);
 
 unlock_out:
-	spin_unlock_irq(zone_lru_lock(zone));
+	spin_unlock_irq(&pgdat->lru_lock);
 
 out:
 	return nr_pages - 1;
···
 	pagevec_init(&pvec_putback);
 
 	/* Phase 1: page isolation */
-	spin_lock_irq(zone_lru_lock(zone));
+	spin_lock_irq(&zone->zone_pgdat->lru_lock);
 	for (i = 0; i < nr; i++) {
 		struct page *page = pvec->pages[i];
 
···
 		pvec->pages[i] = NULL;
 	}
 	__mod_zone_page_state(zone, NR_MLOCK, delta_munlocked);
-	spin_unlock_irq(zone_lru_lock(zone));
+	spin_unlock_irq(&zone->zone_pgdat->lru_lock);
 
 	/* Now we can release pins of pages that we are not munlocking */
 	pagevec_release(&pvec_putback);

mm/mmap.c

···
 {
 	/*
 	 * As it turns out, RB_DECLARE_CALLBACKS() already created a callback
-	 * function that does exacltly what we want.
+	 * function that does exactly what we want.
 	 */
 	vma_gap_callbacks_propagate(&vma->vm_rb, NULL);
 }
···
 	 * VM_SOFTDIRTY should not prevent from VMA merging, if we
 	 * match the flags but dirty bit -- the caller should mark
 	 * merged VMA as dirty. If dirty bit won't be excluded from
-	 * comparison, we increase pressue on the memory system forcing
+	 * comparison, we increase pressure on the memory system forcing
 	 * the kernel to generate new VMAs when old one could be
 	 * extended instead.
 	 */
···
  *    PPPP    NNNN    PPPPPPPPPPPP    PPPPPPPPNNNN    PPPPNNNNNNNN
  *    might become    case 1 below    case 2 below    case 3 below
  *
- * It is important for case 8 that the the vma NNNN overlapping the
+ * It is important for case 8 that the vma NNNN overlapping the
  * region AAAA is never going to extended over XXXX. Instead XXXX must
  * be extended in region AAAA and NNNN must be removed. This way in
  * all cases where vma_merge succeeds, the moment vma_adjust drops the
···
 #endif /* __ARCH_WANT_SYS_OLD_MMAP */
 
 /*
- * Some shared mappigns will want the pages marked read-only
+ * Some shared mappings will want the pages marked read-only
  * to track write events. If so, we'll downgrade vm_page_prot
  * to the private version (using protection_map[] without the
  * VM_SHARED bit).
···
  */
 #ifndef HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 unsigned long
-arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
-			  const unsigned long len, const unsigned long pgoff,
-			  const unsigned long flags)
+arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
+			  unsigned long len, unsigned long pgoff,
+			  unsigned long flags)
 {
 	struct vm_area_struct *vma, *prev;
 	struct mm_struct *mm = current->mm;
-	unsigned long addr = addr0;
 	struct vm_unmapped_area_info info;
 	const unsigned long mmap_end = arch_get_mmap_end(addr);
 

mm/mprotect.c

···
 					continue;
 			}
 
-			ptent = ptep_modify_prot_start(mm, addr, pte);
-			ptent = pte_modify(ptent, newprot);
+			oldpte = ptep_modify_prot_start(vma, addr, pte);
+			ptent = pte_modify(oldpte, newprot);
 			if (preserve_write)
 				ptent = pte_mk_savedwrite(ptent);
 
···
 					 !(vma->vm_flags & VM_SOFTDIRTY))) {
 				ptent = pte_mkwrite(ptent);
 			}
-			ptep_modify_prot_commit(mm, addr, pte, ptent);
+			ptep_modify_prot_commit(vma, addr, pte, oldpte, ptent);
 			pages++;
 		} else if (IS_ENABLED(CONFIG_MIGRATION)) {
 			swp_entry_t entry = pte_to_swp_entry(oldpte);

mm/mremap.c

···
 	if (addr + old_len > new_addr && new_addr + new_len > addr)
 		goto out;
 
+	/*
+	 * move_vma() need us to stay 4 maps below the threshold, otherwise
+	 * it will bail out at the very beginning.
+	 * That is a problem if we have already unmaped the regions here
+	 * (new_addr, and old_addr), because userspace will not know the
+	 * state of the vma's after it gets -ENOMEM.
+	 * So, to avoid such scenario we can pre-compute if the whole
+	 * operation has high chances to success map-wise.
+	 * Worst-scenario case is when both vma's (new_addr and old_addr) get
+	 * split in 3 before unmaping it.
+	 * That means 2 more maps (1 for each) to the ones we already hold.
+	 * Check whether current map count plus 2 still leads us to 4 maps below
+	 * the threshold, otherwise return -ENOMEM here to be more safe.
+	 */
+	if ((mm->map_count + 2) >= sysctl_max_map_count - 3)
+		return -ENOMEM;
+
 	ret = do_munmap(mm, new_addr, new_len, uf_unmap_early);
 	if (ret)
 		goto out;

mm/oom_kill.c

···
 	return ret;
 }
 
-static void __oom_kill_process(struct task_struct *victim)
+static void __oom_kill_process(struct task_struct *victim, const char *message)
 {
 	struct task_struct *p;
 	struct mm_struct *mm;
···
 	 */
 	do_send_sig_info(SIGKILL, SEND_SIG_PRIV, victim, PIDTYPE_TGID);
 	mark_oom_victim(victim);
-	pr_err("Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB\n",
-		task_pid_nr(victim), victim->comm, K(victim->mm->total_vm),
+	pr_err("%s: Killed process %d (%s) total-vm:%lukB, anon-rss:%lukB, file-rss:%lukB, shmem-rss:%lukB\n",
+		message, task_pid_nr(victim), victim->comm,
+		K(victim->mm->total_vm),
 		K(get_mm_counter(victim->mm, MM_ANONPAGES)),
 		K(get_mm_counter(victim->mm, MM_FILEPAGES)),
 		K(get_mm_counter(victim->mm, MM_SHMEMPAGES)));
···
  * Kill provided task unless it's secured by setting
  * oom_score_adj to OOM_SCORE_ADJ_MIN.
  */
-static int oom_kill_memcg_member(struct task_struct *task, void *unused)
+static int oom_kill_memcg_member(struct task_struct *task, void *message)
 {
-	if (task->signal->oom_score_adj != OOM_SCORE_ADJ_MIN) {
+	if (task->signal->oom_score_adj != OOM_SCORE_ADJ_MIN &&
+	    !is_global_init(task)) {
 		get_task_struct(task);
-		__oom_kill_process(task);
+		__oom_kill_process(task, message);
 	}
 	return 0;
 }
 
 static void oom_kill_process(struct oom_control *oc, const char *message)
 {
-	struct task_struct *p = oc->chosen;
-	unsigned int points = oc->chosen_points;
-	struct task_struct *victim = p;
-	struct task_struct *child;
-	struct task_struct *t;
+	struct task_struct *victim = oc->chosen;
 	struct mem_cgroup *oom_group;
-	unsigned int victim_points = 0;
 	static DEFINE_RATELIMIT_STATE(oom_rs, DEFAULT_RATELIMIT_INTERVAL,
 					      DEFAULT_RATELIMIT_BURST);
 
···
 	 * its children or threads, just give it access to memory reserves
 	 * so it can die quickly
 	 */
-	task_lock(p);
-	if (task_will_free_mem(p)) {
-		mark_oom_victim(p);
-		wake_oom_reaper(p);
-		task_unlock(p);
-		put_task_struct(p);
+	task_lock(victim);
+	if (task_will_free_mem(victim)) {
+		mark_oom_victim(victim);
+		wake_oom_reaper(victim);
+		task_unlock(victim);
+		put_task_struct(victim);
 		return;
 	}
-	task_unlock(p);
+	task_unlock(victim);
 
 	if (__ratelimit(&oom_rs))
-		dump_header(oc, p);
-
-	pr_err("%s: Kill process %d (%s) score %u or sacrifice child\n",
-		message, task_pid_nr(p), p->comm, points);
-
-	/*
-	 * If any of p's children has a different mm and is eligible for kill,
-	 * the one with the highest oom_badness() score is sacrificed for its
-	 * parent.  This attempts to lose the minimal amount of work done while
-	 * still freeing memory.
-	 */
-	read_lock(&tasklist_lock);
-
-	/*
-	 * The task 'p' might have already exited before reaching here. The
-	 * put_task_struct() will free task_struct 'p' while the loop still try
-	 * to access the field of 'p', so, get an extra reference.
-	 */
-	get_task_struct(p);
-	for_each_thread(p, t) {
-		list_for_each_entry(child, &t->children, sibling) {
-			unsigned int child_points;
-
-			if (process_shares_mm(child, p->mm))
-				continue;
-			/*
-			 * oom_badness() returns 0 if the thread is unkillable
-			 */
-			child_points = oom_badness(child,
-				oc->memcg, oc->nodemask, oc->totalpages);
-			if (child_points > victim_points) {
-				put_task_struct(victim);
-				victim = child;
-				victim_points = child_points;
-				get_task_struct(victim);
-			}
-		}
-	}
-	put_task_struct(p);
-	read_unlock(&tasklist_lock);
+		dump_header(oc, victim);
 
 	/*
 	 * Do we need to kill the entire memory cgroup?
···
 	 */
 	oom_group = mem_cgroup_get_oom_group(victim, oc->memcg);
 
-	__oom_kill_process(victim);
+	__oom_kill_process(victim, message);
 
 	/*
 	 * If necessary, kill all tasks in the selected memory cgroup.
 	 */
 	if (oom_group) {
 		mem_cgroup_print_oom_group(oom_group);
-		mem_cgroup_scan_tasks(oom_group, oom_kill_memcg_member, NULL);
+		mem_cgroup_scan_tasks(oom_group, oom_kill_memcg_member,
+				      (void*)message);
 		mem_cgroup_put(oom_group);
 	}
 }

mm/page-writeback.c

···
  * node_dirtyable_memory - number of dirtyable pages in a node
  * @pgdat: the node
  *
- * Returns the node's number of pages potentially available for dirty
+ * Return: the node's number of pages potentially available for dirty
  * page cache.  This is the base value for the per-node dirty limits.
  */
 static unsigned long node_dirtyable_memory(struct pglist_data *pgdat)
···
 /**
  * global_dirtyable_memory - number of globally dirtyable pages
  *
- * Returns the global number of pages potentially available for dirty
+ * Return: the global number of pages potentially available for dirty
  * page cache.  This is the base value for the global dirty limits.
  */
 static unsigned long global_dirtyable_memory(void)
···
  * node_dirty_limit - maximum number of dirty pages allowed in a node
  * @pgdat: the node
  *
- * Returns the maximum number of dirty pages allowed in a node, based
+ * Return: the maximum number of dirty pages allowed in a node, based
  * on the node's dirtyable memory.
  */
 static unsigned long node_dirty_limit(struct pglist_data *pgdat)
···
  * node_dirty_ok - tells whether a node is within its dirty limits
  * @pgdat: the node to check
  *
- * Returns %true when the dirty pages in @pgdat are within the node's
+ * Return: %true when the dirty pages in @pgdat are within the node's
  * dirty limit, %false if the limit is exceeded.
  */
 bool node_dirty_ok(struct pglist_data *pgdat)
···
  * __wb_calc_thresh - @wb's share of dirty throttling threshold
  * @dtc: dirty_throttle_context of interest
  *
- * Returns @wb's dirty limit in pages. The term "dirty" in the context of
- * dirty balancing includes all PG_dirty, PG_writeback and NFS unstable pages.
- *
  * Note that balance_dirty_pages() will only seriously take it as a hard limit
  * when sleeping max_pause per page is not enough to keep the dirty pages under
  * control. For example, when the device is completely stalled due to some error
···
  *
  * The wb's share of dirty limit will be adapting to its throughput and
  * bounded by the bdi->min_ratio and/or bdi->max_ratio parameters, if set.
+ *
+ * Return: @wb's dirty limit in pages. The term "dirty" in the context of
+ * dirty balancing includes all PG_dirty, PG_writeback and NFS unstable pages.
  */
 static unsigned long __wb_calc_thresh(struct dirty_throttle_control *dtc)
 {
···
  * @wb: bdi_writeback of interest
  *
  * Determines whether background writeback should keep writing @wb or it's
- * clean enough.  Returns %true if writeback should continue.
+ * clean enough.
+ *
+ * Return: %true if writeback should continue.
  */
 bool wb_over_bg_thresh(struct bdi_writeback *wb)
 {
···
  * lock/page writeback access order inversion - we should only ever lock
  * multiple pages in ascending page->index order, and looping back to the start
  * of the file violates that rule and causes deadlocks.
+ *
+ * Return: %0 on success, negative error code otherwise
  */
 int write_cache_pages(struct address_space *mapping,
 		      struct writeback_control *wbc, writepage_t writepage,
···
  *
  * This is a library function, which implements the writepages()
  * address_space_operation.
+ *
+ * Return: %0 on success, negative error code otherwise
  */
 int generic_writepages(struct address_space *mapping,
 		       struct writeback_control *wbc)
···
  *
  * Note that the mapping's AS_EIO/AS_ENOSPC flags will be cleared when this
  * function returns.
+ *
+ * Return: %0 on success, negative error code otherwise
  */
 int write_one_page(struct page *page)
 {

mm/page_alloc.c

···
 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
 
 #if MAX_NUMNODES > 1
-int nr_node_ids __read_mostly = MAX_NUMNODES;
-int nr_online_nodes __read_mostly = 1;
+unsigned int nr_node_ids __read_mostly = MAX_NUMNODES;
+unsigned int nr_online_nodes __read_mostly = 1;
 EXPORT_SYMBOL(nr_node_ids);
 EXPORT_SYMBOL(nr_online_nodes);
 #endif
···
 	return 0;
 }
 
+#ifdef CONFIG_COMPACTION
+static inline struct capture_control *task_capc(struct zone *zone)
+{
+	struct capture_control *capc = current->capture_control;
+
+	return capc &&
+		!(current->flags & PF_KTHREAD) &&
+		!capc->page &&
+		capc->cc->zone == zone &&
+		capc->cc->direct_compaction ? capc : NULL;
+}
+
+static inline bool
+compaction_capture(struct capture_control *capc, struct page *page,
+		   int order, int migratetype)
+{
+	if (!capc || order != capc->cc->order)
+		return false;
+
+	/* Do not accidentally pollute CMA or isolated regions*/
+	if (is_migrate_cma(migratetype) ||
+	    is_migrate_isolate(migratetype))
+		return false;
+
+	/*
+	 * Do not let lower order allocations polluate a movable pageblock.
+	 * This might let an unmovable request use a reclaimable pageblock
+	 * and vice-versa but no more than normal fallback logic which can
+	 * have trouble finding a high-order free page.
+	 */
+	if (order < pageblock_order && migratetype == MIGRATE_MOVABLE)
+		return false;
+
+	capc->page = page;
+	return true;
+}
+
+#else
+static inline struct capture_control *task_capc(struct zone *zone)
+{
+	return NULL;
+}
+
+static inline bool
+compaction_capture(struct capture_control *capc, struct page *page,
+		   int order, int migratetype)
+{
+	return false;
+}
+#endif /* CONFIG_COMPACTION */
+
 /*
  * Freeing function for a buddy system allocator.
  *
···
 	unsigned long uninitialized_var(buddy_pfn);
 	struct page *buddy;
 	unsigned int max_order;
+	struct capture_control *capc = task_capc(zone);
 
 	max_order = min_t(unsigned int, MAX_ORDER, pageblock_order + 1);
 
···
 
 continue_merging:
 	while (order < max_order - 1) {
+		if (compaction_capture(capc, page, order, migratetype)) {
+			__mod_zone_freepage_state(zone, -(1 << order),
+								migratetype);
+			return;
+		}
 		buddy_pfn = __find_buddy_pfn(pfn, order);
 		buddy = page + (buddy_pfn - pfn);
 
···
 	if (PageMappingFlags(page))
 		page->mapping = NULL;
 	if (memcg_kmem_enabled() && PageKmemcg(page))
-		memcg_kmem_uncharge(page, order);
+		__memcg_kmem_uncharge(page, order);
 	if (check_free)
 		bad += free_pages_check(page);
 	if (bad)
···
 	local_irq_restore(flags);
 }
 
-static void __init __free_pages_boot_core(struct page *page, unsigned int order)
+void __free_pages_core(struct page *page, unsigned int order)
 {
 	unsigned int nr_pages = 1 << order;
 	struct page *p = page;
···
 {
 	if (early_page_uninitialised(pfn))
 		return;
-	return __free_pages_boot_core(page, order);
+	__free_pages_core(page, order);
 }
 
 /*
···
 	if (nr_pages == pageblock_nr_pages &&
 	    (pfn & (pageblock_nr_pages - 1)) == 0) {
 		set_pageblock_migratetype(page, MIGRATE_MOVABLE);
-		__free_pages_boot_core(page, pageblock_order);
+		__free_pages_core(page, pageblock_order);
 		return;
 	}
 
 	for (i = 0; i < nr_pages; i++, page++, pfn++) {
 		if ((pfn & (pageblock_nr_pages - 1)) == 0)
 			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
-		__free_pages_boot_core(page, 0);
+		__free_pages_core(page, 0);
 	}
 }
 
···
 
 	arch_alloc_page(page, order);
 	kernel_map_pages(page, 1 << order, 1);
-	kernel_poison_pages(page, 1 << order, 1);
 	kasan_alloc_pages(page, order);
+	kernel_poison_pages(page, 1 << order, 1);
 	set_page_owner(page, order, gfp_flags);
 }
 
···
 		 * watermark, because we already know our high-order page
 		 * exists.
 		 */
-		watermark = min_wmark_pages(zone) + (1UL << order);
+		watermark = zone->_watermark[WMARK_MIN] + (1UL << order);
 		if (!zone_watermark_ok(zone, 0, watermark, 0, ALLOC_CMA))
 			return 0;
 
···
 
 	dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
 					&fail_page_alloc.attr);
-	if (IS_ERR(dir))
-		return PTR_ERR(dir);
 
-	if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
-				&fail_page_alloc.ignore_gfp_reclaim))
-		goto fail;
-	if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
-				&fail_page_alloc.ignore_gfp_highmem))
-		goto fail;
-	if (!debugfs_create_u32("min-order", mode, dir,
-				&fail_page_alloc.min_order))
-		goto fail;
+	debugfs_create_bool("ignore-gfp-wait", mode, dir,
+			    &fail_page_alloc.ignore_gfp_reclaim);
+	debugfs_create_bool("ignore-gfp-highmem", mode, dir,
+			    &fail_page_alloc.ignore_gfp_highmem);
+	debugfs_create_u32("min-order", mode, dir, &fail_page_alloc.min_order);
 
 	return 0;
-fail:
-	debugfs_remove_recursive(dir);
-
-	return -ENOMEM;
 }
 
 late_initcall(fail_page_alloc_debugfs);
···
 		unsigned int alloc_flags, const struct alloc_context *ac,
 		enum compact_priority prio, enum compact_result *compact_result)
 {
-	struct page *page;
+	struct page *page = NULL;
 	unsigned long pflags;
 	unsigned int noreclaim_flag;
 
···
 	noreclaim_flag = memalloc_noreclaim_save();
 
 	*compact_result = try_to_compact_pages(gfp_mask, order, alloc_flags, ac,
-									prio);
+								prio, &page);
 
 	memalloc_noreclaim_restore(noreclaim_flag);
 	psi_memstall_leave(&pflags);
 
-	if (*compact_result <= COMPACT_INACTIVE)
+	if (*compact_result <= COMPACT_INACTIVE) {
+		WARN_ON_ONCE(page);
 		return NULL;
+	}
 
 	/*
 	 * At least in one zone compaction wasn't deferred or skipped, so let's
···
 	 */
 	count_vm_event(COMPACTSTALL);
 
-	page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
+	/* Prep a captured page if available */
+	if (page)
+		prep_new_page(page, order, gfp_mask, alloc_flags);
+
+	/* Try get a page from the freelist if available */
+	if (!page)
+		page = get_page_from_freelist(gfp_mask, order, alloc_flags, ac);
 
 	if (page) {
 		struct zone *zone = page_zone(page);
···
 
 out:
 	if (memcg_kmem_enabled() && (gfp_mask & __GFP_ACCOUNT) && page &&
-	    unlikely(memcg_kmem_charge(page, gfp_mask, order) != 0)) {
+	    unlikely(__memcg_kmem_charge(page, gfp_mask, order) != 0)) {
 		__free_pages(page, order);
 		page = NULL;
 	}
···
  * This function is also limited by MAX_ORDER.
  *
  * Memory allocated by this function must be released by free_pages_exact().
+ *
+ * Return: pointer to the allocated area or %NULL in case of error.
  */
 void *alloc_pages_exact(size_t size, gfp_t gfp_mask)
 {
···
  *
  * Like alloc_pages_exact(), but try to allocate on node nid first before falling
  * back.
+ *
+ * Return: pointer to the allocated area or %NULL in case of error.
  */
 void * __meminit alloc_pages_exact_nid(int nid, size_t size, gfp_t gfp_mask)
 {
···
  * nr_free_zone_pages - count number of pages beyond high watermark
  * @offset: The zone index of the highest zone
  *
- * nr_free_zone_pages() counts the number of counts pages which are beyond the
+ * nr_free_zone_pages() counts the number of pages which are beyond the
  * high watermark within all zones at or below a given zone index.  For each
  * zone, the number of pages is calculated as:
  *
  *     nr_free_zone_pages = managed_pages - high_pages
+ *
+ * Return: number of pages beyond high watermark.
  */
 static unsigned long nr_free_zone_pages(int offset)
 {
···
  *
  * nr_free_buffer_pages() counts the number of pages which are beyond the high
  * watermark within ZONE_DMA and ZONE_NORMAL.
+ *
+ * Return: number of pages beyond high watermark within ZONE_DMA and
+ * ZONE_NORMAL.
  */
 unsigned long nr_free_buffer_pages(void)
 {
···
  *
  * nr_free_pagecache_pages() counts the number of pages which are beyond the
  * high watermark within all zones.
+ *
+ * Return: number of pages beyond high watermark within all zones.
  */
 unsigned long nr_free_pagecache_pages(void)
 {
···
  * from each node to each node in the system), and should also prefer nodes
  * with no CPUs, since presumably they'll have very little allocation pressure
  * on them otherwise.
- * It returns -1 if no node is found.
+ *
+ * Return: node id of the found node or %NUMA_NO_NODE if no node is found.
  */
 static int find_next_best_node(int node, nodemask_t *used_node_mask)
 {
···
 	else
 		page_group_by_mobility_disabled = 0;
 
-	pr_info("Built %i zonelists, mobility grouping %s.  Total pages: %ld\n",
+	pr_info("Built %u zonelists, mobility grouping %s.  Total pages: %ld\n",
 		nr_online_nodes,
 		page_group_by_mobility_disabled ? "off" : "on",
 		vm_total_pages);
···
 		return state->last_nid;
 
 	nid = memblock_search_pfn_nid(pfn, &start_pfn, &end_pfn);
-	if (nid != -1) {
+	if (nid != NUMA_NO_NODE) {
 		state->last_start = start_pfn;
 		state->last_end = end_pfn;
 		state->last_nid = nid;
···
  * @start_pfn: The start PFN to start searching for holes
  * @end_pfn: The end PFN to stop searching for holes
  *
- * It returns the number of pages frames in memory holes within a range.
+ * Return: the number of pages frames in memory holes within a range.
  */
 unsigned long __init absent_pages_in_range(unsigned long start_pfn,
 							unsigned long end_pfn)
···
 {
 	unsigned long usemapsize = usemap_size(zone_start_pfn, zonesize);
 	zone->pageblock_flags = NULL;
-	if (usemapsize)
+	if (usemapsize) {
 		zone->pageblock_flags =
 			memblock_alloc_node_nopanic(usemapsize,
 							 pgdat->node_id);
+		if (!zone->pageblock_flags)
+			panic("Failed to allocate %ld bytes for zone %s pageblock flags on node %d\n",
+			      usemapsize, zone->name, pgdat->node_id);
+	}
 }
 #else
 static inline void setup_usemap(struct pglist_data *pgdat, struct zone *zone,
···
 		end = ALIGN(end, MAX_ORDER_NR_PAGES);
 		size =  (end - start) * sizeof(struct page);
 		map = memblock_alloc_node_nopanic(size, pgdat->node_id);
+		if (!map)
+			panic("Failed to allocate %ld bytes for node %d memory map\n",
+			      size, pgdat->node_id);
 		pgdat->node_mem_map = map + offset;
 	}
 	pr_debug("%s: node %d, pgdat %08lx, node_mem_map %08lx\n",
···
  * model has fine enough granularity to avoid incorrect mapping for the
  * populated node map.
  *
- * Returns the determined alignment in pfn's.  0 if there is no alignment
+ * Return: the determined alignment in pfn's.  0 if there is no alignment
  * requirement (single node).
  */
 unsigned long __init node_map_pfn_alignment(void)
 {
 	unsigned long accl_mask = 0, last_end = 0;
 	unsigned long start, end, mask;
-	int last_nid = -1;
+	int last_nid = NUMA_NO_NODE;
 	int i, nid;
 
 	for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, &nid) {
···
 /**
  * find_min_pfn_with_active_regions - Find the minimum PFN registered
  *
- * It returns the minimum PFN based on information provided via
+ * Return: the minimum PFN based on information provided via
  * memblock_set_node().
  */
 unsigned long __init find_min_pfn_with_active_regions(void)
···
 
 	return pages;
 }
-EXPORT_SYMBOL(free_reserved_area);
 
 #ifdef	CONFIG_HIGHMEM
 void free_highmem_page(struct page *page)
···
 			 * value here.
 			 *
 			 * The WMARK_HIGH-WMARK_LOW and (WMARK_LOW-WMARK_MIN)
-			 * deltas control asynch page reclaim, and so should
+			 * deltas control async page reclaim, and so should
 			 * not be capped for highmem.
 			 */
 			unsigned long min_pages;
···
 
 		/*
 		 * Hugepages are not in LRU lists, but they're movable.
-		 * We need not scan over tail pages bacause we don't
+		 * We need not scan over tail pages because we don't
 		 * handle each tail page individually in migration.
 		 */
 		if (PageHuge(page)) {
···
  * pageblocks in the range.  Once isolated, the pageblocks should not
  * be modified by others.
  *
- * Returns zero on success or negative error code.  On success all
+ * Return: zero on success or negative error code.  On success all
  * pages which PFN is in [start, end) are allocated for the caller and
  * need to be freed with free_contig_range().
  */
···
 	 */
 
 	lru_add_drain_all();
-	drain_all_pages(cc.zone);
 
 	order = 0;
 	outer_start = start;

mm/page_ext.c

···
 		table_size = get_entry_size() * PAGES_PER_SECTION;
 
 		BUG_ON(PageReserved(page));
+		kmemleak_free(addr);
 		free_pages_exact(addr, table_size);
 	}
 }
···
 	start = SECTION_ALIGN_DOWN(start_pfn);
 	end = SECTION_ALIGN_UP(start_pfn + nr_pages);
 
-	if (nid == -1) {
+	if (nid == NUMA_NO_NODE) {
 		/*
 		 * In this case, "nid" already exists and contains valid memory.
 		 * "start_pfn" passed to us is a pfn which is an arg for

mm/page_idle.c

···
 static struct page *page_idle_get_page(unsigned long pfn)
 {
 	struct page *page;
-	struct zone *zone;
+	pg_data_t *pgdat;
 
 	if (!pfn_valid(pfn))
 		return NULL;
···
 	    !get_page_unless_zero(page))
 		return NULL;
 
-	zone = page_zone(page);
-	spin_lock_irq(zone_lru_lock(zone));
+	pgdat = page_pgdat(page);
+	spin_lock_irq(&pgdat->lru_lock);
 	if (unlikely(!PageLRU(page))) {
 		put_page(page);
 		page = NULL;
 	}
-	spin_unlock_irq(zone_lru_lock(zone));
+	spin_unlock_irq(&pgdat->lru_lock);
 	return page;
 }
 

mm/page_owner.c

···
 
 static int __init pageowner_init(void)
 {
-	struct dentry *dentry;
-
 	if (!static_branch_unlikely(&page_owner_inited)) {
 		pr_info("page_owner is disabled\n");
 		return 0;
 	}
 
-	dentry = debugfs_create_file("page_owner", 0400, NULL,
-				     NULL, &proc_page_owner_operations);
+	debugfs_create_file("page_owner", 0400, NULL, NULL,
+			    &proc_page_owner_operations);
 
-	return PTR_ERR_OR_ZERO(dentry);
+	return 0;
 }
 late_initcall(pageowner_init)

mm/page_poison.c

···
 #include <linux/page_ext.h>
 #include <linux/poison.h>
 #include <linux/ratelimit.h>
+#include <linux/kasan.h>
 
 static bool want_page_poisoning __read_mostly;
 
···
 {
 	void *addr = kmap_atomic(page);
 
+	/* KASAN still think the page is in-use, so skip it. */
+	kasan_disable_current();
 	memset(addr, PAGE_POISON, PAGE_SIZE);
+	kasan_enable_current();
 	kunmap_atomic(addr);
 }
 

mm/readahead.c

···
  * @data: private data for the callback routine.
  *
  * Hides the details of the LRU cache etc from the filesystems.
+ *
+ * Returns: %0 on success, error return by @filler otherwise
  */
 int read_cache_pages(struct address_space *mapping, struct list_head *pages,
 			int (*filler)(void *, struct page *), void *data)

mm/rmap.c

···
  *         mapping->i_mmap_rwsem
  *           anon_vma->rwsem
  *             mm->page_table_lock or pte_lock
- *               zone_lru_lock (in mark_page_accessed, isolate_lru_page)
+ *               pgdat->lru_lock (in mark_page_accessed, isolate_lru_page)
  *               swap_lock (in swap_duplicate, swap_info_get)
  *                 mmlist_lock (in mmput, drain_mmlist and others)
  *                 mapping->private_lock (in __set_page_dirty_buffers)

mm/shmem.c

···
 #include <linux/uio.h>
 #include <linux/khugepaged.h>
 #include <linux/hugetlb.h>
+#include <linux/frontswap.h>
 
 #include <asm/tlbflush.h> /* for arch/microblaze update_mmu_cache() */
 
···
 static bool shmem_should_replace_page(struct page *page, gfp_t gfp);
 static int shmem_replace_page(struct page **pagep, gfp_t gfp,
 				struct shmem_inode_info *info, pgoff_t index);
+static int shmem_swapin_page(struct inode *inode, pgoff_t index,
+			     struct page **pagep, enum sgp_type sgp,
+			     gfp_t gfp, struct vm_area_struct *vma,
+			     vm_fault_t *fault_type);
 static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
 		struct page **pagep, enum sgp_type sgp,
 		gfp_t gfp, struct vm_area_struct *vma,
···
 	clear_inode(inode);
 }
 
-static unsigned long find_swap_entry(struct xarray *xa, void *item)
+extern struct swap_info_struct *swap_info[];
+
+static int shmem_find_swap_entries(struct address_space *mapping,
+				   pgoff_t start, unsigned int nr_entries,
+				   struct page **entries, pgoff_t *indices,
+				   bool frontswap)
 {
-	XA_STATE(xas, xa, 0);
-	unsigned int checked = 0;
-	void *entry;
+	XA_STATE(xas, &mapping->i_pages, start);
+	struct page *page;
+	unsigned int ret = 0;
+
+	if (!nr_entries)
+		return 0;
 
 	rcu_read_lock();
-	xas_for_each(&xas, entry, ULONG_MAX) {
-		if (xas_retry(&xas, entry))
+	xas_for_each(&xas, page, ULONG_MAX) {
+		if (xas_retry(&xas, page))
 			continue;
-		if (entry == item)
+
+		if (!xa_is_value(page))
+			continue;
+
+		if (frontswap) {
+			swp_entry_t entry = radix_to_swp_entry(page);
+
+			if (!frontswap_test(swap_info[swp_type(entry)],
+					    swp_offset(entry)))
+				continue;
+		}
+
+		indices[ret] = xas.xa_index;
+		entries[ret] = page;
+
+		if (need_resched()) {
+			xas_pause(&xas);
+			cond_resched_rcu();
+		}
+		if (++ret == nr_entries)
 			break;
-		checked++;
-		if ((checked % XA_CHECK_SCHED) != 0)
-			continue;
-		xas_pause(&xas);
-		cond_resched_rcu();
 	}
 	rcu_read_unlock();
 
-	return entry ? xas.xa_index : -1;
+	return ret;
+}
+
+/*
+ * Move the swapped pages for an inode to page cache. Returns the count
+ * of pages swapped in, or the error in case of failure.
+ */
+static int shmem_unuse_swap_entries(struct inode *inode, struct pagevec pvec,
+				    pgoff_t *indices)
+{
+	int i = 0;
+	int ret = 0;
+	int error = 0;
+	struct address_space *mapping = inode->i_mapping;
+
+	for (i = 0; i < pvec.nr; i++) {
+		struct page *page = pvec.pages[i];
+
+		if (!xa_is_value(page))
+			continue;
+		error = shmem_swapin_page(inode, indices[i],
+					  &page, SGP_CACHE,
+					  mapping_gfp_mask(mapping),
+					  NULL, NULL);
+		if (error == 0) {
+			unlock_page(page);
+			put_page(page);
+			ret++;
+		}
+		if (error == -ENOMEM)
+			break;
+		error = 0;
+	}
+	return error ? error : ret;
 }
 
 /*
  * If swap found in inode, free it and move page from swapcache to filecache.
  */
-static int shmem_unuse_inode(struct shmem_inode_info *info,
-			     swp_entry_t swap, struct page **pagep)
+static int shmem_unuse_inode(struct inode *inode, unsigned int type,
+			     bool frontswap, unsigned long *fs_pages_to_unuse)
 {
-	struct address_space *mapping = info->vfs_inode.i_mapping;
-	void *radswap;
-	pgoff_t index;
-	gfp_t gfp;
-	int error = 0;
+	struct address_space *mapping = inode->i_mapping;
+	pgoff_t start = 0;
+	struct pagevec pvec;
+	pgoff_t indices[PAGEVEC_SIZE];
+	bool frontswap_partial = (frontswap && *fs_pages_to_unuse > 0);
+	int ret = 0;
 
-	radswap = swp_to_radix_entry(swap);
-	index = find_swap_entry(&mapping->i_pages, radswap);
-	if (index == -1)
-		return -EAGAIN;	/* tell shmem_unuse we found nothing */
+	pagevec_init(&pvec);
+	do {
+		unsigned int nr_entries = PAGEVEC_SIZE;
 
-	/*
-	 * Move _head_ to start search for next from here.
-	 * But be careful: shmem_evict_inode checks list_empty without taking
-	 * mutex, and there's an instant in list_move_tail when info->swaplist
-	 * would appear empty, if it were the only one on shmem_swaplist.
-	 */
-	if (shmem_swaplist.next != &info->swaplist)
-		list_move_tail(&shmem_swaplist, &info->swaplist);
+		if (frontswap_partial && *fs_pages_to_unuse < PAGEVEC_SIZE)
+			nr_entries = *fs_pages_to_unuse;
 
-	gfp = mapping_gfp_mask(mapping);
-	if (shmem_should_replace_page(*pagep, gfp)) {
-		mutex_unlock(&shmem_swaplist_mutex);
-		error = shmem_replace_page(pagep, gfp, info, index);
-		mutex_lock(&shmem_swaplist_mutex);
-		/*
-		 * We needed to drop mutex to make that restrictive page
-		 * allocation, but the inode might have been freed while we
-		 * dropped it: although a racing shmem_evict_inode() cannot
-		 * complete without emptying the page cache, our page lock
-		 * on this swapcache page is not enough to prevent that -
-		 * free_swap_and_cache() of our swap entry will only
-		 * trylock_page(), removing swap from page cache whatever.
-		 *
-		 * We must not proceed to shmem_add_to_page_cache() if the
-		 * inode has been freed, but of course we cannot rely on
-		 * inode or mapping or info to check that.  However, we can
-		 * safely check if our swap entry is still in use (and here
-		 * it can't have got reused for another page): if it's still
-		 * in use, then the inode cannot have been freed yet, and we
-		 * can safely proceed (if it's no longer in use, that tells
-		 * nothing about the inode, but we don't need to unuse swap).
-		 */
-		if (!page_swapcount(*pagep))
-			error = -ENOENT;
-	}
-
-	/*
-	 * We rely on shmem_swaplist_mutex, not only to protect the swaplist,
-	 * but also to hold up shmem_evict_inode(): so inode cannot be freed
-	 * beneath us (pagelock doesn't help until the page is in pagecache).
-	 */
-	if (!error)
-		error = shmem_add_to_page_cache(*pagep, mapping, index,
-						radswap, gfp);
-	if (error != -ENOMEM) {
-		/*
-		 * Truncation and eviction use free_swap_and_cache(), which
-		 * only does trylock page: if we raced, best clean up here.
-		 */
-		delete_from_swap_cache(*pagep);
-		set_page_dirty(*pagep);
-		if (!error) {
-			spin_lock_irq(&info->lock);
-			info->swapped--;
-			spin_unlock_irq(&info->lock);
-			swap_free(swap);
+		pvec.nr = shmem_find_swap_entries(mapping, start, nr_entries,
+						  pvec.pages, indices,
+						  frontswap);
+		if (pvec.nr == 0) {
+			ret = 0;
+			break;
 		}
-	}
-	return error;
+
+		ret = shmem_unuse_swap_entries(inode, pvec, indices);
+		if (ret < 0)
+			break;
+
+		if (frontswap_partial) {
+			*fs_pages_to_unuse -= ret;
+			if (*fs_pages_to_unuse == 0) {
+				ret = FRONTSWAP_PAGES_UNUSED;
+				break;
+			}
+		}
+
+		start = indices[pvec.nr - 1];
+	} while (true);
+
+	return ret;
 }
 
 /*
- * Search through swapped inodes to find and replace swap by page.
+ * Read all the shared memory data that resides in the swap
+ * device 'type' back into memory, so the swap device can be
+ * unused.
  */
-int shmem_unuse(swp_entry_t swap, struct page *page)
+int shmem_unuse(unsigned int type, bool frontswap,
+		unsigned long *fs_pages_to_unuse)
 {
-	struct list_head *this, *next;
-	struct shmem_inode_info *info;
-	struct mem_cgroup *memcg;
+	struct shmem_inode_info *info, *next;
+	struct inode *inode;
+	struct inode *prev_inode = NULL;
 	int error = 0;
 
-	/*
-	 * There's a faint possibility that swap page was replaced before
-	 * caller locked it: caller will come back later with the right page.
-	 */
-	if (unlikely(!PageSwapCache(page) || page_private(page) != swap.val))
-		goto out;
-
-	/*
-	 * Charge page using GFP_KERNEL while we can wait, before taking
-	 * the shmem_swaplist_mutex which might hold up shmem_writepage().
-	 * Charged back to the user (not to caller) when swap account is used.
-	 */
-	error = mem_cgroup_try_charge_delay(page, current->mm, GFP_KERNEL,
-					    &memcg, false);
-	if (error)
-		goto out;
-	/* No memory allocation: swap entry occupies the slot for the page */
-	error = -EAGAIN;
+	if (list_empty(&shmem_swaplist))
+		return 0;
 
 	mutex_lock(&shmem_swaplist_mutex);
-	list_for_each_safe(this, next, &shmem_swaplist) {
-		info = list_entry(this, struct shmem_inode_info, swaplist);
-		if (info->swapped)
-			error = shmem_unuse_inode(info, swap, &page);
-		else
+
+	/*
+	 * The extra refcount on the inode is necessary to safely dereference
+	 * p->next after re-acquiring the lock. New shmem inodes with swap
+	 * get added to the end of the list and we will scan them all.
+	 */
+	list_for_each_entry_safe(info, next, &shmem_swaplist, swaplist) {
+		if (!info->swapped) {
 			list_del_init(&info->swaplist);
+			continue;
+		}
+
+		inode = igrab(&info->vfs_inode);
+		if (!inode)
+			continue;
+
+		mutex_unlock(&shmem_swaplist_mutex);
+		if (prev_inode)
+			iput(prev_inode);
+		prev_inode = inode;
+
+		error = shmem_unuse_inode(inode, type, frontswap,
+					  fs_pages_to_unuse);
 		cond_resched();
-		if (error != -EAGAIN)
+
+		mutex_lock(&shmem_swaplist_mutex);
+		next = list_next_entry(info, swaplist);
+		if (!info->swapped)
+			list_del_init(&info->swaplist);
+		if (error)
 			break;
-		/* found nothing in this: move on to search the next */
 	}
 	mutex_unlock(&shmem_swaplist_mutex);
 
-	if (error) {
-		if (error != -ENOMEM)
-			error = 0;
-		mem_cgroup_cancel_charge(page, memcg, false);
-	} else
-		mem_cgroup_commit_charge(page, memcg, true, false);
-out:
-	unlock_page(page);
-	put_page(page);
+	if (prev_inode)
+		iput(prev_inode);
+
 	return error;
 }
 
···
 	 */
 	mutex_lock(&shmem_swaplist_mutex);
 	if (list_empty(&info->swaplist))
-		list_add_tail(&info->swaplist, &shmem_swaplist);
+		list_add(&info->swaplist, &shmem_swaplist);
 
 	if (add_to_swap_cache(page, swap, GFP_ATOMIC) == 0) {
 		spin_lock_irq(&info->lock);
···
 }
 
 /*
+ * Swap in the page pointed to by *pagep.
+ * Caller has to make sure that *pagep contains a valid swapped page.
+ * Returns 0 and the page in pagep if success. On failure, returns the
+ * the error code and NULL in *pagep.
+ */
+static int shmem_swapin_page(struct inode *inode, pgoff_t index,
+			     struct page **pagep, enum sgp_type sgp,
+			     gfp_t gfp, struct vm_area_struct *vma,
+			     vm_fault_t *fault_type)
+{
+	struct address_space *mapping = inode->i_mapping;
+	struct shmem_inode_info *info = SHMEM_I(inode);
+	struct mm_struct *charge_mm = vma ? vma->vm_mm : current->mm;
+	struct mem_cgroup *memcg;
+	struct page *page;
+	swp_entry_t swap;
+	int error;
+
+	VM_BUG_ON(!*pagep || !xa_is_value(*pagep));
+	swap = radix_to_swp_entry(*pagep);
+	*pagep = NULL;
+
+	/* Look it up and read it in.. */
+	page = lookup_swap_cache(swap, NULL, 0);
+	if (!page) {
+		/* Or update major stats only when swapin succeeds?? */
+		if (fault_type) {
+			*fault_type |= VM_FAULT_MAJOR;
+			count_vm_event(PGMAJFAULT);
+			count_memcg_event_mm(charge_mm, PGMAJFAULT);
+		}
+		/* Here we actually start the io */
+		page = shmem_swapin(swap, gfp, info, index);
+		if (!page) {
+			error = -ENOMEM;
+			goto failed;
+		}
+	}
+
+	/* We have to do this with page locked to prevent races */
+	lock_page(page);
+	if (!PageSwapCache(page) || page_private(page) != swap.val ||
+	    !shmem_confirm_swap(mapping, index, swap)) {
+		error = -EEXIST;
+		goto unlock;
+	}
+	if (!PageUptodate(page)) {
+		error = -EIO;
+		goto failed;
+	}
+	wait_on_page_writeback(page);
+
+	if (shmem_should_replace_page(page, gfp)) {
+		error = shmem_replace_page(&page, gfp, info, index);
+		if (error)
+			goto failed;
+	}
+
+	error = mem_cgroup_try_charge_delay(page, charge_mm, gfp, &memcg,
+					    false);
+	if (!error) {
+		error = shmem_add_to_page_cache(page, mapping, index,
+						swp_to_radix_entry(swap), gfp);
+		/*
+		 * We already confirmed swap under page lock, and make
+		 * no memory allocation here, so usually no possibility
+		 * of error; but free_swap_and_cache() only trylocks a
+		 * page, so it is just possible that the entry has been
+		 * truncated or holepunched since swap was confirmed.
+		 * shmem_undo_range() will have done some of the
+		 * unaccounting, now delete_from_swap_cache() will do
+		 * the rest.
+		 */
+		if (error) {
+			mem_cgroup_cancel_charge(page, memcg, false);
+			delete_from_swap_cache(page);
+		}
+	}
+	if (error)
+		goto failed;
+
+	mem_cgroup_commit_charge(page, memcg, true, false);
+
+	spin_lock_irq(&info->lock);
+	info->swapped--;
+	shmem_recalc_inode(inode);
+	spin_unlock_irq(&info->lock);
+
+	if (sgp == SGP_WRITE)
+		mark_page_accessed(page);
+
+	delete_from_swap_cache(page);
+	set_page_dirty(page);
+	swap_free(swap);
+
+	*pagep = page;
+	return 0;
+failed:
+	if (!shmem_confirm_swap(mapping, index, swap))
+		error = -EEXIST;
+unlock:
+	if (page) {
+		unlock_page(page);
+		put_page(page);
+	}
+
+	return error;
+}
+
+/*
  * shmem_getpage_gfp - find page in cache, or get from swap, or allocate
  *
  * If we allocate a new one we do not mark it dirty. That's up to the
···
 	struct mm_struct *charge_mm;
 	struct mem_cgroup *memcg;
 	struct page *page;
-	swp_entry_t swap;
 	enum sgp_type sgp_huge = sgp;
 	pgoff_t hindex = index;
 	int error;
···
 	if (sgp == SGP_NOHUGE || sgp == SGP_HUGE)
 		sgp = SGP_CACHE;
 repeat:
-	swap.val = 0;
-	page = find_lock_entry(mapping, index);
-	if (xa_is_value(page)) {
-		swap = radix_to_swp_entry(page);
-		page = NULL;
-	}
-
 	if (sgp <= SGP_CACHE &&
 	    ((loff_t)index << PAGE_SHIFT) >= i_size_read(inode)) {
-		error = -EINVAL;
-		goto unlock;
+		return -EINVAL;
+	}
+
+	sbinfo = SHMEM_SB(inode->i_sb);
+	charge_mm = vma ? vma->vm_mm : current->mm;
+
+	page = find_lock_entry(mapping, index);
+	if (xa_is_value(page)) {
+		error = shmem_swapin_page(inode, index, &page,
+					  sgp, gfp, vma, fault_type);
+		if (error == -EEXIST)
+			goto repeat;
+
+		*pagep = page;
+		return error;
 	}
 
 	if (page && sgp == SGP_WRITE)
···
 		put_page(page);
 		page = NULL;
 	}
-	if (page || (sgp == SGP_READ && !swap.val)) {
+	if (page || sgp == SGP_READ) {
 		*pagep = page;
 		return 0;
 	}
···
 	 * Fast cache lookup did not find it:
 	 * bring it back from swap or allocate.
 	 */
-	sbinfo = SHMEM_SB(inode->i_sb);
-	charge_mm = vma ? vma->vm_mm : current->mm;
 
-	if (swap.val) {
-		/* Look it up and read it in.. */
-		page = lookup_swap_cache(swap, NULL, 0);
-		if (!page) {
-			/* Or update major stats only when swapin succeeds?? */
-			if (fault_type) {
-				*fault_type |= VM_FAULT_MAJOR;
-				count_vm_event(PGMAJFAULT);
-				count_memcg_event_mm(charge_mm, PGMAJFAULT);
-			}
-			/* Here we actually start the io */
-			page = shmem_swapin(swap, gfp, info, index);
-			if (!page) {
-				error = -ENOMEM;
-				goto failed;
-			}
-		}
+	if (vma && userfaultfd_missing(vma)) {
+		*fault_type = handle_userfault(vmf, VM_UFFD_MISSING);
+		return 0;
+	}
 
-		/* We have to do this with page locked to prevent races */
-		lock_page(page);
-		if (!PageSwapCache(page) || page_private(page) != swap.val ||
-		    !shmem_confirm_swap(mapping, index, swap)) {
-			error = -EEXIST;	/* try again */
-			goto unlock;
-		}
-		if (!PageUptodate(page)) {
-			error = -EIO;
-			goto failed;
-		}
-		wait_on_page_writeback(page);
-
-		if (shmem_should_replace_page(page, gfp)) {
-			error = shmem_replace_page(&page, gfp, info, index);
-			if (error)
-				goto failed;
-		}
-
-		error = mem_cgroup_try_charge_delay(page, charge_mm, gfp, &memcg,
-				false);
-		if (!error) {
-			error = shmem_add_to_page_cache(page, mapping, index,
-						swp_to_radix_entry(swap), gfp);
-			/*
-			 * We already confirmed swap under page lock, and make
-			 * no memory allocation here, so usually no possibility
-			 * of error; but free_swap_and_cache() only trylocks a
-			 * page, so it is just possible that the entry has been
-			 * truncated or holepunched since swap was confirmed.
-			 * shmem_undo_range() will have done some of the
-			 * unaccounting, now delete_from_swap_cache() will do
-			 * the rest.
-			 * Reset swap.val? No, leave it so "failed" goes back to
-			 * "repeat": reading a hole and writing should succeed.
-			 */
-			if (error) {
-				mem_cgroup_cancel_charge(page, memcg, false);
-				delete_from_swap_cache(page);
-			}
-		}
-		if (error)
-			goto failed;
-
-		mem_cgroup_commit_charge(page, memcg, true, false);
-
-		spin_lock_irq(&info->lock);
-		info->swapped--;
-		shmem_recalc_inode(inode);
-		spin_unlock_irq(&info->lock);
-
-		if (sgp == SGP_WRITE)
-			mark_page_accessed(page);
-
-		delete_from_swap_cache(page);
-		set_page_dirty(page);
-		swap_free(swap);
-
-	} else {
-		if (vma && userfaultfd_missing(vma)) {
-			*fault_type = handle_userfault(vmf, VM_UFFD_MISSING);
-			return 0;
-		}
-
-		/* shmem_symlink() */
-		if (mapping->a_ops != &shmem_aops)
-			goto alloc_nohuge;
-		if (shmem_huge == SHMEM_HUGE_DENY || sgp_huge == SGP_NOHUGE)
-			goto alloc_nohuge;
-		if (shmem_huge == SHMEM_HUGE_FORCE)
+	/* shmem_symlink() */
+	if (mapping->a_ops != &shmem_aops)
+		goto alloc_nohuge;
+	if (shmem_huge == SHMEM_HUGE_DENY || sgp_huge == SGP_NOHUGE)
+		goto alloc_nohuge;
+	if (shmem_huge == SHMEM_HUGE_FORCE)
+		goto alloc_huge;
+	switch (sbinfo->huge) {
+		loff_t i_size;
+		pgoff_t off;
+	case SHMEM_HUGE_NEVER:
+		goto alloc_nohuge;
+	case SHMEM_HUGE_WITHIN_SIZE:
+		off = round_up(index, HPAGE_PMD_NR);
+		i_size = round_up(i_size_read(inode), PAGE_SIZE);
+		if (i_size >= HPAGE_PMD_SIZE &&
+		    i_size >> PAGE_SHIFT >= off)
 			goto alloc_huge;
-		switch (sbinfo->huge) {
-			loff_t i_size;
-			pgoff_t off;
-		case SHMEM_HUGE_NEVER:
-			goto alloc_nohuge;
-		case SHMEM_HUGE_WITHIN_SIZE:
-			off = round_up(index, HPAGE_PMD_NR);
-			i_size = round_up(i_size_read(inode), PAGE_SIZE);
-			if (i_size >= HPAGE_PMD_SIZE &&
-					i_size >> PAGE_SHIFT >= off)
-				goto alloc_huge;
-			/* fallthrough */
-		case SHMEM_HUGE_ADVISE:
-			if (sgp_huge == SGP_HUGE)
-				goto alloc_huge;
-			/* TODO: implement fadvise() hints */
-			goto alloc_nohuge;
-		}
+		/* fallthrough */
+	case SHMEM_HUGE_ADVISE:
+		if (sgp_huge == SGP_HUGE)
+			goto alloc_huge;
+		/* TODO: implement fadvise() hints */
+		goto alloc_nohuge;
+	}
 
 alloc_huge:
-		page = shmem_alloc_and_acct_page(gfp, inode, index, true);
-		if (IS_ERR(page)) {
-alloc_nohuge:		page = shmem_alloc_and_acct_page(gfp, inode,
-					index, false);
-		}
-		if (IS_ERR(page)) {
-			int retry = 5;
-			error = PTR_ERR(page);
-			page = NULL;
-			if (error != -ENOSPC)
-				goto failed;
-			/*
-			 * Try to reclaim some spece by splitting a huge page
-			 * beyond i_size on the filesystem.
-			 */
-			while (retry--) {
-				int ret;
-				ret = shmem_unused_huge_shrink(sbinfo, NULL, 1);
-				if (ret == SHRINK_STOP)
-					break;
-				if (ret)
-					goto alloc_nohuge;
-			}
-			goto failed;
-		}
+	page = shmem_alloc_and_acct_page(gfp, inode, index, true);
+	if (IS_ERR(page)) {
+alloc_nohuge:
+		page = shmem_alloc_and_acct_page(gfp, inode,
+						 index, false);
+	}
+	if (IS_ERR(page)) {
+		int retry = 5;
 
-		if (PageTransHuge(page))
-			hindex = round_down(index, HPAGE_PMD_NR);
-		else
-			hindex = index;
-
-		if (sgp == SGP_WRITE)
-			__SetPageReferenced(page);
-
-		error = mem_cgroup_try_charge_delay(page, charge_mm, gfp, &memcg,
-				PageTransHuge(page));
-		if (error)
-			goto unacct;
-		error = shmem_add_to_page_cache(page, mapping, hindex,
-						NULL, gfp & GFP_RECLAIM_MASK);
-		if (error) {
-			mem_cgroup_cancel_charge(page, memcg,
-					PageTransHuge(page));
-			goto unacct;
-		}
-		mem_cgroup_commit_charge(page, memcg, false,
-				PageTransHuge(page));
-		lru_cache_add_anon(page);
-
-		spin_lock_irq(&info->lock);
-		info->alloced += 1 << compound_order(page);
-		inode->i_blocks += BLOCKS_PER_PAGE << compound_order(page);
-		shmem_recalc_inode(inode);
-		spin_unlock_irq(&info->lock);
-		alloced = true;
-
-		if (PageTransHuge(page) &&
-				DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE) <
-				hindex + HPAGE_PMD_NR - 1) {
-			/*
-			 * Part of the huge page is beyond i_size: subject
-			 * to shrink under memory pressure.
-			 */
-			spin_lock(&sbinfo->shrinklist_lock);
-			/*
-			 * _careful to defend against unlocked access to
-			 * ->shrink_list in shmem_unused_huge_shrink()
-			 */
-			if (list_empty_careful(&info->shrinklist)) {
-				list_add_tail(&info->shrinklist,
-						&sbinfo->shrinklist);
-				sbinfo->shrinklist_len++;
-			}
-			spin_unlock(&sbinfo->shrinklist_lock);
-		}
-
+		error = PTR_ERR(page);
+		page = NULL;
+		if (error != -ENOSPC)
+			goto unlock;
 		/*
-		 * Let SGP_FALLOC use the SGP_WRITE optimization on a new page.
+		 * Try to reclaim some space by splitting a huge page
+		 * beyond i_size on the filesystem.
 		 */
-		if (sgp == SGP_FALLOC)
-			sgp = SGP_WRITE;
+		while (retry--) {
+			int ret;
+
+			ret = shmem_unused_huge_shrink(sbinfo, NULL, 1);
+			if (ret == SHRINK_STOP)
+				break;
+			if (ret)
+				goto alloc_nohuge;
+		}
+		goto unlock;
+	}
+
+	if (PageTransHuge(page))
+		hindex = round_down(index, HPAGE_PMD_NR);
+	else
+		hindex = index;
+
+	if (sgp == SGP_WRITE)
+		__SetPageReferenced(page);
+
+	error = mem_cgroup_try_charge_delay(page, charge_mm, gfp, &memcg,
+					    PageTransHuge(page));
+	if (error)
+		goto unacct;
+	error = shmem_add_to_page_cache(page, mapping, hindex,
+					NULL, gfp & GFP_RECLAIM_MASK);
+	if (error) {
+		mem_cgroup_cancel_charge(page, memcg,
+					 PageTransHuge(page));
+		goto unacct;
+	}
+	mem_cgroup_commit_charge(page, memcg, false,
+				 PageTransHuge(page));
+	lru_cache_add_anon(page);
+
+	spin_lock_irq(&info->lock);
+	info->alloced += 1 << compound_order(page);
+	inode->i_blocks += BLOCKS_PER_PAGE << compound_order(page);
+	shmem_recalc_inode(inode);
+	spin_unlock_irq(&info->lock);
+	alloced = true;
+
+	if (PageTransHuge(page) &&
+	    DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE) <
+			hindex + HPAGE_PMD_NR - 1) {
+		/*
+		 * Part of the huge page is beyond i_size: subject
+		 * to shrink under memory pressure.
+		 */
+		spin_lock(&sbinfo->shrinklist_lock);
+		/*
+		 * _careful to defend against unlocked access to
+		 * ->shrink_list in shmem_unused_huge_shrink()
+		 */
+		if (list_empty_careful(&info->shrinklist)) {
+			list_add_tail(&info->shrinklist,
+				      &sbinfo->shrinklist);
+			sbinfo->shrinklist_len++;
+		}
+		spin_unlock(&sbinfo->shrinklist_lock);
+	}
+
+	/*
+	 * Let SGP_FALLOC use the SGP_WRITE optimization on a new page.
+	 */
+	if (sgp == SGP_FALLOC)
+		sgp = SGP_WRITE;
 clear:
-		/*
-		 * Let SGP_WRITE caller clear ends if write does not fill page;
-		 * but SGP_FALLOC on a page fallocated earlier must initialize
-		 * it now, lest undo on failure cancel our earlier guarantee.
-		 */
-		if (sgp != SGP_WRITE && !PageUptodate(page)) {
-			struct page *head = compound_head(page);
-			int i;
+	/*
+	 * Let SGP_WRITE caller clear ends if write does not fill page;
+	 * but SGP_FALLOC on a page fallocated earlier must initialize
+	 * it now, lest undo on failure cancel our earlier guarantee.
+	 */
+	if (sgp != SGP_WRITE && !PageUptodate(page)) {
+		struct page *head = compound_head(page);
+		int i;
 
-			for (i = 0; i < (1 << compound_order(head)); i++) {
-				clear_highpage(head + i);
-				flush_dcache_page(head + i);
-			}
-			SetPageUptodate(head);
+		for (i = 0; i < (1 << compound_order(head)); i++) {
+			clear_highpage(head + i);
+			flush_dcache_page(head + i);
 		}
+		SetPageUptodate(head);
 	}
 
 	/* Perhaps the file has been truncated since we checked */
···
 		put_page(page);
 		goto alloc_nohuge;
 	}
-failed:
-	if (swap.val && !shmem_confirm_swap(mapping, index, swap))
-		error = -EEXIST;
 unlock:
 	if (page) {
 		unlock_page(page);
···
 
 static int shmem_mmap(struct file *file, struct vm_area_struct *vma)
 {
+	struct shmem_inode_info *info = SHMEM_I(file_inode(file));
+
+	if (info->seals & F_SEAL_FUTURE_WRITE) {
+		/*
+		 * New PROT_WRITE and MAP_SHARED mmaps are not allowed when
+		 * "future write" seal active.
+		 */
+		if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_WRITE))
+			return -EPERM;
+
+		/*
+		 * Since the F_SEAL_FUTURE_WRITE seals allow for a MAP_SHARED
+		 * read-only mapping, take care to not allow mprotect to revert
+		 * protections.
+		 */
+		vma->vm_flags &= ~(VM_MAYWRITE);
+	}
+
 	file_accessed(file);
 	vma->vm_ops = &shmem_vm_ops;
 	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE) &&
···
 	pgoff_t index = pos >> PAGE_SHIFT;
 
 	/* i_mutex is held by caller */
-	if (unlikely(info->seals & (F_SEAL_WRITE | F_SEAL_GROW))) {
-		if (info->seals & F_SEAL_WRITE)
+	if (unlikely(info->seals & (F_SEAL_GROW |
+				   F_SEAL_WRITE | F_SEAL_FUTURE_WRITE))) {
+		if (info->seals & (F_SEAL_WRITE | F_SEAL_FUTURE_WRITE))
 			return -EPERM;
 		if ((info->seals & F_SEAL_GROW) && pos + len > inode->i_size)
 			return -EPERM;
···
 		DECLARE_WAIT_QUEUE_HEAD_ONSTACK(shmem_falloc_waitq);
 
 		/* protected by i_mutex */
-		if (info->seals & F_SEAL_WRITE) {
+		if (info->seals & (F_SEAL_WRITE | F_SEAL_FUTURE_WRITE)) {
 			error = -EPERM;
 			goto out;
 		}
···
 	return 0;
 }
 
-int shmem_unuse(swp_entry_t swap, struct page *page)
+int shmem_unuse(unsigned int type, bool frontswap,
+		unsigned long *fs_pages_to_unuse)
 {
 	return 0;
 }

mm/slab.c

···
 
 static void init_arraycache(struct array_cache *ac, int limit, int batch)
 {
-	/*
-	 * The array_cache structures contain pointers to free object.
-	 * However, when such objects are allocated or transferred to another
-	 * cache the pointers are not cleared and they could be counted as
-	 * valid references during a kmemleak scan. Therefore, kmemleak must
-	 * not scan such objects.
-	 */
-	kmemleak_no_scan(ac);
 	if (ac) {
 		ac->avail = 0;
 		ac->limit = limit;
···
 	struct array_cache *ac = NULL;
 
 	ac = kmalloc_node(memsize, gfp, node);
+	/*
+	 * The array_cache structures contain pointers to free object.
+	 * However, when such objects are allocated or transferred to another
+	 * cache the pointers are not cleared and they could be counted as
+	 * valid references during a kmemleak scan. Therefore, kmemleak must
+	 * not scan such objects.
+	 */
+	kmemleak_no_scan(ac);
 	init_arraycache(ac, entries, batchcount);
 	return ac;
 }
···
 
 	alc = kmalloc_node(memsize, gfp, node);
 	if (alc) {
+		kmemleak_no_scan(alc);
 		init_arraycache(&alc->ac, entries, batch);
 		spin_lock_init(&alc->lock);
 	}
···
 static struct alien_cache **alloc_alien_cache(int node, int limit, gfp_t gfp)
 {
 	struct alien_cache **alc_ptr;
-	size_t memsize = sizeof(void *) * nr_node_ids;
 	int i;
 
 	if (limit > 1)
 		limit = 12;
-	alc_ptr = kzalloc_node(memsize, gfp, node);
+	alc_ptr = kcalloc_node(nr_node_ids, sizeof(void *), gfp, node);
 	if (!alc_ptr)
 		return NULL;
 
···
  * This could be made much more intelligent.  For now, try to avoid using
  * high order pages for slabs.  When the gfp() functions are more friendly
  * towards high-order requests, this should be changed.
+ *
+ * Return: number of left-over bytes in a slab
  */
 static size_t calculate_slab_order(struct kmem_cache *cachep,
 				size_t size, slab_flags_t flags)
···
  * %SLAB_HWCACHE_ALIGN - Align the objects in this cache to a hardware
  * cacheline.  This can be beneficial if you're counting cycles as closely
  * as davem.
+ *
+ * Return: a pointer to the created cache or %NULL in case of error
  */
 int __kmem_cache_create(struct kmem_cache *cachep, slab_flags_t flags)
 {
···
  *
  * Allocate an object from this cache.  The flags are only relevant
  * if the cache has no available objects.
+ *
+ * Return: pointer to the new object or %NULL in case of error
  */
 void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags)
 {
···
  * node, which can improve the performance for cpu bound structures.
  *
  * Fallback to other node is possible if __GFP_THISNODE is not set.
+ *
+ * Return: pointer to the new object or %NULL in case of error
  */
 void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
 {
···
  * @size: how many bytes of memory are required.
  * @flags: the type of memory to allocate (see kmalloc).
  * @caller: function caller for debug tracking of the caller
+ *
+ * Return: pointer to the allocated memory or %NULL in case of error
  */
 static __always_inline void *__do_kmalloc(size_t size, gfp_t flags,
 					  unsigned long caller)
···
  * @buffer: user buffer
  * @count: data length
  * @ppos: unused
+ *
+ * Return: %0 on success, negative error code otherwise.
  */
 ssize_t slabinfo_write(struct file *file, const char __user *buffer,
 		       size_t count, loff_t *ppos)
···
  * The caller must guarantee that objp points to a valid object previously
  * allocated with either kmalloc() or kmem_cache_alloc(). The object
  * must not be freed during the duration of the call.
+ *
+ * Return: size of the actual memory used by @objp in bytes
  */
 size_t ksize(const void *objp)
 {

mm/slab.h

···
 					     gfp_t gfp, int order,
 					     struct kmem_cache *s)
 {
-	if (!memcg_kmem_enabled())
-		return 0;
 	if (is_root_cache(s))
 		return 0;
 	return memcg_kmem_charge_memcg(page, gfp, order, s->memcg_params.memcg);
···
 static __always_inline void memcg_uncharge_slab(struct page *page, int order,
 						struct kmem_cache *s)
 {
-	if (!memcg_kmem_enabled())
-		return;
 	memcg_kmem_uncharge(page, order);
 }
 

mm/slab_common.c

···
  *
  * Releases as many slabs as possible for a cache.
  * To help debugging, a zero exit status indicates all slabs were released.
+ *
+ * Return: %0 if all slabs were released, non-zero otherwise
  */
 int kmem_cache_shrink(struct kmem_cache *cachep)
 {
···
 #if defined(CONFIG_MEMCG)
 void *memcg_slab_start(struct seq_file *m, loff_t *pos)
 {
-	struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+	struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
 
 	mutex_lock(&slab_mutex);
 	return seq_list_start(&memcg->kmem_caches, *pos);
···
 
 void *memcg_slab_next(struct seq_file *m, void *p, loff_t *pos)
 {
-	struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+	struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
 
 	return seq_list_next(p, &memcg->kmem_caches, pos);
 }
···
 {
 	struct kmem_cache *s = list_entry(p, struct kmem_cache,
 					  memcg_params.kmem_caches_node);
-	struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
+	struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
 
 	if (p == memcg->kmem_caches.next)
 		print_slabinfo_header(m);
···
  * This function is like krealloc() except it never frees the originally
  * allocated buffer. Use this if you don't want to free the buffer immediately
  * like, for example, with RCU.
+ *
+ * Return: pointer to the allocated memory or %NULL in case of error
  */
 void *__krealloc(const void *p, size_t new_size, gfp_t flags)
 {
···
  * lesser of the new and old sizes.  If @p is %NULL, krealloc()
  * behaves exactly like kmalloc().  If @new_size is 0 and @p is not a
  * %NULL pointer, the object pointed to is freed.
+ *
+ * Return: pointer to the allocated memory or %NULL in case of error
  */
 void *krealloc(const void *p, size_t new_size, gfp_t flags)
 {

mm/slub.c

···
 }
 
 static inline int alloc_consistency_checks(struct kmem_cache *s,
-					struct page *page,
-					void *object, unsigned long addr)
+					struct page *page, void *object)
 {
 	if (!check_slab(s, page))
 		return 0;
···
 					void *object, unsigned long addr)
 {
 	if (s->flags & SLAB_CONSISTENCY_CHECKS) {
-		if (!alloc_consistency_checks(s, page, object, addr))
+		if (!alloc_consistency_checks(s, page, object))
 			goto bad;
 	}
 
···
 		if (!lock) {
 			lock = 1;
 			/*
-			 * Taking the spinlock removes the possiblity
+			 * Taking the spinlock removes the possibility
 			 * that acquire_slab() will see a slab page that
 			 * is frozen
 			 */
···
 }
 
 /*
- * Put a page that was just frozen (in __slab_free) into a partial page
- * slot if available.
+ * Put a page that was just frozen (in __slab_free|get_partial_node) into a
+ * partial page slot if available.
  *
  * If we did not find a slot then simply move all the partials to the
  * per node partial list.
···
 		stat(s, ALLOC_SLAB);
 		c->page = page;
 		*pc = c;
-	} else
-		freelist = NULL;
+	}
 
 	return freelist;
 }
···
 	cpuhp_setup_state_nocalls(CPUHP_SLUB_DEAD, "slub:dead", NULL,
 				  slub_cpu_dead);
 
-	pr_info("SLUB: HWalign=%d, Order=%u-%u, MinObjects=%u, CPUs=%u, Nodes=%d\n",
+	pr_info("SLUB: HWalign=%d, Order=%u-%u, MinObjects=%u, CPUs=%u, Nodes=%u\n",
 		cache_line_size(),
 		slub_min_order, slub_max_order, slub_min_objects,
 		nr_cpu_ids, nr_node_ids);

mm/sparse.c

···
 }
 #define for_each_present_section_nr(start, section_nr)		\
 	for (section_nr = next_present_section_nr(start-1);	\
-	     ((section_nr >= 0) &&				\
+	     ((section_nr != -1) &&				\
 	      (section_nr <= __highest_present_section_nr));	\
 	     section_nr = next_present_section_nr(section_nr))
 

mm/swap.c

···
 static void __page_cache_release(struct page *page)
 {
 	if (PageLRU(page)) {
-		struct zone *zone = page_zone(page);
+		pg_data_t *pgdat = page_pgdat(page);
 		struct lruvec *lruvec;
 		unsigned long flags;
 
-		spin_lock_irqsave(zone_lru_lock(zone), flags);
-		lruvec = mem_cgroup_page_lruvec(page, zone->zone_pgdat);
+		spin_lock_irqsave(&pgdat->lru_lock, flags);
+		lruvec = mem_cgroup_page_lruvec(page, pgdat);
 		VM_BUG_ON_PAGE(!PageLRU(page), page);
 		__ClearPageLRU(page);
 		del_page_from_lru_list(page, lruvec, page_off_lru(page));
-		spin_unlock_irqrestore(zone_lru_lock(zone), flags);
+		spin_unlock_irqrestore(&pgdat->lru_lock, flags);
 	}
 	__ClearPageWaiters(page);
 	mem_cgroup_uncharge(page);
···
 
 void activate_page(struct page *page)
 {
-	struct zone *zone = page_zone(page);
+	pg_data_t *pgdat = page_pgdat(page);
 
 	page = compound_head(page);
-	spin_lock_irq(zone_lru_lock(zone));
-	__activate_page(page, mem_cgroup_page_lruvec(page, zone->zone_pgdat), NULL);
-	spin_unlock_irq(zone_lru_lock(zone));
+	spin_lock_irq(&pgdat->lru_lock);
+	__activate_page(page, mem_cgroup_page_lruvec(page, pgdat), NULL);
+	spin_unlock_irq(&pgdat->lru_lock);
 }
 #endif
 

mm/swap_state.c

···
  * This has been extended to use the NUMA policies from the mm triggering
  * the readahead.
  *
- * Caller must hold down_read on the vma->vm_mm if vmf->vma is not NULL.
+ * Caller must hold read mmap_sem if vmf->vma is not NULL.
  */
 struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t gfp_mask,
 				struct vm_fault *vmf)
···
 	mask = swapin_nr_pages(offset) - 1;
 	if (!mask)
 		goto skip;
+
+	/* Test swap type to make sure the dereference is safe */
+	if (likely(si->flags & (SWP_BLKDEV | SWP_FS))) {
+		struct inode *inode = si->swap_file->f_mapping->host;
+		if (inode_read_congested(inode))
+			goto skip;
+	}
 
 	do_poll = false;
 	/* Read a page_cluster sized and aligned cluster around offset. */
···
 	pte_unmap(orig_pte);
 }
 
+/**
+ * swap_vma_readahead - swap in pages in hope we need them soon
+ * @entry: swap entry of this memory
+ * @gfp_mask: memory allocation flags
+ * @vmf: fault information
+ *
+ * Returns the struct page for entry and addr, after queueing swapin.
+ *
+ * Primitive swap readahead code. We simply read in a few pages whoes
+ * virtual addresses are around the fault address in the same vma.
+ *
+ * Caller must hold read mmap_sem if vmf->vma is not NULL.
+ *
+ */
 static struct page *swap_vma_readahead(swp_entry_t fentry, gfp_t gfp_mask,
 				       struct vm_fault *vmf)
 {

mm/swapfile.c

···
 
 atomic_t nr_rotate_swap = ATOMIC_INIT(0);
 
+static struct swap_info_struct *swap_type_to_swap_info(int type)
+{
+	if (type >= READ_ONCE(nr_swapfiles))
+		return NULL;
+
+	smp_rmb();	/* Pairs with smp_wmb in alloc_swap_info. */
+	return READ_ONCE(swap_info[type]);
+}
+
 static inline unsigned char swap_count(unsigned char ent)
 {
 	return ent & ~SWAP_HAS_CACHE;	/* may include COUNT_CONTINUED flag */
···
 /* The only caller of this function is now suspend routine */
 swp_entry_t get_swap_page_of_type(int type)
 {
-	struct swap_info_struct *si;
+	struct swap_info_struct *si = swap_type_to_swap_info(type);
 	pgoff_t offset;
 
-	si = swap_info[type];
+	if (!si)
+		goto fail;
+
 	spin_lock(&si->lock);
-	if (si && (si->flags & SWP_WRITEOK)) {
+	if (si->flags & SWP_WRITEOK) {
 		atomic_long_dec(&nr_swap_pages);
 		/* This is called for allocating swap entry, not cache */
 		offset = scan_swap_map(si, 1);
···
 		atomic_long_inc(&nr_swap_pages);
 	}
 	spin_unlock(&si->lock);
+fail:
 	return (swp_entry_t) {0};
 }
 
···
 	if (!entry.val)
 		goto out;
 	type = swp_type(entry);
-	if (type >= nr_swapfiles)
+	p = swap_type_to_swap_info(type);
+	if (!p)
 		goto bad_nofile;
-	p = swap_info[type];
 	if (!(p->flags & SWP_USED))
 		goto bad_device;
 	offset = swp_offset(entry);
···
 sector_t swapdev_block(int type, pgoff_t offset)
 {
 	struct block_device *bdev;
+	struct swap_info_struct *si = swap_type_to_swap_info(type);
 
-	if ((unsigned int)type >= nr_swapfiles)
-		return 0;
-	if (!(swap_info[type]->flags & SWP_WRITEOK))
+	if (!si || !(si->flags & SWP_WRITEOK))
 		return 0;
 	return map_swap_entry(swp_entry(type, offset), &bdev);
 }
···
 }
 
 static int unuse_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
-				unsigned long addr, unsigned long end,
-				swp_entry_t entry, struct page *page)
+			unsigned long addr, unsigned long end,
+			unsigned int type, bool frontswap,
+			unsigned long *fs_pages_to_unuse)
 {
-	pte_t swp_pte = swp_entry_to_pte(entry);
+	struct page *page;
+	swp_entry_t entry;
 	pte_t *pte;
+	struct swap_info_struct *si;
+	unsigned long offset;
 	int ret = 0;
+	volatile unsigned char *swap_map;
 
-	/*
-	 * We don't actually need pte lock while scanning for swp_pte: since
-	 * we hold page lock and mmap_sem, swp_pte cannot be inserted into the
-	 * page table while we're scanning; though it could get zapped, and on
-	 * some architectures (e.g. x86_32 with PAE) we might catch a glimpse
-	 * of unmatched parts which look like swp_pte, so unuse_pte must
-	 * recheck under pte lock.  Scanning without pte lock lets it be
-	 * preemptable whenever CONFIG_PREEMPT but not CONFIG_HIGHPTE.
-	 */
+	si = swap_info[type];
 	pte = pte_offset_map(pmd, addr);
 	do {
-		/*
-		 * swapoff spends a _lot_ of time in this loop!
-		 * Test inline before going to call unuse_pte.
-		 */
-		if (unlikely(pte_same_as_swp(*pte, swp_pte))) {
-			pte_unmap(pte);
-			ret = unuse_pte(vma, pmd, addr, entry, page);
-			if (ret)
-				goto out;
-			pte = pte_offset_map(pmd, addr);
+		struct vm_fault vmf;
+
+		if (!is_swap_pte(*pte))
+			continue;
+
+		entry = pte_to_swp_entry(*pte);
+		if (swp_type(entry) != type)
+			continue;
+
+		offset = swp_offset(entry);
+		if (frontswap && !frontswap_test(si, offset))
+			continue;
+
+		pte_unmap(pte);
+		swap_map = &si->swap_map[offset];
+		vmf.vma = vma;
+		vmf.address = addr;
+		vmf.pmd = pmd;
+		page = swapin_readahead(entry, GFP_HIGHUSER_MOVABLE, &vmf);
+		if (!page) {
+			if (*swap_map == 0 || *swap_map == SWAP_MAP_BAD)
+				goto try_next;
+			return -ENOMEM;
 		}
+
+		lock_page(page);
+		wait_on_page_writeback(page);
+		ret = unuse_pte(vma, pmd, addr, entry, page);
+		if (ret < 0) {
+			unlock_page(page);
+			put_page(page);
+			goto out;
+		}
+
+		try_to_free_swap(page);
+		unlock_page(page);
+		put_page(page);
+
+		if (*fs_pages_to_unuse && !--(*fs_pages_to_unuse)) {
+			ret = FRONTSWAP_PAGES_UNUSED;
+			goto out;
+		}
+try_next:
+		pte = pte_offset_map(pmd, addr);
 	} while (pte++, addr += PAGE_SIZE, addr != end);
 	pte_unmap(pte - 1);
+
+	ret = 0;
 out:
 	return ret;
 }
 
 static inline int unuse_pmd_range(struct vm_area_struct *vma, pud_t *pud,
 				unsigned long addr, unsigned long end,
-				swp_entry_t entry, struct page *page)
+				unsigned int type, bool frontswap,
+				unsigned long *fs_pages_to_unuse)
 {
 	pmd_t *pmd;
 	unsigned long next;
···
 		next = pmd_addr_end(addr, end);
 		if (pmd_none_or_trans_huge_or_clear_bad(pmd))
 			continue;
-		ret = unuse_pte_range(vma, pmd, addr, next, entry, page);
+		ret = unuse_pte_range(vma, pmd, addr, next, type,
+				      frontswap, fs_pages_to_unuse);
 		if (ret)
 			return ret;
 	} while (pmd++, addr = next, addr != end);
···
 
 static inline int unuse_pud_range(struct vm_area_struct *vma, p4d_t *p4d,
 				unsigned long addr, unsigned long end,
-				swp_entry_t entry, struct page *page)
+				unsigned int type, bool frontswap,
+				unsigned long *fs_pages_to_unuse)
 {
 	pud_t *pud;
 	unsigned long next;
···
 		next = pud_addr_end(addr, end);
 		if (pud_none_or_clear_bad(pud))
 			continue;
-		ret = unuse_pmd_range(vma, pud, addr, next, entry, page);
+		ret = unuse_pmd_range(vma, pud, addr, next, type,
+				      frontswap, fs_pages_to_unuse);
 		if (ret)
 			return ret;
 	} while (pud++, addr = next, addr != end);
···
 
 static inline int unuse_p4d_range(struct vm_area_struct *vma, pgd_t *pgd,
 				unsigned long addr, unsigned long end,
-				swp_entry_t entry, struct page *page)
+				unsigned int type, bool frontswap,
+				unsigned long *fs_pages_to_unuse)
 {
 	p4d_t *p4d;
 	unsigned long next;
···
 		next = p4d_addr_end(addr, end);
 		if (p4d_none_or_clear_bad(p4d))
 			continue;
-		ret = unuse_pud_range(vma, p4d, addr, next, entry, page);
+		ret = unuse_pud_range(vma, p4d, addr, next, type,
+				      frontswap, fs_pages_to_unuse);
 		if (ret)
 			return ret;
 	} while (p4d++, addr = next, addr != end);
 	return 0;
 }
 
-static int unuse_vma(struct vm_area_struct *vma,
-				swp_entry_t entry, struct page *page)
+static int unuse_vma(struct vm_area_struct *vma, unsigned int type,
+		     bool frontswap, unsigned long *fs_pages_to_unuse)
 {
 	pgd_t *pgd;
 	unsigned long addr, end, next;
 	int ret;
 
-	if (page_anon_vma(page)) {
-		addr = page_address_in_vma(page, vma);
-		if (addr == -EFAULT)
-			return 0;
-		else
-			end = addr + PAGE_SIZE;
-	} else {
-		addr = vma->vm_start;
-		end = vma->vm_end;
-	}
+	addr = vma->vm_start;
+	end = vma->vm_end;
 
 	pgd = pgd_offset(vma->vm_mm, addr);
 	do {
 		next = pgd_addr_end(addr, end);
 		if (pgd_none_or_clear_bad(pgd))
 			continue;
-		ret = unuse_p4d_range(vma, pgd, addr, next, entry, page);
+		ret = unuse_p4d_range(vma, pgd, addr, next, type,
+				      frontswap, fs_pages_to_unuse);
 		if (ret)
 			return ret;
 	} while (pgd++, addr = next, addr != end);
 	return 0;
 }
 
-static int unuse_mm(struct mm_struct *mm,
-				swp_entry_t entry, struct page *page)
+static int unuse_mm(struct mm_struct *mm, unsigned int type,
+		    bool frontswap, unsigned long *fs_pages_to_unuse)
 {
 	struct vm_area_struct *vma;
 	int ret = 0;
 
-	if (!down_read_trylock(&mm->mmap_sem)) {
-		/*
-		 * Activate page so shrink_inactive_list is unlikely to unmap
-		 * its ptes while lock is dropped, so swapoff can make progress.
-		 */
-		activate_page(page);
-		unlock_page(page);
-		down_read(&mm->mmap_sem);
-		lock_page(page);
-	}
+	down_read(&mm->mmap_sem);
 	for (vma = mm->mmap; vma; vma = vma->vm_next) {
-		if (vma->anon_vma && (ret = unuse_vma(vma, entry, page)))
-			break;
+		if (vma->anon_vma) {
+			ret = unuse_vma(vma, type, frontswap,
+					fs_pages_to_unuse);
+			if (ret)
+				break;
+		}
 		cond_resched();
 	}
 	up_read(&mm->mmap_sem);
-	return (ret < 0)? ret: 0;
+	return ret;
 }
 
 /*
  * Scan swap_map (or frontswap_map if frontswap parameter is true)
- * from current position to next entry still in use.
- * Recycle to start on reaching the end, returning 0 when empty.
+ * from current position to next entry still in use. Return 0
+ * if there are no inuse entries after prev till end of the map.
  */
 static unsigned int find_next_to_unuse(struct swap_info_struct *si,
 					unsigned int prev, bool frontswap)
 {
-	unsigned int max = si->max;
-	unsigned int i = prev;
+	unsigned int i;
 	unsigned char count;
 
 	/*
···
 	 * hits are okay, and sys_swapoff() has already prevented new
 	 * allocations from this area (while holding swap_lock).
 	 */
-	for (;;) {
-		if (++i >= max) {
-			if (!prev) {
-				i = 0;
-				break;
-			}
-			/*
-			 * No entries in use at top of swap_map,
-			 * loop back to start and recheck there.
-			 */
-			max = prev + 1;
-			prev = 0;
-			i = 1;
-		}
+	for (i = prev + 1; i < si->max; i++) {
 		count = READ_ONCE(si->swap_map[i]);
 		if (count && swap_count(count) != SWAP_MAP_BAD)
 			if (!frontswap || frontswap_test(si, i))
···
 		if ((i % LATENCY_LIMIT) == 0)
 			cond_resched();
 	}
+
+	if (i == si->max)
+		i = 0;
+
 	return i;
 }
 
 /*
- * We completely avoid races by reading each swap page in advance,
- * and then search for the process using it.  All the necessary
- * page table adjustments can then be made atomically.
- *
- * if the boolean frontswap is true, only unuse pages_to_unuse pages;
+ * If the boolean frontswap is true, only unuse pages_to_unuse pages;
  * pages_to_unuse==0 means all pages; ignored if frontswap is false
  */
+#define SWAP_UNUSE_MAX_TRIES 3
 int try_to_unuse(unsigned int type, bool frontswap,
 		 unsigned long pages_to_unuse)
 {
+	struct mm_struct *prev_mm;
+	struct mm_struct *mm;
+	struct list_head *p;
+	int retval = 0;
 	struct swap_info_struct *si = swap_info[type];
-	struct mm_struct *start_mm;
-	volatile unsigned char *swap_map; /* swap_map is accessed without
-					   * locking. Mark it as volatile
-					   * to prevent compiler doing
-					   * something odd.
-					   */
-	unsigned char swcount;
 	struct page *page;
 	swp_entry_t entry;
-	unsigned int i = 0;
-	int retval = 0;
+	unsigned int i;
+	int retries = 0;
 
-	/*
-	 * When searching mms for an entry, a good strategy is to
-	 * start at the first mm we freed the previous entry from
-	 * (though actually we don't notice whether we or coincidence
-	 * freed the entry).  Initialize this start_mm with a hold.
-	 *
-	 * A simpler strategy would be to start at the last mm we
-	 * freed the previous entry from; but that would take less
-	 * advantage of mmlist ordering, which clusters forked mms
-	 * together, child after parent.  If we race with dup_mmap(), we
-	 * prefer to resolve parent before child, lest we miss entries
-	 * duplicated after we scanned child: using last mm would invert
-	 * that.
-	 */
-	start_mm = &init_mm;
-	mmget(&init_mm);
+	if (!si->inuse_pages)
+		return 0;
 
-	/*
-	 * Keep on scanning until all entries have gone.  Usually,
-	 * one pass through swap_map is enough, but not necessarily:
-	 * there are races when an instance of an entry might be missed.
-	 */
-	while ((i = find_next_to_unuse(si, i, frontswap)) != 0) {
+	if (!frontswap)
+		pages_to_unuse = 0;
+
+retry:
+	retval = shmem_unuse(type, frontswap, &pages_to_unuse);
+	if (retval)
+		goto out;
+
+	prev_mm = &init_mm;
+	mmget(prev_mm);
+
+	spin_lock(&mmlist_lock);
+	p = &init_mm.mmlist;
+	while ((p = p->next) != &init_mm.mmlist) {
 		if (signal_pending(current)) {
 			retval = -EINTR;
 			break;
 		}
 
-		/*
-		 * Get a page for the entry, using the existing swap
-		 * cache page if there is one.  Otherwise, get a clean
-		 * page and read the swap into it.
-		 */
-		swap_map = &si->swap_map[i];
-		entry = swp_entry(type, i);
-		page = read_swap_cache_async(entry,
-					GFP_HIGHUSER_MOVABLE, NULL, 0, false);
-		if (!page) {
-			/*
-			 * Either swap_duplicate() failed because entry
-			 * has been freed independently, and will not be
-			 * reused since sys_swapoff() already disabled
-			 * allocation from here, or alloc_page() failed.
-			 */
-			swcount = *swap_map;
-			/*
-			 * We don't hold lock here, so the swap entry could be
-			 * SWAP_MAP_BAD (when the cluster is discarding).
-			 * Instead of fail out, We can just skip the swap
-			 * entry because swapoff will wait for discarding
-			 * finish anyway.
-			 */
-			if (!swcount || swcount == SWAP_MAP_BAD)
-				continue;
-			retval = -ENOMEM;
-			break;
-		}
-
-		/*
-		 * Don't hold on to start_mm if it looks like exiting.
-		 */
-		if (atomic_read(&start_mm->mm_users) == 1) {
-			mmput(start_mm);
-			start_mm = &init_mm;
-			mmget(&init_mm);
-		}
-
-		/*
-		 * Wait for and lock page.  When do_swap_page races with
-		 * try_to_unuse, do_swap_page can handle the fault much
-		 * faster than try_to_unuse can locate the entry.  This
-		 * apparently redundant "wait_on_page_locked" lets try_to_unuse
-		 * defer to do_swap_page in such a case - in some tests,
-		 * do_swap_page and try_to_unuse repeatedly compete.
-		 */
-		wait_on_page_locked(page);
-		wait_on_page_writeback(page);
-		lock_page(page);
-		wait_on_page_writeback(page);
-
-		/*
-		 * Remove all references to entry.
-		 */
-		swcount = *swap_map;
-		if (swap_count(swcount) == SWAP_MAP_SHMEM) {
-			retval = shmem_unuse(entry, page);
-			/* page has already been unlocked and released */
-			if (retval < 0)
-				break;
+		mm = list_entry(p, struct mm_struct, mmlist);
+		if (!mmget_not_zero(mm))
 			continue;
-		}
-		if (swap_count(swcount) && start_mm != &init_mm)
-			retval = unuse_mm(start_mm, entry, page);
+		spin_unlock(&mmlist_lock);
+		mmput(prev_mm);
+		prev_mm = mm;
+		retval = unuse_mm(mm, type, frontswap, &pages_to_unuse);
 
-		if (swap_count(*swap_map)) {
-			int set_start_mm = (*swap_map >= swcount);
-			struct list_head *p = &start_mm->mmlist;
-			struct mm_struct *new_start_mm = start_mm;
-			struct mm_struct *prev_mm = start_mm;
-			struct mm_struct *mm;
-
-			mmget(new_start_mm);
-			mmget(prev_mm);
-			spin_lock(&mmlist_lock);
-			while (swap_count(*swap_map) && !retval &&
-					(p = p->next) != &start_mm->mmlist) {
-				mm = list_entry(p, struct mm_struct, mmlist);
-				if (!mmget_not_zero(mm))
-					continue;
-				spin_unlock(&mmlist_lock);
-				mmput(prev_mm);
-				prev_mm = mm;
-
-				cond_resched();
-
-				swcount = *swap_map;
-				if (!swap_count(swcount)) /* any usage ? */
-					;
-				else if (mm == &init_mm)
-					set_start_mm = 1;
-				else
-					retval = unuse_mm(mm, entry, page);
-
-				if (set_start_mm && *swap_map < swcount) {
-					mmput(new_start_mm);
-					mmget(mm);
-					new_start_mm = mm;
-					set_start_mm = 0;
-				}
-				spin_lock(&mmlist_lock);
-			}
-			spin_unlock(&mmlist_lock);
-			mmput(prev_mm);
-			mmput(start_mm);
-			start_mm = new_start_mm;
-		}
 		if (retval) {
-			unlock_page(page);
-			put_page(page);
-			break;
+			mmput(prev_mm);
+			goto out;
 		}
-
-		/*
-		 * If a reference remains (rare), we would like to leave
-		 * the page in the swap cache; but try_to_unmap could
-		 * then re-duplicate the entry once we drop page lock,
-		 * so we might loop indefinitely; also, that page could
-		 * not be swapped out to other storage meanwhile.  So:
-		 * delete from cache even if there's another reference,
-		 * after ensuring that the data has been saved to disk -
-		 * since if the reference remains (rarer), it will be
-		 * read from disk into another page.  Splitting into two
-		 * pages would be incorrect if swap supported "shared
-		 * private" pages, but they are handled by tmpfs files.
-		 *
-		 * Given how unuse_vma() targets one particular offset
-		 * in an anon_vma, once the anon_vma has been determined,
-		 * this splitting happens to be just what is needed to
-		 * handle where KSM pages have been swapped out: re-reading
-		 * is unnecessarily slow, but we can fix that later on.
-		 */
-		if (swap_count(*swap_map) &&
-		     PageDirty(page) && PageSwapCache(page)) {
-			struct writeback_control wbc = {
-				.sync_mode = WB_SYNC_NONE,
-			};
-
-			swap_writepage(compound_head(page), &wbc);
-			lock_page(page);
-			wait_on_page_writeback(page);
-		}
-
-		/*
-		 * It is conceivable that a racing task removed this page from
-		 * swap cache just before we acquired the page lock at the top,
-		 * or while we dropped it in unuse_mm().  The page might even
-		 * be back in swap cache on another swap area: that we must not
-		 * delete, since it may not have been written out to swap yet.
-		 */
-		if (PageSwapCache(page) &&
-		    likely(page_private(page) == entry.val) &&
-		    (!PageTransCompound(page) ||
-		     !swap_page_trans_huge_swapped(si, entry)))
-			delete_from_swap_cache(compound_head(page));
-
-		/*
-		 * So we could skip searching mms once swap count went
-		 * to 1, we did not mark any present ptes as dirty: must
-		 * mark page dirty so shrink_page_list will preserve it.
-		 */
-		SetPageDirty(page);
-		unlock_page(page);
-		put_page(page);
 
 		/*
 		 * Make sure that we aren't completely killing
 		 * interactive performance.
 		 */
 		cond_resched();
-		if (frontswap && pages_to_unuse > 0) {
-			if (!--pages_to_unuse)
-				break;
-		}
+		spin_lock(&mmlist_lock);
+	}
+	spin_unlock(&mmlist_lock);
+
+	mmput(prev_mm);
+
+	i = 0;
+	while ((i = find_next_to_unuse(si, i, frontswap)) != 0) {
+
+		entry = swp_entry(type, i);
+		page = find_get_page(swap_address_space(entry), i);
+		if (!page)
+			continue;
+
+		/*
+		 * It is conceivable that a racing task removed this page from
+		 * swap cache just before we acquired the page lock. The page
+		 * might even be back in swap cache on another swap area. But
+		 * that is okay, try_to_free_swap() only removes stale pages.
+		 */
+		lock_page(page);
+		wait_on_page_writeback(page);
+		try_to_free_swap(page);
+		unlock_page(page);
+		put_page(page);
+
+		/*
+		 * For frontswap, we just need to unuse pages_to_unuse, if
+		 * it was specified. Need not check frontswap again here as
+		 * we already zeroed out pages_to_unuse if not frontswap.
+		 */
+		if (pages_to_unuse && --pages_to_unuse == 0)
+			goto out;
 	}
 
-	mmput(start_mm);
-	return retval;
+	/*
+	 * Lets check again to see if there are still swap entries in the map.
+	 * If yes, we would need to do retry the unuse logic again.
+	 * Under global memory pressure, swap entries can be reinserted back
+	 * into process space after the mmlist loop above passes over them.
+	 * Its not worth continuosuly retrying to unuse the swap in this case.
+	 * So we try SWAP_UNUSE_MAX_TRIES times.
+	 */
+	if (++retries >= SWAP_UNUSE_MAX_TRIES)
+		retval = -EBUSY;
+	else if (si->inuse_pages)
+		goto retry;
+
+out:
+	return (retval == FRONTSWAP_PAGES_UNUSED) ? 0 : retval;
 }
 
 /*
···
 	struct swap_extent *se;
 	pgoff_t offset;
 
-	sis = swap_info[swp_type(entry)];
+	sis = swp_swap_info(entry);
 	*bdev = sis->bdev;
 
 	offset = swp_offset(entry);
···
 	if (!l)
 		return SEQ_START_TOKEN;
 
-	for (type = 0; type < nr_swapfiles; type++) {
-		smp_rmb();	/* read nr_swapfiles before swap_info[type] */
-		si = swap_info[type];
+	for (type = 0; (si = swap_type_to_swap_info(type)); type++) {
 		if (!(si->flags & SWP_USED) || !si->swap_map)
 			continue;
 		if (!--l)
···
 	else
 		type = si->type + 1;
 
-	for (; type < nr_swapfiles; type++) {
-		smp_rmb();	/* read nr_swapfiles before swap_info[type] */
-		si = swap_info[type];
+	for (; (si = swap_type_to_swap_info(type)); type++) {
 		if (!(si->flags & SWP_USED) || !si->swap_map)
 			continue;
 		++*pos;
···
 	struct swap_info_struct *p;
 	unsigned int type;
 	int i;
-	int size = sizeof(*p) + nr_node_ids * sizeof(struct plist_node);
 
-	p = kvzalloc(size, GFP_KERNEL);
+	p = kvzalloc(struct_size(p, avail_lists, nr_node_ids), GFP_KERNEL);
 	if (!p)
 		return ERR_PTR(-ENOMEM);
 
···
 	}
 	if (type >= nr_swapfiles) {
 		p->type = type;
-		swap_info[type] = p;
+		WRITE_ONCE(swap_info[type], p);
 		/*
 		 * Write swap_info[type] before nr_swapfiles, in case a
 		 * racing procfs swap_start() or swap_next() is reading them.
 		 * (We never shrink nr_swapfiles, we never free this entry.)
 		 */
 		smp_wmb();
-		nr_swapfiles++;
+		WRITE_ONCE(nr_swapfiles, nr_swapfiles + 1);
 	} else {
 		kvfree(p);
 		p = swap_info[type];
···
 {
 	struct swap_info_struct *p;
 	struct swap_cluster_info *ci;
-	unsigned long offset, type;
+	unsigned long offset;
 	unsigned char count;
 	unsigned char has_cache;
 	int err = -EINVAL;
···
 	if (non_swap_entry(entry))
 		goto out;
 
-	type = swp_type(entry);
-	if (type >= nr_swapfiles)
+	p = swp_swap_info(entry);
+	if (!p)
 		goto bad_file;
-	p = swap_info[type];
+
 	offset = swp_offset(entry);
 	if (unlikely(offset >= p->max))
 		goto out;
···
 
 struct swap_info_struct *swp_swap_info(swp_entry_t entry)
 {
-	return swap_info[swp_type(entry)];
+	return swap_type_to_swap_info(swp_type(entry));
 }
 
 struct swap_info_struct *page_swap_info(struct page *page)

mm/truncate.c

···
  * invalidate_mapping_pages() will not block on IO activity. It will not
  * invalidate pages which are dirty, locked, under writeback or mapped into
  * pagetables.
+ *
+ * Return: the number of the pages that were invalidated
  */
 unsigned long invalidate_mapping_pages(struct address_space *mapping,
 		pgoff_t start, pgoff_t end)
···
  * Any pages which are found to be mapped into pagetables are unmapped prior to
  * invalidation.
  *
- * Returns -EBUSY if any pages could not be invalidated.
+ * Return: -EBUSY if any pages could not be invalidated.
  */
 int invalidate_inode_pages2_range(struct address_space *mapping,
 				  pgoff_t start, pgoff_t end)
···
  * Any pages which are found to be mapped into pagetables are unmapped prior to
  * invalidation.
  *
- * Returns -EBUSY if any pages could not be invalidated.
+ * Return: -EBUSY if any pages could not be invalidated.
  */
 int invalidate_inode_pages2(struct address_space *mapping)
 {

mm/util.c

···
  * kstrdup - allocate space for and copy an existing string
  * @s: the string to duplicate
  * @gfp: the GFP mask used in the kmalloc() call when allocating memory
+ *
+ * Return: newly allocated copy of @s or %NULL in case of error
  */
 char *kstrdup(const char *s, gfp_t gfp)
 {
···
  * @s: the string to duplicate
  * @gfp: the GFP mask used in the kmalloc() call when allocating memory
  *
- * Function returns source string if it is in .rodata section otherwise it
- * fallbacks to kstrdup.
- * Strings allocated by kstrdup_const should be freed by kfree_const.
+ * Note: Strings allocated by kstrdup_const should be freed by kfree_const.
+ *
+ * Return: source string if it is in .rodata section otherwise
+ * fallback to kstrdup.
  */
 const char *kstrdup_const(const char *s, gfp_t gfp)
 {
···
  * @gfp: the GFP mask used in the kmalloc() call when allocating memory
  *
  * Note: Use kmemdup_nul() instead if the size is known exactly.
+ *
+ * Return: newly allocated copy of @s or %NULL in case of error
  */
 char *kstrndup(const char *s, size_t max, gfp_t gfp)
 {
···
  * @src: memory region to duplicate
  * @len: memory region length
  * @gfp: GFP mask to use
+ *
+ * Return: newly allocated copy of @src or %NULL in case of error
  */
 void *kmemdup(const void *src, size_t len, gfp_t gfp)
 {
···
  * @s: The data to stringify
  * @len: The size of the data
  * @gfp: the GFP mask used in the kmalloc() call when allocating memory
+ *
+ * Return: newly allocated copy of @s with NUL-termination or %NULL in
+ * case of error
  */
 char *kmemdup_nul(const char *s, size_t len, gfp_t gfp)
 {
···
  * @src: source address in user space
  * @len: number of bytes to copy
  *
- * Returns an ERR_PTR() on failure.  Result is physically
+ * Return: an ERR_PTR() on failure.  Result is physically
  * contiguous, to be freed by kfree().
  */
 void *memdup_user(const void __user *src, size_t len)
···
  * @src: source address in user space
  * @len: number of bytes to copy
  *
- * Returns an ERR_PTR() on failure.  Result may be not
+ * Return: an ERR_PTR() on failure.  Result may be not
  * physically contiguous.  Use kvfree() to free.
  */
 void *vmemdup_user(const void __user *src, size_t len)
···
  * strndup_user - duplicate an existing string from user space
  * @s: The string to duplicate
  * @n: Maximum number of bytes to copy, including the trailing NUL.
+ *
+ * Return: newly allocated copy of @s or %NULL in case of error
  */
 char *strndup_user(const char __user *s, long n)
 {
···
  * @src: source address in user space
  * @len: number of bytes to copy
  *
- * Returns an ERR_PTR() on failure.
+ * Return: an ERR_PTR() on failure.
  */
 void *memdup_user_nul(const void __user *src, size_t len)
 {
···
  * @pages:	array that receives pointers to the pages pinned.
  *		Should be at least nr_pages long.
  *
- * Returns number of pages pinned. This may be fewer than the number
- * requested. If nr_pages is 0 or negative, returns 0. If no pages
- * were pinned, returns -errno.
- *
  * get_user_pages_fast provides equivalent functionality to get_user_pages,
  * operating on current and current->mm, with force=0 and vma=NULL. However
  * unlike get_user_pages, it must be called without mmap_sem held.
···
  * pages have to be faulted in, it may turn out to be slightly slower so
  * callers need to carefully consider what to use. On many architectures,
  * get_user_pages_fast simply falls back to get_user_pages.
+ *
+ * Return: number of pages pinned. This may be fewer than the number
+ * requested. If nr_pages is 0 or negative, returns 0. If no pages
+ * were pinned, returns -errno.
  */
 int __weak get_user_pages_fast(unsigned long start,
 				int nr_pages, int write, struct page **pages)
···
  *
  * Please note that any use of gfp flags outside of GFP_KERNEL is careful to not
  * fall back to vmalloc.
+ *
+ * Return: pointer to the allocated memory of %NULL in case of failure
  */
 void *kvmalloc_node(size_t size, gfp_t flags, int node)
 {
···
  * @buffer:   the buffer to copy to.
  * @buflen:   the length of the buffer. Larger cmdline values are truncated
  *            to this length.
- * Returns the size of the cmdline field copied. Note that the copy does
+ *
+ * Return: the size of the cmdline field copied. Note that the copy does
  * not guarantee an ending NULL byte.
  */
 int get_cmdline(struct task_struct *task, char *buffer, int buflen)

mm/vmalloc.c

···
 	}
 
 found:
-	if (addr + size > vend)
+	/*
+	 * Check also calculated address against the vstart,
+	 * because it can be 0 because of big align request.
+	 */
+	if (addr + size > vend || addr < vstart)
 		goto overflow;
 
 	va->va_start = addr;
···
  * @order:    how many 2^order pages should be occupied in newly allocated block
  * @gfp_mask: flags for the page level allocator
  *
- * Returns: virtual address in a newly allocated block or ERR_PTR(-errno)
+ * Return: virtual address in a newly allocated block or ERR_PTR(-errno)
  */
 static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
 {
···
 EXPORT_SYMBOL(vm_map_ram);
 
 static struct vm_struct *vmlist __initdata;
+
 /**
  * vm_area_add_early - add vmap area early during boot
  * @vm: vm_struct to add
···
 }
 
 /**
- *	get_vm_area  -  reserve a contiguous kernel virtual area
- *	@size:		size of the area
- *	@flags:		%VM_IOREMAP for I/O mappings or VM_ALLOC
+ * get_vm_area - reserve a contiguous kernel virtual area
+ * @size:	 size of the area
+ * @flags:	 %VM_IOREMAP for I/O mappings or VM_ALLOC
  *
- *	Search an area of @size in the kernel virtual mapping area,
- *	and reserved it for out purposes.  Returns the area descriptor
- *	on success or %NULL on failure.
+ * Search an area of @size in the kernel virtual mapping area,
+ * and reserved it for out purposes.  Returns the area descriptor
+ * on success or %NULL on failure.
+ *
+ * Return: the area descriptor on success or %NULL on failure.
  */
 struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
 {
···
 }
 
 /**
- *	find_vm_area  -  find a continuous kernel virtual area
- *	@addr:		base address
+ * find_vm_area - find a continuous kernel virtual area
+ * @addr:	  base address
  *
- *	Search for the kernel VM area starting at @addr, and return it.
- *	It is up to the caller to do all required locking to keep the returned
- *	pointer valid.
+ * Search for the kernel VM area starting at @addr, and return it.
+ * It is up to the caller to do all required locking to keep the returned
+ * pointer valid.
+ *
+ * Return: pointer to the found area or %NULL on faulure
  */
 struct vm_struct *find_vm_area(const void *addr)
 {
···
 }
 
 /**
- *	remove_vm_area  -  find and remove a continuous kernel virtual area
- *	@addr:		base address
+ * remove_vm_area - find and remove a continuous kernel virtual area
+ * @addr:	    base address
  *
- *	Search for the kernel VM area starting at @addr, and remove it.
- *	This function returns the found VM area, but using it is NOT safe
- *	on SMP machines, except for its size or flags.
+ * Search for the kernel VM area starting at @addr, and remove it.
+ * This function returns the found VM area, but using it is NOT safe
+ * on SMP machines, except for its size or flags.
+ *
+ * Return: pointer to the found area or %NULL on faulure
  */
 struct vm_struct *remove_vm_area(const void *addr)
 {
···
 			addr))
 		return;
 
-	area = find_vmap_area((unsigned long)addr)->vm;
+	area = find_vm_area(addr);
 	if (unlikely(!area)) {
 		WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
 				addr);
···
 }
 
 /**
- *	vfree_atomic  -  release memory allocated by vmalloc()
- *	@addr:		memory base address
+ * vfree_atomic - release memory allocated by vmalloc()
+ * @addr:	  memory base address
  *
- *	This one is just like vfree() but can be called in any atomic context
- *	except NMIs.
+ * This one is just like vfree() but can be called in any atomic context
+ * except NMIs.
  */
 void vfree_atomic(const void *addr)
 {
···
 	__vfree_deferred(addr);
 }
 
+static void __vfree(const void *addr)
+{
+	if (unlikely(in_interrupt()))
+		__vfree_deferred(addr);
+	else
+		__vunmap(addr, 1);
+}
+
 /**
- *	vfree  -  release memory allocated by vmalloc()
- *	@addr:		memory base address
+ * vfree - release memory allocated by vmalloc()
+ * @addr:  memory base address
  *
- *	Free the virtually continuous memory area starting at @addr, as
- *	obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
- *	NULL, no operation is performed.
+ * Free the virtually continuous memory area starting at @addr, as
+ * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
+ * NULL, no operation is performed.
  *
- *	Must not be called in NMI context (strictly speaking, only if we don't
- *	have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
- *	conventions for vfree() arch-depenedent would be a really bad idea)
+ * Must not be called in NMI context (strictly speaking, only if we don't
+ * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
+ * conventions for vfree() arch-depenedent would be a really bad idea)
  *
- *	May sleep if called *not* from interrupt context.
+ * May sleep if called *not* from interrupt context.
  *
- *	NOTE: assumes that the object at @addr has a size >= sizeof(llist_node)
+ * NOTE: assumes that the object at @addr has a size >= sizeof(llist_node)
  */
 void vfree(const void *addr)
 {
···
 
 	if (!addr)
 		return;
-	if (unlikely(in_interrupt()))
-		__vfree_deferred(addr);
-	else
-		__vunmap(addr, 1);
+
+	__vfree(addr);
 }
 EXPORT_SYMBOL(vfree);
 
 /**
- *	vunmap  -  release virtual mapping obtained by vmap()
- *	@addr:		memory base address
+ * vunmap - release virtual mapping obtained by vmap()
+ * @addr:   memory base address
  *
- *	Free the virtually contiguous memory area starting at @addr,
- *	which was created from the page array passed to vmap().
+ * Free the virtually contiguous memory area starting at @addr,
+ * which was created from the page array passed to vmap().
  *
- *	Must not be called in interrupt context.
+ * Must not be called in interrupt context.
  */
 void vunmap(const void *addr)
 {
···
 EXPORT_SYMBOL(vunmap);
 
 /**
- *	vmap  -  map an array of pages into virtually contiguous space
- *	@pages:		array of page pointers
- *	@count:		number of pages to map
- *	@flags:		vm_area->flags
- *	@prot:		page protection for the mapping
+ * vmap - map an array of pages into virtually contiguous space
+ * @pages: array of page pointers
+ * @count: number of pages to map
+ * @flags: vm_area->flags
+ * @prot: page protection for the mapping
  *
- *	Maps @count pages from @pages into contiguous kernel virtual
- *	space.
+ * Maps @count pages from @pages into contiguous kernel virtual
+ * space.
+ *
+ * Return: the address of the area or %NULL on failure
  */
 void *vmap(struct page **pages, unsigned int count,
-		unsigned long flags, pgprot_t prot)
+	   unsigned long flags, pgprot_t prot)
 {
 	struct vm_struct *area;
 	unsigned long size;		/* In bytes */
···
 	warn_alloc(gfp_mask, NULL,
 			  "vmalloc: allocation failure, allocated %ld of %ld bytes",
 			  (area->nr_pages*PAGE_SIZE), area->size);
-	vfree(area->addr);
+	__vfree(area->addr);
 	return NULL;
 }
 
 /**
- *	__vmalloc_node_range  -  allocate virtually contiguous memory
- *	@size:		allocation size
- *	@align:		desired alignment
- *	@start:		vm area range start
- *	@end:		vm area range end
- *	@gfp_mask:	flags for the page level allocator
- *	@prot:		protection mask for the allocated pages
- *	@vm_flags:	additional vm area flags (e.g. %VM_NO_GUARD)
- *	@node:		node to use for allocation or NUMA_NO_NODE
- *	@caller:	caller's return address
+ * __vmalloc_node_range - allocate virtually contiguous memory
+ * @size:		  allocation size
+ * @align:		  desired alignment
+ * @start:		  vm area range start
+ * @end:		  vm area range end
+ * @gfp_mask:		  flags for the page level allocator
+ * @prot:		  protection mask for the allocated pages
+ * @vm_flags:		  additional vm area flags (e.g. %VM_NO_GUARD)
+ * @node:		  node to use for allocation or NUMA_NO_NODE
+ * @caller:		  caller's return address
  *
- *	Allocate enough pages to cover @size from the page level
- *	allocator with @gfp_mask flags.  Map them into contiguous
- *	kernel virtual space, using a pagetable protection of @prot.
+ * Allocate enough pages to cover @size from the page level
+ * allocator with @gfp_mask flags.  Map them into contiguous
+ * kernel virtual space, using a pagetable protection of @prot.
+ *
+ * Return: the address of the area or %NULL on failure
  */
 void *__vmalloc_node_range(unsigned long size, unsigned long align,
 			unsigned long start, unsigned long end, gfp_t gfp_mask,
···
 	return NULL;
 }
 
+/*
+ * This is only for performance analysis of vmalloc and stress purpose.
+ * It is required by vmalloc test module, therefore do not use it other
+ * than that.
+ */
+#ifdef CONFIG_TEST_VMALLOC_MODULE
+EXPORT_SYMBOL_GPL(__vmalloc_node_range);
+#endif
+
 /**
- *	__vmalloc_node  -  allocate virtually contiguous memory
- *	@size:		allocation size
- *	@align:		desired alignment
- *	@gfp_mask:	flags for the page level allocator
- *	@prot:		protection mask for the allocated pages
- *	@node:		node to use for allocation or NUMA_NO_NODE
- *	@caller:	caller's return address
+ * __vmalloc_node - allocate virtually contiguous memory
+ * @size:	    allocation size
+ * @align:	    desired alignment
+ * @gfp_mask:	    flags for the page level allocator
+ * @prot:	    protection mask for the allocated pages
+ * @node:	    node to use for allocation or NUMA_NO_NODE
+ * @caller:	    caller's return address
  *
- *	Allocate enough pages to cover @size from the page level
- *	allocator with @gfp_mask flags.  Map them into contiguous
- *	kernel virtual space, using a pagetable protection of @prot.
+ * Allocate enough pages to cover @size from the page level
+ * allocator with @gfp_mask flags.  Map them into contiguous
+ * kernel virtual space, using a pagetable protection of @prot.
  *
- *	Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL
- *	and __GFP_NOFAIL are not supported
+ * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL
+ * and __GFP_NOFAIL are not supported
  *
- *	Any use of gfp flags outside of GFP_KERNEL should be consulted
- *	with mm people.
+ * Any use of gfp flags outside of GFP_KERNEL should be consulted
+ * with mm people.
  *
+ * Return: pointer to the allocated memory or %NULL on error
  */
 static void *__vmalloc_node(unsigned long size, unsigned long align,
 			    gfp_t gfp_mask, pgprot_t prot,
···
 }
 
 /**
- *	vmalloc  -  allocate virtually contiguous memory
- *	@size:		allocation size
- *	Allocate enough pages to cover @size from the page level
- *	allocator and map them into contiguous kernel virtual space.
+ * vmalloc - allocate virtually contiguous memory
+ * @size:    allocation size
  *
- *	For tight control over page level allocator and protection flags
- *	use __vmalloc() instead.
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
  */
 void *vmalloc(unsigned long size)
 {
···
 EXPORT_SYMBOL(vmalloc);
 
 /**
- *	vzalloc - allocate virtually contiguous memory with zero fill
- *	@size:	allocation size
- *	Allocate enough pages to cover @size from the page level
- *	allocator and map them into contiguous kernel virtual space.
- *	The memory allocated is set to zero.
+ * vzalloc - allocate virtually contiguous memory with zero fill
+ * @size:    allocation size
  *
- *	For tight control over page level allocator and protection flags
- *	use __vmalloc() instead.
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ * The memory allocated is set to zero.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
  */
 void *vzalloc(unsigned long size)
 {
···
  *
  * The resulting memory area is zeroed so it can be mapped to userspace
  * without leaking data.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
  */
 void *vmalloc_user(unsigned long size)
 {
-	struct vm_struct *area;
-	void *ret;
-
-	ret = __vmalloc_node(size, SHMLBA,
-			     GFP_KERNEL | __GFP_ZERO,
-			     PAGE_KERNEL, NUMA_NO_NODE,
-			     __builtin_return_address(0));
-	if (ret) {
-		area = find_vm_area(ret);
-		area->flags |= VM_USERMAP;
-	}
-	return ret;
+	return __vmalloc_node_range(size, SHMLBA,  VMALLOC_START, VMALLOC_END,
+				    GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL,
+				    VM_USERMAP, NUMA_NO_NODE,
+				    __builtin_return_address(0));
 }
 EXPORT_SYMBOL(vmalloc_user);
 
 /**
- *	vmalloc_node  -  allocate memory on a specific node
- *	@size:		allocation size
- *	@node:		numa node
+ * vmalloc_node - allocate memory on a specific node
+ * @size:	  allocation size
+ * @node:	  numa node
  *
- *	Allocate enough pages to cover @size from the page level
- *	allocator and map them into contiguous kernel virtual space.
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
  *
- *	For tight control over page level allocator and protection flags
- *	use __vmalloc() instead.
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
  */
 void *vmalloc_node(unsigned long size, int node)
 {
···
  *
  * For tight control over page level allocator and protection flags
  * use __vmalloc_node() instead.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
  */
 void *vzalloc_node(unsigned long size, int node)
 {
···
 EXPORT_SYMBOL(vzalloc_node);
 
 /**
- *	vmalloc_exec  -  allocate virtually contiguous, executable memory
- *	@size:		allocation size
+ * vmalloc_exec - allocate virtually contiguous, executable memory
+ * @size:	  allocation size
  *
- *	Kernel-internal function to allocate enough pages to cover @size
- *	the page level allocator and map them into contiguous and
- *	executable kernel virtual space.
+ * Kernel-internal function to allocate enough pages to cover @size
+ * the page level allocator and map them into contiguous and
+ * executable kernel virtual space.
  *
- *	For tight control over page level allocator and protection flags
- *	use __vmalloc() instead.
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
  */
-
 void *vmalloc_exec(unsigned long size)
 {
 	return __vmalloc_node(size, 1, GFP_KERNEL, PAGE_KERNEL_EXEC,
···
 #endif
 
 /**
- *	vmalloc_32  -  allocate virtually contiguous memory (32bit addressable)
- *	@size:		allocation size
+ * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
+ * @size:	allocation size
  *
- *	Allocate enough 32bit PA addressable pages to cover @size from the
- *	page level allocator and map them into contiguous kernel virtual space.
+ * Allocate enough 32bit PA addressable pages to cover @size from the
+ * page level allocator and map them into contiguous kernel virtual space.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
  */
 void *vmalloc_32(unsigned long size)
 {
···
 
 /**
  * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
- *	@size:		allocation size
+ * @size:	     allocation size
  *
  * The resulting memory area is 32bit addressable and zeroed so it can be
  * mapped to userspace without leaking data.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
  */
 void *vmalloc_32_user(unsigned long size)
 {
-	struct vm_struct *area;
-	void *ret;
-
-	ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
-			     NUMA_NO_NODE, __builtin_return_address(0));
-	if (ret) {
-		area = find_vm_area(ret);
-		area->flags |= VM_USERMAP;
-	}
-	return ret;
+	return __vmalloc_node_range(size, SHMLBA,  VMALLOC_START, VMALLOC_END,
+				    GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
+				    VM_USERMAP, NUMA_NO_NODE,
+				    __builtin_return_address(0));
 }
 EXPORT_SYMBOL(vmalloc_32_user);
 
···
 }
 
 /**
- *	vread() -  read vmalloc area in a safe way.
- *	@buf:		buffer for reading data
- *	@addr:		vm address.
- *	@count:		number of bytes to be read.
+ * vread() - read vmalloc area in a safe way.
+ * @buf:     buffer for reading data
+ * @addr:    vm address.
+ * @count:   number of bytes to be read.
  *
- *	Returns # of bytes which addr and buf should be increased.
- *	(same number to @count). Returns 0 if [addr...addr+count) doesn't
- *	includes any intersect with alive vmalloc area.
+ * This function checks that addr is a valid vmalloc'ed area, and
+ * copy data from that area to a given buffer. If the given memory range
+ * of [addr...addr+count) includes some valid address, data is copied to
+ * proper area of @buf. If there are memory holes, they'll be zero-filled.
+ * IOREMAP area is treated as memory hole and no copy is done.
  *
- *	This function checks that addr is a valid vmalloc'ed area, and
- *	copy data from that area to a given buffer. If the given memory range
- *	of [addr...addr+count) includes some valid address, data is copied to
- *	proper area of @buf. If there are memory holes, they'll be zero-filled.
- *	IOREMAP area is treated as memory hole and no copy is done.
+ * If [addr...addr+count) doesn't includes any intersects with alive
+ * vm_struct area, returns 0. @buf should be kernel's buffer.
  *
- *	If [addr...addr+count) doesn't includes any intersects with alive
- *	vm_struct area, returns 0. @buf should be kernel's buffer.
+ * Note: In usual ops, vread() is never necessary because the caller
+ * should know vmalloc() area is valid and can use memcpy().
+ * This is for routines which have to access vmalloc area without
+ * any informaion, as /dev/kmem.
  *
- *	Note: In usual ops, vread() is never necessary because the caller
- *	should know vmalloc() area is valid and can use memcpy().
- *	This is for routines which have to access vmalloc area without
- *	any informaion, as /dev/kmem.
- *
+ * Return: number of bytes for which addr and buf should be increased
+ * (same number as @count) or %0 if [addr...addr+count) doesn't
+ * include any intersection with valid vmalloc area
  */
-
 long vread(char *buf, char *addr, unsigned long count)
 {
 	struct vmap_area *va;
···
 }
 
 /**
- *	vwrite() -  write vmalloc area in a safe way.
- *	@buf:		buffer for source data
- *	@addr:		vm address.
- *	@count:		number of bytes to be read.
+ * vwrite() - write vmalloc area in a safe way.
+ * @buf:      buffer for source data
+ * @addr:     vm address.
+ * @count:    number of bytes to be read.
  *
- *	Returns # of bytes which addr and buf should be incresed.
- *	(same number to @count).
- *	If [addr...addr+count) doesn't includes any intersect with valid
- *	vmalloc area, returns 0.
+ * This function checks that addr is a valid vmalloc'ed area, and
+ * copy data from a buffer to the given addr. If specified range of
+ * [addr...addr+count) includes some valid address, data is copied from
+ * proper area of @buf. If there are memory holes, no copy to hole.
+ * IOREMAP area is treated as memory hole and no copy is done.
  *
- *	This function checks that addr is a valid vmalloc'ed area, and
- *	copy data from a buffer to the given addr. If specified range of
- *	[addr...addr+count) includes some valid address, data is copied from
- *	proper area of @buf. If there are memory holes, no copy to hole.
- *	IOREMAP area is treated as memory hole and no copy is done.
+ * If [addr...addr+count) doesn't includes any intersects with alive
+ * vm_struct area, returns 0. @buf should be kernel's buffer.
  *
- *	If [addr...addr+count) doesn't includes any intersects with alive
- *	vm_struct area, returns 0. @buf should be kernel's buffer.
+ * Note: In usual ops, vwrite() is never necessary because the caller
+ * should know vmalloc() area is valid and can use memcpy().
+ * This is for routines which have to access vmalloc area without
+ * any informaion, as /dev/kmem.
  *
- *	Note: In usual ops, vwrite() is never necessary because the caller
- *	should know vmalloc() area is valid and can use memcpy().
- *	This is for routines which have to access vmalloc area without
- *	any informaion, as /dev/kmem.
+ * Return: number of bytes for which addr and buf should be
+ * increased (same number as @count) or %0 if [addr...addr+count)
+ * doesn't include any intersection with valid vmalloc area
  */
-
 long vwrite(char *buf, char *addr, unsigned long count)
 {
 	struct vmap_area *va;
···
 }
 
 /**
- *	remap_vmalloc_range_partial  -  map vmalloc pages to userspace
- *	@vma:		vma to cover
- *	@uaddr:		target user address to start at
- *	@kaddr:		virtual address of vmalloc kernel memory
- *	@size:		size of map area
+ * remap_vmalloc_range_partial - map vmalloc pages to userspace
+ * @vma:		vma to cover
+ * @uaddr:		target user address to start at
+ * @kaddr:		virtual address of vmalloc kernel memory
+ * @size:		size of map area
  *
- *	Returns:	0 for success, -Exxx on failure
+ * Returns:	0 for success, -Exxx on failure
  *
- *	This function checks that @kaddr is a valid vmalloc'ed area,
- *	and that it is big enough to cover the range starting at
- *	@uaddr in @vma. Will return failure if that criteria isn't
- *	met.
+ * This function checks that @kaddr is a valid vmalloc'ed area,
+ * and that it is big enough to cover the range starting at
+ * @uaddr in @vma. Will return failure if that criteria isn't
+ * met.
  *
- *	Similar to remap_pfn_range() (see mm/memory.c)
+ * Similar to remap_pfn_range() (see mm/memory.c)
  */
 int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
 				void *kaddr, unsigned long size)
···
 	if (!(area->flags & VM_USERMAP))
 		return -EINVAL;
 
-	if (kaddr + size > area->addr + area->size)
+	if (kaddr + size > area->addr + get_vm_area_size(area))
 		return -EINVAL;
 
 	do {
···
 EXPORT_SYMBOL(remap_vmalloc_range_partial);
 
 /**
- *	remap_vmalloc_range  -  map vmalloc pages to userspace
- *	@vma:		vma to cover (map full range of vma)
- *	@addr:		vmalloc memory
- *	@pgoff:		number of pages into addr before first page to map
+ * remap_vmalloc_range - map vmalloc pages to userspace
+ * @vma:		vma to cover (map full range of vma)
+ * @addr:		vmalloc memory
+ * @pgoff:		number of pages into addr before first page to map
  *
- *	Returns:	0 for success, -Exxx on failure
+ * Returns:	0 for success, -Exxx on failure
  *
- *	This function checks that addr is a valid vmalloc'ed area, and
- *	that it is big enough to cover the vma. Will return failure if
- *	that criteria isn't met.
+ * This function checks that addr is a valid vmalloc'ed area, and
+ * that it is big enough to cover the vma. Will return failure if
+ * that criteria isn't met.
  *
- *	Similar to remap_pfn_range() (see mm/memory.c)
+ * Similar to remap_pfn_range() (see mm/memory.c)
  */
 int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
 						unsigned long pgoff)
···
 }
 
 /**
- *	alloc_vm_area - allocate a range of kernel address space
- *	@size:		size of the area
- *	@ptes:		returns the PTEs for the address space
+ * alloc_vm_area - allocate a range of kernel address space
+ * @size:	   size of the area
+ * @ptes:	   returns the PTEs for the address space
  *
- *	Returns:	NULL on failure, vm_struct on success
+ * Returns:	NULL on failure, vm_struct on success
  *
- *	This function reserves a range of kernel address space, and
- *	allocates pagetables to map that range.  No actual mappings
- *	are created.
+ * This function reserves a range of kernel address space, and
+ * allocates pagetables to map that range.  No actual mappings
+ * are created.
  *
- *	If @ptes is non-NULL, pointers to the PTEs (in init_mm)
- *	allocated for the VM area are returned.
+ * If @ptes is non-NULL, pointers to the PTEs (in init_mm)
+ * allocated for the VM area are returned.
  */
 struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
 {
···
 module_init(proc_vmalloc_init);
 
 #endif
-

mm/vmscan.c

···
  */
 int prealloc_shrinker(struct shrinker *shrinker)
 {
-	size_t size = sizeof(*shrinker->nr_deferred);
+	unsigned int size = sizeof(*shrinker->nr_deferred);
 
 	if (shrinker->flags & SHRINKER_NUMA_AWARE)
 		size *= nr_node_ids;
···
 		 */
 		if (reclaimed && page_is_file_cache(page) &&
 		    !mapping_exiting(mapping) && !dax_mapping(mapping))
-			shadow = workingset_eviction(mapping, page);
+			shadow = workingset_eviction(page);
 		__delete_from_page_cache(page, shadow);
 		xa_unlock_irqrestore(&mapping->i_pages, flags);
 
···
 {
 	LIST_HEAD(ret_pages);
 	LIST_HEAD(free_pages);
-	int pgactivate = 0;
-	unsigned nr_unqueued_dirty = 0;
-	unsigned nr_dirty = 0;
-	unsigned nr_congested = 0;
 	unsigned nr_reclaimed = 0;
-	unsigned nr_writeback = 0;
-	unsigned nr_immediate = 0;
-	unsigned nr_ref_keep = 0;
-	unsigned nr_unmap_fail = 0;
 
+	memset(stat, 0, sizeof(*stat));
 	cond_resched();
 
 	while (!list_empty(page_list)) {
···
 		 */
 		page_check_dirty_writeback(page, &dirty, &writeback);
 		if (dirty || writeback)
-			nr_dirty++;
+			stat->nr_dirty++;
 
 		if (dirty && !writeback)
-			nr_unqueued_dirty++;
+			stat->nr_unqueued_dirty++;
 
 		/*
 		 * Treat this page as congested if the underlying BDI is or if
···
 		if (((dirty || writeback) && mapping &&
 		     inode_write_congested(mapping->host)) ||
 		    (writeback && PageReclaim(page)))
-			nr_congested++;
+			stat->nr_congested++;
 
 		/*
 		 * If a page at the tail of the LRU is under writeback, there
···
 			if (current_is_kswapd() &&
 			    PageReclaim(page) &&
 			    test_bit(PGDAT_WRITEBACK, &pgdat->flags)) {
-				nr_immediate++;
+				stat->nr_immediate++;
 				goto activate_locked;
 
 			/* Case 2 above */
···
 				 * and it's also appropriate in global reclaim.
 				 */
 				SetPageReclaim(page);
-				nr_writeback++;
+				stat->nr_writeback++;
 				goto activate_locked;
 
 			/* Case 3 above */
···
 		case PAGEREF_ACTIVATE:
 			goto activate_locked;
 		case PAGEREF_KEEP:
-			nr_ref_keep++;
+			stat->nr_ref_keep++;
 			goto keep_locked;
 		case PAGEREF_RECLAIM:
 		case PAGEREF_RECLAIM_CLEAN:
···
 			if (unlikely(PageTransHuge(page)))
 				flags |= TTU_SPLIT_HUGE_PMD;
 			if (!try_to_unmap(page, flags)) {
-				nr_unmap_fail++;
+				stat->nr_unmap_fail++;
 				goto activate_locked;
 			}
 		}
···
 		VM_BUG_ON_PAGE(PageActive(page), page);
 		if (!PageMlocked(page)) {
 			SetPageActive(page);
-			pgactivate++;
+			stat->nr_activate++;
 			count_memcg_page_event(page, PGACTIVATE);
 		}
 keep_locked:
···
 	free_unref_page_list(&free_pages);
 
 	list_splice(&ret_pages, page_list);
-	count_vm_events(PGACTIVATE, pgactivate);
+	count_vm_events(PGACTIVATE, stat->nr_activate);
 
-	if (stat) {
-		stat->nr_dirty = nr_dirty;
-		stat->nr_congested = nr_congested;
-		stat->nr_unqueued_dirty = nr_unqueued_dirty;
-		stat->nr_writeback = nr_writeback;
-		stat->nr_immediate = nr_immediate;
-		stat->nr_activate = pgactivate;
-		stat->nr_ref_keep = nr_ref_keep;
-		stat->nr_unmap_fail = nr_unmap_fail;
-	}
 	return nr_reclaimed;
 }
 
···
 		.priority = DEF_PRIORITY,
 		.may_unmap = 1,
 	};
+	struct reclaim_stat dummy_stat;
 	unsigned long ret;
 	struct page *page, *next;
 	LIST_HEAD(clean_pages);
···
 	}
 
 	ret = shrink_page_list(&clean_pages, zone->zone_pgdat, &sc,
-			TTU_IGNORE_ACCESS, NULL, true);
+			TTU_IGNORE_ACCESS, &dummy_stat, true);
 	list_splice(&clean_pages, page_list);
 	mod_node_page_state(zone->zone_pgdat, NR_ISOLATED_FILE, -ret);
 	return ret;
···
 
 }
 
-/*
- * zone_lru_lock is heavily contended.  Some of the functions that
+/**
+ * pgdat->lru_lock is heavily contended.  Some of the functions that
  * shrink the lists perform better by taking out a batch of pages
  * and working on them outside the LRU lock.
  *
···
 static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
 		struct lruvec *lruvec, struct list_head *dst,
 		unsigned long *nr_scanned, struct scan_control *sc,
-		isolate_mode_t mode, enum lru_list lru)
+		enum lru_list lru)
 {
 	struct list_head *src = &lruvec->lists[lru];
 	unsigned long nr_taken = 0;
···
 	unsigned long skipped = 0;
 	unsigned long scan, total_scan, nr_pages;
 	LIST_HEAD(pages_skipped);
+	isolate_mode_t mode = (sc->may_unmap ? 0 : ISOLATE_UNMAPPED);
 
 	scan = 0;
 	for (total_scan = 0;
···
 	WARN_RATELIMIT(PageTail(page), "trying to isolate tail page");
 
 	if (PageLRU(page)) {
-		struct zone *zone = page_zone(page);
+		pg_data_t *pgdat = page_pgdat(page);
 		struct lruvec *lruvec;
 
-		spin_lock_irq(zone_lru_lock(zone));
-		lruvec = mem_cgroup_page_lruvec(page, zone->zone_pgdat);
+		spin_lock_irq(&pgdat->lru_lock);
+		lruvec = mem_cgroup_page_lruvec(page, pgdat);
 		if (PageLRU(page)) {
 			int lru = page_lru(page);
 			get_page(page);
···
 			del_page_from_lru_list(page, lruvec, lru);
 			ret = 0;
 		}
-		spin_unlock_irq(zone_lru_lock(zone));
+		spin_unlock_irq(&pgdat->lru_lock);
 	}
 	return ret;
 }
···
 	unsigned long nr_scanned;
 	unsigned long nr_reclaimed = 0;
 	unsigned long nr_taken;
-	struct reclaim_stat stat = {};
-	isolate_mode_t isolate_mode = 0;
+	struct reclaim_stat stat;
 	int file = is_file_lru(lru);
 	struct pglist_data *pgdat = lruvec_pgdat(lruvec);
 	struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat;
···
 
 	lru_add_drain();
 
-	if (!sc->may_unmap)
-		isolate_mode |= ISOLATE_UNMAPPED;
-
 	spin_lock_irq(&pgdat->lru_lock);
 
 	nr_taken = isolate_lru_pages(nr_to_scan, lruvec, &page_list,
-				     &nr_scanned, sc, isolate_mode, lru);
+				     &nr_scanned, sc, lru);
 
 	__mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, nr_taken);
 	reclaim_stat->recent_scanned[file] += nr_taken;
···
  * processes, from rmap.
  *
  * If the pages are mostly unmapped, the processing is fast and it is
- * appropriate to hold zone_lru_lock across the whole operation.  But if
+ * appropriate to hold pgdat->lru_lock across the whole operation.  But if
  * the pages are mapped, the processing is slow (page_referenced()) so we
- * should drop zone_lru_lock around each page.  It's impossible to balance
+ * should drop pgdat->lru_lock around each page.  It's impossible to balance
  * this, so instead we remove the pages from the LRU while processing them.
  * It is safe to rely on PG_active against the non-LRU pages in here because
  * nobody will play with that bit on a non-LRU page.
···
 	struct zone_reclaim_stat *reclaim_stat = &lruvec->reclaim_stat;
 	unsigned nr_deactivate, nr_activate;
 	unsigned nr_rotated = 0;
-	isolate_mode_t isolate_mode = 0;
 	int file = is_file_lru(lru);
 	struct pglist_data *pgdat = lruvec_pgdat(lruvec);
 
 	lru_add_drain();
 
-	if (!sc->may_unmap)
-		isolate_mode |= ISOLATE_UNMAPPED;
-
 	spin_lock_irq(&pgdat->lru_lock);
 
 	nr_taken = isolate_lru_pages(nr_to_scan, lruvec, &l_hold,
-				     &nr_scanned, sc, isolate_mode, lru);
+				     &nr_scanned, sc, lru);
 
 	__mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, nr_taken);
 	reclaim_stat->recent_scanned[file] += nr_taken;
···
 				   sc->nr_reclaimed - reclaimed);
 
 			/*
-			 * Direct reclaim and kswapd have to scan all memory
-			 * cgroups to fulfill the overall scan target for the
-			 * node.
+			 * Kswapd have to scan all memory cgroups to fulfill
+			 * the overall scan target for the node.
 			 *
 			 * Limit reclaim, on the other hand, only cares about
 			 * nr_to_reclaim pages to be reclaimed and it will
 			 * retry with decreasing priority if one round over the
 			 * whole hierarchy is not sufficient.
 			 */
-			if (!global_reclaim(sc) &&
+			if (!current_is_kswapd() &&
 					sc->nr_reclaimed >= sc->nr_to_reclaim) {
 				mem_cgroup_iter_break(root, memcg);
 				break;
···
  *
  * kswapd scans the zones in the highmem->normal->dma direction.  It skips
  * zones which have free_pages > high_wmark_pages(zone), but once a zone is
- * found to have free_pages <= high_wmark_pages(zone), any page is that zone
+ * found to have free_pages <= high_wmark_pages(zone), any page in that zone
  * or lower is eligible for reclaim until at least one usable zone is
  * balanced.
  */

mm/vmstat.c

···
 	struct dentry *extfrag_debug_root;
 
 	extfrag_debug_root = debugfs_create_dir("extfrag", NULL);
-	if (!extfrag_debug_root)
-		return -ENOMEM;
 
-	if (!debugfs_create_file("unusable_index", 0444,
-			extfrag_debug_root, NULL, &unusable_file_ops))
-		goto fail;
+	debugfs_create_file("unusable_index", 0444, extfrag_debug_root, NULL,
+			    &unusable_file_ops);
 
-	if (!debugfs_create_file("extfrag_index", 0444,
-			extfrag_debug_root, NULL, &extfrag_file_ops))
-		goto fail;
+	debugfs_create_file("extfrag_index", 0444, extfrag_debug_root, NULL,
+			    &extfrag_file_ops);
 
 	return 0;
-fail:
-	debugfs_remove_recursive(extfrag_debug_root);
-	return -ENOMEM;
 }
 
 module_init(extfrag_debug_init);

mm/workingset.c

···
 
 /**
  * workingset_eviction - note the eviction of a page from memory
- * @mapping: address space the page was backing
  * @page: the page being evicted
  *
- * Returns a shadow entry to be stored in @mapping->i_pages in place
+ * Returns a shadow entry to be stored in @page->mapping->i_pages in place
  * of the evicted @page so that a later refault can be detected.
  */
-void *workingset_eviction(struct address_space *mapping, struct page *page)
+void *workingset_eviction(struct page *page)
 {
 	struct pglist_data *pgdat = page_pgdat(page);
 	struct mem_cgroup *memcg = page_memcg(page);

net/core/pktgen.c

···
 #include <linux/etherdevice.h>
 #include <linux/kthread.h>
 #include <linux/prefetch.h>
+#include <linux/mmzone.h>
 #include <net/net_namespace.h>
 #include <net/checksum.h>
 #include <net/ipv6.h>
···
 	pkt_dev->svlan_cfi = 0;
 	pkt_dev->svlan_id = 0xffff;
 	pkt_dev->burst = 1;
-	pkt_dev->node = -1;
+	pkt_dev->node = NUMA_NO_NODE;
 
 	err = pktgen_setup_dev(t->net, pkt_dev, ifname);
 	if (err)

net/qrtr/qrtr.c

···
 #include <linux/netlink.h>
 #include <linux/qrtr.h>
 #include <linux/termios.h>	/* For TIOCINQ/OUTQ */
+#include <linux/numa.h>
 
 #include <net/sock.h>
 
···
 	return container_of(sk, struct qrtr_sock, sk);
 }
 
-static unsigned int qrtr_local_nid = -1;
+static unsigned int qrtr_local_nid = NUMA_NO_NODE;
 
 /* for node ids */
 static RADIX_TREE(qrtr_nodes, GFP_KERNEL);

scripts/Makefile.kasan

···
 	 $(call cc-param,asan-globals=1) \
 	 $(call cc-param,asan-instrumentation-with-call-threshold=$(call_threshold)) \
 	 $(call cc-param,asan-stack=$(CONFIG_KASAN_STACK)) \
-	 $(call cc-param,asan-use-after-scope=1) \
 	 $(call cc-param,asan-instrument-allocas=1)
-endif
-
-ifdef CONFIG_KASAN_EXTRA
-CFLAGS_KASAN += $(call cc-option, -fsanitize-address-use-after-scope)
 endif
 
 endif # CONFIG_KASAN_GENERIC

scripts/decode_stacktrace.sh

···
 	symbol=${symbol#\(}
 	symbol=${symbol%\)}
 
+	# Strip segment
+	local segment
+	if [[ $symbol == *:* ]] ; then
+		segment=${symbol%%:*}:
+		symbol=${symbol#*:}
+	fi
+
 	# Strip the symbol name so that we could look it up
 	local name=${symbol%+*}
 
···
 	code=${code//$'\n'/' '}
 
 	# Replace old address with pretty line numbers
-	symbol="$name ($code)"
+	symbol="$segment$name ($code)"
 }
 
 decode_code() {

scripts/gcc-plugins/Kconfig

···
 
 config GCC_PLUGIN_STRUCTLEAK
 	bool "Force initialization of variables containing userspace addresses"
-	# Currently STRUCTLEAK inserts initialization out of live scope of
-	# variables from KASAN point of view. This leads to KASAN false
-	# positive reports. Prohibit this combination for now.
-	depends on !KASAN_EXTRA
 	help
 	  This plugin zero-initializes any structures containing a
 	  __user attribute. This can prevent some classes of information

tools/include/linux/numa.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_NUMA_H
+#define _LINUX_NUMA_H
+
+
+#ifdef CONFIG_NODES_SHIFT
+#define NODES_SHIFT     CONFIG_NODES_SHIFT
+#else
+#define NODES_SHIFT     0
+#endif
+
+#define MAX_NUMNODES    (1 << NODES_SHIFT)
+
+#define	NUMA_NO_NODE	(-1)
+
+#endif /* _LINUX_NUMA_H */

tools/perf/bench/numa.c

···
 #include <sys/types.h>
 #include <linux/kernel.h>
 #include <linux/time64.h>
+#include <linux/numa.h>
 
 #include <numa.h>
 #include <numaif.h>
···
 
 	CPU_ZERO(&mask);
 
-	if (target_node == -1) {
+	if (target_node == NUMA_NO_NODE) {
 		for (cpu = 0; cpu < g->p.nr_cpus; cpu++)
 			CPU_SET(cpu, &mask);
 	} else {
···
 	unsigned long nodemask;
 	int ret;
 
-	if (node == -1)
+	if (node == NUMA_NO_NODE)
 		return;
 
 	BUG_ON(g->p.nr_nodes > (int)sizeof(nodemask)*8);
···
 		int cpu;
 
 		/* Allow all nodes by default: */
-		td->bind_node = -1;
+		td->bind_node = NUMA_NO_NODE;
 
 		/* Allow all CPUs by default: */
 		CPU_ZERO(&td->bind_cpumask);

tools/testing/selftests/Makefile

···
 ifneq (1, $(quicktest))
 TARGETS += timers
 endif
+TARGETS += tmpfs
 TARGETS += user
 TARGETS += vm
 TARGETS += x86

tools/testing/selftests/memfd/memfd_test.c

···
 	return fd;
 }
 
+static int mfd_assert_reopen_fd(int fd_in)
+{
+	int r, fd;
+	char path[100];
+
+	sprintf(path, "/proc/self/fd/%d", fd_in);
+
+	fd = open(path, O_RDWR);
+	if (fd < 0) {
+		printf("re-open of existing fd %d failed\n", fd_in);
+		abort();
+	}
+
+	return fd;
+}
+
 static void mfd_fail_new(const char *name, unsigned int flags)
 {
 	int r;
···
 		 mfd_def_size,
 		 PROT_READ | PROT_WRITE,
 		 MAP_PRIVATE,
+		 fd,
+		 0);
+	if (p == MAP_FAILED) {
+		printf("mmap() failed: %m\n");
+		abort();
+	}
+	munmap(p, mfd_def_size);
+}
+
+/* Test that PROT_READ + MAP_SHARED mappings work. */
+static void mfd_assert_read_shared(int fd)
+{
+	void *p;
+
+	/* verify PROT_READ and MAP_SHARED *is* allowed */
+	p = mmap(NULL,
+		 mfd_def_size,
+		 PROT_READ,
+		 MAP_SHARED,
 		 fd,
 		 0);
 	if (p == MAP_FAILED) {
···
 }
 
 /*
+ * Test SEAL_FUTURE_WRITE
+ * Test whether SEAL_FUTURE_WRITE actually prevents modifications.
+ */
+static void test_seal_future_write(void)
+{
+	int fd, fd2;
+	void *p;
+
+	printf("%s SEAL-FUTURE-WRITE\n", memfd_str);
+
+	fd = mfd_assert_new("kern_memfd_seal_future_write",
+			    mfd_def_size,
+			    MFD_CLOEXEC | MFD_ALLOW_SEALING);
+
+	p = mfd_assert_mmap_shared(fd);
+
+	mfd_assert_has_seals(fd, 0);
+
+	mfd_assert_add_seals(fd, F_SEAL_FUTURE_WRITE);
+	mfd_assert_has_seals(fd, F_SEAL_FUTURE_WRITE);
+
+	/* read should pass, writes should fail */
+	mfd_assert_read(fd);
+	mfd_assert_read_shared(fd);
+	mfd_fail_write(fd);
+
+	fd2 = mfd_assert_reopen_fd(fd);
+	/* read should pass, writes should still fail */
+	mfd_assert_read(fd2);
+	mfd_assert_read_shared(fd2);
+	mfd_fail_write(fd2);
+
+	munmap(p, mfd_def_size);
+	close(fd2);
+	close(fd);
+}
+
+/*
  * Test SEAL_SHRINK
  * Test whether SEAL_SHRINK actually prevents shrinking
  */
···
 	test_basic();
 
 	test_seal_write();
+	test_seal_future_write();
 	test_seal_shrink();
 	test_seal_grow();
 	test_seal_resize();

tools/testing/selftests/proc/.gitignore

···
 /fd-002-posix-eq
 /fd-003-kthread
 /proc-loadavg-001
+/proc-pid-vm
 /proc-self-map-files-001
 /proc-self-map-files-002
 /proc-self-syscall

tools/testing/selftests/proc/Makefile

···
 TEST_GEN_PROGS += fd-002-posix-eq
 TEST_GEN_PROGS += fd-003-kthread
 TEST_GEN_PROGS += proc-loadavg-001
+TEST_GEN_PROGS += proc-pid-vm
 TEST_GEN_PROGS += proc-self-map-files-001
 TEST_GEN_PROGS += proc-self-map-files-002
 TEST_GEN_PROGS += proc-self-syscall

tools/testing/selftests/proc/proc-loadavg-001.c

···
 
 	if (unshare(CLONE_NEWPID) == -1) {
 		if (errno == ENOSYS || errno == EPERM)
-			return 2;
+			return 4;
 		return 1;
 	}
 

tools/testing/selftests/proc/proc-pid-vm.c

···
+/*
+ * Copyright (c) 2019 Alexey Dobriyan <[e-mail]>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+/*
+ * Fork and exec tiny 1 page executable which precisely controls its VM.
+ * Test /proc/$PID/maps
+ * Test /proc/$PID/smaps
+ * Test /proc/$PID/smaps_rollup
+ * Test /proc/$PID/statm
+ *
+ * FIXME require CONFIG_TMPFS which can be disabled
+ * FIXME test other values from "smaps"
+ * FIXME support other archs
+ */
+#undef NDEBUG
+#include <assert.h>
+#include <errno.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/mount.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <sys/uio.h>
+#include <linux/kdev_t.h>
+
+static inline long sys_execveat(int dirfd, const char *pathname, char **argv, char **envp, int flags)
+{
+	return syscall(SYS_execveat, dirfd, pathname, argv, envp, flags);
+}
+
+static void make_private_tmp(void)
+{
+	if (unshare(CLONE_NEWNS) == -1) {
+		if (errno == ENOSYS || errno == EPERM) {
+			exit(4);
+		}
+		exit(1);
+	}
+	if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) == -1) {
+		exit(1);
+	}
+	if (mount(NULL, "/tmp", "tmpfs", 0, NULL) == -1) {
+		exit(1);
+	}
+}
+
+static pid_t pid = -1;
+static void ate(void)
+{
+	if (pid > 0) {
+		kill(pid, SIGTERM);
+	}
+}
+
+struct elf64_hdr {
+	uint8_t e_ident[16];
+	uint16_t e_type;
+	uint16_t e_machine;
+	uint32_t e_version;
+	uint64_t e_entry;
+	uint64_t e_phoff;
+	uint64_t e_shoff;
+	uint32_t e_flags;
+	uint16_t e_ehsize;
+	uint16_t e_phentsize;
+	uint16_t e_phnum;
+	uint16_t e_shentsize;
+	uint16_t e_shnum;
+	uint16_t e_shstrndx;
+};
+
+struct elf64_phdr {
+	uint32_t p_type;
+	uint32_t p_flags;
+	uint64_t p_offset;
+	uint64_t p_vaddr;
+	uint64_t p_paddr;
+	uint64_t p_filesz;
+	uint64_t p_memsz;
+	uint64_t p_align;
+};
+
+#ifdef __x86_64__
+#define PAGE_SIZE 4096
+#define VADDR (1UL << 32)
+#define MAPS_OFFSET 73
+
+#define syscall	0x0f, 0x05
+#define mov_rdi(x)	\
+	0x48, 0xbf,	\
+	(x)&0xff, ((x)>>8)&0xff, ((x)>>16)&0xff, ((x)>>24)&0xff,	\
+	((x)>>32)&0xff, ((x)>>40)&0xff, ((x)>>48)&0xff, ((x)>>56)&0xff
+
+#define mov_rsi(x)	\
+	0x48, 0xbe,	\
+	(x)&0xff, ((x)>>8)&0xff, ((x)>>16)&0xff, ((x)>>24)&0xff,	\
+	((x)>>32)&0xff, ((x)>>40)&0xff, ((x)>>48)&0xff, ((x)>>56)&0xff
+
+#define mov_eax(x)	\
+	0xb8, (x)&0xff, ((x)>>8)&0xff, ((x)>>16)&0xff, ((x)>>24)&0xff
+
+static const uint8_t payload[] = {
+	/* Casually unmap stack, vDSO and everything else. */
+	/* munmap */
+	mov_rdi(VADDR + 4096),
+	mov_rsi((1ULL << 47) - 4096 - VADDR - 4096),
+	mov_eax(11),
+	syscall,
+
+	/* Ping parent. */
+	/* write(0, &c, 1); */
+	0x31, 0xff,					/* xor edi, edi */
+	0x48, 0x8d, 0x35, 0x00, 0x00, 0x00, 0x00,	/* lea rsi, [rip] */
+	0xba, 0x01, 0x00, 0x00, 0x00,			/* mov edx, 1 */
+	mov_eax(1),
+	syscall,
+
+	/* 1: pause(); */
+	mov_eax(34),
+	syscall,
+
+	0xeb, 0xf7,	/* jmp 1b */
+};
+
+static int make_exe(const uint8_t *payload, size_t len)
+{
+	struct elf64_hdr h;
+	struct elf64_phdr ph;
+
+	struct iovec iov[3] = {
+		{&h, sizeof(struct elf64_hdr)},
+		{&ph, sizeof(struct elf64_phdr)},
+		{(void *)payload, len},
+	};
+	int fd, fd1;
+	char buf[64];
+
+	memset(&h, 0, sizeof(h));
+	h.e_ident[0] = 0x7f;
+	h.e_ident[1] = 'E';
+	h.e_ident[2] = 'L';
+	h.e_ident[3] = 'F';
+	h.e_ident[4] = 2;
+	h.e_ident[5] = 1;
+	h.e_ident[6] = 1;
+	h.e_ident[7] = 0;
+	h.e_type = 2;
+	h.e_machine = 0x3e;
+	h.e_version = 1;
+	h.e_entry = VADDR + sizeof(struct elf64_hdr) + sizeof(struct elf64_phdr);
+	h.e_phoff = sizeof(struct elf64_hdr);
+	h.e_shoff = 0;
+	h.e_flags = 0;
+	h.e_ehsize = sizeof(struct elf64_hdr);
+	h.e_phentsize = sizeof(struct elf64_phdr);
+	h.e_phnum = 1;
+	h.e_shentsize = 0;
+	h.e_shnum = 0;
+	h.e_shstrndx = 0;
+
+	memset(&ph, 0, sizeof(ph));
+	ph.p_type = 1;
+	ph.p_flags = (1<<2)|1;
+	ph.p_offset = 0;
+	ph.p_vaddr = VADDR;
+	ph.p_paddr = 0;
+	ph.p_filesz = sizeof(struct elf64_hdr) + sizeof(struct elf64_phdr) + sizeof(payload);
+	ph.p_memsz = sizeof(struct elf64_hdr) + sizeof(struct elf64_phdr) + sizeof(payload);
+	ph.p_align = 4096;
+
+	fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_EXCL|O_TMPFILE, 0700);
+	if (fd == -1) {
+		exit(1);
+	}
+
+	if (writev(fd, iov, 3) != sizeof(struct elf64_hdr) + sizeof(struct elf64_phdr) + len) {
+		exit(1);
+	}
+
+	/* Avoid ETXTBSY on exec. */
+	snprintf(buf, sizeof(buf), "/proc/self/fd/%u", fd);
+	fd1 = open(buf, O_RDONLY|O_CLOEXEC);
+	close(fd);
+
+	return fd1;
+}
+#endif
+
+#ifdef __x86_64__
+int main(void)
+{
+	int pipefd[2];
+	int exec_fd;
+
+	atexit(ate);
+
+	make_private_tmp();
+
+	/* Reserve fd 0 for 1-byte pipe ping from child. */
+	close(0);
+	if (open("/", O_RDONLY|O_DIRECTORY|O_PATH) != 0) {
+		return 1;
+	}
+
+	exec_fd = make_exe(payload, sizeof(payload));
+
+	if (pipe(pipefd) == -1) {
+		return 1;
+	}
+	if (dup2(pipefd[1], 0) != 0) {
+		return 1;
+	}
+
+	pid = fork();
+	if (pid == -1) {
+		return 1;
+	}
+	if (pid == 0) {
+		sys_execveat(exec_fd, "", NULL, NULL, AT_EMPTY_PATH);
+		return 1;
+	}
+
+	char _;
+	if (read(pipefd[0], &_, 1) != 1) {
+		return 1;
+	}
+
+	struct stat st;
+	if (fstat(exec_fd, &st) == -1) {
+		return 1;
+	}
+
+	/* Generate "head -n1 /proc/$PID/maps" */
+	char buf0[256];
+	memset(buf0, ' ', sizeof(buf0));
+	int len = snprintf(buf0, sizeof(buf0),
+			"%08lx-%08lx r-xp 00000000 %02lx:%02lx %llu",
+			VADDR, VADDR + PAGE_SIZE,
+			MAJOR(st.st_dev), MINOR(st.st_dev),
+			(unsigned long long)st.st_ino);
+	buf0[len] = ' ';
+	snprintf(buf0 + MAPS_OFFSET, sizeof(buf0) - MAPS_OFFSET,
+		 "/tmp/#%llu (deleted)\n", (unsigned long long)st.st_ino);
+
+
+	/* Test /proc/$PID/maps */
+	{
+		char buf[256];
+		ssize_t rv;
+		int fd;
+
+		snprintf(buf, sizeof(buf), "/proc/%u/maps", pid);
+		fd = open(buf, O_RDONLY);
+		if (fd == -1) {
+			return 1;
+		}
+		rv = read(fd, buf, sizeof(buf));
+		assert(rv == strlen(buf0));
+		assert(memcmp(buf, buf0, strlen(buf0)) == 0);
+	}
+
+	/* Test /proc/$PID/smaps */
+	{
+		char buf[1024];
+		ssize_t rv;
+		int fd;
+
+		snprintf(buf, sizeof(buf), "/proc/%u/smaps", pid);
+		fd = open(buf, O_RDONLY);
+		if (fd == -1) {
+			return 1;
+		}
+		rv = read(fd, buf, sizeof(buf));
+		assert(0 <= rv && rv <= sizeof(buf));
+
+		assert(rv >= strlen(buf0));
+		assert(memcmp(buf, buf0, strlen(buf0)) == 0);
+
+#define RSS1 "Rss:                   4 kB\n"
+#define RSS2 "Rss:                   0 kB\n"
+#define PSS1 "Pss:                   4 kB\n"
+#define PSS2 "Pss:                   0 kB\n"
+		assert(memmem(buf, rv, RSS1, strlen(RSS1)) ||
+		       memmem(buf, rv, RSS2, strlen(RSS2)));
+		assert(memmem(buf, rv, PSS1, strlen(PSS1)) ||
+		       memmem(buf, rv, PSS2, strlen(PSS2)));
+
+		static const char *S[] = {
+			"Size:                  4 kB\n",
+			"KernelPageSize:        4 kB\n",
+			"MMUPageSize:           4 kB\n",
+			"Anonymous:             0 kB\n",
+			"AnonHugePages:         0 kB\n",
+			"Shared_Hugetlb:        0 kB\n",
+			"Private_Hugetlb:       0 kB\n",
+			"Locked:                0 kB\n",
+		};
+		int i;
+
+		for (i = 0; i < sizeof(S)/sizeof(S[0]); i++) {
+			assert(memmem(buf, rv, S[i], strlen(S[i])));
+		}
+	}
+
+	/* Test /proc/$PID/smaps_rollup */
+	{
+		char bufr[256];
+		memset(bufr, ' ', sizeof(bufr));
+		len = snprintf(bufr, sizeof(bufr),
+				"%08lx-%08lx ---p 00000000 00:00 0",
+				VADDR, VADDR + PAGE_SIZE);
+		bufr[len] = ' ';
+		snprintf(bufr + MAPS_OFFSET, sizeof(bufr) - MAPS_OFFSET,
+			 "[rollup]\n");
+
+		char buf[1024];
+		ssize_t rv;
+		int fd;
+
+		snprintf(buf, sizeof(buf), "/proc/%u/smaps_rollup", pid);
+		fd = open(buf, O_RDONLY);
+		if (fd == -1) {
+			return 1;
+		}
+		rv = read(fd, buf, sizeof(buf));
+		assert(0 <= rv && rv <= sizeof(buf));
+
+		assert(rv >= strlen(bufr));
+		assert(memcmp(buf, bufr, strlen(bufr)) == 0);
+
+		assert(memmem(buf, rv, RSS1, strlen(RSS1)) ||
+		       memmem(buf, rv, RSS2, strlen(RSS2)));
+		assert(memmem(buf, rv, PSS1, strlen(PSS1)) ||
+		       memmem(buf, rv, PSS2, strlen(PSS2)));
+
+		static const char *S[] = {
+			"Anonymous:             0 kB\n",
+			"AnonHugePages:         0 kB\n",
+			"Shared_Hugetlb:        0 kB\n",
+			"Private_Hugetlb:       0 kB\n",
+			"Locked:                0 kB\n",
+		};
+		int i;
+
+		for (i = 0; i < sizeof(S)/sizeof(S[0]); i++) {
+			assert(memmem(buf, rv, S[i], strlen(S[i])));
+		}
+	}
+
+	/* Test /proc/$PID/statm */
+	{
+		char buf[64];
+		ssize_t rv;
+		int fd;
+
+		snprintf(buf, sizeof(buf), "/proc/%u/statm", pid);
+		fd = open(buf, O_RDONLY);
+		if (fd == -1) {
+			return 1;
+		}
+		rv = read(fd, buf, sizeof(buf));
+		assert(rv == 7 * 2);
+
+		assert(buf[0] == '1');	/* ->total_vm */
+		assert(buf[1] == ' ');
+		assert(buf[2] == '0' || buf[2] == '1');	/* rss */
+		assert(buf[3] == ' ');
+		assert(buf[4] == '0' || buf[2] == '1');	/* file rss */
+		assert(buf[5] == ' ');
+		assert(buf[6] == '1');	/* ELF executable segments */
+		assert(buf[7] == ' ');
+		assert(buf[8] == '0');
+		assert(buf[9] == ' ');
+		assert(buf[10] == '0');	/* ->data_vm + ->stack_vm */
+		assert(buf[11] == ' ');
+		assert(buf[12] == '0');
+		assert(buf[13] == '\n');
+	}
+
+	return 0;
+}
+#else
+int main(void)
+{
+	return 4;
+}
+#endif

tools/testing/selftests/proc/proc-self-map-files-002.c

···
 	p = mmap((void *)va, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE|MAP_FIXED, fd, 0);
 	if (p == MAP_FAILED) {
 		if (errno == EPERM)
-			return 2;
+			return 4;
 		return 1;
 	}
 

tools/testing/selftests/proc/proc-self-syscall.c

···
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <errno.h>
-#include <unistd.h>
 #include <string.h>
 #include <stdio.h>
 
···
 	fd = open("/proc/self/syscall", O_RDONLY);
 	if (fd == -1) {
 		if (errno == ENOENT)
-			return 2;
+			return 4;
 		return 1;
 	}
 

tools/testing/selftests/proc/proc-self-wchan.c

···
 	fd = open("/proc/self/wchan", O_RDONLY);
 	if (fd == -1) {
 		if (errno == ENOENT)
-			return 2;
+			return 4;
 		return 1;
 	}
 

tools/testing/selftests/proc/read.c

···
 #include <dirent.h>
 #include <stdbool.h>
 #include <stdlib.h>
+#include <stdio.h>
 #include <string.h>
 #include <sys/stat.h>
+#include <sys/vfs.h>
 #include <fcntl.h>
 #include <unistd.h>
 
···
 int main(void)
 {
 	DIR *d;
+	struct statfs sfs;
 
 	d = opendir("/proc");
 	if (!d)
+		return 4;
+
+	/* Ensure /proc is proc. */
+	if (fstatfs(dirfd(d), &sfs) == -1) {
+		return 1;
+	}
+	if (sfs.f_type != 0x9fa0) {
+		fprintf(stderr, "error: unexpected f_type %lx\n", (long)sfs.f_type);
 		return 2;
+	}
+
 	f(d, 0);
+
 	return 0;
 }

tools/testing/selftests/tmpfs/.gitignore

···
+/bug-link-o-tmpfile

tools/testing/selftests/tmpfs/Makefile

···
+CFLAGS += -Wall -O2
+CFLAGS += -D_GNU_SOURCE
+
+TEST_GEN_PROGS :=
+TEST_GEN_PROGS += bug-link-o-tmpfile
+
+include ../lib.mk

tools/testing/selftests/tmpfs/bug-link-o-tmpfile.c

···
+/*
+ * Copyright (c) 2019 Alexey Dobriyan <[e-mail]>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+/* Test that open(O_TMPFILE), linkat() doesn't screw accounting. */
+#include <errno.h>
+#include <sched.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/mount.h>
+#include <unistd.h>
+
+int main(void)
+{
+	int fd;
+
+	if (unshare(CLONE_NEWNS) == -1) {
+		if (errno == ENOSYS || errno == EPERM) {
+			fprintf(stderr, "error: unshare, errno %d\n", errno);
+			return 4;
+		}
+		fprintf(stderr, "error: unshare, errno %d\n", errno);
+		return 1;
+	}
+	if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) == -1) {
+		fprintf(stderr, "error: mount '/', errno %d\n", errno);
+		return 1;
+	}
+
+	/* Our heroes: 1 root inode, 1 O_TMPFILE inode, 1 permanent inode. */
+	if (mount(NULL, "/tmp", "tmpfs", 0, "nr_inodes=3") == -1) {
+		fprintf(stderr, "error: mount tmpfs, errno %d\n", errno);
+		return 1;
+	}
+
+	fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_TMPFILE, 0600);
+	if (fd == -1) {
+		fprintf(stderr, "error: open 1, errno %d\n", errno);
+		return 1;
+	}
+	if (linkat(fd, "", AT_FDCWD, "/tmp/1", AT_EMPTY_PATH) == -1) {
+		fprintf(stderr, "error: linkat, errno %d\n", errno);
+		return 1;
+	}
+	close(fd);
+
+	fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_TMPFILE, 0600);
+	if (fd == -1) {
+		fprintf(stderr, "error: open 2, errno %d\n", errno);
+		return 1;
+	}
+
+	return 0;
+}

tools/testing/selftests/vm/run_vmtests

···
     echo "[PASS]"
 fi
 
+echo "------------------------------------"
+echo "running vmalloc stability smoke test"
+echo "------------------------------------"
+./test_vmalloc.sh smoke
+ret_val=$?
+
+if [ $ret_val -eq 0 ]; then
+	echo "[PASS]"
+elif [ $ret_val -eq $ksft_skip ]; then
+	 echo "[SKIP]"
+	 exitcode=$ksft_skip
+else
+	echo "[FAIL]"
+	exitcode=1
+fi
+
 exit $exitcode

tools/testing/selftests/vm/test_vmalloc.sh

···
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) 2018 Uladzislau Rezki (Sony) <[e-mail]>
+#
+# This is a test script for the kernel test driver to analyse vmalloc
+# allocator. Therefore it is just a kernel module loader. You can specify
+# and pass different parameters in order to:
+#     a) analyse performance of vmalloc allocations;
+#     b) stressing and stability check of vmalloc subsystem.
+
+TEST_NAME="vmalloc"
+DRIVER="test_${TEST_NAME}"
+
+# 1 if fails
+exitcode=1
+
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+
+#
+# Static templates for performance, stressing and smoke tests.
+# Also it is possible to pass any supported parameters manualy.
+#
+PERF_PARAM="single_cpu_test=1 sequential_test_order=1 test_repeat_count=3"
+SMOKE_PARAM="single_cpu_test=1 test_loop_count=10000 test_repeat_count=10"
+STRESS_PARAM="test_repeat_count=20"
+
+check_test_requirements()
+{
+	uid=$(id -u)
+	if [ $uid -ne 0 ]; then
+		echo "$0: Must be run as root"
+		exit $ksft_skip
+	fi
+
+	if ! which modprobe > /dev/null 2>&1; then
+		echo "$0: You need modprobe installed"
+		exit $ksft_skip
+	fi
+
+	if ! modinfo $DRIVER > /dev/null 2>&1; then
+		echo "$0: You must have the following enabled in your kernel:"
+		echo "CONFIG_TEST_VMALLOC=m"
+		exit $ksft_skip
+	fi
+}
+
+run_perfformance_check()
+{
+	echo "Run performance tests to evaluate how fast vmalloc allocation is."
+	echo "It runs all test cases on one single CPU with sequential order."
+
+	modprobe $DRIVER $PERF_PARAM > /dev/null 2>&1
+	echo "Done."
+	echo "Ccheck the kernel message buffer to see the summary."
+}
+
+run_stability_check()
+{
+	echo "Run stability tests. In order to stress vmalloc subsystem we run"
+	echo "all available test cases on all available CPUs simultaneously."
+	echo "It will take time, so be patient."
+
+	modprobe $DRIVER $STRESS_PARAM > /dev/null 2>&1
+	echo "Done."
+	echo "Check the kernel ring buffer to see the summary."
+}
+
+run_smoke_check()
+{
+	echo "Run smoke test. Note, this test provides basic coverage."
+	echo "Please check $0 output how it can be used"
+	echo "for deep performance analysis as well as stress testing."
+
+	modprobe $DRIVER $SMOKE_PARAM > /dev/null 2>&1
+	echo "Done."
+	echo "Check the kernel ring buffer to see the summary."
+}
+
+usage()
+{
+	echo -n "Usage: $0 [ performance ] | [ stress ] | | [ smoke ] | "
+	echo "manual parameters"
+	echo
+	echo "Valid tests and parameters:"
+	echo
+	modinfo $DRIVER
+	echo
+	echo "Example usage:"
+	echo
+	echo "# Shows help message"
+	echo "./${DRIVER}.sh"
+	echo
+	echo "# Runs 1 test(id_1), repeats it 5 times on all online CPUs"
+	echo "./${DRIVER}.sh run_test_mask=1 test_repeat_count=5"
+	echo
+	echo -n "# Runs 4 tests(id_1|id_2|id_4|id_16) on one CPU with "
+	echo "sequential order"
+	echo -n "./${DRIVER}.sh single_cpu_test=1 sequential_test_order=1 "
+	echo "run_test_mask=23"
+	echo
+	echo -n "# Runs all tests on all online CPUs, shuffled order, repeats "
+	echo "20 times"
+	echo "./${DRIVER}.sh test_repeat_count=20"
+	echo
+	echo "# Performance analysis"
+	echo "./${DRIVER}.sh performance"
+	echo
+	echo "# Stress testing"
+	echo "./${DRIVER}.sh stress"
+	echo
+	exit 0
+}
+
+function validate_passed_args()
+{
+	VALID_ARGS=`modinfo $DRIVER | awk '/parm:/ {print $2}' | sed 's/:.*//'`
+
+	#
+	# Something has been passed, check it.
+	#
+	for passed_arg in $@; do
+		key=${passed_arg//=*/}
+		val="${passed_arg:$((${#key}+1))}"
+		valid=0
+
+		for valid_arg in $VALID_ARGS; do
+			if [[ $key = $valid_arg ]] && [[ $val -gt 0 ]]; then
+				valid=1
+				break
+			fi
+		done
+
+		if [[ $valid -ne 1 ]]; then
+			echo "Error: key or value is not correct: ${key} $val"
+			exit $exitcode
+		fi
+	done
+}
+
+function run_manual_check()
+{
+	#
+	# Validate passed parameters. If there is wrong one,
+	# the script exists and does not execute further.
+	#
+	validate_passed_args $@
+
+	echo "Run the test with following parameters: $@"
+	modprobe $DRIVER $@ > /dev/null 2>&1
+	echo "Done."
+	echo "Check the kernel ring buffer to see the summary."
+}
+
+function run_test()
+{
+	if [ $# -eq 0 ]; then
+		usage
+	else
+		if [[ "$1" = "performance" ]]; then
+			run_perfformance_check
+		elif [[ "$1" = "stress" ]]; then
+			run_stability_check
+		elif [[ "$1" = "smoke" ]]; then
+			run_smoke_check
+		else
+			run_manual_check $@
+		fi
+	fi
+}
+
+check_test_requirements
+run_test $@
+
+exit 0

tools/vm/page-types.c

···
 	[KPF_NOPAGE]		= "n:nopage",
 	[KPF_KSM]		= "x:ksm",
 	[KPF_THP]		= "t:thp",
-	[KPF_BALLOON]		= "o:balloon",
+	[KPF_OFFLINE]		= "o:offline",
 	[KPF_PGTABLE]		= "g:pgtable",
 	[KPF_ZERO_PAGE]		= "z:zero_page",
 	[KPF_IDLE]              = "i:idle_page",

tools/vm/slabinfo.c

···
 static void usage(void)
 {
 	printf("slabinfo 4/15/2011. (c) 2007 sgi/(c) 2011 Linux Foundation.\n\n"
-		"slabinfo [-ahnpvtsz] [-d debugopts] [slab-regexp]\n"
+		"slabinfo [-aADefhilnosrStTvz1LXBU] [N=K] [-dafzput] [slab-regexp]\n"
 		"-a|--aliases           Show aliases\n"
 		"-A|--activity          Most active slabs first\n"
-		"-d<options>|--debug=<options> Set/Clear Debug options\n"
+		"-B|--Bytes             Show size in bytes\n"
 		"-D|--display-active    Switch line format to activity\n"
 		"-e|--empty             Show empty slabs\n"
 		"-f|--first-alias       Show first alias\n"
 		"-h|--help              Show usage information\n"
 		"-i|--inverted          Inverted list\n"
 		"-l|--slabs             Show slabs\n"
+		"-L|--Loss              Sort by loss\n"
 		"-n|--numa              Show NUMA information\n"
-		"-o|--ops		Show kmem_cache_ops\n"
+		"-N|--lines=K           Show the first K slabs\n"
+		"-o|--ops               Show kmem_cache_ops\n"
+		"-r|--report            Detailed report on single slabs\n"
 		"-s|--shrink            Shrink slabs\n"
-		"-r|--report		Detailed report on single slabs\n"
 		"-S|--Size              Sort by size\n"
 		"-t|--tracking          Show alloc/free information\n"
 		"-T|--Totals            Show summary information\n"
+		"-U|--Unreclaim         Show unreclaimable slabs only\n"
 		"-v|--validate          Validate slabs\n"
 		"-z|--zero              Include empty slabs\n"
 		"-1|--1ref              Single reference\n"
-		"-N|--lines=K           Show the first K slabs\n"
-		"-L|--Loss              Sort by loss\n"
 		"-X|--Xtotals           Show extended summary information\n"
-		"-B|--Bytes             Show size in bytes\n"
-		"-U|--Unreclaim		Show unreclaimable slabs only\n"
-		"\nValid debug options (FZPUT may be combined)\n"
-		"a / A          Switch on all debug options (=FZUP)\n"
-		"-              Switch off all debug options\n"
-		"f / F          Sanity Checks (SLAB_CONSISTENCY_CHECKS)\n"
-		"z / Z          Redzoning\n"
-		"p / P          Poisoning\n"
-		"u / U          Tracking\n"
-		"t / T          Tracing\n"
+
+		"\n"
+		"-d  | --debug          Switch off all debug options\n"
+		"-da | --debug=a        Switch on all debug options (--debug=FZPU)\n"
+
+		"\n"
+		"-d[afzput] | --debug=[afzput]\n"
+		"    f | F              Sanity Checks (SLAB_CONSISTENCY_CHECKS)\n"
+		"    z | Z              Redzoning\n"
+		"    p | P              Poisoning\n"
+		"    u | U              Tracking\n"
+		"    t | T              Tracing\n"
 	);
 }