Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:
"173 patches.

Subsystems affected by this series: ia64, ocfs2, block, and mm (debug,
pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap,
bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure,
hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock,
oom-kill, migration, ksm, percpu, vmstat, and madvise)"

* emailed patches from Andrew Morton <[e-mail]>: (173 commits)
mm/madvise: add MADV_WILLNEED to process_madvise()
mm/vmstat: remove unneeded return value
mm/vmstat: simplify the array size calculation
mm/vmstat: correct some wrong comments
mm/percpu,c: remove obsolete comments of pcpu_chunk_populated()
selftests: vm: add COW time test for KSM pages
selftests: vm: add KSM merging time test
mm: KSM: fix data type
selftests: vm: add KSM merging across nodes test
selftests: vm: add KSM zero page merging test
selftests: vm: add KSM unmerge test
selftests: vm: add KSM merge test
mm/migrate: correct kernel-doc notation
mm: wire up syscall process_mrelease
mm: introduce process_mrelease system call
memblock: make memblock_find_in_range method private
mm/mempolicy.c: use in_task() in mempolicy_slab_node()
mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies
mm/mempolicy: advertise new MPOL_PREFERRED_MANY
mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY
...

Documentation/ABI/testing/sysfs-kernel-mm-numa

···
+What:		/sys/kernel/mm/numa/
+Date:		June 2021
+Contact:	Linux memory management mailing list <[e-mail]>
+Description:	Interface for NUMA
+
+What:		/sys/kernel/mm/numa/demotion_enabled
+Date:		June 2021
+Contact:	Linux memory management mailing list <[e-mail]>
+Description:	Enable/disable demoting pages during reclaim
+
+		Page migration during reclaim is intended for systems
+		with tiered memory configurations.  These systems have
+		multiple types of memory with varied performance
+		characteristics instead of plain NUMA systems where
+		the same kind of memory is found at varied distances.
+		Allowing page migration during reclaim enables these
+		systems to migrate pages from fast tiers to slow tiers
+		when the fast tier is under pressure.  This migration
+		is performed before swap.  It may move data to a NUMA
+		node that does not fall into the cpuset of the
+		allocating process which might be construed to violate
+		the guarantees of cpusets.  This should not be enabled
+		on systems which need strict cpuset location
+		guarantees.

Documentation/admin-guide/mm/numa_memory_policy.rst

···
 	address range or file.  During system boot up, the temporary
 	interleaved system default policy works in this mode.
 
+MPOL_PREFERRED_MANY
+	This mode specifices that the allocation should be preferrably
+	satisfied from the nodemask specified in the policy. If there is
+	a memory pressure on all nodes in the nodemask, the allocation
+	can fall back to all existing numa nodes. This is effectively
+	MPOL_PREFERRED allowed for a mask rather than a single node.
+
 NUMA memory policy supports the following optional mode flags:
 
 MPOL_F_STATIC_NODES
···
 	nodes changes after the memory policy has been defined.
 
 	Without this flag, any time a mempolicy is rebound because of a
-	change in the set of allowed nodes, the node (Preferred) or
-	nodemask (Bind, Interleave) is remapped to the new set of
-	allowed nodes.  This may result in nodes being used that were
-	previously undesired.
+        change in the set of allowed nodes, the preferred nodemask (Preferred
+        Many), preferred node (Preferred) or nodemask (Bind, Interleave) is
+        remapped to the new set of allowed nodes.  This may result in nodes
+        being used that were previously undesired.
 
 	With this flag, if the user-specified nodes overlap with the
 	nodes allowed by the task's cpuset, then the memory policy is

Documentation/admin-guide/sysctl/vm.rst

···
 
 This tunable takes a value in the range [0, 100] with a default value of
 20. This tunable determines how aggressively compaction is done in the
-background. Setting it to 0 disables proactive compaction.
+background. Write of a non zero value to this tunable will immediately
+trigger the proactive compaction. Setting it to 0 disables proactive compaction.
 
 Note that compaction has a non-trivial system-wide impact as pages
 belonging to different processes are moved around, which could also lead

Documentation/core-api/cachetlb.rst

···
 
   ``void flush_dcache_page(struct page *page)``
 
-	Any time the kernel writes to a page cache page, _OR_
-	the kernel is about to read from a page cache page and
-	user space shared/writable mappings of this page potentially
-	exist, this routine is called.
+        This routines must be called when:
+
+	  a) the kernel did write to a page that is in the page cache page
+	     and / or in high memory
+	  b) the kernel is about to read from a page cache page and user space
+	     shared/writable mappings of this page potentially exist.  Note
+	     that {get,pin}_user_pages{_fast} already call flush_dcache_page
+	     on any page found in the user address space and thus driver
+	     code rarely needs to take this into account.
 
 	.. note::
 
···
 	      handling vfs symlinks in the page cache need not call
 	      this interface at all.
 
-	The phrase "kernel writes to a page cache page" means,
-	specifically, that the kernel executes store instructions
-	that dirty data in that page at the page->virtual mapping
-	of that page.  It is important to flush here to handle
-	D-cache aliasing, to make sure these kernel stores are
-	visible to user space mappings of that page.
+	The phrase "kernel writes to a page cache page" means, specifically,
+	that the kernel executes store instructions that dirty data in that
+	page at the page->virtual mapping of that page.  It is important to
+	flush here to handle D-cache aliasing, to make sure these kernel stores
+	are visible to user space mappings of that page.
 
-	The corollary case is just as important, if there are users
-	which have shared+writable mappings of this file, we must make
-	sure that kernel reads of these pages will see the most recent
-	stores done by the user.
+	The corollary case is just as important, if there are users which have
+	shared+writable mappings of this file, we must make sure that kernel
+	reads of these pages will see the most recent stores done by the user.
 
-	If D-cache aliasing is not an issue, this routine may
-	simply be defined as a nop on that architecture.
+	If D-cache aliasing is not an issue, this routine may simply be defined
+	as a nop on that architecture.
 
-        There is a bit set aside in page->flags (PG_arch_1) as
-	"architecture private".  The kernel guarantees that,
-	for pagecache pages, it will clear this bit when such
-	a page first enters the pagecache.
+        There is a bit set aside in page->flags (PG_arch_1) as "architecture
+	private".  The kernel guarantees that, for pagecache pages, it will
+	clear this bit when such a page first enters the pagecache.
 
-	This allows these interfaces to be implemented much more
-	efficiently.  It allows one to "defer" (perhaps indefinitely)
-	the actual flush if there are currently no user processes
-	mapping this page.  See sparc64's flush_dcache_page and
-	update_mmu_cache implementations for an example of how to go
-	about doing this.
+	This allows these interfaces to be implemented much more efficiently.
+	It allows one to "defer" (perhaps indefinitely) the actual flush if
+	there are currently no user processes mapping this page.  See sparc64's
+	flush_dcache_page and update_mmu_cache implementations for an example
+	of how to go about doing this.
 
-	The idea is, first at flush_dcache_page() time, if
-	page->mapping->i_mmap is an empty tree, just mark the architecture
-	private page flag bit.  Later, in update_mmu_cache(), a check is
-	made of this flag bit, and if set the flush is done and the flag
-	bit is cleared.
+	The idea is, first at flush_dcache_page() time, if page_file_mapping()
+	returns a mapping, and mapping_mapped on that mapping returns %false,
+	just mark the architecture private page flag bit.  Later, in
+	update_mmu_cache(), a check is made of this flag bit, and if set the
+	flush is done and the flag bit is cleared.
 
 	.. important::
 
···
 	implementation is a nop (and should remain so for all coherent
 	architectures).  For incoherent architectures, it should flush
 	the cache of the page at vmaddr.
-
-  ``void flush_kernel_dcache_page(struct page *page)``
-
-	When the kernel needs to modify a user page is has obtained
-	with kmap, it calls this function after all modifications are
-	complete (but before kunmapping it) to bring the underlying
-	page up to date.  It is assumed here that the user has no
-	incoherent cached copies (i.e. the original page was obtained
-	from a mechanism like get_user_pages()).  The default
-	implementation is a nop and should remain so on all coherent
-	architectures.  On incoherent architectures, this should flush
-	the kernel cache for page (using page_address(page)).
-
 
   ``void flush_icache_range(unsigned long start, unsigned long end)``
 

Documentation/dev-tools/kasan.rst

···
 With ``kasan_multi_shot``, KASAN prints a report on every invalid access. This
 effectively disables ``panic_on_warn`` for KASAN reports.
 
+Alternatively, independent of ``panic_on_warn`` the ``kasan.fault=`` boot
+parameter can be used to control panic and reporting behaviour:
+
+- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
+  report or also panic the kernel (default: ``report``). The panic happens even
+  if ``kasan_multi_shot`` is enabled.
+
 Hardware tag-based KASAN mode (see the section about various modes below) is
 intended for use in production as a security mitigation. Therefore, it supports
-boot parameters that allow disabling KASAN or controlling its features.
+additional boot parameters that allow disabling KASAN or controlling features:
 
 - ``kasan=off`` or ``=on`` controls whether KASAN is enabled (default: ``on``).
 
···
 
 - ``kasan.stacktrace=off`` or ``=on`` disables or enables alloc and free stack
   traces collection (default: ``on``).
-
-- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
-  report or also panic the kernel (default: ``report``). The panic happens even
-  if ``kasan_multi_shot`` is enabled.
 
 Implementation details
 ----------------------

Documentation/translations/zh_CN/core-api/cachetlb.rst

···
 	用。默认的实现是nop（对于所有相干的架构应该保持这样）。对于不一致性
 	的架构，它应该刷新vmaddr处的页面缓存。
 
-  ``void flush_kernel_dcache_page(struct page *page)``
-
-	当内核需要修改一个用kmap获得的用户页时，它会在所有修改完成后（但在
-	kunmapping之前）调用这个函数，以使底层页面达到最新状态。这里假定用
-	户没有不一致性的缓存副本（即原始页面是从类似get_user_pages()的机制
-	中获得的）。默认的实现是一个nop，在所有相干的架构上都应该如此。在不
-	一致性的架构上，这应该刷新内核缓存中的页面（使用page_address(page)）。
-
-
   ``void flush_icache_range(unsigned long start, unsigned long end)``
 
 	当内核存储到它将执行的地址中时（例如在加载模块时），这个函数被调用。

Documentation/vm/hwpoison.rst

···
 ===========
 - Not all page types are supported and never will. Most kernel internal
   objects cannot be recovered, only LRU pages for now.
-- Right now hugepage support is missing.
 
 ---
 Andi Kleen, Oct 2009

arch/alpha/kernel/syscalls/syscall.tbl

···
 554	common	landlock_create_ruleset		sys_landlock_create_ruleset
 555	common	landlock_add_rule		sys_landlock_add_rule
 556	common	landlock_restrict_self		sys_landlock_restrict_self
+# 557 reserved for memfd_secret
+558	common	process_mrelease		sys_process_mrelease

arch/arm/include/asm/cacheflush.h

···
 #define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
 extern void flush_dcache_page(struct page *);
 
+#define ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE 1
 static inline void flush_kernel_vmap_range(void *addr, int size)
 {
 	if ((cache_is_vivt() || cache_is_vipt_aliasing()))
···
 	if (PageAnon(page))
 		__flush_anon_page(vma, page, vmaddr);
 }
-
-#define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
-extern void flush_kernel_dcache_page(struct page *);
 
 #define flush_dcache_mmap_lock(mapping)		xa_lock_irq(&mapping->i_pages)
 #define flush_dcache_mmap_unlock(mapping)	xa_unlock_irq(&mapping->i_pages)

arch/arm/kernel/setup.c

···
 		unsigned long long lowmem_max = __pa(high_memory - 1) + 1;
 		if (crash_max > lowmem_max)
 			crash_max = lowmem_max;
-		crash_base = memblock_find_in_range(CRASH_ALIGN, crash_max,
-						    crash_size, CRASH_ALIGN);
+
+		crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
+						       CRASH_ALIGN, crash_max);
 		if (!crash_base) {
 			pr_err("crashkernel reservation failed - No suitable area found.\n");
 			return;
 		}
 	} else {
+		unsigned long long crash_max = crash_base + crash_size;
 		unsigned long long start;
 
-		start = memblock_find_in_range(crash_base,
-					       crash_base + crash_size,
-					       crash_size, SECTION_SIZE);
-		if (start != crash_base) {
+		start = memblock_phys_alloc_range(crash_size, SECTION_SIZE,
+						  crash_base, crash_max);
+		if (!start) {
 			pr_err("crashkernel reservation failed - memory is in use.\n");
 			return;
 		}
-	}
-
-	ret = memblock_reserve(crash_base, crash_size);
-	if (ret < 0) {
-		pr_warn("crashkernel reservation failed - memory is in use (0x%lx)\n",
-			(unsigned long)crash_base);
-		return;
 	}
 
 	pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n",

arch/arm/mm/flush.c

···
 EXPORT_SYMBOL(flush_dcache_page);
 
 /*
- * Ensure cache coherency for the kernel mapping of this page. We can
- * assume that the page is pinned via kmap.
- *
- * If the page only exists in the page cache and there are no user
- * space mappings, this is a no-op since the page was already marked
- * dirty at creation.  Otherwise, we need to flush the dirty kernel
- * cache lines directly.
- */
-void flush_kernel_dcache_page(struct page *page)
-{
-	if (cache_is_vivt() || cache_is_vipt_aliasing()) {
-		struct address_space *mapping;
-
-		mapping = page_mapping_file(page);
-
-		if (!mapping || mapping_mapped(mapping)) {
-			void *addr;
-
-			addr = page_address(page);
-			/*
-			 * kmap_atomic() doesn't set the page virtual
-			 * address for highmem pages, and
-			 * kunmap_atomic() takes care of cache
-			 * flushing already.
-			 */
-			if (!IS_ENABLED(CONFIG_HIGHMEM) || addr)
-				__cpuc_flush_dcache_area(addr, PAGE_SIZE);
-		}
-	}
-}
-EXPORT_SYMBOL(flush_kernel_dcache_page);
-
-/*
  * Flush an anonymous page so that users of get_user_pages()
  * can safely access the data.  The expected sequence is:
  *

arch/arm/mm/nommu.c

···
 }
 EXPORT_SYMBOL(flush_dcache_page);
 
-void flush_kernel_dcache_page(struct page *page)
-{
-	__cpuc_flush_dcache_area(page_address(page), PAGE_SIZE);
-}
-EXPORT_SYMBOL(flush_kernel_dcache_page);
-
 void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
 		       unsigned long uaddr, void *dst, const void *src,
 		       unsigned long len)

arch/arm/tools/syscall.tbl

···
 444	common	landlock_create_ruleset		sys_landlock_create_ruleset
 445	common	landlock_add_rule		sys_landlock_add_rule
 446	common	landlock_restrict_self		sys_landlock_restrict_self
+# 447 reserved for memfd_secret
+448	common	process_mrelease		sys_process_mrelease

arch/arm64/include/asm/unistd.h

···
 #define __ARM_NR_compat_set_tls		(__ARM_NR_COMPAT_BASE + 5)
 #define __ARM_NR_COMPAT_END		(__ARM_NR_COMPAT_BASE + 0x800)
 
-#define __NR_compat_syscalls		447
+#define __NR_compat_syscalls		449
 #endif
 
 #define __ARCH_WANT_SYS_CLONE

arch/arm64/include/asm/unistd32.h

···
 __SYSCALL(__NR_landlock_add_rule, sys_landlock_add_rule)
 #define __NR_landlock_restrict_self 446
 __SYSCALL(__NR_landlock_restrict_self, sys_landlock_restrict_self)
+#define __NR_process_mrelease 448
+__SYSCALL(__NR_process_mrelease, sys_process_mrelease)
 
 /*
  * Please add new compat syscalls above this comment and update

arch/arm64/kvm/hyp/reserved_mem.c

···
 	 * this is unmapped from the host stage-2, and fallback to PAGE_SIZE.
 	 */
 	hyp_mem_size = hyp_mem_pages << PAGE_SHIFT;
-	hyp_mem_base = memblock_find_in_range(0, memblock_end_of_DRAM(),
-					      ALIGN(hyp_mem_size, PMD_SIZE),
-					      PMD_SIZE);
+	hyp_mem_base = memblock_phys_alloc(ALIGN(hyp_mem_size, PMD_SIZE),
+					   PMD_SIZE);
 	if (!hyp_mem_base)
-		hyp_mem_base = memblock_find_in_range(0, memblock_end_of_DRAM(),
-						      hyp_mem_size, PAGE_SIZE);
+		hyp_mem_base = memblock_phys_alloc(hyp_mem_size, PAGE_SIZE);
 	else
 		hyp_mem_size = ALIGN(hyp_mem_size, PMD_SIZE);
 
···
 		kvm_err("Failed to reserve hyp memory\n");
 		return;
 	}
-	memblock_reserve(hyp_mem_base, hyp_mem_size);
 
 	kvm_info("Reserved %lld MiB at 0x%llx\n", hyp_mem_size >> 20,
 		 hyp_mem_base);

arch/arm64/mm/init.c

···
 static void __init reserve_crashkernel(void)
 {
 	unsigned long long crash_base, crash_size;
+	unsigned long long crash_max = arm64_dma_phys_limit;
 	int ret;
 
 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
···
 
 	crash_size = PAGE_ALIGN(crash_size);
 
-	if (crash_base == 0) {
-		/* Current arm64 boot protocol requires 2MB alignment */
-		crash_base = memblock_find_in_range(0, arm64_dma_phys_limit,
-				crash_size, SZ_2M);
-		if (crash_base == 0) {
-			pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
-				crash_size);
-			return;
-		}
-	} else {
-		/* User specifies base address explicitly. */
-		if (!memblock_is_region_memory(crash_base, crash_size)) {
-			pr_warn("cannot reserve crashkernel: region is not memory\n");
-			return;
-		}
+	/* User specifies base address explicitly. */
+	if (crash_base)
+		crash_max = crash_base + crash_size;
 
-		if (memblock_is_region_reserved(crash_base, crash_size)) {
-			pr_warn("cannot reserve crashkernel: region overlaps reserved memory\n");
-			return;
-		}
-
-		if (!IS_ALIGNED(crash_base, SZ_2M)) {
-			pr_warn("cannot reserve crashkernel: base address is not 2MB aligned\n");
-			return;
-		}
+	/* Current arm64 boot protocol requires 2MB alignment */
+	crash_base = memblock_phys_alloc_range(crash_size, SZ_2M,
+					       crash_base, crash_max);
+	if (!crash_base) {
+		pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
+			crash_size);
+		return;
 	}
-	memblock_reserve(crash_base, crash_size);
 
 	pr_info("crashkernel reserved: 0x%016llx - 0x%016llx (%lld MB)\n",
 		crash_base, crash_base + crash_size, crash_size >> 20);

arch/csky/abiv1/cacheflush.c

···
 	}
 }
 
-void flush_kernel_dcache_page(struct page *page)
-{
-	struct address_space *mapping;
-
-	mapping = page_mapping_file(page);
-
-	if (!mapping || mapping_mapped(mapping))
-		dcache_wbinv_all();
-}
-EXPORT_SYMBOL(flush_kernel_dcache_page);
-
 void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
 	unsigned long end)
 {

arch/csky/abiv1/inc/abi/cacheflush.h

···
 #define flush_cache_page(vma, page, pfn)	cache_wbinv_all()
 #define flush_cache_dup_mm(mm)			cache_wbinv_all()
 
-#define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
-extern void flush_kernel_dcache_page(struct page *);
-
 #define flush_dcache_mmap_lock(mapping)		xa_lock_irq(&mapping->i_pages)
 #define flush_dcache_mmap_unlock(mapping)	xa_unlock_irq(&mapping->i_pages)
 
+#define ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE 1
 static inline void flush_kernel_vmap_range(void *addr, int size)
 {
 	dcache_wbinv_all();

arch/csky/kernel/probes/kprobes.c

···
 		 * normal page fault.
 		 */
 		regs->pc = (unsigned long) cur->addr;
-		if (!instruction_pointer(regs))
-			BUG();
+		BUG_ON(!instruction_pointer(regs));
 
 		if (kcb->kprobe_status == KPROBE_REENTER)
 			restore_previous_kprobe(kcb);

arch/ia64/include/asm/meminit.h

···
 };
 
 extern struct rsvd_region rsvd_region[IA64_MAX_RSVD_REGIONS + 1];
-extern int num_rsvd_regions;
 
 extern void find_memory (void);
 extern void reserve_memory (void);
···
 extern int find_max_min_low_pfn (u64, u64, void *);
 
 extern unsigned long vmcore_find_descriptor_size(unsigned long address);
-extern int reserve_elfcorehdr(u64 *start, u64 *end);
 
 /*
  * For rounding an address to the next IA64_GRANULE_SIZE or order

arch/ia64/kernel/acpi.c

···
 /*
  * acpi_suspend_lowlevel() - save kernel state and suspend.
  *
- * TBD when when IA64 starts to support suspend...
+ * TBD when IA64 starts to support suspend...
  */
 int acpi_suspend_lowlevel(void) { return 0; }

arch/ia64/kernel/setup.c

···
  * We use a special marker for the end of memory and it uses the extra (+1) slot
  */
 struct rsvd_region rsvd_region[IA64_MAX_RSVD_REGIONS + 1] __initdata;
-int num_rsvd_regions __initdata;
+static int num_rsvd_regions __initdata;
 
 
 /*
···
 static inline void __init setup_crashkernel(unsigned long total, int *n)
 {}
 #endif
+
+#ifdef CONFIG_CRASH_DUMP
+static int __init reserve_elfcorehdr(u64 *start, u64 *end)
+{
+	u64 length;
+
+	/* We get the address using the kernel command line,
+	 * but the size is extracted from the EFI tables.
+	 * Both address and size are required for reservation
+	 * to work properly.
+	 */
+
+	if (!is_vmcore_usable())
+		return -EINVAL;
+
+	if ((length = vmcore_find_descriptor_size(elfcorehdr_addr)) == 0) {
+		vmcore_unusable();
+		return -EINVAL;
+	}
+
+	*start = (unsigned long)__va(elfcorehdr_addr);
+	*end = *start + length;
+	return 0;
+}
+#endif /* CONFIG_CRASH_DUMP */
 
 /**
  * reserve_memory - setup reserved memory areas
···
 	return 0;
 }
 early_param("nomca", setup_nomca);
-
-#ifdef CONFIG_CRASH_DUMP
-int __init reserve_elfcorehdr(u64 *start, u64 *end)
-{
-	u64 length;
-
-	/* We get the address using the kernel command line,
-	 * but the size is extracted from the EFI tables.
-	 * Both address and size are required for reservation
-	 * to work properly.
-	 */
-
-	if (!is_vmcore_usable())
-		return -EINVAL;
-
-	if ((length = vmcore_find_descriptor_size(elfcorehdr_addr)) == 0) {
-		vmcore_unusable();
-		return -EINVAL;
-	}
-
-	*start = (unsigned long)__va(elfcorehdr_addr);
-	*end = *start + length;
-	return 0;
-}
-
-#endif /* CONFIG_PROC_VMCORE */
 
 void __init
 setup_arch (char **cmdline_p)

arch/ia64/kernel/syscalls/syscall.tbl

···
 444	common	landlock_create_ruleset		sys_landlock_create_ruleset
 445	common	landlock_add_rule		sys_landlock_add_rule
 446	common	landlock_restrict_self		sys_landlock_restrict_self
+# 447 reserved for memfd_secret
+448	common	process_mrelease		sys_process_mrelease

arch/m68k/kernel/syscalls/syscall.tbl

···
 444	common	landlock_create_ruleset		sys_landlock_create_ruleset
 445	common	landlock_add_rule		sys_landlock_add_rule
 446	common	landlock_restrict_self		sys_landlock_restrict_self
+# 447 reserved for memfd_secret
+448	common	process_mrelease		sys_process_mrelease

arch/microblaze/include/asm/page.h

···
 #  define page_to_phys(page)     (page_to_pfn(page) << PAGE_SHIFT)
 
 #  define ARCH_PFN_OFFSET	(memory_start >> PAGE_SHIFT)
-#  define pfn_valid(pfn)	((pfn) < (max_mapnr + ARCH_PFN_OFFSET))
-
+#  define pfn_valid(pfn)	((pfn) >= ARCH_PFN_OFFSET && (pfn) < (max_mapnr + ARCH_PFN_OFFSET))
 # endif /* __ASSEMBLY__ */
 
 #define	virt_addr_valid(vaddr)	(pfn_valid(virt_to_pfn(vaddr)))

arch/microblaze/include/asm/pgtable.h

···
 
 asmlinkage void __init mmu_init(void);
 
-void __init *early_get_page(void);
-
 #endif /* __ASSEMBLY__ */
 #endif /* __KERNEL__ */
 

arch/microblaze/kernel/syscalls/syscall.tbl

···
 444	common	landlock_create_ruleset		sys_landlock_create_ruleset
 445	common	landlock_add_rule		sys_landlock_add_rule
 446	common	landlock_restrict_self		sys_landlock_restrict_self
+# 447 reserved for memfd_secret
+448	common	process_mrelease		sys_process_mrelease

arch/microblaze/mm/init.c

···
 	dma_contiguous_reserve(memory_start + lowmem_size - 1);
 }
 
-/* This is only called until mem_init is done. */
-void __init *early_get_page(void)
-{
-	/*
-	 * Mem start + kernel_tlb -> here is limit
-	 * because of mem mapping from head.S
-	 */
-	return memblock_alloc_try_nid_raw(PAGE_SIZE, PAGE_SIZE,
-				MEMBLOCK_LOW_LIMIT, memory_start + kernel_tlb,
-				NUMA_NO_NODE);
-}
-
 void * __ref zalloc_maybe_bootmem(size_t size, gfp_t mask)
 {
 	void *p;

arch/microblaze/mm/pgtable.c

···
 #include <linux/init.h>
 #include <linux/mm_types.h>
 #include <linux/pgtable.h>
+#include <linux/memblock.h>
 
 #include <asm/pgalloc.h>
 #include <linux/io.h>
···
 
 __ref pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
 {
-	pte_t *pte;
-	if (mem_init_done) {
-		pte = (pte_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
-	} else {
-		pte = (pte_t *)early_get_page();
-		if (pte)
-			clear_page(pte);
-	}
-	return pte;
+	if (mem_init_done)
+		return (pte_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+	else
+		return memblock_alloc_try_nid(PAGE_SIZE, PAGE_SIZE,
+					      MEMBLOCK_LOW_LIMIT,
+					      memory_start + kernel_tlb,
+					      NUMA_NO_NODE);
 }
 
 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)

arch/mips/include/asm/cacheflush.h

···
 	kunmap_coherent();
 }
 
-#define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
-static inline void flush_kernel_dcache_page(struct page *page)
-{
-	BUG_ON(cpu_has_dc_aliases && PageHighMem(page));
-	flush_dcache_page(page);
-}
-
+#define ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE 1
 /*
  * For now flush_kernel_vmap_range and invalidate_kernel_vmap_range both do a
  * cache writeback and invalidate operation.

arch/mips/kernel/setup.c

···
 		return;
 
 	if (crash_base <= 0) {
-		crash_base = memblock_find_in_range(CRASH_ALIGN, CRASH_ADDR_MAX,
-							crash_size, CRASH_ALIGN);
+		crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
+						       CRASH_ALIGN,
+						       CRASH_ADDR_MAX);
 		if (!crash_base) {
 			pr_warn("crashkernel reservation failed - No suitable area found.\n");
 			return;
···
 	} else {
 		unsigned long long start;
 
-		start = memblock_find_in_range(crash_base, crash_base + crash_size,
-						crash_size, 1);
+		start = memblock_phys_alloc_range(crash_size, 1,
+						  crash_base,
+						  crash_base + crash_size);
 		if (start != crash_base) {
 			pr_warn("Invalid memory region reserved for crash kernel\n");
 			return;
···
 	mips_reserve_vmcore();
 
 	mips_parse_crashkernel();
-#ifdef CONFIG_KEXEC
-	if (crashk_res.start != crashk_res.end)
-		memblock_reserve(crashk_res.start, resource_size(&crashk_res));
-#endif
 	device_tree_init();
 
 	/*

arch/mips/kernel/syscalls/syscall_n32.tbl

···
 444	n32	landlock_create_ruleset		sys_landlock_create_ruleset
 445	n32	landlock_add_rule		sys_landlock_add_rule
 446	n32	landlock_restrict_self		sys_landlock_restrict_self
+# 447 reserved for memfd_secret
+448	n32	process_mrelease		sys_process_mrelease

arch/mips/kernel/syscalls/syscall_n64.tbl

···
 444	n64	landlock_create_ruleset		sys_landlock_create_ruleset
 445	n64	landlock_add_rule		sys_landlock_add_rule
 446	n64	landlock_restrict_self		sys_landlock_restrict_self
+# 447 reserved for memfd_secret
+448	n64	process_mrelease		sys_process_mrelease

arch/mips/kernel/syscalls/syscall_o32.tbl

···
 444	o32	landlock_create_ruleset		sys_landlock_create_ruleset
 445	o32	landlock_add_rule		sys_landlock_add_rule
 446	o32	landlock_restrict_self		sys_landlock_restrict_self
+# 447 reserved for memfd_secret
+448	o32	process_mrelease		sys_process_mrelease

arch/nds32/include/asm/cacheflush.h

···
 void flush_anon_page(struct vm_area_struct *vma,
 		     struct page *page, unsigned long vaddr);
 
-#define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
-void flush_kernel_dcache_page(struct page *page);
+#define ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE 1
 void flush_kernel_vmap_range(void *addr, int size);
 void invalidate_kernel_vmap_range(void *addr, int size);
 #define flush_dcache_mmap_lock(mapping)   xa_lock_irq(&(mapping)->i_pages)

arch/nds32/mm/cacheflush.c

···
 	local_irq_restore(flags);
 }
 
-void flush_kernel_dcache_page(struct page *page)
-{
-	unsigned long flags;
-	local_irq_save(flags);
-	cpu_dcache_wbinval_page((unsigned long)page_address(page));
-	local_irq_restore(flags);
-}
-EXPORT_SYMBOL(flush_kernel_dcache_page);
-
 void flush_kernel_vmap_range(void *addr, int size)
 {
 	unsigned long flags;

arch/parisc/include/asm/cacheflush.h

···
 void flush_cache_all(void);
 void flush_cache_mm(struct mm_struct *mm);
 
-#define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
 void flush_kernel_dcache_page_addr(void *addr);
-static inline void flush_kernel_dcache_page(struct page *page)
-{
-	flush_kernel_dcache_page_addr(page_address(page));
-}
 
 #define flush_kernel_dcache_range(start,size) \
 	flush_kernel_dcache_range_asm((start), (start)+(size));
 
+#define ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE 1
 void flush_kernel_vmap_range(void *vaddr, int size);
 void invalidate_kernel_vmap_range(void *vaddr, int size);
 
···
 #define flush_dcache_mmap_unlock(mapping)	xa_unlock_irq(&mapping->i_pages)
 
 #define flush_icache_page(vma,page)	do { 		\
-	flush_kernel_dcache_page(page);			\
+	flush_kernel_dcache_page_addr(page_address(page)); \
 	flush_kernel_icache_page(page_address(page)); 	\
 } while (0)
 

arch/parisc/kernel/cache.c

···
 		return;
 	}
 
-	flush_kernel_dcache_page(page);
+	flush_kernel_dcache_page_addr(page_address(page));
 
 	if (!mapping)
 		return;
···
 
 /* Defined in arch/parisc/kernel/pacache.S */
 EXPORT_SYMBOL(flush_kernel_dcache_range_asm);
-EXPORT_SYMBOL(flush_kernel_dcache_page_asm);
 EXPORT_SYMBOL(flush_data_cache_local);
 EXPORT_SYMBOL(flush_kernel_icache_range_asm);
 

arch/parisc/kernel/syscalls/syscall.tbl

···
 444	common	landlock_create_ruleset		sys_landlock_create_ruleset
 445	common	landlock_add_rule		sys_landlock_add_rule
 446	common	landlock_restrict_self		sys_landlock_restrict_self
+# 447 reserved for memfd_secret
+448	common	process_mrelease		sys_process_mrelease

arch/powerpc/kernel/syscalls/syscall.tbl

···
 444	common	landlock_create_ruleset		sys_landlock_create_ruleset
 445	common	landlock_add_rule		sys_landlock_add_rule
 446	common	landlock_restrict_self		sys_landlock_restrict_self
+# 447 reserved for memfd_secret
+448	common	process_mrelease		sys_process_mrelease

arch/powerpc/platforms/pseries/hotplug-memory.c

···
 static struct memory_block *lmb_to_memblock(struct drmem_lmb *lmb)
 {
 	unsigned long section_nr;
-	struct mem_section *mem_sect;
 	struct memory_block *mem_block;
 
 	section_nr = pfn_to_section_nr(PFN_DOWN(lmb->base_addr));
-	mem_sect = __nr_to_section(section_nr);
 
-	mem_block = find_memory_block(mem_sect);
+	mem_block = find_memory_block(section_nr);
 	return mem_block;
 }
 

arch/riscv/mm/init.c

···
 
 	crash_size = PAGE_ALIGN(crash_size);
 
-	if (crash_base == 0) {
-		/*
-		 * Current riscv boot protocol requires 2MB alignment for
-		 * RV64 and 4MB alignment for RV32 (hugepage size)
-		 */
-		crash_base = memblock_find_in_range(search_start, search_end,
-						    crash_size, PMD_SIZE);
-
-		if (crash_base == 0) {
-			pr_warn("crashkernel: couldn't allocate %lldKB\n",
-				crash_size >> 10);
-			return;
-		}
-	} else {
-		/* User specifies base address explicitly. */
-		if (!memblock_is_region_memory(crash_base, crash_size)) {
-			pr_warn("crashkernel: requested region is not memory\n");
-			return;
-		}
-
-		if (memblock_is_region_reserved(crash_base, crash_size)) {
-			pr_warn("crashkernel: requested region is reserved\n");
-			return;
-		}
-
-
-		if (!IS_ALIGNED(crash_base, PMD_SIZE)) {
-			pr_warn("crashkernel: requested region is misaligned\n");
-			return;
-		}
+	if (crash_base) {
+		search_start = crash_base;
+		search_end = crash_base + crash_size;
 	}
-	memblock_reserve(crash_base, crash_size);
+
+	/*
+	 * Current riscv boot protocol requires 2MB alignment for
+	 * RV64 and 4MB alignment for RV32 (hugepage size)
+	 */
+	crash_base = memblock_phys_alloc_range(crash_size, PMD_SIZE,
+					       search_start, search_end);
+	if (crash_base == 0) {
+		pr_warn("crashkernel: couldn't allocate %lldKB\n",
+			crash_size >> 10);
+		return;
+	}
 
 	pr_info("crashkernel: reserved 0x%016llx - 0x%016llx (%lld MB)\n",
 		crash_base, crash_base + crash_size, crash_size >> 20);

arch/s390/kernel/setup.c

···
 			return;
 		}
 		low = crash_base ?: low;
-		crash_base = memblock_find_in_range(low, high, crash_size,
-						    KEXEC_CRASH_MEM_ALIGN);
+		crash_base = memblock_phys_alloc_range(crash_size,
+						       KEXEC_CRASH_MEM_ALIGN,
+						       low, high);
 	}
 
 	if (!crash_base) {
···
 		return;
 	}
 
-	if (register_memory_notifier(&kdump_mem_nb))
+	if (register_memory_notifier(&kdump_mem_nb)) {
+		memblock_free(crash_base, crash_size);
 		return;
+	}
 
 	if (!oldmem_data.start && MACHINE_IS_VM)
 		diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));

arch/s390/kernel/syscalls/syscall.tbl

···
 444  common	landlock_create_ruleset	sys_landlock_create_ruleset	sys_landlock_create_ruleset
 445  common	landlock_add_rule	sys_landlock_add_rule		sys_landlock_add_rule
 446  common	landlock_restrict_self	sys_landlock_restrict_self	sys_landlock_restrict_self
+# 447 reserved for memfd_secret
+448  common	process_mrelease	sys_process_mrelease		sys_process_mrelease

arch/s390/mm/fault.c

···
 		break;
 	case KERNEL_FAULT:
 		page = phys_to_page(addr);
-		if (unlikely(!try_get_page(page)))
+		if (unlikely(!try_get_compound_head(page, 1)))
 			break;
 		rc = arch_make_page_accessible(page);
 		put_page(page);

arch/sh/include/asm/cacheflush.h

···
 	if (boot_cpu_data.dcache.n_aliases && PageAnon(page))
 		__flush_anon_page(page, vmaddr);
 }
+
+#define ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE 1
 static inline void flush_kernel_vmap_range(void *addr, int size)
 {
 	__flush_wback_region(addr, size);
···
 static inline void invalidate_kernel_vmap_range(void *addr, int size)
 {
 	__flush_invalidate_region(addr, size);
-}
-
-#define ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
-static inline void flush_kernel_dcache_page(struct page *page)
-{
-	flush_dcache_page(page);
 }
 
 extern void copy_to_user_page(struct vm_area_struct *vma,

arch/sh/kernel/syscalls/syscall.tbl

···
 444	common	landlock_create_ruleset		sys_landlock_create_ruleset
 445	common	landlock_add_rule		sys_landlock_add_rule
 446	common	landlock_restrict_self		sys_landlock_restrict_self
+# 447 reserved for memfd_secret
+448	common	process_mrelease		sys_process_mrelease

arch/sparc/kernel/syscalls/syscall.tbl

···
 444	common	landlock_create_ruleset		sys_landlock_create_ruleset
 445	common	landlock_add_rule		sys_landlock_add_rule
 446	common	landlock_restrict_self		sys_landlock_restrict_self
+# 447 reserved for memfd_secret
+448	common	process_mrelease		sys_process_mrelease

arch/x86/entry/syscalls/syscall_32.tbl

···
 445	i386	landlock_add_rule	sys_landlock_add_rule
 446	i386	landlock_restrict_self	sys_landlock_restrict_self
 447	i386	memfd_secret		sys_memfd_secret
+448	i386	process_mrelease	sys_process_mrelease

arch/x86/entry/syscalls/syscall_64.tbl

···
 445	common	landlock_add_rule	sys_landlock_add_rule
 446	common	landlock_restrict_self	sys_landlock_restrict_self
 447	common	memfd_secret		sys_memfd_secret
+448	common	process_mrelease	sys_process_mrelease
 
 #
 # Due to a historical design error, certain syscalls are numbered differently

arch/x86/kernel/aperture_64.c

···
 	 * memory. Unfortunately we cannot move it up because that would
 	 * make the IOMMU useless.
 	 */
-	addr = memblock_find_in_range(GART_MIN_ADDR, GART_MAX_ADDR,
-				      aper_size, aper_size);
+	addr = memblock_phys_alloc_range(aper_size, aper_size,
+					 GART_MIN_ADDR, GART_MAX_ADDR);
 	if (!addr) {
 		pr_err("Cannot allocate aperture memory hole [mem %#010lx-%#010lx] (%uKB)\n",
 		       addr, addr + aper_size - 1, aper_size >> 10);
 		return 0;
 	}
-	memblock_reserve(addr, aper_size);
 	pr_info("Mapping aperture over RAM [mem %#010lx-%#010lx] (%uKB)\n",
 		addr, addr + aper_size - 1, aper_size >> 10);
 	register_nosave_region(addr >> PAGE_SHIFT,

arch/x86/kernel/ldt.c

···
 	if (num_entries > LDT_ENTRIES)
 		return NULL;
 
-	new_ldt = kmalloc(sizeof(struct ldt_struct), GFP_KERNEL);
+	new_ldt = kmalloc(sizeof(struct ldt_struct), GFP_KERNEL_ACCOUNT);
 	if (!new_ldt)
 		return NULL;
 
···
 	 * than PAGE_SIZE.
 	 */
 	if (alloc_size > PAGE_SIZE)
-		new_ldt->entries = vzalloc(alloc_size);
+		new_ldt->entries = __vmalloc(alloc_size, GFP_KERNEL_ACCOUNT | __GFP_ZERO);
 	else
-		new_ldt->entries = (void *)get_zeroed_page(GFP_KERNEL);
+		new_ldt->entries = (void *)get_zeroed_page(GFP_KERNEL_ACCOUNT);
 
 	if (!new_ldt->entries) {
 		kfree(new_ldt);

arch/x86/mm/init.c

···
 		unsigned long ret = 0;
 
 		if (min_pfn_mapped < max_pfn_mapped) {
-			ret = memblock_find_in_range(
+			ret = memblock_phys_alloc_range(
+					PAGE_SIZE * num, PAGE_SIZE,
 					min_pfn_mapped << PAGE_SHIFT,
-					max_pfn_mapped << PAGE_SHIFT,
-					PAGE_SIZE * num , PAGE_SIZE);
+					max_pfn_mapped << PAGE_SHIFT);
 		}
-		if (ret)
-			memblock_reserve(ret, PAGE_SIZE * num);
-		else if (can_use_brk_pgt)
+		if (!ret && can_use_brk_pgt)
 			ret = __pa(extend_brk(PAGE_SIZE * num, PAGE_SIZE));
 
 		if (!ret)
···
 	unsigned long addr;
 	unsigned long mapped_ram_size = 0;
 
-	/* xen has big range in reserved near end of ram, skip it at first.*/
-	addr = memblock_find_in_range(map_start, map_end, PMD_SIZE, PMD_SIZE);
+	/*
+	 * Systems that have many reserved areas near top of the memory,
+	 * e.g. QEMU with less than 1G RAM and EFI enabled, or Xen, will
+	 * require lots of 4K mappings which may exhaust pgt_buf.
+	 * Start with top-most PMD_SIZE range aligned at PMD_SIZE to ensure
+	 * there is enough mapped memory that can be allocated from
+	 * memblock.
+	 */
+	addr = memblock_phys_alloc_range(PMD_SIZE, PMD_SIZE, map_start,
+					 map_end);
+	memblock_free(addr, PMD_SIZE);
 	real_end = addr + PMD_SIZE;
 
 	/* step_size need to be small so pgt_buf from BRK could cover it */

arch/x86/mm/numa.c

···
 	cnt++;
 	size = cnt * cnt * sizeof(numa_distance[0]);
 
-	phys = memblock_find_in_range(0, PFN_PHYS(max_pfn_mapped),
-				      size, PAGE_SIZE);
+	phys = memblock_phys_alloc_range(size, PAGE_SIZE, 0,
+					 PFN_PHYS(max_pfn_mapped));
 	if (!phys) {
 		pr_warn("Warning: can't allocate distance table!\n");
 		/* don't retry until explicitly reset */
 		numa_distance = (void *)1LU;
 		return -ENOMEM;
 	}
-	memblock_reserve(phys, size);
 
 	numa_distance = __va(phys);
 	numa_distance_cnt = cnt;

arch/x86/mm/numa_emulation.c

···
 	if (numa_dist_cnt) {
 		u64 phys;
 
-		phys = memblock_find_in_range(0, PFN_PHYS(max_pfn_mapped),
-					      phys_size, PAGE_SIZE);
+		phys = memblock_phys_alloc_range(phys_size, PAGE_SIZE, 0,
+						 PFN_PHYS(max_pfn_mapped));
 		if (!phys) {
 			pr_warn("NUMA: Warning: can't allocate copy of distance table, disabling emulation\n");
 			goto no_emu;
 		}
-		memblock_reserve(phys, phys_size);
 		phys_dist = __va(phys);
 
 		for (i = 0; i < numa_dist_cnt; i++)

arch/x86/realmode/init.c

···
 	WARN_ON(slab_is_available());
 
 	/* Has to be under 1M so we can execute real-mode AP code. */
-	mem = memblock_find_in_range(0, 1<<20, size, PAGE_SIZE);
+	mem = memblock_phys_alloc_range(size, PAGE_SIZE, 0, 1<<20);
 	if (!mem)
 		pr_info("No sub-1M memory is available for the trampoline\n");
 	else

arch/xtensa/kernel/syscalls/syscall.tbl

···
 444	common	landlock_create_ruleset		sys_landlock_create_ruleset
 445	common	landlock_add_rule		sys_landlock_add_rule
 446	common	landlock_restrict_self		sys_landlock_restrict_self
+# 447 reserved for memfd_secret
+448	common	process_mrelease		sys_process_mrelease

block/blk-map.c

···
 
 static void bio_invalidate_vmalloc_pages(struct bio *bio)
 {
-#ifdef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
+#ifdef ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE
 	if (bio->bi_private && !op_is_write(bio_op(bio))) {
 		unsigned long i, len = 0;
 

drivers/acpi/tables.c

···
 	}
 
 	acpi_tables_addr =
-		memblock_find_in_range(0, ACPI_TABLE_UPGRADE_MAX_PHYS,
-				       all_tables_size, PAGE_SIZE);
+		memblock_phys_alloc_range(all_tables_size, PAGE_SIZE,
+					  0, ACPI_TABLE_UPGRADE_MAX_PHYS);
 	if (!acpi_tables_addr) {
 		WARN_ON(1);
 		return;
···
 	 * Both memblock_reserve and e820__range_add (via arch_reserve_mem_area)
 	 * works fine.
 	 */
-	memblock_reserve(acpi_tables_addr, all_tables_size);
 	arch_reserve_mem_area(acpi_tables_addr, all_tables_size);
 
 	/*

drivers/base/arch_numa.c

···
 	int i, j;
 
 	size = nr_node_ids * nr_node_ids * sizeof(numa_distance[0]);
-	phys = memblock_find_in_range(0, PFN_PHYS(max_pfn),
-				      size, PAGE_SIZE);
+	phys = memblock_phys_alloc_range(size, PAGE_SIZE, 0, PFN_PHYS(max_pfn));
 	if (WARN_ON(!phys))
 		return -ENOMEM;
-
-	memblock_reserve(phys, size);
 
 	numa_distance = __va(phys);
 	numa_distance_cnt = nr_node_ids;

drivers/base/memory.c

···
 /*
  * Called under device_hotplug_lock.
  */
-struct memory_block *find_memory_block(struct mem_section *section)
+struct memory_block *find_memory_block(unsigned long section_nr)
 {
-	unsigned long block_id = memory_block_id(__section_nr(section));
+	unsigned long block_id = memory_block_id(section_nr);
 
 	return find_memory_block_by_id(block_id);
 }

drivers/mmc/host/jz4740_mmc.c

···
 			}
 		}
 		data->bytes_xfered += miter->length;
-
-		/* This can go away once MIPS implements
-		 * flush_kernel_dcache_page */
-		flush_dcache_page(miter->page);
 	}
 	sg_miter_stop(miter);
 

drivers/mmc/host/mmc_spi.c

···
 
 		/* discard mappings */
 		if (direction == DMA_FROM_DEVICE)
-			flush_kernel_dcache_page(sg_page(sg));
+			flush_dcache_page(sg_page(sg));
 		kunmap(sg_page(sg));
 		if (dma_dev)
 			dma_unmap_page(dma_dev, dma_addr, PAGE_SIZE, dir);

drivers/of/of_reserved_mem.c

···
 	phys_addr_t *res_base)
 {
 	phys_addr_t base;
+	int err = 0;
 
 	end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
 	align = !align ? SMP_CACHE_BYTES : align;
-	base = memblock_find_in_range(start, end, size, align);
+	base = memblock_phys_alloc_range(size, align, start, end);
 	if (!base)
 		return -ENOMEM;
 
 	*res_base = base;
-	if (nomap)
-		return memblock_mark_nomap(base, size);
+	if (nomap) {
+		err = memblock_mark_nomap(base, size);
+		if (err)
+			memblock_free(base, size);
+	}
 
-	return memblock_reserve(base, size);
+	return err;
 }
 
 /*

fs/drop_caches.c

···
  * Implement the manual drop-all-pagecache function
  */
 
+#include <linux/pagemap.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/fs.h>
···
 		 * we need to reschedule to avoid softlockups.
 		 */
 		if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
-		    (inode->i_mapping->nrpages == 0 && !need_resched())) {
+		    (mapping_empty(inode->i_mapping) && !need_resched())) {
 			spin_unlock(&inode->i_lock);
 			continue;
 		}

fs/exec.c

···
 	 * We are doing an exec().  'current' is the process
 	 * doing the exec and bprm->mm is the new process's mm.
 	 */
+	mmap_read_lock(bprm->mm);
 	ret = get_user_pages_remote(bprm->mm, pos, 1, gup_flags,
 			&page, NULL, NULL);
+	mmap_read_unlock(bprm->mm);
 	if (ret <= 0)
 		return NULL;
 
···
 				}
 
 				if (kmapped_page) {
-					flush_kernel_dcache_page(kmapped_page);
+					flush_dcache_page(kmapped_page);
 					kunmap(kmapped_page);
 					put_arg_page(kmapped_page);
 				}
···
 	ret = 0;
 out:
 	if (kmapped_page) {
-		flush_kernel_dcache_page(kmapped_page);
+		flush_dcache_page(kmapped_page);
 		kunmap(kmapped_page);
 		put_arg_page(kmapped_page);
 	}
···
 		kaddr = kmap_atomic(page);
 		flush_arg_page(bprm, pos & PAGE_MASK, page);
 		memcpy(kaddr + offset_in_page(pos), arg, bytes_to_copy);
-		flush_kernel_dcache_page(page);
+		flush_dcache_page(page);
 		kunmap_atomic(kaddr);
 		put_arg_page(page);
 	}

fs/fcntl.c

···
 			__FMODE_EXEC | __FMODE_NONOTIFY));
 
 	fasync_cache = kmem_cache_create("fasync_cache",
-		sizeof(struct fasync_struct), 0, SLAB_PANIC, NULL);
+					 sizeof(struct fasync_struct), 0,
+					 SLAB_PANIC | SLAB_ACCOUNT, NULL);
 	return 0;
 }
 

fs/fs-writeback.c

···
 		inc_wb_stat(new_wb, WB_WRITEBACK);
 	}
 
+	if (mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK)) {
+		atomic_dec(&old_wb->writeback_inodes);
+		atomic_inc(&new_wb->writeback_inodes);
+	}
+
 	wb_get(new_wb);
 
 	/*
···
  * cgroup_writeback_by_id - initiate cgroup writeback from bdi and memcg IDs
  * @bdi_id: target bdi id
  * @memcg_id: target memcg css id
- * @nr: number of pages to write, 0 for best-effort dirty flushing
  * @reason: reason why some writeback work initiated
  * @done: target wb_completion
  *
  * Initiate flush of the bdi_writeback identified by @bdi_id and @memcg_id
  * with the specified parameters.
  */
-int cgroup_writeback_by_id(u64 bdi_id, int memcg_id, unsigned long nr,
+int cgroup_writeback_by_id(u64 bdi_id, int memcg_id,
 			   enum wb_reason reason, struct wb_completion *done)
 {
 	struct backing_dev_info *bdi;
 	struct cgroup_subsys_state *memcg_css;
 	struct bdi_writeback *wb;
 	struct wb_writeback_work *work;
+	unsigned long dirty;
 	int ret;
 
 	/* lookup bdi and memcg */
···
 	}
 
 	/*
-	 * If @nr is zero, the caller is attempting to write out most of
+	 * The caller is attempting to write out most of
 	 * the currently dirty pages.  Let's take the current dirty page
 	 * count and inflate it by 25% which should be large enough to
 	 * flush out most dirty pages while avoiding getting livelocked by
 	 * concurrent dirtiers.
+	 *
+	 * BTW the memcg stats are flushed periodically and this is best-effort
+	 * estimation, so some potential error is ok.
 	 */
-	if (!nr) {
-		unsigned long filepages, headroom, dirty, writeback;
-
-		mem_cgroup_wb_stats(wb, &filepages, &headroom, &dirty,
-				      &writeback);
-		nr = dirty * 10 / 8;
-	}
+	dirty = memcg_page_state(mem_cgroup_from_css(memcg_css), NR_FILE_DIRTY);
+	dirty = dirty * 10 / 8;
 
 	/* issue the writeback work */
 	work = kzalloc(sizeof(*work), GFP_NOWAIT | __GFP_NOWARN);
 	if (work) {
-		work->nr_pages = nr;
+		work->nr_pages = dirty;
 		work->sync_mode = WB_SYNC_NONE;
 		work->range_cyclic = 1;
 		work->reason = reason;
···
 static long wb_writeback(struct bdi_writeback *wb,
 			 struct wb_writeback_work *work)
 {
-	unsigned long wb_start = jiffies;
 	long nr_pages = work->nr_pages;
 	unsigned long dirtied_before = jiffies;
 	struct inode *inode;
···
 		else
 			progress = __writeback_inodes_wb(wb, work);
 		trace_writeback_written(wb, work);
-
-		wb_update_bandwidth(wb, wb_start);
 
 		/*
 		 * Did we write something? Try for more

fs/fs_context.c

···
 	struct fs_context *fc;
 	int ret = -ENOMEM;
 
-	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
+	fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL_ACCOUNT);
 	if (!fc)
 		return ERR_PTR(-ENOMEM);
 
···
  */
 static int legacy_init_fs_context(struct fs_context *fc)
 {
-	fc->fs_private = kzalloc(sizeof(struct legacy_fs_context), GFP_KERNEL);
+	fc->fs_private = kzalloc(sizeof(struct legacy_fs_context), GFP_KERNEL_ACCOUNT);
 	if (!fc->fs_private)
 		return -ENOMEM;
 	fc->ops = &legacy_fs_context_ops;

fs/inode.c

···
 		return LRU_ROTATE;
 	}
 
-	if (inode_has_buffers(inode) || inode->i_data.nrpages) {
+	if (inode_has_buffers(inode) || !mapping_empty(&inode->i_data)) {
 		__iget(inode);
 		spin_unlock(&inode->i_lock);
 		spin_unlock(lru_lock);

fs/locks.c

···
 	int i;
 
 	flctx_cache = kmem_cache_create("file_lock_ctx",
-			sizeof(struct file_lock_context), 0, SLAB_PANIC, NULL);
+			sizeof(struct file_lock_context), 0,
+			SLAB_PANIC | SLAB_ACCOUNT, NULL);
 
 	filelock_cache = kmem_cache_create("file_lock_cache",
-			sizeof(struct file_lock), 0, SLAB_PANIC, NULL);
+			sizeof(struct file_lock), 0,
+			SLAB_PANIC | SLAB_ACCOUNT, NULL);
 
 	for_each_possible_cpu(i) {
 		struct file_lock_list_struct *fll = per_cpu_ptr(&file_lock_list, i);

fs/namei.c

···
 		return -EPERM;
 
 	inode_lock(target);
-	if (is_local_mountpoint(dentry))
+	if (IS_SWAPFILE(target))
+		error = -EPERM;
+	else if (is_local_mountpoint(dentry))
 		error = -EBUSY;
 	else {
 		error = security_inode_unlink(dir, dentry);
···
 		lock_two_nondirectories(source, target);
 	else if (target)
 		inode_lock(target);
+
+	error = -EPERM;
+	if (IS_SWAPFILE(source) || (target && IS_SWAPFILE(target)))
+		goto out;
 
 	error = -EBUSY;
 	if (is_local_mountpoint(old_dentry) || is_local_mountpoint(new_dentry))

fs/namespace.c

···
 			goto out_free_cache;
 
 		if (name) {
-			mnt->mnt_devname = kstrdup_const(name, GFP_KERNEL);
+			mnt->mnt_devname = kstrdup_const(name,
+							 GFP_KERNEL_ACCOUNT);
 			if (!mnt->mnt_devname)
 				goto out_free_id;
 		}
···
 	if (!ucounts)
 		return ERR_PTR(-ENOSPC);
 
-	new_ns = kzalloc(sizeof(struct mnt_namespace), GFP_KERNEL);
+	new_ns = kzalloc(sizeof(struct mnt_namespace), GFP_KERNEL_ACCOUNT);
 	if (!new_ns) {
 		dec_mnt_namespaces(ucounts);
 		return ERR_PTR(-ENOMEM);
···
 	int err;
 
 	mnt_cache = kmem_cache_create("mnt_cache", sizeof(struct mount),
-			0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
+			0, SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_ACCOUNT, NULL);
 
 	mount_hashtable = alloc_large_system_hash("Mount-cache",
 				sizeof(struct hlist_head),

fs/ocfs2/dlmglue.c

···
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
 #include <linux/time.h>
+#include <linux/delay.h>
 #include <linux/quotaops.h>
 #include <linux/sched/signal.h>
 
···
 			return status;
 		}
 	}
-	return tmp_oh ? 1 : 0;
+	return 1;
 }
 
 void ocfs2_inode_unlock_tracker(struct inode *inode,
···
 	spin_unlock_irqrestore(&lockres->l_lock, flags);
 	ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb,
 				     gen);
+	/* The dlm lock convert is being cancelled in background,
+	 * ocfs2_cancel_convert() is asynchronous in fs/dlm,
+	 * requeue it, try again later.
+	 */
+	if (ret == -EBUSY) {
+		ctl->requeue = 1;
+		mlog(ML_BASTS, "lockres %s, ReQ: Downconvert busy\n",
+		     lockres->l_name);
+		ret = 0;
+		msleep(20);
+	}
 
 leave:
 	if (ret)

fs/ocfs2/quota_global.c

···
 	}
 	oinfo->dqi_gi.dqi_sb = sb;
 	oinfo->dqi_gi.dqi_type = type;
-	ocfs2_qinfo_lock_res_init(&oinfo->dqi_gqlock, oinfo);
 	oinfo->dqi_gi.dqi_entry_size = sizeof(struct ocfs2_global_disk_dqblk);
 	oinfo->dqi_gi.dqi_ops = &ocfs2_global_ops;
 	oinfo->dqi_gqi_bh = NULL;

fs/ocfs2/quota_local.c

···
 	info->dqi_priv = oinfo;
 	oinfo->dqi_type = type;
 	INIT_LIST_HEAD(&oinfo->dqi_chunk);
+	oinfo->dqi_gqinode = NULL;
+	ocfs2_qinfo_lock_res_init(&oinfo->dqi_gqlock, oinfo);
 	oinfo->dqi_rec = NULL;
 	oinfo->dqi_lqi_bh = NULL;
 	oinfo->dqi_libh = NULL;

fs/pipe.c

···
  */
 bool generic_pipe_buf_get(struct pipe_inode_info *pipe, struct pipe_buffer *buf)
 {
-	return try_get_page(buf->page);
+	return try_get_compound_head(buf->page, 1);
 }
 EXPORT_SYMBOL(generic_pipe_buf_get);
 

fs/select.c

···
 			goto out_nofds;
 
 		alloc_size = 6 * size;
-		bits = kvmalloc(alloc_size, GFP_KERNEL);
+		bits = kvmalloc(alloc_size, GFP_KERNEL_ACCOUNT);
 		if (!bits)
 			goto out_nofds;
 	}
···
 
 		len = min(todo, POLLFD_PER_PAGE);
 		walk = walk->next = kmalloc(struct_size(walk, entries, len),
-					    GFP_KERNEL);
+					    GFP_KERNEL_ACCOUNT);
 		if (!walk) {
 			err = -ENOMEM;
 			goto out_fds;

fs/userfaultfd.c

···
 
 static struct kmem_cache *userfaultfd_ctx_cachep __read_mostly;
 
-enum userfaultfd_state {
-	UFFD_STATE_WAIT_API,
-	UFFD_STATE_RUNNING,
-};
-
 /*
  * Start with fault_pending_wqh and fault_wqh so they're more likely
  * to be in the same cacheline.
···
 	unsigned int flags;
 	/* features requested from the userspace */
 	unsigned int features;
-	/* state machine */
-	enum userfaultfd_state state;
 	/* released */
 	bool released;
 	/* memory mappings are changing because of non-cooperative event */
-	bool mmap_changing;
+	atomic_t mmap_changing;
 	/* mm with one ore more vmas attached to this userfaultfd_ctx */
 	struct mm_struct *mm;
 };
···
 	unsigned long start;
 	unsigned long len;
 };
+
+/* internal indication that UFFD_API ioctl was successfully executed */
+#define UFFD_FEATURE_INITIALIZED		(1u << 31)
+
+static bool userfaultfd_is_initialized(struct userfaultfd_ctx *ctx)
+{
+	return ctx->features & UFFD_FEATURE_INITIALIZED;
+}
 
 static int userfaultfd_wake_function(wait_queue_entry_t *wq, unsigned mode,
 				     int wake_flags, void *key)
···
 	 * already released.
 	 */
 out:
-	WRITE_ONCE(ctx->mmap_changing, false);
+	atomic_dec(&ctx->mmap_changing);
+	VM_BUG_ON(atomic_read(&ctx->mmap_changing) < 0);
 	userfaultfd_ctx_put(ctx);
 }
 
···
 
 		refcount_set(&ctx->refcount, 1);
 		ctx->flags = octx->flags;
-		ctx->state = UFFD_STATE_RUNNING;
 		ctx->features = octx->features;
 		ctx->released = false;
-		ctx->mmap_changing = false;
+		atomic_set(&ctx->mmap_changing, 0);
 		ctx->mm = vma->vm_mm;
 		mmgrab(ctx->mm);
 
 		userfaultfd_ctx_get(octx);
-		WRITE_ONCE(octx->mmap_changing, true);
+		atomic_inc(&octx->mmap_changing);
 		fctx->orig = octx;
 		fctx->new = ctx;
 		list_add_tail(&fctx->list, fcs);
···
 	if (ctx->features & UFFD_FEATURE_EVENT_REMAP) {
 		vm_ctx->ctx = ctx;
 		userfaultfd_ctx_get(ctx);
-		WRITE_ONCE(ctx->mmap_changing, true);
+		atomic_inc(&ctx->mmap_changing);
 	} else {
 		/* Drop uffd context if remap feature not enabled */
 		vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;
···
 		return true;
 
 	userfaultfd_ctx_get(ctx);
-	WRITE_ONCE(ctx->mmap_changing, true);
+	atomic_inc(&ctx->mmap_changing);
 	mmap_read_unlock(mm);
 
 	msg_init(&ewq.msg);
···
 			return -ENOMEM;
 
 		userfaultfd_ctx_get(ctx);
-		WRITE_ONCE(ctx->mmap_changing, true);
+		atomic_inc(&ctx->mmap_changing);
 		unmap_ctx->ctx = ctx;
 		unmap_ctx->start = start;
 		unmap_ctx->end = end;
···
 
 	poll_wait(file, &ctx->fd_wqh, wait);
 
-	switch (ctx->state) {
-	case UFFD_STATE_WAIT_API:
+	if (!userfaultfd_is_initialized(ctx))
 		return EPOLLERR;
-	case UFFD_STATE_RUNNING:
-		/*
-		 * poll() never guarantees that read won't block.
-		 * userfaults can be waken before they're read().
-		 */
-		if (unlikely(!(file->f_flags & O_NONBLOCK)))
-			return EPOLLERR;
-		/*
-		 * lockless access to see if there are pending faults
-		 * __pollwait last action is the add_wait_queue but
-		 * the spin_unlock would allow the waitqueue_active to
-		 * pass above the actual list_add inside
-		 * add_wait_queue critical section. So use a full
-		 * memory barrier to serialize the list_add write of
-		 * add_wait_queue() with the waitqueue_active read
-		 * below.
-		 */
-		ret = 0;
-		smp_mb();
-		if (waitqueue_active(&ctx->fault_pending_wqh))
-			ret = EPOLLIN;
-		else if (waitqueue_active(&ctx->event_wqh))
-			ret = EPOLLIN;
 
-		return ret;
-	default:
-		WARN_ON_ONCE(1);
+	/*
+	 * poll() never guarantees that read won't block.
+	 * userfaults can be waken before they're read().
+	 */
+	if (unlikely(!(file->f_flags & O_NONBLOCK)))
 		return EPOLLERR;
-	}
+	/*
+	 * lockless access to see if there are pending faults
+	 * __pollwait last action is the add_wait_queue but
+	 * the spin_unlock would allow the waitqueue_active to
+	 * pass above the actual list_add inside
+	 * add_wait_queue critical section. So use a full
+	 * memory barrier to serialize the list_add write of
+	 * add_wait_queue() with the waitqueue_active read
+	 * below.
+	 */
+	ret = 0;
+	smp_mb();
+	if (waitqueue_active(&ctx->fault_pending_wqh))
+		ret = EPOLLIN;
+	else if (waitqueue_active(&ctx->event_wqh))
+		ret = EPOLLIN;
+
+	return ret;
 }
 
 static const struct file_operations userfaultfd_fops;
···
 	int no_wait = file->f_flags & O_NONBLOCK;
 	struct inode *inode = file_inode(file);
 
-	if (ctx->state == UFFD_STATE_WAIT_API)
+	if (!userfaultfd_is_initialized(ctx))
 		return -EINVAL;
 
 	for (;;) {
···
 	user_uffdio_copy = (struct uffdio_copy __user *) arg;
 
 	ret = -EAGAIN;
-	if (READ_ONCE(ctx->mmap_changing))
+	if (atomic_read(&ctx->mmap_changing))
 		goto out;
 
 	ret = -EFAULT;
···
 	user_uffdio_zeropage = (struct uffdio_zeropage __user *) arg;
 
 	ret = -EAGAIN;
-	if (READ_ONCE(ctx->mmap_changing))
+	if (atomic_read(&ctx->mmap_changing))
 		goto out;
 
 	ret = -EFAULT;
···
 	struct userfaultfd_wake_range range;
 	bool mode_wp, mode_dontwake;
 
-	if (READ_ONCE(ctx->mmap_changing))
+	if (atomic_read(&ctx->mmap_changing))
 		return -EAGAIN;
 
 	user_uffdio_wp = (struct uffdio_writeprotect __user *) arg;
···
 	user_uffdio_continue = (struct uffdio_continue __user *)arg;
 
 	ret = -EAGAIN;
-	if (READ_ONCE(ctx->mmap_changing))
+	if (atomic_read(&ctx->mmap_changing))
 		goto out;
 
 	ret = -EFAULT;
···
 static inline unsigned int uffd_ctx_features(__u64 user_features)
 {
 	/*
-	 * For the current set of features the bits just coincide
+	 * For the current set of features the bits just coincide. Set
+	 * UFFD_FEATURE_INITIALIZED to mark the features as enabled.
 	 */
-	return (unsigned int)user_features;
+	return (unsigned int)user_features | UFFD_FEATURE_INITIALIZED;
 }
 
 /*
···
 {
 	struct uffdio_api uffdio_api;
 	void __user *buf = (void __user *)arg;
+	unsigned int ctx_features;
 	int ret;
 	__u64 features;
 
-	ret = -EINVAL;
-	if (ctx->state != UFFD_STATE_WAIT_API)
-		goto out;
 	ret = -EFAULT;
 	if (copy_from_user(&uffdio_api, buf, sizeof(uffdio_api)))
 		goto out;
···
 	ret = -EFAULT;
 	if (copy_to_user(buf, &uffdio_api, sizeof(uffdio_api)))
 		goto out;
-	ctx->state = UFFD_STATE_RUNNING;
+
 	/* only enable the requested features for this uffd context */
-	ctx->features = uffd_ctx_features(features);
+	ctx_features = uffd_ctx_features(features);
+	ret = -EINVAL;
+	if (cmpxchg(&ctx->features, 0, ctx_features) != 0)
+		goto err_out;
+
 	ret = 0;
 out:
 	return ret;
···
 	int ret = -EINVAL;
 	struct userfaultfd_ctx *ctx = file->private_data;
 
-	if (cmd != UFFDIO_API && ctx->state == UFFD_STATE_WAIT_API)
+	if (cmd != UFFDIO_API && !userfaultfd_is_initialized(ctx))
 		return -EINVAL;
 
 	switch(cmd) {
···
 	refcount_set(&ctx->refcount, 1);
 	ctx->flags = flags;
 	ctx->features = 0;
-	ctx->state = UFFD_STATE_WAIT_API;
 	ctx->released = false;
-	ctx->mmap_changing = false;
+	atomic_set(&ctx->mmap_changing, 0);
 	ctx->mm = current->mm;
 	/* prevent the mm struct to be freed */
 	mmgrab(ctx->mm);

include/linux/backing-dev-defs.h

···
 	struct list_head b_dirty_time;	/* time stamps are dirty */
 	spinlock_t list_lock;		/* protects the b_* lists */
 
+	atomic_t writeback_inodes;	/* number of inodes under writeback */
 	struct percpu_counter stat[NR_WB_STAT_ITEMS];
 
 	unsigned long congested;	/* WB_[a]sync_congested flags */
···
 	spinlock_t work_lock;		/* protects work_list & dwork scheduling */
 	struct list_head work_list;
 	struct delayed_work dwork;	/* work item used for writeback */
+	struct delayed_work bw_dwork;	/* work item used for bandwidth estimate */
 
 	unsigned long dirty_sleep;	/* last wait */
 

include/linux/backing-dev.h

···
 	return inode->i_wb;
 }
 
+static inline struct bdi_writeback *inode_to_wb_wbc(
+				struct inode *inode,
+				struct writeback_control *wbc)
+{
+	/*
+	 * If wbc does not have inode attached, it means cgroup writeback was
+	 * disabled when wbc started. Just use the default wb in that case.
+	 */
+	return wbc->wb ? wbc->wb : &inode_to_bdi(inode)->wb;
+}
+
 /**
  * unlocked_inode_to_wb_begin - begin unlocked inode wb access transaction
  * @inode: target inode
···
 {
 	return &inode_to_bdi(inode)->wb;
 }
+
+static inline struct bdi_writeback *inode_to_wb_wbc(
+				struct inode *inode,
+				struct writeback_control *wbc)
+{
+	return inode_to_wb(inode);
+}
+
 
 static inline struct bdi_writeback *
 unlocked_inode_to_wb_begin(struct inode *inode, struct wb_lock_cookie *cookie)

include/linux/buffer_head.h

···
 static inline int remove_inode_buffers(struct inode *inode) { return 1; }
 static inline int sync_mapping_buffers(struct address_space *mapping) { return 0; }
 static inline void invalidate_bh_lrus_cpu(int cpu) {}
-static inline bool has_bh_in_lru(int cpu, void *dummy) { return 0; }
+static inline bool has_bh_in_lru(int cpu, void *dummy) { return false; }
 #define buffer_heads_over_limit 0
 
 #endif /* CONFIG_BLOCK */

include/linux/compaction.h

···
 extern unsigned int sysctl_compaction_proactiveness;
 extern int sysctl_compaction_handler(struct ctl_table *table, int write,
 			void *buffer, size_t *length, loff_t *ppos);
+extern int compaction_proactiveness_sysctl_handler(struct ctl_table *table,
+		int write, void *buffer, size_t *length, loff_t *ppos);
 extern int sysctl_extfrag_threshold;
 extern int sysctl_compact_unevictable_allowed;
 

include/linux/highmem.h

···
 }
 #endif
 
-#ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
-static inline void flush_kernel_dcache_page(struct page *page)
-{
-}
+#ifndef ARCH_IMPLEMENTS_FLUSH_KERNEL_VMAP_RANGE
 static inline void flush_kernel_vmap_range(void *vaddr, int size)
 {
 }

include/linux/hugetlb_cgroup.h

···
 	css_put(&h_cg->css);
 }
 
+static inline void resv_map_dup_hugetlb_cgroup_uncharge_info(
+						struct resv_map *resv_map)
+{
+	if (resv_map->css)
+		css_get(resv_map->css);
+}
+
 extern int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages,
 					struct hugetlb_cgroup **ptr);
 extern int hugetlb_cgroup_charge_cgroup_rsvd(int idx, unsigned long nr_pages,
···
 }
 
 static inline void hugetlb_cgroup_put_rsvd_cgroup(struct hugetlb_cgroup *h_cg)
+{
+}
+
+static inline void resv_map_dup_hugetlb_cgroup_uncharge_info(
+						struct resv_map *resv_map)
 {
 }
 

include/linux/memblock.h

···
 static inline void memblock_discard(void) {}
 #endif
 
-phys_addr_t memblock_find_in_range(phys_addr_t start, phys_addr_t end,
-				   phys_addr_t size, phys_addr_t align);
 void memblock_allow_resize(void);
 int memblock_add_node(phys_addr_t base, phys_addr_t size, int nid);
 int memblock_add(phys_addr_t base, phys_addr_t size);

include/linux/memcontrol.h

···
 	unsigned int generation;
 };
 
-struct lruvec_stat {
-	long count[NR_VM_NODE_STAT_ITEMS];
-};
-
-struct batched_lruvec_stat {
-	s32 count[NR_VM_NODE_STAT_ITEMS];
-};
-
 /*
  * Bitmap and deferred work of shrinker::id corresponding to memcg-aware
  * shrinkers, which have elements charged to this memcg.
···
 	unsigned long *map;
 };
 
+struct lruvec_stats_percpu {
+	/* Local (CPU and cgroup) state */
+	long state[NR_VM_NODE_STAT_ITEMS];
+
+	/* Delta calculation for lockless upward propagation */
+	long state_prev[NR_VM_NODE_STAT_ITEMS];
+};
+
+struct lruvec_stats {
+	/* Aggregated (CPU and subtree) state */
+	long state[NR_VM_NODE_STAT_ITEMS];
+
+	/* Pending child counts during tree propagation */
+	long state_pending[NR_VM_NODE_STAT_ITEMS];
+};
+
 /*
  * per-node information in memory controller.
  */
 struct mem_cgroup_per_node {
 	struct lruvec		lruvec;
 
-	/*
-	 * Legacy local VM stats. This should be struct lruvec_stat and
-	 * cannot be optimized to struct batched_lruvec_stat. Because
-	 * the threshold of the lruvec_stat_cpu can be as big as
-	 * MEMCG_CHARGE_BATCH * PAGE_SIZE. It can fit into s32. But this
-	 * filed has no upper limit.
-	 */
-	struct lruvec_stat __percpu *lruvec_stat_local;
-
-	/* Subtree VM stats (batched updates) */
-	struct batched_lruvec_stat __percpu *lruvec_stat_cpu;
-	atomic_long_t		lruvec_stat[NR_VM_NODE_STAT_ITEMS];
+	struct lruvec_stats_percpu __percpu	*lruvec_stats_percpu;
+	struct lruvec_stats			lruvec_stats;
 
 	unsigned long		lru_zone_size[MAX_NR_ZONES][NR_LRU_LISTS];
 
···
 }
 #endif
 
-static __always_inline bool memcg_stat_item_in_bytes(int idx)
-{
-	if (idx == MEMCG_PERCPU_B)
-		return true;
-	return vmstat_item_in_bytes(idx);
-}
-
 static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
 {
 	return (memcg == root_mem_cgroup);
···
 		page_counter_read(&memcg->memory);
 }
 
-int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask);
+int __mem_cgroup_charge(struct page *page, struct mm_struct *mm,
+			gfp_t gfp_mask);
+static inline int mem_cgroup_charge(struct page *page, struct mm_struct *mm,
+				    gfp_t gfp_mask)
+{
+	if (mem_cgroup_disabled())
+		return 0;
+	return __mem_cgroup_charge(page, mm, gfp_mask);
+}
+
 int mem_cgroup_swapin_charge_page(struct page *page, struct mm_struct *mm,
 				  gfp_t gfp, swp_entry_t entry);
 void mem_cgroup_swapin_uncharge_swap(swp_entry_t entry);
 
-void mem_cgroup_uncharge(struct page *page);
-void mem_cgroup_uncharge_list(struct list_head *page_list);
+void __mem_cgroup_uncharge(struct page *page);
+static inline void mem_cgroup_uncharge(struct page *page)
+{
+	if (mem_cgroup_disabled())
+		return;
+	__mem_cgroup_uncharge(page);
+}
+
+void __mem_cgroup_uncharge_list(struct list_head *page_list);
+static inline void mem_cgroup_uncharge_list(struct list_head *page_list)
+{
+	if (mem_cgroup_disabled())
+		return;
+	__mem_cgroup_uncharge_list(page_list);
+}
 
 void mem_cgroup_migrate(struct page *oldpage, struct page *newpage);
 
···
 	return !!(memcg->css.flags & CSS_ONLINE);
 }
 
-/*
- * For memory reclaim.
- */
-int mem_cgroup_select_victim_node(struct mem_cgroup *memcg);
-
 void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
 		int zid, int nr_pages);
 
···
 	local_irq_restore(flags);
 }
 
+static inline unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx)
+{
+	return READ_ONCE(memcg->vmstats.state[idx]);
+}
+
 static inline unsigned long lruvec_page_state(struct lruvec *lruvec,
 					      enum node_stat_item idx)
 {
 	struct mem_cgroup_per_node *pn;
-	long x;
 
 	if (mem_cgroup_disabled())
 		return node_page_state(lruvec_pgdat(lruvec), idx);
 
 	pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
-	x = atomic_long_read(&pn->lruvec_stat[idx]);
-#ifdef CONFIG_SMP
-	if (x < 0)
-		x = 0;
-#endif
-	return x;
+	return READ_ONCE(pn->lruvec_stats.state[idx]);
 }
 
 static inline unsigned long lruvec_page_state_local(struct lruvec *lruvec,
···
 
 	pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
 	for_each_possible_cpu(cpu)
-		x += per_cpu(pn->lruvec_stat_local->count[idx], cpu);
+		x += per_cpu(pn->lruvec_stats_percpu->state[idx], cpu);
 #ifdef CONFIG_SMP
 	if (x < 0)
 		x = 0;
 #endif
 	return x;
 }
+
+void mem_cgroup_flush_stats(void);
 
 void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
 			      int val);
···
 {
 }
 
+static inline unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx)
+{
+	return 0;
+}
+
 static inline unsigned long lruvec_page_state(struct lruvec *lruvec,
 					      enum node_stat_item idx)
 {
···
 						    enum node_stat_item idx)
 {
 	return node_page_state(lruvec_pgdat(lruvec), idx);
+}
+
+static inline void mem_cgroup_flush_stats(void)
+{
 }
 
 static inline void __mod_memcg_lruvec_state(struct lruvec *lruvec,

include/linux/memory.h

···
 void remove_memory_block_devices(unsigned long start, unsigned long size);
 extern void memory_dev_init(void);
 extern int memory_notify(unsigned long val, void *v);
-extern struct memory_block *find_memory_block(struct mem_section *);
+extern struct memory_block *find_memory_block(unsigned long section_nr);
 typedef int (*walk_memory_blocks_func_t)(struct memory_block *, void *);
 extern int walk_memory_blocks(unsigned long start, unsigned long size,
 			      void *arg, walk_memory_blocks_func_t func);

include/linux/mempolicy.h

···
 extern int mpol_misplaced(struct page *, struct vm_area_struct *, unsigned long);
 extern void mpol_put_task_policy(struct task_struct *);
 
+extern bool numa_demotion_enabled;
+
+static inline bool mpol_is_preferred_many(struct mempolicy *pol)
+{
+	return  (pol->mode == MPOL_PREFERRED_MANY);
+}
+
+
 #else
 
 struct mempolicy {};
···
 {
 	return NULL;
 }
+
+#define numa_demotion_enabled	false
+
+static inline bool mpol_is_preferred_many(struct mempolicy *pol)
+{
+	return  false;
+}
+
 #endif /* CONFIG_NUMA */
 #endif

include/linux/migrate.h

···
 	MR_NUMA_MISPLACED,
 	MR_CONTIG_RANGE,
 	MR_LONGTERM_PIN,
+	MR_DEMOTION,
 	MR_TYPES
 };
 
···
 			struct page *newpage, struct page *page,
 			enum migrate_mode mode);
 extern int migrate_pages(struct list_head *l, new_page_t new, free_page_t free,
-		unsigned long private, enum migrate_mode mode, int reason);
+		unsigned long private, enum migrate_mode mode, int reason,
+		unsigned int *ret_succeeded);
 extern struct page *alloc_migration_target(struct page *page, unsigned long private);
 extern int isolate_movable_page(struct page *page, isolate_mode_t mode);
 
···
 static inline void putback_movable_pages(struct list_head *l) {}
 static inline int migrate_pages(struct list_head *l, new_page_t new,
 		free_page_t free, unsigned long private, enum migrate_mode mode,
-		int reason)
+		int reason, unsigned int *ret_succeeded)
 	{ return -ENOSYS; }
 static inline struct page *alloc_migration_target(struct page *page,
 		unsigned long private)
···
 int migrate_vma_setup(struct migrate_vma *args);
 void migrate_vma_pages(struct migrate_vma *migrate);
 void migrate_vma_finalize(struct migrate_vma *migrate);
+int next_demotion_node(int node);
+
+#else /* CONFIG_MIGRATION disabled: */
+
+static inline int next_demotion_node(int node)
+{
+	return NUMA_NO_NODE;
+}
 
 #endif /* CONFIG_MIGRATION */
 

include/linux/mm.h

···
 }
 
 bool __must_check try_grab_page(struct page *page, unsigned int flags);
-__maybe_unused struct page *try_grab_compound_head(struct page *page, int refs,
-						   unsigned int flags);
+struct page *try_grab_compound_head(struct page *page, int refs,
+				    unsigned int flags);
 
-
-static inline __must_check bool try_get_page(struct page *page)
-{
-	page = compound_head(page);
-	if (WARN_ON_ONCE(page_ref_count(page) <= 0))
-		return false;
-	page_ref_inc(page);
-	return true;
-}
+struct page *try_get_compound_head(struct page *page, int refs);
 
 static inline void put_page(struct page *page)
 {
···
 struct kvec;
 int get_kernel_pages(const struct kvec *iov, int nr_pages, int write,
 			struct page **pages);
-int get_kernel_page(unsigned long start, int write, struct page **pages);
 struct page *get_dump_page(unsigned long addr);
 
 extern int try_to_release_page(struct page * page, gfp_t gfp_mask);
···
 extern int unpoison_memory(unsigned long pfn);
 extern int sysctl_memory_failure_early_kill;
 extern int sysctl_memory_failure_recovery;
-extern void shake_page(struct page *p, int access);
+extern void shake_page(struct page *p);
 extern atomic_long_t num_poisoned_pages __read_mostly;
 extern int soft_offline_page(unsigned long pfn, int flags);
 

include/linux/mmzone.h

···
 	enum zone_type kcompactd_highest_zoneidx;
 	wait_queue_head_t kcompactd_wait;
 	struct task_struct *kcompactd;
+	bool proactive_compact_trigger;
 #endif
 	/*
 	 * This is a per-node reserve of pages that are not available
···
 		return NULL;
 	return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
 }
-extern unsigned long __section_nr(struct mem_section *ms);
 extern size_t mem_section_usage_size(void);
 
 /*
···
 #define SECTION_TAINT_ZONE_DEVICE	(1UL<<4)
 #define SECTION_MAP_LAST_BIT		(1UL<<5)
 #define SECTION_MAP_MASK		(~(SECTION_MAP_LAST_BIT-1))
-#define SECTION_NID_SHIFT		3
+#define SECTION_NID_SHIFT		6
 
 static inline struct page *__section_mem_map_addr(struct mem_section *section)
 {

include/linux/pagemap.h

···
 /*
  * Fault everything in given userspace address range in.
  */
-static inline int fault_in_pages_writeable(char __user *uaddr, int size)
+static inline int fault_in_pages_writeable(char __user *uaddr, size_t size)
 {
 	char __user *end = uaddr + size - 1;
 
···
 	return 0;
 }
 
-static inline int fault_in_pages_readable(const char __user *uaddr, int size)
+static inline int fault_in_pages_readable(const char __user *uaddr, size_t size)
 {
 	volatile char c;
 	const char __user *end = uaddr + size - 1;

include/linux/sched/mm.h

···
 }
 
 #ifdef CONFIG_LOCKDEP
-extern void __fs_reclaim_acquire(void);
-extern void __fs_reclaim_release(void);
+extern void __fs_reclaim_acquire(unsigned long ip);
+extern void __fs_reclaim_release(unsigned long ip);
 extern void fs_reclaim_acquire(gfp_t gfp_mask);
 extern void fs_reclaim_release(gfp_t gfp_mask);
 #else
-static inline void __fs_reclaim_acquire(void) { }
-static inline void __fs_reclaim_release(void) { }
+static inline void __fs_reclaim_acquire(unsigned long ip) { }
+static inline void __fs_reclaim_release(unsigned long ip) { }
 static inline void fs_reclaim_acquire(gfp_t gfp_mask) { }
 static inline void fs_reclaim_release(gfp_t gfp_mask) { }
 #endif
···
 {
 	struct mem_cgroup *old;
 
-	if (in_interrupt()) {
+	if (!in_task()) {
 		old = this_cpu_read(int_active_memcg);
 		this_cpu_write(int_active_memcg, memcg);
 	} else {

include/linux/shmem_fs.h

···
 	unsigned long		flags;
 	unsigned long		alloced;	/* data pages alloced to file */
 	unsigned long		swapped;	/* subtotal assigned to swap */
+	pgoff_t			fallocend;	/* highest fallocate endindex */
 	struct list_head        shrinklist;     /* shrinkable hpage inodes */
 	struct list_head	swaplist;	/* chain of maybes on swap */
 	struct shared_policy	policy;		/* NUMA memory alloc policy */
···
 	struct percpu_counter used_blocks;  /* How many are allocated */
 	unsigned long max_inodes;   /* How many inodes are allowed */
 	unsigned long free_inodes;  /* How many are left for allocation */
-	spinlock_t stat_lock;	    /* Serialize shmem_sb_info changes */
+	raw_spinlock_t stat_lock;   /* Serialize shmem_sb_info changes */
 	umode_t mode;		    /* Mount mode for root directory */
 	unsigned char huge;	    /* Whether to try for hugepages */
 	kuid_t uid;		    /* Mount uid for root directory */
···
 extern int shmem_unuse(unsigned int type, bool frontswap,
 		       unsigned long *fs_pages_to_unuse);
 
-extern bool shmem_huge_enabled(struct vm_area_struct *vma);
+extern bool shmem_is_huge(struct vm_area_struct *vma,
+			  struct inode *inode, pgoff_t index);
+static inline bool shmem_huge_enabled(struct vm_area_struct *vma)
+{
+	return shmem_is_huge(vma, file_inode(vma->vm_file), vma->vm_pgoff);
+}
 extern unsigned long shmem_swap_usage(struct vm_area_struct *vma);
 extern unsigned long shmem_partial_swap_usage(struct address_space *mapping,
 						pgoff_t start, pgoff_t end);
···
 /* Flag allocation requirements to shmem_getpage */
 enum sgp_type {
 	SGP_READ,	/* don't exceed i_size, don't allocate page */
+	SGP_NOALLOC,	/* similar, but fail on hole or use fallocated page */
 	SGP_CACHE,	/* don't exceed i_size, may allocate page */
-	SGP_NOHUGE,	/* like SGP_CACHE, but no huge pages */
-	SGP_HUGE,	/* like SGP_CACHE, huge pages preferred */
 	SGP_WRITE,	/* may exceed i_size, may allocate !Uptodate page */
 	SGP_FALLOC,	/* like SGP_WRITE, but make existing page Uptodate */
 };
···
 	if (!file || !file->f_mapping)
 		return false;
 	return shmem_mapping(file->f_mapping);
+}
+
+/*
+ * If fallocate(FALLOC_FL_KEEP_SIZE) has been used, there may be pages
+ * beyond i_size's notion of EOF, which fallocate has committed to reserving:
+ * which split_huge_page() must therefore not delete.  This use of a single
+ * "fallocend" per inode errs on the side of not deleting a reservation when
+ * in doubt: there are plenty of cases when it preserves unreserved pages.
+ */
+static inline pgoff_t shmem_fallocend(struct inode *inode, pgoff_t eof)
+{
+	return max(eof, SHMEM_I(inode)->fallocend);
 }
 
 extern bool shmem_charge(struct inode *inode, long pages);

include/linux/swap.h

···
 
 extern void check_move_unevictable_pages(struct pagevec *pvec);
 
-extern int kswapd_run(int nid);
+extern void kswapd_run(int nid);
 extern void kswapd_stop(int nid);
 
 #ifdef CONFIG_SWAP
···
 #endif
 
 #if defined(CONFIG_SWAP) && defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
-extern void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask);
+extern void __cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask);
+static inline  void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)
+{
+	if (mem_cgroup_disabled())
+		return;
+	__cgroup_throttle_swaprate(page, gfp_mask);
+}
 #else
 static inline void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)
 {
···
 
 #ifdef CONFIG_MEMCG_SWAP
 extern void mem_cgroup_swapout(struct page *page, swp_entry_t entry);
-extern int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry);
-extern void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages);
+extern int __mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry);
+static inline int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry)
+{
+	if (mem_cgroup_disabled())
+		return 0;
+	return __mem_cgroup_try_charge_swap(page, entry);
+}
+
+extern void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages);
+static inline void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages)
+{
+	if (mem_cgroup_disabled())
+		return;
+	__mem_cgroup_uncharge_swap(entry, nr_pages);
+}
+
 extern long mem_cgroup_get_nr_swap_pages(struct mem_cgroup *memcg);
 extern bool mem_cgroup_swap_full(struct page *page);
 #else

include/linux/syscalls.h

···
 asmlinkage long sys_madvise(unsigned long start, size_t len, int behavior);
 asmlinkage long sys_process_madvise(int pidfd, const struct iovec __user *vec,
 			size_t vlen, int behavior, unsigned int flags);
+asmlinkage long sys_process_mrelease(int pidfd, unsigned int flags);
 asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size,
 			unsigned long prot, unsigned long pgoff,
 			unsigned long flags);

include/linux/userfaultfd_k.h

···
 
 extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
 			    unsigned long src_start, unsigned long len,
-			    bool *mmap_changing, __u64 mode);
+			    atomic_t *mmap_changing, __u64 mode);
 extern ssize_t mfill_zeropage(struct mm_struct *dst_mm,
 			      unsigned long dst_start,
 			      unsigned long len,
-			      bool *mmap_changing);
+			      atomic_t *mmap_changing);
 extern ssize_t mcopy_continue(struct mm_struct *dst_mm, unsigned long dst_start,
-			      unsigned long len, bool *mmap_changing);
+			      unsigned long len, atomic_t *mmap_changing);
 extern int mwriteprotect_range(struct mm_struct *dst_mm,
 			       unsigned long start, unsigned long len,
-			       bool enable_wp, bool *mmap_changing);
+			       bool enable_wp, atomic_t *mmap_changing);
 
 /* mm helpers */
 static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,

include/linux/vm_event_item.h

···
 		PGREUSE,
 		PGSTEAL_KSWAPD,
 		PGSTEAL_DIRECT,
+		PGDEMOTE_KSWAPD,
+		PGDEMOTE_DIRECT,
 		PGSCAN_KSWAPD,
 		PGSCAN_DIRECT,
 		PGSCAN_DIRECT_THROTTLE,

include/linux/vmpressure.h

···
 extern void vmpressure_init(struct vmpressure *vmpr);
 extern void vmpressure_cleanup(struct vmpressure *vmpr);
 extern struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg);
-extern struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr);
+extern struct mem_cgroup *vmpressure_to_memcg(struct vmpressure *vmpr);
 extern int vmpressure_register_event(struct mem_cgroup *memcg,
 				     struct eventfd_ctx *eventfd,
 				     const char *args);

include/linux/writeback.h

···
 void wbc_detach_inode(struct writeback_control *wbc);
 void wbc_account_cgroup_owner(struct writeback_control *wbc, struct page *page,
 			      size_t bytes);
-int cgroup_writeback_by_id(u64 bdi_id, int memcg_id, unsigned long nr_pages,
+int cgroup_writeback_by_id(u64 bdi_id, int memcg_id,
 			   enum wb_reason reason, struct wb_completion *done);
 void cgroup_writeback_umount(void);
 bool cleanup_offline_cgwb(struct bdi_writeback *wb);
···
 void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty);
 unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh);
 
-void wb_update_bandwidth(struct bdi_writeback *wb, unsigned long start_time);
+void wb_update_bandwidth(struct bdi_writeback *wb);
 void balance_dirty_pages_ratelimited(struct address_space *mapping);
 bool wb_over_bg_thresh(struct bdi_writeback *wb);
 

include/trace/events/migrate.h

···
 	EM( MR_MEMPOLICY_MBIND,	"mempolicy_mbind")		\
 	EM( MR_NUMA_MISPLACED,	"numa_misplaced")		\
 	EM( MR_CONTIG_RANGE,	"contig_range")			\
-	EMe(MR_LONGTERM_PIN,	"longterm_pin")
+	EM( MR_LONGTERM_PIN,	"longterm_pin")			\
+	EMe(MR_DEMOTION,	"demotion")
 
 /*
  * First define the enums in the above macros to be exported to userspace

include/uapi/asm-generic/unistd.h

···
 #define __NR_memfd_secret 447
 __SYSCALL(__NR_memfd_secret, sys_memfd_secret)
 #endif
+#define __NR_process_mrelease 448
+__SYSCALL(__NR_process_mrelease, sys_process_mrelease)
 
 #undef __NR_syscalls
-#define __NR_syscalls 448
+#define __NR_syscalls 449
 
 /*
  * 32 bit systems traditionally used different

include/uapi/linux/mempolicy.h

···
 	MPOL_BIND,
 	MPOL_INTERLEAVE,
 	MPOL_LOCAL,
+	MPOL_PREFERRED_MANY,
 	MPOL_MAX,	/* always last member of enum */
 };
 

ipc/msg.c

···
 	key_t key = params->key;
 	int msgflg = params->flg;
 
-	msq = kmalloc(sizeof(*msq), GFP_KERNEL);
+	msq = kmalloc(sizeof(*msq), GFP_KERNEL_ACCOUNT);
 	if (unlikely(!msq))
 		return -ENOMEM;
 

ipc/namespace.c

···
 		goto fail;
 
 	err = -ENOMEM;
-	ns = kzalloc(sizeof(struct ipc_namespace), GFP_KERNEL);
+	ns = kzalloc(sizeof(struct ipc_namespace), GFP_KERNEL_ACCOUNT);
 	if (ns == NULL)
 		goto fail_dec;
 

ipc/sem.c

···
 	if (nsems > (INT_MAX - sizeof(*sma)) / sizeof(sma->sems[0]))
 		return NULL;
 
-	sma = kvzalloc(struct_size(sma, sems, nsems), GFP_KERNEL);
+	sma = kvzalloc(struct_size(sma, sems, nsems), GFP_KERNEL_ACCOUNT);
 	if (unlikely(!sma))
 		return NULL;
 
···
 
 	undo_list = current->sysvsem.undo_list;
 	if (!undo_list) {
-		undo_list = kzalloc(sizeof(*undo_list), GFP_KERNEL);
+		undo_list = kzalloc(sizeof(*undo_list), GFP_KERNEL_ACCOUNT);
 		if (undo_list == NULL)
 			return -ENOMEM;
 		spin_lock_init(&undo_list->lock);
···
 
 	/* step 2: allocate new undo structure */
 	new = kvzalloc(sizeof(struct sem_undo) + sizeof(short)*nsems,
-		       GFP_KERNEL);
+		       GFP_KERNEL_ACCOUNT);
 	if (!new) {
 		ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
 		return ERR_PTR(-ENOMEM);
···
 	if (nsops > ns->sc_semopm)
 		return -E2BIG;
 	if (nsops > SEMOPM_FAST) {
-		sops = kvmalloc_array(nsops, sizeof(*sops), GFP_KERNEL);
+		sops = kvmalloc_array(nsops, sizeof(*sops),
+				      GFP_KERNEL_ACCOUNT);
 		if (sops == NULL)
 			return -ENOMEM;
 	}

ipc/shm.c

···
 			ns->shm_tot + numpages > ns->shm_ctlall)
 		return -ENOSPC;
 
-	shp = kmalloc(sizeof(*shp), GFP_KERNEL);
+	shp = kmalloc(sizeof(*shp), GFP_KERNEL_ACCOUNT);
 	if (unlikely(!shp))
 		return -ENOMEM;
 

kernel/cgroup/namespace.c

···
 	struct cgroup_namespace *new_ns;
 	int ret;
 
-	new_ns = kzalloc(sizeof(struct cgroup_namespace), GFP_KERNEL);
+	new_ns = kzalloc(sizeof(struct cgroup_namespace), GFP_KERNEL_ACCOUNT);
 	if (!new_ns)
 		return ERR_PTR(-ENOMEM);
 	ret = ns_alloc_inum(&new_ns->ns);

kernel/nsproxy.c

···
 
 int __init nsproxy_cache_init(void)
 {
-	nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);
+	nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC|SLAB_ACCOUNT);
 	return 0;
 }

kernel/pid_namespace.c

···
 	mutex_lock(&pid_caches_mutex);
 	/* Name collision forces to do allocation under mutex. */
 	if (!*pkc)
-		*pkc = kmem_cache_create(name, len, 0, SLAB_HWCACHE_ALIGN, 0);
+		*pkc = kmem_cache_create(name, len, 0,
+					 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, 0);
 	mutex_unlock(&pid_caches_mutex);
 	/* current can fail, but someone else can succeed. */
 	return READ_ONCE(*pkc);
···
 
 static __init int pid_namespaces_init(void)
 {
-	pid_ns_cachep = KMEM_CACHE(pid_namespace, SLAB_PANIC);
+	pid_ns_cachep = KMEM_CACHE(pid_namespace, SLAB_PANIC | SLAB_ACCOUNT);
 
 #ifdef CONFIG_CHECKPOINT_RESTORE
 	register_sysctl_paths(kern_path, pid_ns_ctl_table);

kernel/signal.c

···
 {
 	siginfo_buildtime_checks();
 
-	sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC);
+	sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC | SLAB_ACCOUNT);
 }
 
 #ifdef CONFIG_KGDB_KDB

kernel/sys_ni.c

···
 COND_SYSCALL(mincore);
 COND_SYSCALL(madvise);
 COND_SYSCALL(process_madvise);
+COND_SYSCALL(process_mrelease);
 COND_SYSCALL(remap_file_pages);
 COND_SYSCALL(mbind);
 COND_SYSCALL_COMPAT(mbind);

kernel/sysctl.c

···
 		.data		= &sysctl_compaction_proactiveness,
 		.maxlen		= sizeof(sysctl_compaction_proactiveness),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
+		.proc_handler	= compaction_proactiveness_sysctl_handler,
 		.extra1		= SYSCTL_ZERO,
 		.extra2		= &one_hundred,
 	},

kernel/time/namespace.c

···
 		goto fail;
 
 	err = -ENOMEM;
-	ns = kmalloc(sizeof(*ns), GFP_KERNEL);
+	ns = kmalloc(sizeof(*ns), GFP_KERNEL_ACCOUNT);
 	if (!ns)
 		goto fail_dec;
 
 	refcount_set(&ns->ns.count, 1);
 
-	ns->vvar_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+	ns->vvar_page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO);
 	if (!ns->vvar_page)
 		goto fail_free;
 

kernel/time/posix-timers.c

···
 static __init int init_posix_timers(void)
 {
 	posix_timers_cache = kmem_cache_create("posix_timers_cache",
-					sizeof (struct k_itimer), 0, SLAB_PANIC,
-					NULL);
+					sizeof(struct k_itimer), 0,
+					SLAB_PANIC | SLAB_ACCOUNT, NULL);
 	return 0;
 }
 __initcall(init_posix_timers);

kernel/user_namespace.c

···
 
 static __init int user_namespaces_init(void)
 {
-	user_ns_cachep = KMEM_CACHE(user_namespace, SLAB_PANIC);
+	user_ns_cachep = KMEM_CACHE(user_namespace, SLAB_PANIC | SLAB_ACCOUNT);
 	return 0;
 }
 subsys_initcall(user_namespaces_init);

lib/scatterlist.c

···
 		miter->__offset += miter->consumed;
 		miter->__remaining -= miter->consumed;
 
-		if ((miter->__flags & SG_MITER_TO_SG) &&
-		    !PageSlab(miter->page))
-			flush_kernel_dcache_page(miter->page);
+		if (miter->__flags & SG_MITER_TO_SG)
+			flush_dcache_page(miter->page);
 
 		if (miter->__flags & SG_MITER_ATOMIC) {
 			WARN_ON_ONCE(preemptible());

lib/test_kasan.c

···
 static void kmalloc_oob_right(struct kunit *test)
 {
 	char *ptr;
-	size_t size = 123;
+	size_t size = 128 - KASAN_GRANULE_SIZE - 5;
 
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
-	KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + OOB_TAG_OFF] = 'x');
+	/*
+	 * An unaligned access past the requested kmalloc size.
+	 * Only generic KASAN can precisely detect these.
+	 */
+	if (IS_ENABLED(CONFIG_KASAN_GENERIC))
+		KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 'x');
+
+	/*
+	 * An aligned access into the first out-of-bounds granule that falls
+	 * within the aligned kmalloc object.
+	 */
+	KUNIT_EXPECT_KASAN_FAIL(test, ptr[size + 5] = 'y');
+
+	/* Out-of-bounds access past the aligned kmalloc object. */
+	KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] =
+					ptr[size + KASAN_GRANULE_SIZE + 5]);
+
 	kfree(ptr);
 }
 
···
 	ptr = kmalloc_node(size, GFP_KERNEL, 0);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
-	KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
+	KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = ptr[size]);
 	kfree(ptr);
 }
 
···
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 	kfree(ptr);
 
-	KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = 0);
+	KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]);
 }
 
 static void kmalloc_pagealloc_invalid_free(struct kunit *test)
···
 	ptr = page_address(pages);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
-	KUNIT_EXPECT_KASAN_FAIL(test, ptr[size] = 0);
+	KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = ptr[size]);
 	free_pages((unsigned long)ptr, order);
 }
 
···
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 	free_pages((unsigned long)ptr, order);
 
-	KUNIT_EXPECT_KASAN_FAIL(test, ptr[0] = 0);
+	KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]);
 }
 
 static void kmalloc_large_oob_right(struct kunit *test)
···
 	kfree(ptr1);
 }
 
+/*
+ * Note: in the memset tests below, the written range touches both valid and
+ * invalid memory. This makes sure that the instrumentation does not only check
+ * the starting address but the whole range.
+ */
+
 static void kmalloc_oob_memset_2(struct kunit *test)
 {
 	char *ptr;
-	size_t size = 8;
+	size_t size = 128 - KASAN_GRANULE_SIZE;
 
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
-	KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 7 + OOB_TAG_OFF, 0, 2));
+	KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 1, 0, 2));
 	kfree(ptr);
 }
 
 static void kmalloc_oob_memset_4(struct kunit *test)
 {
 	char *ptr;
-	size_t size = 8;
+	size_t size = 128 - KASAN_GRANULE_SIZE;
 
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
-	KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 5 + OOB_TAG_OFF, 0, 4));
+	KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 3, 0, 4));
 	kfree(ptr);
 }
-
 
 static void kmalloc_oob_memset_8(struct kunit *test)
 {
 	char *ptr;
-	size_t size = 8;
+	size_t size = 128 - KASAN_GRANULE_SIZE;
 
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
-	KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 1 + OOB_TAG_OFF, 0, 8));
+	KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 7, 0, 8));
 	kfree(ptr);
 }
 
 static void kmalloc_oob_memset_16(struct kunit *test)
 {
 	char *ptr;
-	size_t size = 16;
+	size_t size = 128 - KASAN_GRANULE_SIZE;
 
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
-	KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + 1 + OOB_TAG_OFF, 0, 16));
+	KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr + size - 15, 0, 16));
 	kfree(ptr);
 }
 
 static void kmalloc_oob_in_memset(struct kunit *test)
 {
 	char *ptr;
-	size_t size = 666;
+	size_t size = 128 - KASAN_GRANULE_SIZE;
 
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
-	KUNIT_EXPECT_KASAN_FAIL(test, memset(ptr, 0, size + 5 + OOB_TAG_OFF));
+	KUNIT_EXPECT_KASAN_FAIL(test,
+				memset(ptr, 0, size + KASAN_GRANULE_SIZE));
 	kfree(ptr);
 }
 
···
 	size_t size = 64;
 	volatile size_t invalid_size = -2;
 
+	/*
+	 * Hardware tag-based mode doesn't check memmove for negative size.
+	 * As a result, this test introduces a side-effect memory corruption,
+	 * which can result in a crash.
+	 */
+	KASAN_TEST_NEEDS_CONFIG_OFF(test, CONFIG_KASAN_HW_TAGS);
+
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
 	memset((char *)ptr, 0, 64);
-
 	KUNIT_EXPECT_KASAN_FAIL(test,
 		memmove((char *)ptr, (char *)ptr + 4, invalid_size));
 	kfree(ptr);
···
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
 
 	kfree(ptr);
-	KUNIT_EXPECT_KASAN_FAIL(test, *(ptr + 8) = 'x');
+	KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[8]);
 }
 
 static void kmalloc_uaf_memset(struct kunit *test)
 {
 	char *ptr;
 	size_t size = 33;
+
+	/*
+	 * Only generic KASAN uses quarantine, which is required to avoid a
+	 * kernel memory corruption this test causes.
+	 */
+	KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_GENERIC);
 
 	ptr = kmalloc(size, GFP_KERNEL);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ptr);
···
 		goto again;
 	}
 
-	KUNIT_EXPECT_KASAN_FAIL(test, ptr1[40] = 'x');
+	KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr1)[40]);
 	KUNIT_EXPECT_PTR_NE(test, ptr1, ptr2);
 
 	kfree(ptr2);
···
 	ptr[size] = 'x';
 
 	/* This one must. */
-	KUNIT_EXPECT_KASAN_FAIL(test, ptr[real_size] = 'y');
+	KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[real_size]);
 
 	kfree(ptr);
 }
···
 	kfree(ptr);
 
 	KUNIT_EXPECT_KASAN_FAIL(test, ksize(ptr));
-	KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = *ptr);
-	KUNIT_EXPECT_KASAN_FAIL(test, kasan_int_result = *(ptr + size));
+	KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[0]);
+	KUNIT_EXPECT_KASAN_FAIL(test, ((volatile char *)ptr)[size]);
 }
 
 static void kasan_stack_oob(struct kunit *test)

lib/test_kasan_module.c

···
 
 #include "../mm/kasan/kasan.h"
 
-#define OOB_TAG_OFF (IS_ENABLED(CONFIG_KASAN_GENERIC) ? 0 : KASAN_GRANULE_SIZE)
-
 static noinline void __init copy_user_test(void)
 {
 	char *kmem;
 	char __user *usermem;
-	size_t size = 10;
+	size_t size = 128 - KASAN_GRANULE_SIZE;
 	int __maybe_unused unused;
 
 	kmem = kmalloc(size, GFP_KERNEL);
···
 	}
 
 	pr_info("out-of-bounds in copy_from_user()\n");
-	unused = copy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF);
+	unused = copy_from_user(kmem, usermem, size + 1);
 
 	pr_info("out-of-bounds in copy_to_user()\n");
-	unused = copy_to_user(usermem, kmem, size + 1 + OOB_TAG_OFF);
+	unused = copy_to_user(usermem, kmem, size + 1);
 
 	pr_info("out-of-bounds in __copy_from_user()\n");
-	unused = __copy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF);
+	unused = __copy_from_user(kmem, usermem, size + 1);
 
 	pr_info("out-of-bounds in __copy_to_user()\n");
-	unused = __copy_to_user(usermem, kmem, size + 1 + OOB_TAG_OFF);
+	unused = __copy_to_user(usermem, kmem, size + 1);
 
 	pr_info("out-of-bounds in __copy_from_user_inatomic()\n");
-	unused = __copy_from_user_inatomic(kmem, usermem, size + 1 + OOB_TAG_OFF);
+	unused = __copy_from_user_inatomic(kmem, usermem, size + 1);
 
 	pr_info("out-of-bounds in __copy_to_user_inatomic()\n");
-	unused = __copy_to_user_inatomic(usermem, kmem, size + 1 + OOB_TAG_OFF);
+	unused = __copy_to_user_inatomic(usermem, kmem, size + 1);
 
 	pr_info("out-of-bounds in strncpy_from_user()\n");
-	unused = strncpy_from_user(kmem, usermem, size + 1 + OOB_TAG_OFF);
+	unused = strncpy_from_user(kmem, usermem, size + 1);
 
 	vm_munmap((unsigned long)usermem, PAGE_SIZE);
 	kfree(kmem);
···
 						struct kasan_rcu_info, rcu);
 
 	kfree(fp);
-	fp->i = 1;
+	((volatile struct kasan_rcu_info *)fp)->i;
 }
 
 static noinline void __init kasan_rcu_uaf(void)

lib/test_vmalloc.c

···
 __param(int, test_loop_count, 1000000,
 	"Set test loop counter");
 
+__param(int, nr_pages, 0,
+	"Set number of pages for fix_size_alloc_test(default: 1)");
+
 __param(int, run_test_mask, INT_MAX,
 	"Set tests specified in the mask.\n\n"
 		"\t\tid: 1,    name: fix_size_alloc_test\n"
···
 	int i;
 
 	for (i = 0; i < test_loop_count; i++) {
-		ptr = vmalloc(3 * PAGE_SIZE);
+		ptr = vmalloc((nr_pages > 0 ? nr_pages:1) * PAGE_SIZE);
 
 		if (!ptr)
 			return -1;

mm/backing-dev.c

···
 	spin_unlock_bh(&wb->work_lock);
 }
 
+static void wb_update_bandwidth_workfn(struct work_struct *work)
+{
+	struct bdi_writeback *wb = container_of(to_delayed_work(work),
+						struct bdi_writeback, bw_dwork);
+
+	wb_update_bandwidth(wb);
+}
+
 /*
  * Initial write bandwidth: 100 MB/s
  */
···
 	INIT_LIST_HEAD(&wb->b_dirty_time);
 	spin_lock_init(&wb->list_lock);
 
+	atomic_set(&wb->writeback_inodes, 0);
 	wb->bw_time_stamp = jiffies;
 	wb->balanced_dirty_ratelimit = INIT_BW;
 	wb->dirty_ratelimit = INIT_BW;
···
 	spin_lock_init(&wb->work_lock);
 	INIT_LIST_HEAD(&wb->work_list);
 	INIT_DELAYED_WORK(&wb->dwork, wb_workfn);
+	INIT_DELAYED_WORK(&wb->bw_dwork, wb_update_bandwidth_workfn);
 	wb->dirty_sleep = jiffies;
 
 	err = fprop_local_init_percpu(&wb->completions, gfp);
···
 	mod_delayed_work(bdi_wq, &wb->dwork, 0);
 	flush_delayed_work(&wb->dwork);
 	WARN_ON(!list_empty(&wb->work_list));
+	flush_delayed_work(&wb->bw_dwork);
 }
 
 static void wb_exit(struct bdi_writeback *wb)

mm/bootmem_info.c

···
 }
 
 #ifndef CONFIG_SPARSEMEM_VMEMMAP
-static void register_page_bootmem_info_section(unsigned long start_pfn)
+static void __init register_page_bootmem_info_section(unsigned long start_pfn)
 {
 	unsigned long mapsize, section_nr, i;
 	struct mem_section *ms;
···
 
 }
 #else /* CONFIG_SPARSEMEM_VMEMMAP */
-static void register_page_bootmem_info_section(unsigned long start_pfn)
+static void __init register_page_bootmem_info_section(unsigned long start_pfn)
 {
 	unsigned long mapsize, section_nr, i;
 	struct mem_section *ms;

mm/compaction.c

···
 
 		err = migrate_pages(&cc->migratepages, compaction_alloc,
 				compaction_free, (unsigned long)cc, cc->mode,
-				MR_COMPACTION);
+				MR_COMPACTION, NULL);
 
 		trace_mm_compaction_migratepages(cc->nr_migratepages, err,
 							&cc->migratepages);
···
  */
 unsigned int __read_mostly sysctl_compaction_proactiveness = 20;
 
+int compaction_proactiveness_sysctl_handler(struct ctl_table *table, int write,
+		void *buffer, size_t *length, loff_t *ppos)
+{
+	int rc, nid;
+
+	rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
+	if (rc)
+		return rc;
+
+	if (write && sysctl_compaction_proactiveness) {
+		for_each_online_node(nid) {
+			pg_data_t *pgdat = NODE_DATA(nid);
+
+			if (pgdat->proactive_compact_trigger)
+				continue;
+
+			pgdat->proactive_compact_trigger = true;
+			wake_up_interruptible(&pgdat->kcompactd_wait);
+		}
+	}
+
+	return 0;
+}
+
 /*
  * This is the entry point for compacting all nodes via
  * /proc/sys/vm/compact_memory
···
 
 static inline bool kcompactd_work_requested(pg_data_t *pgdat)
 {
-	return pgdat->kcompactd_max_order > 0 || kthread_should_stop();
+	return pgdat->kcompactd_max_order > 0 || kthread_should_stop() ||
+		pgdat->proactive_compact_trigger;
 }
 
 static bool kcompactd_node_suitable(pg_data_t *pgdat)
···
 {
 	pg_data_t *pgdat = (pg_data_t *)p;
 	struct task_struct *tsk = current;
-	unsigned int proactive_defer = 0;
+	long default_timeout = msecs_to_jiffies(HPAGE_FRAG_CHECK_INTERVAL_MSEC);
+	long timeout = default_timeout;
 
 	const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id);
 
···
 	while (!kthread_should_stop()) {
 		unsigned long pflags;
 
+		/*
+		 * Avoid the unnecessary wakeup for proactive compaction
+		 * when it is disabled.
+		 */
+		if (!sysctl_compaction_proactiveness)
+			timeout = MAX_SCHEDULE_TIMEOUT;
 		trace_mm_compaction_kcompactd_sleep(pgdat->node_id);
 		if (wait_event_freezable_timeout(pgdat->kcompactd_wait,
-			kcompactd_work_requested(pgdat),
-			msecs_to_jiffies(HPAGE_FRAG_CHECK_INTERVAL_MSEC))) {
+			kcompactd_work_requested(pgdat), timeout) &&
+			!pgdat->proactive_compact_trigger) {
 
 			psi_memstall_enter(&pflags);
 			kcompactd_do_work(pgdat);
 			psi_memstall_leave(&pflags);
+			/*
+			 * Reset the timeout value. The defer timeout from
+			 * proactive compaction is lost here but that is fine
+			 * as the condition of the zone changing substantionally
+			 * then carrying on with the previous defer interval is
+			 * not useful.
+			 */
+			timeout = default_timeout;
 			continue;
 		}
 
-		/* kcompactd wait timeout */
+		/*
+		 * Start the proactive work with default timeout. Based
+		 * on the fragmentation score, this timeout is updated.
+		 */
+		timeout = default_timeout;
 		if (should_proactive_compact_node(pgdat)) {
 			unsigned int prev_score, score;
 
-			if (proactive_defer) {
-				proactive_defer--;
-				continue;
-			}
 			prev_score = fragmentation_score_node(pgdat);
 			proactive_compact_node(pgdat);
 			score = fragmentation_score_node(pgdat);
···
 			 * Defer proactive compaction if the fragmentation
 			 * score did not go down i.e. no progress made.
 			 */
-			proactive_defer = score < prev_score ?
-					0 : 1 << COMPACT_MAX_DEFER_SHIFT;
+			if (unlikely(score >= prev_score))
+				timeout =
+				   default_timeout << COMPACT_MAX_DEFER_SHIFT;
 		}
+		if (unlikely(pgdat->proactive_compact_trigger))
+			pgdat->proactive_compact_trigger = false;
 	}
 
 	return 0;

mm/debug_vm_pgtable.c

···
 #include <linux/start_kernel.h>
 #include <linux/sched/mm.h>
 #include <linux/io.h>
+
+#include <asm/cacheflush.h>
 #include <asm/pgalloc.h>
 #include <asm/tlbflush.h>
 
···
 #define RANDOM_ORVALUE (GENMASK(BITS_PER_LONG - 1, 0) & ~ARCH_SKIP_MASK)
 #define RANDOM_NZVALUE	GENMASK(7, 0)
 
-static void __init pte_basic_tests(unsigned long pfn, int idx)
+struct pgtable_debug_args {
+	struct mm_struct	*mm;
+	struct vm_area_struct	*vma;
+
+	pgd_t			*pgdp;
+	p4d_t			*p4dp;
+	pud_t			*pudp;
+	pmd_t			*pmdp;
+	pte_t			*ptep;
+
+	p4d_t			*start_p4dp;
+	pud_t			*start_pudp;
+	pmd_t			*start_pmdp;
+	pgtable_t		start_ptep;
+
+	unsigned long		vaddr;
+	pgprot_t		page_prot;
+	pgprot_t		page_prot_none;
+
+	bool			is_contiguous_page;
+	unsigned long		pud_pfn;
+	unsigned long		pmd_pfn;
+	unsigned long		pte_pfn;
+
+	unsigned long		fixed_pgd_pfn;
+	unsigned long		fixed_p4d_pfn;
+	unsigned long		fixed_pud_pfn;
+	unsigned long		fixed_pmd_pfn;
+	unsigned long		fixed_pte_pfn;
+};
+
+static void __init pte_basic_tests(struct pgtable_debug_args *args, int idx)
 {
 	pgprot_t prot = protection_map[idx];
-	pte_t pte = pfn_pte(pfn, prot);
+	pte_t pte = pfn_pte(args->fixed_pte_pfn, prot);
 	unsigned long val = idx, *ptr = &val;
 
 	pr_debug("Validating PTE basic (%pGv)\n", ptr);
···
 	WARN_ON(!pte_dirty(pte_wrprotect(pte_mkdirty(pte))));
 }
 
-static void __init pte_advanced_tests(struct mm_struct *mm,
-				      struct vm_area_struct *vma, pte_t *ptep,
-				      unsigned long pfn, unsigned long vaddr,
-				      pgprot_t prot)
+static void __init pte_advanced_tests(struct pgtable_debug_args *args)
 {
+	struct page *page;
 	pte_t pte;
 
 	/*
 	 * Architectures optimize set_pte_at by avoiding TLB flush.
 	 * This requires set_pte_at to be not used to update an
 	 * existing pte entry. Clear pte before we do set_pte_at
+	 *
+	 * flush_dcache_page() is called after set_pte_at() to clear
+	 * PG_arch_1 for the page on ARM64. The page flag isn't cleared
+	 * when it's released and page allocation check will fail when
+	 * the page is allocated again. For architectures other than ARM64,
+	 * the unexpected overhead of cache flushing is acceptable.
 	 */
+	page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL;
+	if (!page)
+		return;
 
 	pr_debug("Validating PTE advanced\n");
-	pte = pfn_pte(pfn, prot);
-	set_pte_at(mm, vaddr, ptep, pte);
-	ptep_set_wrprotect(mm, vaddr, ptep);
-	pte = ptep_get(ptep);
+	pte = pfn_pte(args->pte_pfn, args->page_prot);
+	set_pte_at(args->mm, args->vaddr, args->ptep, pte);
+	flush_dcache_page(page);
+	ptep_set_wrprotect(args->mm, args->vaddr, args->ptep);
+	pte = ptep_get(args->ptep);
 	WARN_ON(pte_write(pte));
-	ptep_get_and_clear(mm, vaddr, ptep);
-	pte = ptep_get(ptep);
+	ptep_get_and_clear(args->mm, args->vaddr, args->ptep);
+	pte = ptep_get(args->ptep);
 	WARN_ON(!pte_none(pte));
 
-	pte = pfn_pte(pfn, prot);
+	pte = pfn_pte(args->pte_pfn, args->page_prot);
 	pte = pte_wrprotect(pte);
 	pte = pte_mkclean(pte);
-	set_pte_at(mm, vaddr, ptep, pte);
+	set_pte_at(args->mm, args->vaddr, args->ptep, pte);
+	flush_dcache_page(page);
 	pte = pte_mkwrite(pte);
 	pte = pte_mkdirty(pte);
-	ptep_set_access_flags(vma, vaddr, ptep, pte, 1);
-	pte = ptep_get(ptep);
+	ptep_set_access_flags(args->vma, args->vaddr, args->ptep, pte, 1);
+	pte = ptep_get(args->ptep);
 	WARN_ON(!(pte_write(pte) && pte_dirty(pte)));
-	ptep_get_and_clear_full(mm, vaddr, ptep, 1);
-	pte = ptep_get(ptep);
+	ptep_get_and_clear_full(args->mm, args->vaddr, args->ptep, 1);
+	pte = ptep_get(args->ptep);
 	WARN_ON(!pte_none(pte));
 
-	pte = pfn_pte(pfn, prot);
+	pte = pfn_pte(args->pte_pfn, args->page_prot);
 	pte = pte_mkyoung(pte);
-	set_pte_at(mm, vaddr, ptep, pte);
-	ptep_test_and_clear_young(vma, vaddr, ptep);
-	pte = ptep_get(ptep);
+	set_pte_at(args->mm, args->vaddr, args->ptep, pte);
+	flush_dcache_page(page);
+	ptep_test_and_clear_young(args->vma, args->vaddr, args->ptep);
+	pte = ptep_get(args->ptep);
 	WARN_ON(pte_young(pte));
 }
 
-static void __init pte_savedwrite_tests(unsigned long pfn, pgprot_t prot)
+static void __init pte_savedwrite_tests(struct pgtable_debug_args *args)
 {
-	pte_t pte = pfn_pte(pfn, prot);
+	pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot_none);
 
 	if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
 		return;
···
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-static void __init pmd_basic_tests(unsigned long pfn, int idx)
+static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx)
 {
 	pgprot_t prot = protection_map[idx];
 	unsigned long val = idx, *ptr = &val;
···
 		return;
 
 	pr_debug("Validating PMD basic (%pGv)\n", ptr);
-	pmd = pfn_pmd(pfn, prot);
+	pmd = pfn_pmd(args->fixed_pmd_pfn, prot);
 
 	/*
 	 * This test needs to be executed after the given page table entry
···
 	WARN_ON(!pmd_bad(pmd_mkhuge(pmd)));
 }
 
-static void __init pmd_advanced_tests(struct mm_struct *mm,
-				      struct vm_area_struct *vma, pmd_t *pmdp,
-				      unsigned long pfn, unsigned long vaddr,
-				      pgprot_t prot, pgtable_t pgtable)
+static void __init pmd_advanced_tests(struct pgtable_debug_args *args)
 {
+	struct page *page;
 	pmd_t pmd;
+	unsigned long vaddr = args->vaddr;
 
 	if (!has_transparent_hugepage())
 		return;
 
+	page = (args->pmd_pfn != ULONG_MAX) ? pfn_to_page(args->pmd_pfn) : NULL;
+	if (!page)
+		return;
+
+	/*
+	 * flush_dcache_page() is called after set_pmd_at() to clear
+	 * PG_arch_1 for the page on ARM64. The page flag isn't cleared
+	 * when it's released and page allocation check will fail when
+	 * the page is allocated again. For architectures other than ARM64,
+	 * the unexpected overhead of cache flushing is acceptable.
+	 */
 	pr_debug("Validating PMD advanced\n");
 	/* Align the address wrt HPAGE_PMD_SIZE */
 	vaddr &= HPAGE_PMD_MASK;
 
-	pgtable_trans_huge_deposit(mm, pmdp, pgtable);
+	pgtable_trans_huge_deposit(args->mm, args->pmdp, args->start_ptep);
 
-	pmd = pfn_pmd(pfn, prot);
-	set_pmd_at(mm, vaddr, pmdp, pmd);
-	pmdp_set_wrprotect(mm, vaddr, pmdp);
-	pmd = READ_ONCE(*pmdp);
+	pmd = pfn_pmd(args->pmd_pfn, args->page_prot);
+	set_pmd_at(args->mm, vaddr, args->pmdp, pmd);
+	flush_dcache_page(page);
+	pmdp_set_wrprotect(args->mm, vaddr, args->pmdp);
+	pmd = READ_ONCE(*args->pmdp);
 	WARN_ON(pmd_write(pmd));
-	pmdp_huge_get_and_clear(mm, vaddr, pmdp);
-	pmd = READ_ONCE(*pmdp);
+	pmdp_huge_get_and_clear(args->mm, vaddr, args->pmdp);
+	pmd = READ_ONCE(*args->pmdp);
 	WARN_ON(!pmd_none(pmd));
 
-	pmd = pfn_pmd(pfn, prot);
+	pmd = pfn_pmd(args->pmd_pfn, args->page_prot);
 	pmd = pmd_wrprotect(pmd);
 	pmd = pmd_mkclean(pmd);
-	set_pmd_at(mm, vaddr, pmdp, pmd);
+	set_pmd_at(args->mm, vaddr, args->pmdp, pmd);
+	flush_dcache_page(page);
 	pmd = pmd_mkwrite(pmd);
 	pmd = pmd_mkdirty(pmd);
-	pmdp_set_access_flags(vma, vaddr, pmdp, pmd, 1);
-	pmd = READ_ONCE(*pmdp);
+	pmdp_set_access_flags(args->vma, vaddr, args->pmdp, pmd, 1);
+	pmd = READ_ONCE(*args->pmdp);
 	WARN_ON(!(pmd_write(pmd) && pmd_dirty(pmd)));
-	pmdp_huge_get_and_clear_full(vma, vaddr, pmdp, 1);
-	pmd = READ_ONCE(*pmdp);
+	pmdp_huge_get_and_clear_full(args->vma, vaddr, args->pmdp, 1);
+	pmd = READ_ONCE(*args->pmdp);
 	WARN_ON(!pmd_none(pmd));
 
-	pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
+	pmd = pmd_mkhuge(pfn_pmd(args->pmd_pfn, args->page_prot));
 	pmd = pmd_mkyoung(pmd);
-	set_pmd_at(mm, vaddr, pmdp, pmd);
-	pmdp_test_and_clear_young(vma, vaddr, pmdp);
-	pmd = READ_ONCE(*pmdp);
+	set_pmd_at(args->mm, vaddr, args->pmdp, pmd);
+	flush_dcache_page(page);
+	pmdp_test_and_clear_young(args->vma, vaddr, args->pmdp);
+	pmd = READ_ONCE(*args->pmdp);
 	WARN_ON(pmd_young(pmd));
 
 	/*  Clear the pte entries  */
-	pmdp_huge_get_and_clear(mm, vaddr, pmdp);
-	pgtable = pgtable_trans_huge_withdraw(mm, pmdp);
+	pmdp_huge_get_and_clear(args->mm, vaddr, args->pmdp);
+	pgtable_trans_huge_withdraw(args->mm, args->pmdp);
 }
 
-static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot)
+static void __init pmd_leaf_tests(struct pgtable_debug_args *args)
 {
 	pmd_t pmd;
 
···
 		return;
 
 	pr_debug("Validating PMD leaf\n");
-	pmd = pfn_pmd(pfn, prot);
+	pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
 
 	/*
 	 * PMD based THP is a leaf entry.
···
 	WARN_ON(!pmd_leaf(pmd));
 }
 
-static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot)
+static void __init pmd_savedwrite_tests(struct pgtable_debug_args *args)
 {
 	pmd_t pmd;
 
···
 		return;
 
 	pr_debug("Validating PMD saved write\n");
-	pmd = pfn_pmd(pfn, prot);
+	pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot_none);
 	WARN_ON(!pmd_savedwrite(pmd_mk_savedwrite(pmd_clear_savedwrite(pmd))));
 	WARN_ON(pmd_savedwrite(pmd_clear_savedwrite(pmd_mk_savedwrite(pmd))));
 }
 
 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
-static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx)
+static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx)
 {
 	pgprot_t prot = protection_map[idx];
 	unsigned long val = idx, *ptr = &val;
···
 		return;
 
 	pr_debug("Validating PUD basic (%pGv)\n", ptr);
-	pud = pfn_pud(pfn, prot);
+	pud = pfn_pud(args->fixed_pud_pfn, prot);
 
 	/*
 	 * This test needs to be executed after the given page table entry
···
 	WARN_ON(pud_dirty(pud_wrprotect(pud_mkclean(pud))));
 	WARN_ON(!pud_dirty(pud_wrprotect(pud_mkdirty(pud))));
 
-	if (mm_pmd_folded(mm))
+	if (mm_pmd_folded(args->mm))
 		return;
 
 	/*
···
 	WARN_ON(!pud_bad(pud_mkhuge(pud)));
 }
 
-static void __init pud_advanced_tests(struct mm_struct *mm,
-				      struct vm_area_struct *vma, pud_t *pudp,
-				      unsigned long pfn, unsigned long vaddr,
-				      pgprot_t prot)
+static void __init pud_advanced_tests(struct pgtable_debug_args *args)
 {
+	struct page *page;
+	unsigned long vaddr = args->vaddr;
 	pud_t pud;
 
 	if (!has_transparent_hugepage())
 		return;
 
+	page = (args->pud_pfn != ULONG_MAX) ? pfn_to_page(args->pud_pfn) : NULL;
+	if (!page)
+		return;
+
+	/*
+	 * flush_dcache_page() is called after set_pud_at() to clear
+	 * PG_arch_1 for the page on ARM64. The page flag isn't cleared
+	 * when it's released and page allocation check will fail when
+	 * the page is allocated again. For architectures other than ARM64,
+	 * the unexpected overhead of cache flushing is acceptable.
+	 */
 	pr_debug("Validating PUD advanced\n");
 	/* Align the address wrt HPAGE_PUD_SIZE */
 	vaddr &= HPAGE_PUD_MASK;
 
-	pud = pfn_pud(pfn, prot);
-	set_pud_at(mm, vaddr, pudp, pud);
-	pudp_set_wrprotect(mm, vaddr, pudp);
-	pud = READ_ONCE(*pudp);
+	pud = pfn_pud(args->pud_pfn, args->page_prot);
+	set_pud_at(args->mm, vaddr, args->pudp, pud);
+	flush_dcache_page(page);
+	pudp_set_wrprotect(args->mm, vaddr, args->pudp);
+	pud = READ_ONCE(*args->pudp);
 	WARN_ON(pud_write(pud));
 
 #ifndef __PAGETABLE_PMD_FOLDED
-	pudp_huge_get_and_clear(mm, vaddr, pudp);
-	pud = READ_ONCE(*pudp);
+	pudp_huge_get_and_clear(args->mm, vaddr, args->pudp);
+	pud = READ_ONCE(*args->pudp);
 	WARN_ON(!pud_none(pud));
 #endif /* __PAGETABLE_PMD_FOLDED */
-	pud = pfn_pud(pfn, prot);
+	pud = pfn_pud(args->pud_pfn, args->page_prot);
 	pud = pud_wrprotect(pud);
 	pud = pud_mkclean(pud);
-	set_pud_at(mm, vaddr, pudp, pud);
+	set_pud_at(args->mm, vaddr, args->pudp, pud);
+	flush_dcache_page(page);
 	pud = pud_mkwrite(pud);
 	pud = pud_mkdirty(pud);
-	pudp_set_access_flags(vma, vaddr, pudp, pud, 1);
-	pud = READ_ONCE(*pudp);
+	pudp_set_access_flags(args->vma, vaddr, args->pudp, pud, 1);
+	pud = READ_ONCE(*args->pudp);
 	WARN_ON(!(pud_write(pud) && pud_dirty(pud)));
 
 #ifndef __PAGETABLE_PMD_FOLDED
-	pudp_huge_get_and_clear_full(mm, vaddr, pudp, 1);
-	pud = READ_ONCE(*pudp);
+	pudp_huge_get_and_clear_full(args->mm, vaddr, args->pudp, 1);
+	pud = READ_ONCE(*args->pudp);
 	WARN_ON(!pud_none(pud));
 #endif /* __PAGETABLE_PMD_FOLDED */
 
-	pud = pfn_pud(pfn, prot);
+	pud = pfn_pud(args->pud_pfn, args->page_prot);
 	pud = pud_mkyoung(pud);
-	set_pud_at(mm, vaddr, pudp, pud);
-	pudp_test_and_clear_young(vma, vaddr, pudp);
-	pud = READ_ONCE(*pudp);
+	set_pud_at(args->mm, vaddr, args->pudp, pud);
+	flush_dcache_page(page);
+	pudp_test_and_clear_young(args->vma, vaddr, args->pudp);
+	pud = READ_ONCE(*args->pudp);
 	WARN_ON(pud_young(pud));
 
-	pudp_huge_get_and_clear(mm, vaddr, pudp);
+	pudp_huge_get_and_clear(args->mm, vaddr, args->pudp);
 }
 
-static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot)
+static void __init pud_leaf_tests(struct pgtable_debug_args *args)
 {
 	pud_t pud;
 
···
 		return;
 
 	pr_debug("Validating PUD leaf\n");
-	pud = pfn_pud(pfn, prot);
+	pud = pfn_pud(args->fixed_pud_pfn, args->page_prot);
 	/*
 	 * PUD based THP is a leaf entry.
 	 */
···
 	WARN_ON(!pud_leaf(pud));
 }
 #else  /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
-static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx) { }
-static void __init pud_advanced_tests(struct mm_struct *mm,
-				      struct vm_area_struct *vma, pud_t *pudp,
-				      unsigned long pfn, unsigned long vaddr,
-				      pgprot_t prot)
-{
-}
-static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) { }
+static void __init pud_advanced_tests(struct pgtable_debug_args *args) { }
+static void __init pud_leaf_tests(struct pgtable_debug_args *args) { }
 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 #else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
-static void __init pmd_basic_tests(unsigned long pfn, int idx) { }
-static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx) { }
-static void __init pmd_advanced_tests(struct mm_struct *mm,
-				      struct vm_area_struct *vma, pmd_t *pmdp,
-				      unsigned long pfn, unsigned long vaddr,
-				      pgprot_t prot, pgtable_t pgtable)
-{
-}
-static void __init pud_advanced_tests(struct mm_struct *mm,
-				      struct vm_area_struct *vma, pud_t *pudp,
-				      unsigned long pfn, unsigned long vaddr,
-				      pgprot_t prot)
-{
-}
-static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot) { }
-static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) { }
-static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pmd_basic_tests(struct pgtable_debug_args *args, int idx) { }
+static void __init pud_basic_tests(struct pgtable_debug_args *args, int idx) { }
+static void __init pmd_advanced_tests(struct pgtable_debug_args *args) { }
+static void __init pud_advanced_tests(struct pgtable_debug_args *args) { }
+static void __init pmd_leaf_tests(struct pgtable_debug_args *args) { }
+static void __init pud_leaf_tests(struct pgtable_debug_args *args) { }
+static void __init pmd_savedwrite_tests(struct pgtable_debug_args *args) { }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
-static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
+static void __init pmd_huge_tests(struct pgtable_debug_args *args)
 {
 	pmd_t pmd;
 
-	if (!arch_vmap_pmd_supported(prot))
+	if (!arch_vmap_pmd_supported(args->page_prot))
 		return;
 
 	pr_debug("Validating PMD huge\n");
···
 	 * X86 defined pmd_set_huge() verifies that the given
 	 * PMD is not a populated non-leaf entry.
 	 */
-	WRITE_ONCE(*pmdp, __pmd(0));
-	WARN_ON(!pmd_set_huge(pmdp, __pfn_to_phys(pfn), prot));
-	WARN_ON(!pmd_clear_huge(pmdp));
-	pmd = READ_ONCE(*pmdp);
+	WRITE_ONCE(*args->pmdp, __pmd(0));
+	WARN_ON(!pmd_set_huge(args->pmdp, __pfn_to_phys(args->fixed_pmd_pfn), args->page_prot));
+	WARN_ON(!pmd_clear_huge(args->pmdp));
+	pmd = READ_ONCE(*args->pmdp);
 	WARN_ON(!pmd_none(pmd));
 }
 
-static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
+static void __init pud_huge_tests(struct pgtable_debug_args *args)
 {
 	pud_t pud;
 
-	if (!arch_vmap_pud_supported(prot))
+	if (!arch_vmap_pud_supported(args->page_prot))
 		return;
 
 	pr_debug("Validating PUD huge\n");
···
 	 * X86 defined pud_set_huge() verifies that the given
 	 * PUD is not a populated non-leaf entry.
 	 */
-	WRITE_ONCE(*pudp, __pud(0));
-	WARN_ON(!pud_set_huge(pudp, __pfn_to_phys(pfn), prot));
-	WARN_ON(!pud_clear_huge(pudp));
-	pud = READ_ONCE(*pudp);
+	WRITE_ONCE(*args->pudp, __pud(0));
+	WARN_ON(!pud_set_huge(args->pudp, __pfn_to_phys(args->fixed_pud_pfn), args->page_prot));
+	WARN_ON(!pud_clear_huge(args->pudp));
+	pud = READ_ONCE(*args->pudp);
 	WARN_ON(!pud_none(pud));
 }
 #else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
-static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot) { }
-static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot) { }
+static void __init pmd_huge_tests(struct pgtable_debug_args *args) { }
+static void __init pud_huge_tests(struct pgtable_debug_args *args) { }
 #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
 
-static void __init p4d_basic_tests(unsigned long pfn, pgprot_t prot)
+static void __init p4d_basic_tests(struct pgtable_debug_args *args)
 {
 	p4d_t p4d;
 
···
 	WARN_ON(!p4d_same(p4d, p4d));
 }
 
-static void __init pgd_basic_tests(unsigned long pfn, pgprot_t prot)
+static void __init pgd_basic_tests(struct pgtable_debug_args *args)
 {
 	pgd_t pgd;
 
···
 }
 
 #ifndef __PAGETABLE_PUD_FOLDED
-static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp)
+static void __init pud_clear_tests(struct pgtable_debug_args *args)
 {
-	pud_t pud = READ_ONCE(*pudp);
+	pud_t pud = READ_ONCE(*args->pudp);
 
-	if (mm_pmd_folded(mm))
+	if (mm_pmd_folded(args->mm))
 		return;
 
 	pr_debug("Validating PUD clear\n");
 	pud = __pud(pud_val(pud) | RANDOM_ORVALUE);
-	WRITE_ONCE(*pudp, pud);
-	pud_clear(pudp);
-	pud = READ_ONCE(*pudp);
+	WRITE_ONCE(*args->pudp, pud);
+	pud_clear(args->pudp);
+	pud = READ_ONCE(*args->pudp);
 	WARN_ON(!pud_none(pud));
 }
 
-static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
-				      pmd_t *pmdp)
+static void __init pud_populate_tests(struct pgtable_debug_args *args)
 {
 	pud_t pud;
 
-	if (mm_pmd_folded(mm))
+	if (mm_pmd_folded(args->mm))
 		return;
 
 	pr_debug("Validating PUD populate\n");
···
 	 * This entry points to next level page table page.
 	 * Hence this must not qualify as pud_bad().
 	 */
-	pud_populate(mm, pudp, pmdp);
-	pud = READ_ONCE(*pudp);
+	pud_populate(args->mm, args->pudp, args->start_pmdp);
+	pud = READ_ONCE(*args->pudp);
 	WARN_ON(pud_bad(pud));
 }
 #else  /* !__PAGETABLE_PUD_FOLDED */
-static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp) { }
-static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
-				      pmd_t *pmdp)
-{
-}
+static void __init pud_clear_tests(struct pgtable_debug_args *args) { }
+static void __init pud_populate_tests(struct pgtable_debug_args *args) { }
 #endif /* PAGETABLE_PUD_FOLDED */
 
 #ifndef __PAGETABLE_P4D_FOLDED
-static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp)
+static void __init p4d_clear_tests(struct pgtable_debug_args *args)
 {
-	p4d_t p4d = READ_ONCE(*p4dp);
+	p4d_t p4d = READ_ONCE(*args->p4dp);
 
-	if (mm_pud_folded(mm))
+	if (mm_pud_folded(args->mm))
 		return;
 
 	pr_debug("Validating P4D clear\n");
 	p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE);
-	WRITE_ONCE(*p4dp, p4d);
-	p4d_clear(p4dp);
-	p4d = READ_ONCE(*p4dp);
+	WRITE_ONCE(*args->p4dp, p4d);
+	p4d_clear(args->p4dp);
+	p4d = READ_ONCE(*args->p4dp);
 	WARN_ON(!p4d_none(p4d));
 }
 
-static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
-				      pud_t *pudp)
+static void __init p4d_populate_tests(struct pgtable_debug_args *args)
 {
 	p4d_t p4d;
 
-	if (mm_pud_folded(mm))
+	if (mm_pud_folded(args->mm))
 		return;
 
 	pr_debug("Validating P4D populate\n");
···
 	 * This entry points to next level page table page.
 	 * Hence this must not qualify as p4d_bad().
 	 */
-	pud_clear(pudp);
-	p4d_clear(p4dp);
-	p4d_populate(mm, p4dp, pudp);
-	p4d = READ_ONCE(*p4dp);
+	pud_clear(args->pudp);
+	p4d_clear(args->p4dp);
+	p4d_populate(args->mm, args->p4dp, args->start_pudp);
+	p4d = READ_ONCE(*args->p4dp);
 	WARN_ON(p4d_bad(p4d));
 }
 
-static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp)
+static void __init pgd_clear_tests(struct pgtable_debug_args *args)
 {
-	pgd_t pgd = READ_ONCE(*pgdp);
+	pgd_t pgd = READ_ONCE(*(args->pgdp));
 
-	if (mm_p4d_folded(mm))
+	if (mm_p4d_folded(args->mm))
 		return;
 
 	pr_debug("Validating PGD clear\n");
 	pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE);
-	WRITE_ONCE(*pgdp, pgd);
-	pgd_clear(pgdp);
-	pgd = READ_ONCE(*pgdp);
+	WRITE_ONCE(*args->pgdp, pgd);
+	pgd_clear(args->pgdp);
+	pgd = READ_ONCE(*args->pgdp);
 	WARN_ON(!pgd_none(pgd));
 }
 
-static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
-				      p4d_t *p4dp)
+static void __init pgd_populate_tests(struct pgtable_debug_args *args)
 {
 	pgd_t pgd;
 
-	if (mm_p4d_folded(mm))
+	if (mm_p4d_folded(args->mm))
 		return;
 
 	pr_debug("Validating PGD populate\n");
···
 	 * This entry points to next level page table page.
 	 * Hence this must not qualify as pgd_bad().
 	 */
-	p4d_clear(p4dp);
-	pgd_clear(pgdp);
-	pgd_populate(mm, pgdp, p4dp);
-	pgd = READ_ONCE(*pgdp);
+	p4d_clear(args->p4dp);
+	pgd_clear(args->pgdp);
+	pgd_populate(args->mm, args->pgdp, args->start_p4dp);
+	pgd = READ_ONCE(*args->pgdp);
 	WARN_ON(pgd_bad(pgd));
 }
 #else  /* !__PAGETABLE_P4D_FOLDED */
-static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp) { }
-static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp) { }
-static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
-				      pud_t *pudp)
-{
-}
-static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
-				      p4d_t *p4dp)
-{
-}
+static void __init p4d_clear_tests(struct pgtable_debug_args *args) { }
+static void __init pgd_clear_tests(struct pgtable_debug_args *args) { }
+static void __init p4d_populate_tests(struct pgtable_debug_args *args) { }
+static void __init pgd_populate_tests(struct pgtable_debug_args *args) { }
 #endif /* PAGETABLE_P4D_FOLDED */
 
-static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep,
-				   unsigned long pfn, unsigned long vaddr,
-				   pgprot_t prot)
+static void __init pte_clear_tests(struct pgtable_debug_args *args)
 {
-	pte_t pte = pfn_pte(pfn, prot);
+	struct page *page;
+	pte_t pte = pfn_pte(args->pte_pfn, args->page_prot);
 
+	page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL;
+	if (!page)
+		return;
+
+	/*
+	 * flush_dcache_page() is called after set_pte_at() to clear
+	 * PG_arch_1 for the page on ARM64. The page flag isn't cleared
+	 * when it's released and page allocation check will fail when
+	 * the page is allocated again. For architectures other than ARM64,
+	 * the unexpected overhead of cache flushing is acceptable.
+	 */
 	pr_debug("Validating PTE clear\n");
 #ifndef CONFIG_RISCV
 	pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
 #endif
-	set_pte_at(mm, vaddr, ptep, pte);
+	set_pte_at(args->mm, args->vaddr, args->ptep, pte);
+	flush_dcache_page(page);
 	barrier();
-	pte_clear(mm, vaddr, ptep);
-	pte = ptep_get(ptep);
+	pte_clear(args->mm, args->vaddr, args->ptep);
+	pte = ptep_get(args->ptep);
 	WARN_ON(!pte_none(pte));
 }
 
-static void __init pmd_clear_tests(struct mm_struct *mm, pmd_t *pmdp)
+static void __init pmd_clear_tests(struct pgtable_debug_args *args)
 {
-	pmd_t pmd = READ_ONCE(*pmdp);
+	pmd_t pmd = READ_ONCE(*args->pmdp);
 
 	pr_debug("Validating PMD clear\n");
 	pmd = __pmd(pmd_val(pmd) | RANDOM_ORVALUE);
-	WRITE_ONCE(*pmdp, pmd);
-	pmd_clear(pmdp);
-	pmd = READ_ONCE(*pmdp);
+	WRITE_ONCE(*args->pmdp, pmd);
+	pmd_clear(args->pmdp);
+	pmd = READ_ONCE(*args->pmdp);
 	WARN_ON(!pmd_none(pmd));
 }
 
-static void __init pmd_populate_tests(struct mm_struct *mm, pmd_t *pmdp,
-				      pgtable_t pgtable)
+static void __init pmd_populate_tests(struct pgtable_debug_args *args)
 {
 	pmd_t pmd;
 
···
 	 * This entry points to next level page table page.
 	 * Hence this must not qualify as pmd_bad().
 	 */
-	pmd_populate(mm, pmdp, pgtable);
-	pmd = READ_ONCE(*pmdp);
+	pmd_populate(args->mm, args->pmdp, args->start_ptep);
+	pmd = READ_ONCE(*args->pmdp);
 	WARN_ON(pmd_bad(pmd));
 }
 
-static void __init pte_special_tests(unsigned long pfn, pgprot_t prot)
+static void __init pte_special_tests(struct pgtable_debug_args *args)
 {
-	pte_t pte = pfn_pte(pfn, prot);
+	pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
 
 	if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_SPECIAL))
 		return;
···
 	WARN_ON(!pte_special(pte_mkspecial(pte)));
 }
 
-static void __init pte_protnone_tests(unsigned long pfn, pgprot_t prot)
+static void __init pte_protnone_tests(struct pgtable_debug_args *args)
 {
-	pte_t pte = pfn_pte(pfn, prot);
+	pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot_none);
 
 	if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
 		return;
···
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot)
+static void __init pmd_protnone_tests(struct pgtable_debug_args *args)
 {
 	pmd_t pmd;
 
···
 		return;
 
 	pr_debug("Validating PMD protnone\n");
-	pmd = pmd_mkhuge(pfn_pmd(pfn, prot));
+	pmd = pmd_mkhuge(pfn_pmd(args->fixed_pmd_pfn, args->page_prot_none));
 	WARN_ON(!pmd_protnone(pmd));
 	WARN_ON(!pmd_present(pmd));
 }
 #else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
-static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pmd_protnone_tests(struct pgtable_debug_args *args) { }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 #ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
-static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot)
+static void __init pte_devmap_tests(struct pgtable_debug_args *args)
 {
-	pte_t pte = pfn_pte(pfn, prot);
+	pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
 
 	pr_debug("Validating PTE devmap\n");
 	WARN_ON(!pte_devmap(pte_mkdevmap(pte)));
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot)
+static void __init pmd_devmap_tests(struct pgtable_debug_args *args)
 {
 	pmd_t pmd;
 
···
 		return;
 
 	pr_debug("Validating PMD devmap\n");
-	pmd = pfn_pmd(pfn, prot);
+	pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
 	WARN_ON(!pmd_devmap(pmd_mkdevmap(pmd)));
 }
 
 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
-static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot)
+static void __init pud_devmap_tests(struct pgtable_debug_args *args)
 {
 	pud_t pud;
 
···
 		return;
 
 	pr_debug("Validating PUD devmap\n");
-	pud = pfn_pud(pfn, prot);
+	pud = pfn_pud(args->fixed_pud_pfn, args->page_prot);
 	WARN_ON(!pud_devmap(pud_mkdevmap(pud)));
 }
 #else  /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
-static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 #else  /* CONFIG_TRANSPARENT_HUGEPAGE */
-static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) { }
-static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pmd_devmap_tests(struct pgtable_debug_args *args) { }
+static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 #else
-static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot) { }
-static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) { }
-static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pte_devmap_tests(struct pgtable_debug_args *args) { }
+static void __init pmd_devmap_tests(struct pgtable_debug_args *args) { }
+static void __init pud_devmap_tests(struct pgtable_debug_args *args) { }
 #endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
 
-static void __init pte_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
+static void __init pte_soft_dirty_tests(struct pgtable_debug_args *args)
 {
-	pte_t pte = pfn_pte(pfn, prot);
+	pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
 
 	if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
 		return;
···
 	WARN_ON(pte_soft_dirty(pte_clear_soft_dirty(pte)));
 }
 
-static void __init pte_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
+static void __init pte_swap_soft_dirty_tests(struct pgtable_debug_args *args)
 {
-	pte_t pte = pfn_pte(pfn, prot);
+	pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
 
 	if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY))
 		return;
···
 }
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
+static void __init pmd_soft_dirty_tests(struct pgtable_debug_args *args)
 {
 	pmd_t pmd;
 
···
 		return;
 
 	pr_debug("Validating PMD soft dirty\n");
-	pmd = pfn_pmd(pfn, prot);
+	pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
 	WARN_ON(!pmd_soft_dirty(pmd_mksoft_dirty(pmd)));
 	WARN_ON(pmd_soft_dirty(pmd_clear_soft_dirty(pmd)));
 }
 
-static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
+static void __init pmd_swap_soft_dirty_tests(struct pgtable_debug_args *args)
 {
 	pmd_t pmd;
 
···
 		return;
 
 	pr_debug("Validating PMD swap soft dirty\n");
-	pmd = pfn_pmd(pfn, prot);
+	pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
 	WARN_ON(!pmd_swp_soft_dirty(pmd_swp_mksoft_dirty(pmd)));
 	WARN_ON(pmd_swp_soft_dirty(pmd_swp_clear_soft_dirty(pmd)));
 }
 #else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
-static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot) { }
-static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot)
-{
-}
+static void __init pmd_soft_dirty_tests(struct pgtable_debug_args *args) { }
+static void __init pmd_swap_soft_dirty_tests(struct pgtable_debug_args *args) { }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
-static void __init pte_swap_tests(unsigned long pfn, pgprot_t prot)
+static void __init pte_swap_tests(struct pgtable_debug_args *args)
 {
 	swp_entry_t swp;
 	pte_t pte;
 
 	pr_debug("Validating PTE swap\n");
-	pte = pfn_pte(pfn, prot);
+	pte = pfn_pte(args->fixed_pte_pfn, args->page_prot);
 	swp = __pte_to_swp_entry(pte);
 	pte = __swp_entry_to_pte(swp);
-	WARN_ON(pfn != pte_pfn(pte));
+	WARN_ON(args->fixed_pte_pfn != pte_pfn(pte));
 }
 
 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
-static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot)
+static void __init pmd_swap_tests(struct pgtable_debug_args *args)
 {
 	swp_entry_t swp;
 	pmd_t pmd;
···
 		return;
 
 	pr_debug("Validating PMD swap\n");
-	pmd = pfn_pmd(pfn, prot);
+	pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
 	swp = __pmd_to_swp_entry(pmd);
 	pmd = __swp_entry_to_pmd(swp);
-	WARN_ON(pfn != pmd_pfn(pmd));
+	WARN_ON(args->fixed_pmd_pfn != pmd_pfn(pmd));
 }
 #else  /* !CONFIG_ARCH_ENABLE_THP_MIGRATION */
-static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pmd_swap_tests(struct pgtable_debug_args *args) { }
 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
 
-static void __init swap_migration_tests(void)
+static void __init swap_migration_tests(struct pgtable_debug_args *args)
 {
 	struct page *page;
 	swp_entry_t swp;
···
 	if (!IS_ENABLED(CONFIG_MIGRATION))
 		return;
 
-	pr_debug("Validating swap migration\n");
 	/*
 	 * swap_migration_tests() requires a dedicated page as it needs to
 	 * be locked before creating a migration entry from it. Locking the
 	 * page that actually maps kernel text ('start_kernel') can be real
-	 * problematic. Lets allocate a dedicated page explicitly for this
-	 * purpose that will be freed subsequently.
+	 * problematic. Lets use the allocated page explicitly for this
+	 * purpose.
 	 */
-	page = alloc_page(GFP_KERNEL);
-	if (!page) {
-		pr_err("page allocation failed\n");
+	page = (args->pte_pfn != ULONG_MAX) ? pfn_to_page(args->pte_pfn) : NULL;
+	if (!page)
 		return;
-	}
+
+	pr_debug("Validating swap migration\n");
 
 	/*
 	 * make_migration_entry() expects given page to be
···
 	WARN_ON(!is_migration_entry(swp));
 	WARN_ON(is_writable_migration_entry(swp));
 	__ClearPageLocked(page);
-	__free_page(page);
 }
 
 #ifdef CONFIG_HUGETLB_PAGE
-static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot)
+static void __init hugetlb_basic_tests(struct pgtable_debug_args *args)
 {
 	struct page *page;
 	pte_t pte;
···
 	 * Accessing the page associated with the pfn is safe here,
 	 * as it was previously derived from a real kernel symbol.
 	 */
-	page = pfn_to_page(pfn);
-	pte = mk_huge_pte(page, prot);
+	page = pfn_to_page(args->fixed_pmd_pfn);
+	pte = mk_huge_pte(page, args->page_prot);
 
 	WARN_ON(!huge_pte_dirty(huge_pte_mkdirty(pte)));
 	WARN_ON(!huge_pte_write(huge_pte_mkwrite(huge_pte_wrprotect(pte))));
 	WARN_ON(huge_pte_write(huge_pte_wrprotect(huge_pte_mkwrite(pte))));
 
 #ifdef CONFIG_ARCH_WANT_GENERAL_HUGETLB
-	pte = pfn_pte(pfn, prot);
+	pte = pfn_pte(args->fixed_pmd_pfn, args->page_prot);
 
 	WARN_ON(!pte_huge(pte_mkhuge(pte)));
 #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */
 }
 #else  /* !CONFIG_HUGETLB_PAGE */
-static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init hugetlb_basic_tests(struct pgtable_debug_args *args) { }
 #endif /* CONFIG_HUGETLB_PAGE */
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot)
+static void __init pmd_thp_tests(struct pgtable_debug_args *args)
 {
 	pmd_t pmd;
 
···
 	 * needs to return true. pmd_present() should be true whenever
 	 * pmd_trans_huge() returns true.
 	 */
-	pmd = pfn_pmd(pfn, prot);
+	pmd = pfn_pmd(args->fixed_pmd_pfn, args->page_prot);
 	WARN_ON(!pmd_trans_huge(pmd_mkhuge(pmd)));
 
 #ifndef __HAVE_ARCH_PMDP_INVALIDATE
···
 }
 
 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
-static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot)
+static void __init pud_thp_tests(struct pgtable_debug_args *args)
 {
 	pud_t pud;
 
···
 		return;
 
 	pr_debug("Validating PUD based THP\n");
-	pud = pfn_pud(pfn, prot);
+	pud = pfn_pud(args->fixed_pud_pfn, args->page_prot);
 	WARN_ON(!pud_trans_huge(pud_mkhuge(pud)));
 
 	/*
···
 	 */
 }
 #else  /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
-static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pud_thp_tests(struct pgtable_debug_args *args) { }
 #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
 #else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
-static void __init pmd_thp_tests(unsigned long pfn, pgprot_t prot) { }
-static void __init pud_thp_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pmd_thp_tests(struct pgtable_debug_args *args) { }
+static void __init pud_thp_tests(struct pgtable_debug_args *args) { }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 static unsigned long __init get_random_vaddr(void)
···
 	return random_vaddr;
 }
 
-static int __init debug_vm_pgtable(void)
+static void __init destroy_args(struct pgtable_debug_args *args)
 {
-	struct vm_area_struct *vma;
-	struct mm_struct *mm;
-	pgd_t *pgdp;
-	p4d_t *p4dp, *saved_p4dp;
-	pud_t *pudp, *saved_pudp;
-	pmd_t *pmdp, *saved_pmdp, pmd;
-	pte_t *ptep;
-	pgtable_t saved_ptep;
-	pgprot_t prot, protnone;
-	phys_addr_t paddr;
-	unsigned long vaddr, pte_aligned, pmd_aligned;
-	unsigned long pud_aligned, p4d_aligned, pgd_aligned;
-	spinlock_t *ptl = NULL;
-	int idx;
+	struct page *page = NULL;
 
-	pr_info("Validating architecture page table helpers\n");
-	prot = vm_get_page_prot(VMFLAGS);
-	vaddr = get_random_vaddr();
-	mm = mm_alloc();
-	if (!mm) {
-		pr_err("mm_struct allocation failed\n");
-		return 1;
+	/* Free (huge) page */
+	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
+	    IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD) &&
+	    has_transparent_hugepage() &&
+	    args->pud_pfn != ULONG_MAX) {
+		if (args->is_contiguous_page) {
+			free_contig_range(args->pud_pfn,
+					  (1 << (HPAGE_PUD_SHIFT - PAGE_SHIFT)));
+		} else {
+			page = pfn_to_page(args->pud_pfn);
+			__free_pages(page, HPAGE_PUD_SHIFT - PAGE_SHIFT);
+		}
+
+		args->pud_pfn = ULONG_MAX;
+		args->pmd_pfn = ULONG_MAX;
+		args->pte_pfn = ULONG_MAX;
 	}
 
+	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
+	    has_transparent_hugepage() &&
+	    args->pmd_pfn != ULONG_MAX) {
+		if (args->is_contiguous_page) {
+			free_contig_range(args->pmd_pfn, (1 << HPAGE_PMD_ORDER));
+		} else {
+			page = pfn_to_page(args->pmd_pfn);
+			__free_pages(page, HPAGE_PMD_ORDER);
+		}
+
+		args->pmd_pfn = ULONG_MAX;
+		args->pte_pfn = ULONG_MAX;
+	}
+
+	if (args->pte_pfn != ULONG_MAX) {
+		page = pfn_to_page(args->pte_pfn);
+		__free_pages(page, 0);
+
+		args->pte_pfn = ULONG_MAX;
+	}
+
+	/* Free page table entries */
+	if (args->start_ptep) {
+		pte_free(args->mm, args->start_ptep);
+		mm_dec_nr_ptes(args->mm);
+	}
+
+	if (args->start_pmdp) {
+		pmd_free(args->mm, args->start_pmdp);
+		mm_dec_nr_pmds(args->mm);
+	}
+
+	if (args->start_pudp) {
+		pud_free(args->mm, args->start_pudp);
+		mm_dec_nr_puds(args->mm);
+	}
+
+	if (args->start_p4dp)
+		p4d_free(args->mm, args->start_p4dp);
+
+	/* Free vma and mm struct */
+	if (args->vma)
+		vm_area_free(args->vma);
+
+	if (args->mm)
+		mmdrop(args->mm);
+}
+
+static struct page * __init
+debug_vm_pgtable_alloc_huge_page(struct pgtable_debug_args *args, int order)
+{
+	struct page *page = NULL;
+
+#ifdef CONFIG_CONTIG_ALLOC
+	if (order >= MAX_ORDER) {
+		page = alloc_contig_pages((1 << order), GFP_KERNEL,
+					  first_online_node, NULL);
+		if (page) {
+			args->is_contiguous_page = true;
+			return page;
+		}
+	}
+#endif
+
+	if (order < MAX_ORDER)
+		page = alloc_pages(GFP_KERNEL, order);
+
+	return page;
+}
+
+static int __init init_args(struct pgtable_debug_args *args)
+{
+	struct page *page = NULL;
+	phys_addr_t phys;
+	int ret = 0;
+
 	/*
+	 * Initialize the debugging data.
+	 *
 	 * __P000 (or even __S000) will help create page table entries with
 	 * PROT_NONE permission as required for pxx_protnone_tests().
 	 */
-	protnone = __P000;
+	memset(args, 0, sizeof(*args));
+	args->vaddr              = get_random_vaddr();
+	args->page_prot          = vm_get_page_prot(VMFLAGS);
+	args->page_prot_none     = __P000;
+	args->is_contiguous_page = false;
+	args->pud_pfn            = ULONG_MAX;
+	args->pmd_pfn            = ULONG_MAX;
+	args->pte_pfn            = ULONG_MAX;
+	args->fixed_pgd_pfn      = ULONG_MAX;
+	args->fixed_p4d_pfn      = ULONG_MAX;
+	args->fixed_pud_pfn      = ULONG_MAX;
+	args->fixed_pmd_pfn      = ULONG_MAX;
+	args->fixed_pte_pfn      = ULONG_MAX;
 
-	vma = vm_area_alloc(mm);
-	if (!vma) {
-		pr_err("vma allocation failed\n");
-		return 1;
+	/* Allocate mm and vma */
+	args->mm = mm_alloc();
+	if (!args->mm) {
+		pr_err("Failed to allocate mm struct\n");
+		ret = -ENOMEM;
+		goto error;
 	}
+
+	args->vma = vm_area_alloc(args->mm);
+	if (!args->vma) {
+		pr_err("Failed to allocate vma\n");
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	/*
+	 * Allocate page table entries. They will be modified in the tests.
+	 * Lets save the page table entries so that they can be released
+	 * when the tests are completed.
+	 */
+	args->pgdp = pgd_offset(args->mm, args->vaddr);
+	args->p4dp = p4d_alloc(args->mm, args->pgdp, args->vaddr);
+	if (!args->p4dp) {
+		pr_err("Failed to allocate p4d entries\n");
+		ret = -ENOMEM;
+		goto error;
+	}
+	args->start_p4dp = p4d_offset(args->pgdp, 0UL);
+	WARN_ON(!args->start_p4dp);
+
+	args->pudp = pud_alloc(args->mm, args->p4dp, args->vaddr);
+	if (!args->pudp) {
+		pr_err("Failed to allocate pud entries\n");
+		ret = -ENOMEM;
+		goto error;
+	}
+	args->start_pudp = pud_offset(args->p4dp, 0UL);
+	WARN_ON(!args->start_pudp);
+
+	args->pmdp = pmd_alloc(args->mm, args->pudp, args->vaddr);
+	if (!args->pmdp) {
+		pr_err("Failed to allocate pmd entries\n");
+		ret = -ENOMEM;
+		goto error;
+	}
+	args->start_pmdp = pmd_offset(args->pudp, 0UL);
+	WARN_ON(!args->start_pmdp);
+
+	if (pte_alloc(args->mm, args->pmdp)) {
+		pr_err("Failed to allocate pte entries\n");
+		ret = -ENOMEM;
+		goto error;
+	}
+	args->start_ptep = pmd_pgtable(READ_ONCE(*args->pmdp));
+	WARN_ON(!args->start_ptep);
 
 	/*
 	 * PFN for mapping at PTE level is determined from a standard kernel
···
 	 * exist on the platform but that does not really matter as pfn_pxx()
 	 * helpers will still create appropriate entries for the test. This
 	 * helps avoid large memory block allocations to be used for mapping
-	 * at higher page table levels.
+	 * at higher page table levels in some of the tests.
 	 */
-	paddr = __pa_symbol(&start_kernel);
+	phys = __pa_symbol(&start_kernel);
+	args->fixed_pgd_pfn = __phys_to_pfn(phys & PGDIR_MASK);
+	args->fixed_p4d_pfn = __phys_to_pfn(phys & P4D_MASK);
+	args->fixed_pud_pfn = __phys_to_pfn(phys & PUD_MASK);
+	args->fixed_pmd_pfn = __phys_to_pfn(phys & PMD_MASK);
+	args->fixed_pte_pfn = __phys_to_pfn(phys & PAGE_MASK);
+	WARN_ON(!pfn_valid(args->fixed_pte_pfn));
 
-	pte_aligned = (paddr & PAGE_MASK) >> PAGE_SHIFT;
-	pmd_aligned = (paddr & PMD_MASK) >> PAGE_SHIFT;
-	pud_aligned = (paddr & PUD_MASK) >> PAGE_SHIFT;
-	p4d_aligned = (paddr & P4D_MASK) >> PAGE_SHIFT;
-	pgd_aligned = (paddr & PGDIR_MASK) >> PAGE_SHIFT;
-	WARN_ON(!pfn_valid(pte_aligned));
-
-	pgdp = pgd_offset(mm, vaddr);
-	p4dp = p4d_alloc(mm, pgdp, vaddr);
-	pudp = pud_alloc(mm, p4dp, vaddr);
-	pmdp = pmd_alloc(mm, pudp, vaddr);
 	/*
-	 * Allocate pgtable_t
+	 * Allocate (huge) pages because some of the tests need to access
+	 * the data in the pages. The corresponding tests will be skipped
+	 * if we fail to allocate (huge) pages.
 	 */
-	if (pte_alloc(mm, pmdp)) {
-		pr_err("pgtable allocation failed\n");
-		return 1;
+	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
+	    IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD) &&
+	    has_transparent_hugepage()) {
+		page = debug_vm_pgtable_alloc_huge_page(args,
+				HPAGE_PUD_SHIFT - PAGE_SHIFT);
+		if (page) {
+			args->pud_pfn = page_to_pfn(page);
+			args->pmd_pfn = args->pud_pfn;
+			args->pte_pfn = args->pud_pfn;
+			return 0;
+		}
 	}
 
-	/*
-	 * Save all the page table page addresses as the page table
-	 * entries will be used for testing with random or garbage
-	 * values. These saved addresses will be used for freeing
-	 * page table pages.
-	 */
-	pmd = READ_ONCE(*pmdp);
-	saved_p4dp = p4d_offset(pgdp, 0UL);
-	saved_pudp = pud_offset(p4dp, 0UL);
-	saved_pmdp = pmd_offset(pudp, 0UL);
-	saved_ptep = pmd_pgtable(pmd);
+	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
+	    has_transparent_hugepage()) {
+		page = debug_vm_pgtable_alloc_huge_page(args, HPAGE_PMD_ORDER);
+		if (page) {
+			args->pmd_pfn = page_to_pfn(page);
+			args->pte_pfn = args->pmd_pfn;
+			return 0;
+		}
+	}
+
+	page = alloc_pages(GFP_KERNEL, 0);
+	if (page)
+		args->pte_pfn = page_to_pfn(page);
+
+	return 0;
+
+error:
+	destroy_args(args);
+	return ret;
+}
+
+static int __init debug_vm_pgtable(void)
+{
+	struct pgtable_debug_args args;
+	spinlock_t *ptl = NULL;
+	int idx, ret;
+
+	pr_info("Validating architecture page table helpers\n");
+	ret = init_args(&args);
+	if (ret)
+		return ret;
 
 	/*
 	 * Iterate over the protection_map[] to make sure that all
···
 	 * given page table entry.
 	 */
 	for (idx = 0; idx < ARRAY_SIZE(protection_map); idx++) {
-		pte_basic_tests(pte_aligned, idx);
-		pmd_basic_tests(pmd_aligned, idx);
-		pud_basic_tests(mm, pud_aligned, idx);
+		pte_basic_tests(&args, idx);
+		pmd_basic_tests(&args, idx);
+		pud_basic_tests(&args, idx);
 	}
 
 	/*
···
 	 * the above iteration for now to save some test execution
 	 * time.
 	 */
-	p4d_basic_tests(p4d_aligned, prot);
-	pgd_basic_tests(pgd_aligned, prot);
+	p4d_basic_tests(&args);
+	pgd_basic_tests(&args);
 
-	pmd_leaf_tests(pmd_aligned, prot);
-	pud_leaf_tests(pud_aligned, prot);
+	pmd_leaf_tests(&args);
+	pud_leaf_tests(&args);
 
-	pte_savedwrite_tests(pte_aligned, protnone);
-	pmd_savedwrite_tests(pmd_aligned, protnone);
+	pte_savedwrite_tests(&args);
+	pmd_savedwrite_tests(&args);
 
-	pte_special_tests(pte_aligned, prot);
-	pte_protnone_tests(pte_aligned, protnone);
-	pmd_protnone_tests(pmd_aligned, protnone);
+	pte_special_tests(&args);
+	pte_protnone_tests(&args);
+	pmd_protnone_tests(&args);
 
-	pte_devmap_tests(pte_aligned, prot);
-	pmd_devmap_tests(pmd_aligned, prot);
-	pud_devmap_tests(pud_aligned, prot);
+	pte_devmap_tests(&args);
+	pmd_devmap_tests(&args);
+	pud_devmap_tests(&args);
 
-	pte_soft_dirty_tests(pte_aligned, prot);
-	pmd_soft_dirty_tests(pmd_aligned, prot);
-	pte_swap_soft_dirty_tests(pte_aligned, prot);
-	pmd_swap_soft_dirty_tests(pmd_aligned, prot);
+	pte_soft_dirty_tests(&args);
+	pmd_soft_dirty_tests(&args);
+	pte_swap_soft_dirty_tests(&args);
+	pmd_swap_soft_dirty_tests(&args);
 
-	pte_swap_tests(pte_aligned, prot);
-	pmd_swap_tests(pmd_aligned, prot);
+	pte_swap_tests(&args);
+	pmd_swap_tests(&args);
 
-	swap_migration_tests();
+	swap_migration_tests(&args);
 
-	pmd_thp_tests(pmd_aligned, prot);
-	pud_thp_tests(pud_aligned, prot);
+	pmd_thp_tests(&args);
+	pud_thp_tests(&args);
 
-	hugetlb_basic_tests(pte_aligned, prot);
+	hugetlb_basic_tests(&args);
 
 	/*
 	 * Page table modifying tests. They need to hold
 	 * proper page table lock.
 	 */
 
-	ptep = pte_offset_map_lock(mm, pmdp, vaddr, &ptl);
-	pte_clear_tests(mm, ptep, pte_aligned, vaddr, prot);
-	pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot);
-	pte_unmap_unlock(ptep, ptl);
+	args.ptep = pte_offset_map_lock(args.mm, args.pmdp, args.vaddr, &ptl);
+	pte_clear_tests(&args);
+	pte_advanced_tests(&args);
+	pte_unmap_unlock(args.ptep, ptl);
 
-	ptl = pmd_lock(mm, pmdp);
-	pmd_clear_tests(mm, pmdp);
-	pmd_advanced_tests(mm, vma, pmdp, pmd_aligned, vaddr, prot, saved_ptep);
-	pmd_huge_tests(pmdp, pmd_aligned, prot);
-	pmd_populate_tests(mm, pmdp, saved_ptep);
+	ptl = pmd_lock(args.mm, args.pmdp);
+	pmd_clear_tests(&args);
+	pmd_advanced_tests(&args);
+	pmd_huge_tests(&args);
+	pmd_populate_tests(&args);
 	spin_unlock(ptl);
 
-	ptl = pud_lock(mm, pudp);
-	pud_clear_tests(mm, pudp);
-	pud_advanced_tests(mm, vma, pudp, pud_aligned, vaddr, prot);
-	pud_huge_tests(pudp, pud_aligned, prot);
-	pud_populate_tests(mm, pudp, saved_pmdp);
+	ptl = pud_lock(args.mm, args.pudp);
+	pud_clear_tests(&args);
+	pud_advanced_tests(&args);
+	pud_huge_tests(&args);
+	pud_populate_tests(&args);
 	spin_unlock(ptl);
 
-	spin_lock(&mm->page_table_lock);
-	p4d_clear_tests(mm, p4dp);
-	pgd_clear_tests(mm, pgdp);
-	p4d_populate_tests(mm, p4dp, saved_pudp);
-	pgd_populate_tests(mm, pgdp, saved_p4dp);
-	spin_unlock(&mm->page_table_lock);
+	spin_lock(&(args.mm->page_table_lock));
+	p4d_clear_tests(&args);
+	pgd_clear_tests(&args);
+	p4d_populate_tests(&args);
+	pgd_populate_tests(&args);
+	spin_unlock(&(args.mm->page_table_lock));
 
-	p4d_free(mm, saved_p4dp);
-	pud_free(mm, saved_pudp);
-	pmd_free(mm, saved_pmdp);
-	pte_free(mm, saved_ptep);
-
-	vm_area_free(vma);
-	mm_dec_nr_puds(mm);
-	mm_dec_nr_pmds(mm);
-	mm_dec_nr_ptes(mm);
-	mmdrop(mm);
+	destroy_args(&args);
 	return 0;
 }
 late_initcall(debug_vm_pgtable);

mm/filemap.c

···
 void delete_from_page_cache(struct page *page)
 {
 	struct address_space *mapping = page_mapping(page);
-	unsigned long flags;
 
 	BUG_ON(!PageLocked(page));
-	xa_lock_irqsave(&mapping->i_pages, flags);
+	xa_lock_irq(&mapping->i_pages);
 	__delete_from_page_cache(page, NULL);
-	xa_unlock_irqrestore(&mapping->i_pages, flags);
+	xa_unlock_irq(&mapping->i_pages);
 
 	page_cache_free_page(mapping, page);
 }
···
 				  struct pagevec *pvec)
 {
 	int i;
-	unsigned long flags;
 
 	if (!pagevec_count(pvec))
 		return;
 
-	xa_lock_irqsave(&mapping->i_pages, flags);
+	xa_lock_irq(&mapping->i_pages);
 	for (i = 0; i < pagevec_count(pvec); i++) {
 		trace_mm_filemap_delete_from_page_cache(pvec->pages[i]);
 
 		unaccount_page_cache_page(mapping, pvec->pages[i]);
 	}
 	page_cache_delete_batch(mapping, pvec);
-	xa_unlock_irqrestore(&mapping->i_pages, flags);
+	xa_unlock_irq(&mapping->i_pages);
 
 	for (i = 0; i < pagevec_count(pvec); i++)
 		page_cache_free_page(mapping, pvec->pages[i]);
···
 	void (*freepage)(struct page *) = mapping->a_ops->freepage;
 	pgoff_t offset = old->index;
 	XA_STATE(xas, &mapping->i_pages, offset);
-	unsigned long flags;
 
 	VM_BUG_ON_PAGE(!PageLocked(old), old);
 	VM_BUG_ON_PAGE(!PageLocked(new), new);
···
 
 	mem_cgroup_migrate(old, new);
 
-	xas_lock_irqsave(&xas, flags);
+	xas_lock_irq(&xas);
 	xas_store(&xas, new);
 
 	old->mapping = NULL;
···
 		__dec_lruvec_page_state(old, NR_SHMEM);
 	if (PageSwapBacked(new))
 		__inc_lruvec_page_state(new, NR_SHMEM);
-	xas_unlock_irqrestore(&xas, flags);
+	xas_unlock_irq(&xas);
 	if (freepage)
 		freepage(old);
 	put_page(old);

mm/gup.c

···
 	put_page(page);
 }
 
-/*
- * Return the compound head page with ref appropriately incremented,
- * or NULL if that failed.
+/**
+ * try_get_compound_head() - return the compound head page with refcount
+ * appropriately incremented, or NULL if that failed.
+ *
+ * This handles potential refcount overflow correctly. It also works correctly
+ * for various lockless get_user_pages()-related callers, due to the use of
+ * page_cache_add_speculative().
+ *
+ * Even though the name includes "compound_head", this function is still
+ * appropriate for callers that have a non-compound @page to get.
+ *
+ * @page:  pointer to page to be gotten
+ * @refs:  the value to add to the page's refcount
+ *
+ * Return: head page (with refcount appropriately incremented) for success, or
+ * NULL upon failure.
  */
-static inline struct page *try_get_compound_head(struct page *page, int refs)
+struct page *try_get_compound_head(struct page *page, int refs)
 {
 	struct page *head = compound_head(page);
 
···
 	return head;
 }
 
-/*
+/**
  * try_grab_compound_head() - attempt to elevate a page's refcount, by a
  * flags-dependent amount.
+ *
+ * Even though the name includes "compound_head", this function is still
+ * appropriate for callers that have a non-compound @page to get.
+ *
+ * @page:  pointer to page to be grabbed
+ * @refs:  the value to (effectively) add to the page's refcount
+ * @flags: gup flags: these are the FOLL_* flag values.
  *
  * "grab" names in this file mean, "look at flags to decide whether to use
  * FOLL_PIN or FOLL_GET behavior, when incrementing the page's refcount.
···
  * same time. (That's true throughout the get_user_pages*() and
  * pin_user_pages*() APIs.) Cases:
  *
- *    FOLL_GET: page's refcount will be incremented by 1.
- *    FOLL_PIN: page's refcount will be incremented by GUP_PIN_COUNTING_BIAS.
+ *    FOLL_GET: page's refcount will be incremented by @refs.
+ *
+ *    FOLL_PIN on compound pages that are > two pages long: page's refcount will
+ *    be incremented by @refs, and page[2].hpage_pinned_refcount will be
+ *    incremented by @refs * GUP_PIN_COUNTING_BIAS.
+ *
+ *    FOLL_PIN on normal pages, or compound pages that are two pages long:
+ *    page's refcount will be incremented by @refs * GUP_PIN_COUNTING_BIAS.
  *
  * Return: head page (with refcount appropriately incremented) for success, or
  * NULL upon failure. If neither FOLL_GET nor FOLL_PIN was set, that's
  * considered failure, and furthermore, a likely bug in the caller, so a warning
  * is also emitted.
  */
-__maybe_unused struct page *try_grab_compound_head(struct page *page,
-						   int refs, unsigned int flags)
+struct page *try_grab_compound_head(struct page *page,
+				    int refs, unsigned int flags)
 {
 	if (flags & FOLL_GET)
 		return try_get_compound_head(page, refs);
 	else if (flags & FOLL_PIN) {
-		int orig_refs = refs;
-
 		/*
 		 * Can't do FOLL_LONGTERM + FOLL_PIN gup fast path if not in a
 		 * right zone, so fail and let the caller fall back to the slow
···
 		 *
 		 * However, be sure to *also* increment the normal page refcount
 		 * field at least once, so that the page really is pinned.
+		 * That's why the refcount from the earlier
+		 * try_get_compound_head() is left intact.
 		 */
 		if (hpage_pincount_available(page))
 			hpage_pincount_add(page, refs);
···
 			page_ref_add(page, refs * (GUP_PIN_COUNTING_BIAS - 1));
 
 		mod_node_page_state(page_pgdat(page), NR_FOLL_PIN_ACQUIRED,
-				    orig_refs);
+				    refs);
 
 		return page;
 	}
···
  * @flags:   gup flags: these are the FOLL_* flag values.
  *
  * Either FOLL_PIN or FOLL_GET (or neither) may be set, but not both at the same
- * time. Cases:
- *
- *    FOLL_GET: page's refcount will be incremented by 1.
- *    FOLL_PIN: page's refcount will be incremented by GUP_PIN_COUNTING_BIAS.
+ * time. Cases: please see the try_grab_compound_head() documentation, with
+ * "refs=1".
  *
  * Return: true for success, or if no action was required (if neither FOLL_PIN
  * nor FOLL_GET was set, nothing is done). False for failure: FOLL_GET or
···
  */
 bool __must_check try_grab_page(struct page *page, unsigned int flags)
 {
-	WARN_ON_ONCE((flags & (FOLL_GET | FOLL_PIN)) == (FOLL_GET | FOLL_PIN));
+	if (!(flags & (FOLL_GET | FOLL_PIN)))
+		return true;
 
-	if (flags & FOLL_GET)
-		return try_get_page(page);
-	else if (flags & FOLL_PIN) {
-		int refs = 1;
-
-		page = compound_head(page);
-
-		if (WARN_ON_ONCE(page_ref_count(page) <= 0))
-			return false;
-
-		if (hpage_pincount_available(page))
-			hpage_pincount_add(page, 1);
-		else
-			refs = GUP_PIN_COUNTING_BIAS;
-
-		/*
-		 * Similar to try_grab_compound_head(): even if using the
-		 * hpage_pincount_add/_sub() routines, be sure to
-		 * *also* increment the normal page refcount field at least
-		 * once, so that the page really is pinned.
-		 */
-		page_ref_add(page, refs);
-
-		mod_node_page_state(page_pgdat(page), NR_FOLL_PIN_ACQUIRED, 1);
-	}
-
-	return true;
+	return try_grab_compound_head(page, 1, flags);
 }
 
 /**
···
 					 * We must stop here.
 					 */
 					BUG_ON(gup_flags & FOLL_NOWAIT);
-					BUG_ON(ret != 0);
 					goto out;
 				}
 				continue;
···
 		     bool *unlocked)
 {
 	struct vm_area_struct *vma;
-	vm_fault_t ret, major = 0;
+	vm_fault_t ret;
 
 	address = untagged_addr(address);
 
···
 		return -EINTR;
 
 	ret = handle_mm_fault(vma, address, fault_flags, NULL);
-	major |= ret & VM_FAULT_MAJOR;
 	if (ret & VM_FAULT_ERROR) {
 		int err = vm_fault_to_errno(ret, 0);
 
···
 	unsigned long nr_pages = (end - start) / PAGE_SIZE;
 	int gup_flags;
 
-	VM_BUG_ON(start & ~PAGE_MASK);
-	VM_BUG_ON(end   & ~PAGE_MASK);
+	VM_BUG_ON(!PAGE_ALIGNED(start));
+	VM_BUG_ON(!PAGE_ALIGNED(end));
 	VM_BUG_ON_VMA(start < vma->vm_start, vma);
 	VM_BUG_ON_VMA(end   > vma->vm_end, vma);
 	mmap_assert_locked(mm);
···
 	if (!list_empty(&movable_page_list)) {
 		ret = migrate_pages(&movable_page_list, alloc_migration_target,
 				    NULL, (unsigned long)&mtc, MIGRATE_SYNC,
-				    MR_LONGTERM_PIN);
+				    MR_LONGTERM_PIN, NULL);
 		if (ret && !list_empty(&movable_page_list))
 			putback_movable_pages(&movable_page_list);
 	}
···
 {
 	int nr_start = *nr;
 	struct dev_pagemap *pgmap = NULL;
+	int ret = 1;
 
 	do {
 		struct page *page = pfn_to_page(pfn);
···
 		pgmap = get_dev_pagemap(pfn, pgmap);
 		if (unlikely(!pgmap)) {
 			undo_dev_pagemap(nr, nr_start, flags, pages);
-			return 0;
+			ret = 0;
+			break;
 		}
 		SetPageReferenced(page);
 		pages[*nr] = page;
 		if (unlikely(!try_grab_page(page, flags))) {
 			undo_dev_pagemap(nr, nr_start, flags, pages);
-			return 0;
+			ret = 0;
+			break;
 		}
 		(*nr)++;
 		pfn++;
 	} while (addr += PAGE_SIZE, addr != end);
 
-	if (pgmap)
-		put_dev_pagemap(pgmap);
-	return 1;
+	put_dev_pagemap(pgmap);
+	return ret;
 }
 
 static int __gup_device_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr,

mm/huge_memory.c

···
 		goto out;
 	}
 
-	/*
-	 * Since we took the NUMA fault, we must have observed the !accessible
-	 * bit. Make sure all other CPUs agree with that, to avoid them
-	 * modifying the page we're about to migrate.
-	 *
-	 * Must be done under PTL such that we'll observe the relevant
-	 * inc_tlb_flush_pending().
-	 *
-	 * We are not sure a pending tlb flush here is for a huge page
-	 * mapping or not. Hence use the tlb range variant
-	 */
-	if (mm_tlb_flush_pending(vma->vm_mm)) {
-		flush_tlb_range(vma, haddr, haddr + HPAGE_PMD_SIZE);
-		/*
-		 * change_huge_pmd() released the pmd lock before
-		 * invalidating the secondary MMUs sharing the primary
-		 * MMU pagetables (with ->invalidate_range()). The
-		 * mmu_notifier_invalidate_range_end() (which
-		 * internally calls ->invalidate_range()) in
-		 * change_pmd_range() will run after us, so we can't
-		 * rely on it here and we need an explicit invalidate.
-		 */
-		mmu_notifier_invalidate_range(vma->vm_mm, haddr,
-					      haddr + HPAGE_PMD_SIZE);
-	}
-
 	pmd = pmd_modify(oldpmd, vma->vm_page_prot);
 	page = vm_normal_page_pmd(vma, haddr, pmd);
 	if (!page)
···
 
 	for (i = nr - 1; i >= 1; i--) {
 		__split_huge_page_tail(head, i, lruvec, list);
-		/* Some pages can be beyond i_size: drop them from page cache */
+		/* Some pages can be beyond EOF: drop them from page cache */
 		if (head[i].index >= end) {
 			ClearPageDirty(head + i);
 			__delete_from_page_cache(head + i, NULL);
-			if (IS_ENABLED(CONFIG_SHMEM) && PageSwapBacked(head))
+			if (shmem_mapping(head->mapping))
 				shmem_uncharge(head->mapping->host, 1);
 			put_page(head + i);
 		} else if (!PageAnon(page)) {
···
 		 * head page lock is good enough to serialize the trimming.
 		 */
 		end = DIV_ROUND_UP(i_size_read(mapping->host), PAGE_SIZE);
+		if (shmem_mapping(mapping))
+			end = shmem_fallocend(mapping->host, end);
 	}
 
 	/*

mm/hugetlb.c

···
 	int nid = page_to_nid(page);
 
 	lockdep_assert_held(&hugetlb_lock);
+	VM_BUG_ON_PAGE(page_count(page), page);
+
 	list_move(&page->lru, &h->hugepage_freelists[nid]);
 	h->free_huge_pages++;
 	h->free_huge_pages_node[nid]++;
···
 				unsigned long address, int avoid_reserve,
 				long chg)
 {
-	struct page *page;
+	struct page *page = NULL;
 	struct mempolicy *mpol;
 	gfp_t gfp_mask;
 	nodemask_t *nodemask;
···
 
 	gfp_mask = htlb_alloc_mask(h);
 	nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask);
-	page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask);
+
+	if (mpol_is_preferred_many(mpol)) {
+		page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask);
+
+		/* Fallback to all nodes if page==NULL */
+		nodemask = NULL;
+	}
+
+	if (!page)
+		page = dequeue_huge_page_nodemask(h, gfp_mask, nid, nodemask);
+
 	if (page && !avoid_reserve && vma_has_reserves(vma, chg)) {
 		SetHPageRestoreReserve(page);
 		h->resv_huge_pages--;
···
 		h->surplus_huge_pages_node[nid]--;
 	}
 
+	/*
+	 * Very subtle
+	 *
+	 * For non-gigantic pages set the destructor to the normal compound
+	 * page dtor.  This is needed in case someone takes an additional
+	 * temporary ref to the page, and freeing is delayed until they drop
+	 * their reference.
+	 *
+	 * For gigantic pages set the destructor to the null dtor.  This
+	 * destructor will never be called.  Before freeing the gigantic
+	 * page destroy_compound_gigantic_page will turn the compound page
+	 * into a simple group of pages.  After this the destructor does not
+	 * apply.
+	 *
+	 * This handles the case where more than one ref is held when and
+	 * after update_and_free_page is called.
+	 */
 	set_page_refcounted(page);
-	set_compound_page_dtor(page, NULL_COMPOUND_DTOR);
+	if (hstate_is_gigantic(h))
+		set_compound_page_dtor(page, NULL_COMPOUND_DTOR);
+	else
+		set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
 
 	h->nr_huge_pages--;
 	h->nr_huge_pages_node[nid]--;
···
 	SetHPageVmemmapOptimized(page);
 
 	/*
-	 * This page is now managed by the hugetlb allocator and has
-	 * no users -- drop the last reference.
+	 * This page is about to be managed by the hugetlb allocator and
+	 * should have no users.  Drop our reference, and check for others
+	 * just in case.
 	 */
 	zeroed = put_page_testzero(page);
-	VM_BUG_ON_PAGE(!zeroed, page);
+	if (!zeroed)
+		/*
+		 * It is VERY unlikely soneone else has taken a ref on
+		 * the page.  In this case, we simply return as the
+		 * hugetlb destructor (free_huge_page) will be called
+		 * when this other ref is dropped.
+		 */
+		return;
+
 	arch_clear_hugepage_flags(page);
 	enqueue_huge_page(h, page);
 }
···
 		 * cache adding could take a ref on a 'to be' tail page.
 		 * We need to respect any increased ref count, and only set
 		 * the ref count to zero if count is currently 1.  If count
-		 * is not 1, we call synchronize_rcu in the hope that a rcu
-		 * grace period will cause ref count to drop and then retry.
-		 * If count is still inflated on retry we return an error and
-		 * must discard the pages.
+		 * is not 1, we return an error.  An error return indicates
+		 * the set of pages can not be converted to a gigantic page.
+		 * The caller who allocated the pages should then discard the
+		 * pages using the appropriate free interface.
 		 */
 		if (!page_ref_freeze(p, 1)) {
-			pr_info("HugeTLB unexpected inflated ref count on freshly allocated page\n");
-			synchronize_rcu();
-			if (!page_ref_freeze(p, 1))
-				goto out_error;
+			pr_warn("HugeTLB page can not be used due to unexpected inflated ref count\n");
+			goto out_error;
 		}
 		set_page_count(p, 0);
 		set_compound_head(p, page);
···
 				retry = true;
 				goto retry;
 			}
-			pr_warn("HugeTLB page can not be used due to unexpected inflated ref count\n");
 			return NULL;
 		}
 	}
···
  * Allocates a fresh surplus page from the page allocator.
  */
 static struct page *alloc_surplus_huge_page(struct hstate *h, gfp_t gfp_mask,
-		int nid, nodemask_t *nmask)
+		int nid, nodemask_t *nmask, bool zero_ref)
 {
 	struct page *page = NULL;
+	bool retry = false;
 
 	if (hstate_is_gigantic(h))
 		return NULL;
···
 		goto out_unlock;
 	spin_unlock_irq(&hugetlb_lock);
 
+retry:
 	page = alloc_fresh_huge_page(h, gfp_mask, nid, nmask, NULL);
 	if (!page)
 		return NULL;
···
 		spin_unlock_irq(&hugetlb_lock);
 		put_page(page);
 		return NULL;
-	} else {
-		h->surplus_huge_pages++;
-		h->surplus_huge_pages_node[page_to_nid(page)]++;
 	}
+
+	if (zero_ref) {
+		/*
+		 * Caller requires a page with zero ref count.
+		 * We will drop ref count here.  If someone else is holding
+		 * a ref, the page will be freed when they drop it.  Abuse
+		 * temporary page flag to accomplish this.
+		 */
+		SetHPageTemporary(page);
+		if (!put_page_testzero(page)) {
+			/*
+			 * Unexpected inflated ref count on freshly allocated
+			 * huge.  Retry once.
+			 */
+			pr_info("HugeTLB unexpected inflated ref count on freshly allocated page\n");
+			spin_unlock_irq(&hugetlb_lock);
+			if (retry)
+				return NULL;
+
+			retry = true;
+			goto retry;
+		}
+		ClearHPageTemporary(page);
+	}
+
+	h->surplus_huge_pages++;
+	h->surplus_huge_pages_node[page_to_nid(page)]++;
 
 out_unlock:
 	spin_unlock_irq(&hugetlb_lock);
···
 struct page *alloc_buddy_huge_page_with_mpol(struct hstate *h,
 		struct vm_area_struct *vma, unsigned long addr)
 {
-	struct page *page;
+	struct page *page = NULL;
 	struct mempolicy *mpol;
 	gfp_t gfp_mask = htlb_alloc_mask(h);
 	int nid;
 	nodemask_t *nodemask;
 
 	nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask);
-	page = alloc_surplus_huge_page(h, gfp_mask, nid, nodemask);
-	mpol_cond_put(mpol);
+	if (mpol_is_preferred_many(mpol)) {
+		gfp_t gfp = gfp_mask | __GFP_NOWARN;
 
+		gfp &=  ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL);
+		page = alloc_surplus_huge_page(h, gfp, nid, nodemask, false);
+
+		/* Fallback to all nodes if page==NULL */
+		nodemask = NULL;
+	}
+
+	if (!page)
+		page = alloc_surplus_huge_page(h, gfp_mask, nid, nodemask, false);
+	mpol_cond_put(mpol);
 	return page;
 }
 
···
 	spin_unlock_irq(&hugetlb_lock);
 	for (i = 0; i < needed; i++) {
 		page = alloc_surplus_huge_page(h, htlb_alloc_mask(h),
-				NUMA_NO_NODE, NULL);
+				NUMA_NO_NODE, NULL, true);
 		if (!page) {
 			alloc_ok = false;
 			break;
···
 
 	/* Free the needed pages to the hugetlb pool */
 	list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
-		int zeroed;
-
 		if ((--needed) < 0)
 			break;
-		/*
-		 * This page is now managed by the hugetlb allocator and has
-		 * no users -- drop the buddy allocator's reference.
-		 */
-		zeroed = put_page_testzero(page);
-		VM_BUG_ON_PAGE(!zeroed, page);
+		/* Add the page to the hugetlb allocator */
 		enqueue_huge_page(h, page);
 	}
 free:
 	spin_unlock_irq(&hugetlb_lock);
 
-	/* Free unnecessary surplus pages to the buddy allocator */
+	/*
+	 * Free unnecessary surplus pages to the buddy allocator.
+	 * Pages have no ref count, call free_huge_page directly.
+	 */
 	list_for_each_entry_safe(page, tmp, &surplus_list, lru)
-		put_page(page);
+		free_huge_page(page);
 	spin_lock_irq(&hugetlb_lock);
 
 	return ret;
···
 {
 	gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE;
 	int nid = page_to_nid(old_page);
+	bool alloc_retry = false;
 	struct page *new_page;
 	int ret = 0;
 
···
 	 * the pool.  This simplifies and let us do most of the processing
 	 * under the lock.
 	 */
+alloc_retry:
 	new_page = alloc_buddy_huge_page(h, gfp_mask, nid, NULL, NULL);
 	if (!new_page)
 		return -ENOMEM;
+	/*
+	 * If all goes well, this page will be directly added to the free
+	 * list in the pool.  For this the ref count needs to be zero.
+	 * Attempt to drop now, and retry once if needed.  It is VERY
+	 * unlikely there is another ref on the page.
+	 *
+	 * If someone else has a reference to the page, it will be freed
+	 * when they drop their ref.  Abuse temporary page flag to accomplish
+	 * this.  Retry once if there is an inflated ref count.
+	 */
+	SetHPageTemporary(new_page);
+	if (!put_page_testzero(new_page)) {
+		if (alloc_retry)
+			return -EBUSY;
+
+		alloc_retry = true;
+		goto alloc_retry;
+	}
+	ClearHPageTemporary(new_page);
+
 	__prep_new_huge_page(h, new_page);
 
 retry:
···
 		remove_hugetlb_page(h, old_page, false);
 
 		/*
-		 * Reference count trick is needed because allocator gives us
-		 * referenced page but the pool requires pages with 0 refcount.
+		 * Ref count on new page is already zero as it was dropped
+		 * earlier.  It can be directly added to the pool free list.
 		 */
 		__prep_account_new_huge_page(h, nid);
-		page_ref_dec(new_page);
 		enqueue_huge_page(h, new_page);
 
 		/*
···
 
 free_new:
 	spin_unlock_irq(&hugetlb_lock);
+	/* Page has a zero ref count, but needs a ref to be freed */
+	set_page_refcounted(new_page);
 	update_and_free_page(h, new_page, false);
 
 	return ret;
···
 			prep_new_huge_page(h, page, page_to_nid(page));
 			put_page(page); /* add to the hugepage allocator */
 		} else {
+			/* VERY unlikely inflated ref count on a tail page */
 			free_gigantic_page(page, huge_page_order(h));
-			pr_warn("HugeTLB page can not be used due to unexpected inflated ref count\n");
 		}
 
 		/*
···
 	 * after this open call completes.  It is therefore safe to take a
 	 * new reference here without additional locking.
 	 */
-	if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER))
+	if (resv && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
+		resv_map_dup_hugetlb_cgroup_uncharge_info(resv);
 		kref_get(&resv->refs);
+	}
 }
 
 static void hugetlb_vm_op_close(struct vm_area_struct *vma)

mm/hwpoison-inject.c

···
 	if (!hwpoison_filter_enable)
 		goto inject;
 
-	shake_page(hpage, 0);
+	shake_page(hpage);
 	/*
 	 * This implies unable to support non-LRU pages.
 	 */

mm/internal.h

···
 extern void zone_pcp_disable(struct zone *zone);
 extern void zone_pcp_enable(struct zone *zone);
 
+extern void *memmap_alloc(phys_addr_t size, phys_addr_t align,
+			  phys_addr_t min_addr,
+			  int nid, bool exact_nid);
+
 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
 
 /*
···
 
 #ifdef CONFIG_NUMA
 extern int node_reclaim(struct pglist_data *, gfp_t, unsigned int);
+extern int find_next_best_node(int node, nodemask_t *used_node_mask);
 #else
 static inline int node_reclaim(struct pglist_data *pgdat, gfp_t mask,
 				unsigned int order)
 {
 	return NODE_RECLAIM_NOSCAN;
+}
+static inline int find_next_best_node(int node, nodemask_t *used_node_mask)
+{
+	return NUMA_NO_NODE;
 }
 #endif
 

mm/kasan/hw_tags.c

···
 	KASAN_ARG_STACKTRACE_ON,
 };
 
-enum kasan_arg_fault {
-	KASAN_ARG_FAULT_DEFAULT,
-	KASAN_ARG_FAULT_REPORT,
-	KASAN_ARG_FAULT_PANIC,
-};
-
 static enum kasan_arg kasan_arg __ro_after_init;
 static enum kasan_arg_mode kasan_arg_mode __ro_after_init;
 static enum kasan_arg_stacktrace kasan_arg_stacktrace __ro_after_init;
-static enum kasan_arg_fault kasan_arg_fault __ro_after_init;
 
 /* Whether KASAN is enabled at all. */
 DEFINE_STATIC_KEY_FALSE(kasan_flag_enabled);
···
 
 /* Whether to collect alloc/free stack traces. */
 DEFINE_STATIC_KEY_FALSE(kasan_flag_stacktrace);
-
-/* Whether to panic or print a report and disable tag checking on fault. */
-bool kasan_flag_panic __ro_after_init;
 
 /* kasan=off/on */
 static int __init early_kasan_flag(char *arg)
···
 	return 0;
 }
 early_param("kasan.stacktrace", early_kasan_flag_stacktrace);
-
-/* kasan.fault=report/panic */
-static int __init early_kasan_fault(char *arg)
-{
-	if (!arg)
-		return -EINVAL;
-
-	if (!strcmp(arg, "report"))
-		kasan_arg_fault = KASAN_ARG_FAULT_REPORT;
-	else if (!strcmp(arg, "panic"))
-		kasan_arg_fault = KASAN_ARG_FAULT_PANIC;
-	else
-		return -EINVAL;
-
-	return 0;
-}
-early_param("kasan.fault", early_kasan_fault);
 
 /* kasan_init_hw_tags_cpu() is called for each CPU. */
 void kasan_init_hw_tags_cpu(void)
···
 		break;
 	case KASAN_ARG_STACKTRACE_ON:
 		static_branch_enable(&kasan_flag_stacktrace);
-		break;
-	}
-
-	switch (kasan_arg_fault) {
-	case KASAN_ARG_FAULT_DEFAULT:
-		/*
-		 * Default to no panic on report.
-		 * Do nothing, kasan_flag_panic keeps its default value.
-		 */
-		break;
-	case KASAN_ARG_FAULT_REPORT:
-		/* Do nothing, kasan_flag_panic keeps its default value. */
-		break;
-	case KASAN_ARG_FAULT_PANIC:
-		/* Enable panic on report. */
-		kasan_flag_panic = true;
 		break;
 	}
 

mm/kasan/kasan.h

···
 
 #endif
 
-extern bool kasan_flag_panic __ro_after_init;
 extern bool kasan_flag_async __ro_after_init;
 
 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)

mm/kasan/report.c

···
 #define KASAN_BIT_REPORTED	0
 #define KASAN_BIT_MULTI_SHOT	1
 
+enum kasan_arg_fault {
+	KASAN_ARG_FAULT_DEFAULT,
+	KASAN_ARG_FAULT_REPORT,
+	KASAN_ARG_FAULT_PANIC,
+};
+
+static enum kasan_arg_fault kasan_arg_fault __ro_after_init = KASAN_ARG_FAULT_DEFAULT;
+
+/* kasan.fault=report/panic */
+static int __init early_kasan_fault(char *arg)
+{
+	if (!arg)
+		return -EINVAL;
+
+	if (!strcmp(arg, "report"))
+		kasan_arg_fault = KASAN_ARG_FAULT_REPORT;
+	else if (!strcmp(arg, "panic"))
+		kasan_arg_fault = KASAN_ARG_FAULT_PANIC;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+early_param("kasan.fault", early_kasan_fault);
+
 bool kasan_save_enable_multi_shot(void)
 {
 	return test_and_set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags);
···
 		panic_on_warn = 0;
 		panic("panic_on_warn set ...\n");
 	}
-#ifdef CONFIG_KASAN_HW_TAGS
-	if (kasan_flag_panic)
+	if (kasan_arg_fault == KASAN_ARG_FAULT_PANIC)
 		panic("kasan.fault=panic set ...\n");
-#endif
 	kasan_enable_current();
 }
 

mm/khugepaged.c

···
 				xas_unlock_irq(&xas);
 				/* swap in or instantiate fallocated page */
 				if (shmem_getpage(mapping->host, index, &page,
-						  SGP_NOHUGE)) {
+						  SGP_NOALLOC)) {
 					result = SCAN_FAIL;
 					goto xa_unlocked;
 				}

mm/ksm.c

···
 static unsigned long ksm_stable_node_dups;
 
 /* Delay in pruning stale stable_node_dups in the stable_node_chains */
-static int ksm_stable_node_chains_prune_millisecs = 2000;
+static unsigned int ksm_stable_node_chains_prune_millisecs = 2000;
 
 /* Maximum number of page slots sharing a stable node */
 static int ksm_max_page_sharing = 256;
···
 					 struct kobj_attribute *attr,
 					 const char *buf, size_t count)
 {
-	unsigned long msecs;
+	unsigned int msecs;
 	int err;
 
-	err = kstrtoul(buf, 10, &msecs);
-	if (err || msecs > UINT_MAX)
+	err = kstrtouint(buf, 10, &msecs);
+	if (err)
 		return -EINVAL;
 
 	ksm_stable_node_chains_prune_millisecs = msecs;

mm/madvise.c

···
 	switch (behavior) {
 	case MADV_COLD:
 	case MADV_PAGEOUT:
+	case MADV_WILLNEED:
 		return true;
 	default:
 		return false;

mm/memblock.c

···
  * Return:
  * Found address on success, 0 on failure.
  */
-phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start,
+static phys_addr_t __init_memblock memblock_find_in_range(phys_addr_t start,
 					phys_addr_t end, phys_addr_t size,
 					phys_addr_t align)
 {
···
 			phys_addr_t min_addr, phys_addr_t max_addr,
 			int nid)
 {
-	void *ptr;
-
 	memblock_dbg("%s: %llu bytes align=0x%llx nid=%d from=%pa max_addr=%pa %pS\n",
 		     __func__, (u64)size, (u64)align, nid, &min_addr,
 		     &max_addr, (void *)_RET_IP_);
 
-	ptr = memblock_alloc_internal(size, align,
-					   min_addr, max_addr, nid, true);
-	if (ptr && size > 0)
-		page_init_poison(ptr, size);
-
-	return ptr;
+	return memblock_alloc_internal(size, align, min_addr, max_addr, nid,
+				       true);
 }
 
 /**
···
 			phys_addr_t min_addr, phys_addr_t max_addr,
 			int nid)
 {
-	void *ptr;
-
 	memblock_dbg("%s: %llu bytes align=0x%llx nid=%d from=%pa max_addr=%pa %pS\n",
 		     __func__, (u64)size, (u64)align, nid, &min_addr,
 		     &max_addr, (void *)_RET_IP_);
 
-	ptr = memblock_alloc_internal(size, align,
-					   min_addr, max_addr, nid, false);
-	if (ptr && size > 0)
-		page_init_poison(ptr, size);
-
-	return ptr;
+	return memblock_alloc_internal(size, align, min_addr, max_addr, nid,
+				       false);
 }
 
 /**

mm/memcontrol.c

···
 	return !cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_noswap;
 }
 
+/* memcg and lruvec stats flushing */
+static void flush_memcg_stats_dwork(struct work_struct *w);
+static DECLARE_DEFERRABLE_WORK(stats_flush_dwork, flush_memcg_stats_dwork);
+static void flush_memcg_stats_work(struct work_struct *w);
+static DECLARE_WORK(stats_flush_work, flush_memcg_stats_work);
+static DEFINE_PER_CPU(unsigned int, stats_flush_threshold);
+static DEFINE_SPINLOCK(stats_flush_lock);
+
 #define THRESHOLDS_EVENTS_TARGET 128
 #define SOFTLIMIT_EVENTS_TARGET 1024
 
···
 	return &memcg->vmpressure;
 }
 
-struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr)
+struct mem_cgroup *vmpressure_to_memcg(struct vmpressure *vmpr)
 {
-	return &container_of(vmpr, struct mem_cgroup, vmpressure)->css;
+	return container_of(vmpr, struct mem_cgroup, vmpressure);
 }
 
 #ifdef CONFIG_MEMCG_KMEM
···
 }
 
 /* idx can be of type enum memcg_stat_item or node_stat_item. */
-static unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx)
-{
-	long x = READ_ONCE(memcg->vmstats.state[idx]);
-#ifdef CONFIG_SMP
-	if (x < 0)
-		x = 0;
-#endif
-	return x;
-}
-
-/* idx can be of type enum memcg_stat_item or node_stat_item. */
 static unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx)
 {
 	long x = 0;
···
 	return x;
 }
 
-static struct mem_cgroup_per_node *
-parent_nodeinfo(struct mem_cgroup_per_node *pn, int nid)
-{
-	struct mem_cgroup *parent;
-
-	parent = parent_mem_cgroup(pn->memcg);
-	if (!parent)
-		return NULL;
-	return parent->nodeinfo[nid];
-}
-
 void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx,
 			      int val)
 {
 	struct mem_cgroup_per_node *pn;
 	struct mem_cgroup *memcg;
-	long x, threshold = MEMCG_CHARGE_BATCH;
 
 	pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
 	memcg = pn->memcg;
···
 	__mod_memcg_state(memcg, idx, val);
 
 	/* Update lruvec */
-	__this_cpu_add(pn->lruvec_stat_local->count[idx], val);
-
-	if (vmstat_item_in_bytes(idx))
-		threshold <<= PAGE_SHIFT;
-
-	x = val + __this_cpu_read(pn->lruvec_stat_cpu->count[idx]);
-	if (unlikely(abs(x) > threshold)) {
-		pg_data_t *pgdat = lruvec_pgdat(lruvec);
-		struct mem_cgroup_per_node *pi;
-
-		for (pi = pn; pi; pi = parent_nodeinfo(pi, pgdat->node_id))
-			atomic_long_add(x, &pi->lruvec_stat[idx]);
-		x = 0;
-	}
-	__this_cpu_write(pn->lruvec_stat_cpu->count[idx], x);
+	__this_cpu_add(pn->lruvec_stats_percpu->state[idx], val);
+	if (!(__this_cpu_inc_return(stats_flush_threshold) % MEMCG_CHARGE_BATCH))
+		queue_work(system_unbound_wq, &stats_flush_work);
 }
 
 /**
···
 
 static __always_inline struct mem_cgroup *active_memcg(void)
 {
-	if (in_interrupt())
+	if (!in_task())
 		return this_cpu_read(int_active_memcg);
 	else
 		return current->active_memcg;
···
 	unsigned long flags;
 
 	/*
-	 * The only protection from memory hotplug vs. drain_stock races is
-	 * that we always operate on local CPU stock here with IRQ disabled
+	 * The only protection from cpu hotplug (memcg_hotplug_cpu_dead) vs.
+	 * drain_stock races is that we always operate on local CPU stock
+	 * here with IRQ disabled
 	 */
 	local_irq_save(flags);
 
···
 		if (memcg && stock->nr_pages &&
 		    mem_cgroup_is_descendant(memcg, root_memcg))
 			flush = true;
-		if (obj_stock_flush_required(stock, root_memcg))
+		else if (obj_stock_flush_required(stock, root_memcg))
 			flush = true;
 		rcu_read_unlock();
 
···
 	mutex_unlock(&percpu_charge_mutex);
 }
 
-static void memcg_flush_lruvec_page_state(struct mem_cgroup *memcg, int cpu)
-{
-	int nid;
-
-	for_each_node(nid) {
-		struct mem_cgroup_per_node *pn = memcg->nodeinfo[nid];
-		unsigned long stat[NR_VM_NODE_STAT_ITEMS];
-		struct batched_lruvec_stat *lstatc;
-		int i;
-
-		lstatc = per_cpu_ptr(pn->lruvec_stat_cpu, cpu);
-		for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
-			stat[i] = lstatc->count[i];
-			lstatc->count[i] = 0;
-		}
-
-		do {
-			for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
-				atomic_long_add(stat[i], &pn->lruvec_stat[i]);
-		} while ((pn = parent_nodeinfo(pn, nid)));
-	}
-}
-
 static int memcg_hotplug_cpu_dead(unsigned int cpu)
 {
 	struct memcg_stock_pcp *stock;
-	struct mem_cgroup *memcg;
 
 	stock = &per_cpu(memcg_stock, cpu);
 	drain_stock(stock);
-
-	for_each_mem_cgroup(memcg)
-		memcg_flush_lruvec_page_state(memcg, cpu);
 
 	return 0;
 }
···
 {
 	struct mem_cgroup *memcg = mem_cgroup_from_css(css);
 
-	if (val > 100)
+	if (val > 200)
 		return -EINVAL;
 
 	if (!mem_cgroup_is_root(memcg))
···
 		    atomic_read(&frn->done.cnt) == 1) {
 			frn->at = 0;
 			trace_flush_foreign(wb, frn->bdi_id, frn->memcg_id);
-			cgroup_writeback_by_id(frn->bdi_id, frn->memcg_id, 0,
+			cgroup_writeback_by_id(frn->bdi_id, frn->memcg_id,
 					       WB_REASON_FOREIGN_FLUSH,
 					       &frn->done);
 		}
···
 
 	vfs_poll(efile.file, &event->pt);
 
-	spin_lock(&memcg->event_list_lock);
+	spin_lock_irq(&memcg->event_list_lock);
 	list_add(&event->list, &memcg->event_list);
-	spin_unlock(&memcg->event_list_lock);
+	spin_unlock_irq(&memcg->event_list_lock);
 
 	fdput(cfile);
 	fdput(efile);
···
 	if (!pn)
 		return 1;
 
-	pn->lruvec_stat_local = alloc_percpu_gfp(struct lruvec_stat,
-						 GFP_KERNEL_ACCOUNT);
-	if (!pn->lruvec_stat_local) {
-		kfree(pn);
-		return 1;
-	}
-
-	pn->lruvec_stat_cpu = alloc_percpu_gfp(struct batched_lruvec_stat,
-					       GFP_KERNEL_ACCOUNT);
-	if (!pn->lruvec_stat_cpu) {
-		free_percpu(pn->lruvec_stat_local);
+	pn->lruvec_stats_percpu = alloc_percpu_gfp(struct lruvec_stats_percpu,
+						   GFP_KERNEL_ACCOUNT);
+	if (!pn->lruvec_stats_percpu) {
 		kfree(pn);
 		return 1;
 	}
···
 	if (!pn)
 		return;
 
-	free_percpu(pn->lruvec_stat_cpu);
-	free_percpu(pn->lruvec_stat_local);
+	free_percpu(pn->lruvec_stats_percpu);
 	kfree(pn);
 }
 
···
 
 static void mem_cgroup_free(struct mem_cgroup *memcg)
 {
-	int cpu;
-
 	memcg_wb_domain_exit(memcg);
-	/*
-	 * Flush percpu lruvec stats to guarantee the value
-	 * correctness on parent's and all ancestor levels.
-	 */
-	for_each_online_cpu(cpu)
-		memcg_flush_lruvec_page_state(memcg, cpu);
 	__mem_cgroup_free(memcg);
 }
 
···
 	/* Online state pins memcg ID, memcg ID pins CSS */
 	refcount_set(&memcg->id.ref, 1);
 	css_get(css);
+
+	if (unlikely(mem_cgroup_is_root(memcg)))
+		queue_delayed_work(system_unbound_wq, &stats_flush_dwork,
+				   2UL*HZ);
 	return 0;
 }
 
···
 	 * Notify userspace about cgroup removing only after rmdir of cgroup
 	 * directory to avoid race between userspace and kernelspace.
 	 */
-	spin_lock(&memcg->event_list_lock);
+	spin_lock_irq(&memcg->event_list_lock);
 	list_for_each_entry_safe(event, tmp, &memcg->event_list, list) {
 		list_del_init(&event->list);
 		schedule_work(&event->remove);
 	}
-	spin_unlock(&memcg->event_list_lock);
+	spin_unlock_irq(&memcg->event_list_lock);
 
 	page_counter_set_min(&memcg->memory, 0);
 	page_counter_set_low(&memcg->memory, 0);
···
 	memcg_wb_domain_size_changed(memcg);
 }
 
+void mem_cgroup_flush_stats(void)
+{
+	if (!spin_trylock(&stats_flush_lock))
+		return;
+
+	cgroup_rstat_flush_irqsafe(root_mem_cgroup->css.cgroup);
+	spin_unlock(&stats_flush_lock);
+}
+
+static void flush_memcg_stats_dwork(struct work_struct *w)
+{
+	mem_cgroup_flush_stats();
+	queue_delayed_work(system_unbound_wq, &stats_flush_dwork, 2UL*HZ);
+}
+
+static void flush_memcg_stats_work(struct work_struct *w)
+{
+	mem_cgroup_flush_stats();
+}
+
 static void mem_cgroup_css_rstat_flush(struct cgroup_subsys_state *css, int cpu)
 {
 	struct mem_cgroup *memcg = mem_cgroup_from_css(css);
 	struct mem_cgroup *parent = parent_mem_cgroup(memcg);
 	struct memcg_vmstats_percpu *statc;
 	long delta, v;
-	int i;
+	int i, nid;
 
 	statc = per_cpu_ptr(memcg->vmstats_percpu, cpu);
 
···
 		memcg->vmstats.events[i] += delta;
 		if (parent)
 			parent->vmstats.events_pending[i] += delta;
+	}
+
+	for_each_node_state(nid, N_MEMORY) {
+		struct mem_cgroup_per_node *pn = memcg->nodeinfo[nid];
+		struct mem_cgroup_per_node *ppn = NULL;
+		struct lruvec_stats_percpu *lstatc;
+
+		if (parent)
+			ppn = parent->nodeinfo[nid];
+
+		lstatc = per_cpu_ptr(pn->lruvec_stats_percpu, cpu);
+
+		for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
+			delta = pn->lruvec_stats.state_pending[i];
+			if (delta)
+				pn->lruvec_stats.state_pending[i] = 0;
+
+			v = READ_ONCE(lstatc->state[i]);
+			if (v != lstatc->state_prev[i]) {
+				delta += v - lstatc->state_prev[i];
+				lstatc->state_prev[i] = v;
+			}
+
+			if (!delta)
+				continue;
+
+			pn->lruvec_stats.state[i] += delta;
+			if (ppn)
+				ppn->lruvec_stats.state_pending[i] += delta;
+		}
 	}
 }
 
···
 	int i;
 	struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
 
+	cgroup_rstat_flush(memcg->css.cgroup);
+
 	for (i = 0; i < ARRAY_SIZE(memory_stats); i++) {
 		int nid;
 
···
 			atomic_long_read(&parent->memory.children_low_usage)));
 }
 
-static int __mem_cgroup_charge(struct page *page, struct mem_cgroup *memcg,
-			       gfp_t gfp)
+static int charge_memcg(struct page *page, struct mem_cgroup *memcg, gfp_t gfp)
 {
 	unsigned int nr_pages = thp_nr_pages(page);
 	int ret;
···
 }
 
 /**
- * mem_cgroup_charge - charge a newly allocated page to a cgroup
+ * __mem_cgroup_charge - charge a newly allocated page to a cgroup
  * @page: page to charge
  * @mm: mm context of the victim
  * @gfp_mask: reclaim mode
···
  *
  * Returns 0 on success. Otherwise, an error code is returned.
  */
-int mem_cgroup_charge(struct page *page, struct mm_struct *mm, gfp_t gfp_mask)
+int __mem_cgroup_charge(struct page *page, struct mm_struct *mm,
+			gfp_t gfp_mask)
 {
 	struct mem_cgroup *memcg;
 	int ret;
 
-	if (mem_cgroup_disabled())
-		return 0;
-
 	memcg = get_mem_cgroup_from_mm(mm);
-	ret = __mem_cgroup_charge(page, memcg, gfp_mask);
+	ret = charge_memcg(page, memcg, gfp_mask);
 	css_put(&memcg->css);
 
 	return ret;
···
 		memcg = get_mem_cgroup_from_mm(mm);
 	rcu_read_unlock();
 
-	ret = __mem_cgroup_charge(page, memcg, gfp);
+	ret = charge_memcg(page, memcg, gfp);
 
 	css_put(&memcg->css);
 	return ret;
···
 }
 
 /**
- * mem_cgroup_uncharge - uncharge a page
+ * __mem_cgroup_uncharge - uncharge a page
  * @page: page to uncharge
  *
- * Uncharge a page previously charged with mem_cgroup_charge().
+ * Uncharge a page previously charged with __mem_cgroup_charge().
  */
-void mem_cgroup_uncharge(struct page *page)
+void __mem_cgroup_uncharge(struct page *page)
 {
 	struct uncharge_gather ug;
-
-	if (mem_cgroup_disabled())
-		return;
 
 	/* Don't touch page->lru of any random page, pre-check: */
 	if (!page_memcg(page))
···
 }
 
 /**
- * mem_cgroup_uncharge_list - uncharge a list of page
+ * __mem_cgroup_uncharge_list - uncharge a list of page
  * @page_list: list of pages to uncharge
  *
  * Uncharge a list of pages previously charged with
- * mem_cgroup_charge().
+ * __mem_cgroup_charge().
  */
-void mem_cgroup_uncharge_list(struct list_head *page_list)
+void __mem_cgroup_uncharge_list(struct list_head *page_list)
 {
 	struct uncharge_gather ug;
 	struct page *page;
-
-	if (mem_cgroup_disabled())
-		return;
 
 	uncharge_gather_clear(&ug);
 	list_for_each_entry(page, page_list, lru)
···
 }
 
 /**
- * mem_cgroup_try_charge_swap - try charging swap space for a page
+ * __mem_cgroup_try_charge_swap - try charging swap space for a page
  * @page: page being added to swap
  * @entry: swap entry to charge
  *
···
  *
  * Returns 0 on success, -ENOMEM on failure.
  */
-int mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry)
+int __mem_cgroup_try_charge_swap(struct page *page, swp_entry_t entry)
 {
 	unsigned int nr_pages = thp_nr_pages(page);
 	struct page_counter *counter;
 	struct mem_cgroup *memcg;
 	unsigned short oldid;
-
-	if (mem_cgroup_disabled())
-		return 0;
 
 	if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
 		return 0;
···
 }
 
 /**
- * mem_cgroup_uncharge_swap - uncharge swap space
+ * __mem_cgroup_uncharge_swap - uncharge swap space
  * @entry: swap entry to uncharge
  * @nr_pages: the amount of swap space to uncharge
  */
-void mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages)
+void __mem_cgroup_uncharge_swap(swp_entry_t entry, unsigned int nr_pages)
 {
 	struct mem_cgroup *memcg;
 	unsigned short id;

mm/memory-failure.c

···
 
 static bool __page_handle_poison(struct page *page)
 {
-	bool ret;
+	int ret;
 
 	zone_pcp_disable(page_zone(page));
 	ret = dissolve_free_huge_page(page);
···
 		ret = take_page_off_buddy(page);
 	zone_pcp_enable(page_zone(page));
 
-	return ret;
+	return ret > 0;
 }
 
 static bool page_handle_poison(struct page *page, bool hugepage_or_freepage, bool release)
···
 
 /*
  * Unknown page type encountered. Try to check whether it can turn PageLRU by
- * lru_add_drain_all, or a free page by reclaiming slabs when possible.
+ * lru_add_drain_all.
  */
-void shake_page(struct page *p, int access)
+void shake_page(struct page *p)
 {
 	if (PageHuge(p))
 		return;
···
 	}
 
 	/*
-	 * Only call shrink_node_slabs here (which would also shrink
-	 * other caches) if access is not potentially fatal.
+	 * TODO: Could shrink slab caches here if a lightweight range-based
+	 * shrinker will be available.
 	 */
-	if (access)
-		drop_slab_node(page_to_nid(p));
 }
 EXPORT_SYMBOL_GPL(shake_page);
 
···
 /*
  * Kill the processes that have been collected earlier.
  *
- * Only do anything when DOIT is set, otherwise just free the list
- * (this is used for clean pages which do not need killing)
+ * Only do anything when FORCEKILL is set, otherwise just free the
+ * list (this is used for clean pages which do not need killing)
  * Also when FAIL is set do a force kill because something went
  * wrong earlier.
  */
···
 {
 	struct hwp_walk *hwp = (struct hwp_walk *)walk->private;
 	int ret = 0;
-	pte_t *ptep;
+	pte_t *ptep, *mapped_pte;
 	spinlock_t *ptl;
 
 	ptl = pmd_trans_huge_lock(pmdp, walk->vma);
···
 	if (pmd_trans_unstable(pmdp))
 		goto out;
 
-	ptep = pte_offset_map_lock(walk->vma->vm_mm, pmdp, addr, &ptl);
+	mapped_pte = ptep = pte_offset_map_lock(walk->vma->vm_mm, pmdp,
+						addr, &ptl);
 	for (; addr != end; ptep++, addr += PAGE_SIZE) {
 		ret = check_hwpoisoned_entry(*ptep, addr, PAGE_SHIFT,
 					     hwp->pfn, &hwp->tk);
 		if (ret == 1)
 			break;
 	}
-	pte_unmap_unlock(ptep - 1, ptl);
+	pte_unmap_unlock(mapped_pte, ptl);
 out:
 	cond_resched();
 	return ret;
···
 			 * page, retry.
 			 */
 			if (pass++ < 3) {
-				shake_page(p, 1);
+				shake_page(p);
 				goto try_again;
 			}
 			ret = -EIO;
···
 		 */
 		if (pass++ < 3) {
 			put_page(p);
-			shake_page(p, 1);
+			shake_page(p);
 			count_increased = false;
 			goto try_again;
 		}
···
 		ret = -EIO;
 	}
 out:
+	if (ret == -EIO)
+		dump_page(p, "hwpoison: unhandlable page");
+
 	return ret;
 }
 
···
  * the pages and send SIGBUS to the processes if the data was dirty.
  */
 static bool hwpoison_user_mappings(struct page *p, unsigned long pfn,
-				  int flags, struct page **hpagep)
+				  int flags, struct page *hpage)
 {
 	enum ttu_flags ttu = TTU_IGNORE_MLOCK | TTU_SYNC;
 	struct address_space *mapping;
 	LIST_HEAD(tokill);
 	bool unmap_success;
 	int kill = 1, forcekill;
-	struct page *hpage = *hpagep;
 	bool mlocked = PageMlocked(hpage);
 
 	/*
···
 	 * shake_page() again to ensure that it's flushed.
 	 */
 	if (mlocked)
-		shake_page(hpage, 0);
+		shake_page(hpage);
 
 	/*
 	 * Now that the dirty bit has been propagated to the
···
 		goto out;
 	}
 
-	if (!hwpoison_user_mappings(p, pfn, flags, &head)) {
+	if (!hwpoison_user_mappings(p, pfn, flags, head)) {
 		action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED);
 		res = -EBUSY;
 		goto out;
···
 		struct dev_pagemap *pgmap)
 {
 	struct page *page = pfn_to_page(pfn);
-	const bool unmap_success = true;
 	unsigned long size = 0;
 	struct to_kill *tk;
 	LIST_HEAD(tokill);
···
 		start = (page->index << PAGE_SHIFT) & ~(size - 1);
 		unmap_mapping_range(page->mapping, start, size, 0);
 	}
-	kill_procs(&tokill, flags & MF_MUST_KILL, !unmap_success, pfn, flags);
+	kill_procs(&tokill, flags & MF_MUST_KILL, false, pfn, flags);
 	rc = 0;
 unlock:
 	dax_unlock_page(page, cookie);
···
 	 * The check (unnecessarily) ignores LRU pages being isolated and
 	 * walked by the page reclaim code, however that's not a big loss.
 	 */
-	shake_page(p, 0);
+	shake_page(p);
 
 	lock_page(p);
 
···
 	 * Now take care of user space mappings.
 	 * Abort on fail: __delete_from_page_cache() assumes unmapped page.
 	 */
-	if (!hwpoison_user_mappings(p, pfn, flags, &p)) {
+	if (!hwpoison_user_mappings(p, pfn, flags, p)) {
 		action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED);
 		res = -EBUSY;
 		goto unlock_page;
···
 
 	if (isolate_page(hpage, &pagelist)) {
 		ret = migrate_pages(&pagelist, alloc_migration_target, NULL,
-			(unsigned long)&mtc, MIGRATE_SYNC, MR_MEMORY_FAILURE);
+			(unsigned long)&mtc, MIGRATE_SYNC, MR_MEMORY_FAILURE, NULL);
 		if (!ret) {
 			bool release = !huge;
 
···
 			try_again = false;
 			goto retry;
 		}
-	} else if (ret == -EIO) {
-		pr_info("%s: %#lx: unknown page type: %lx (%pGp)\n",
-			 __func__, pfn, page->flags, &page->flags);
 	}
 
 	return ret;

mm/memory_hotplug.c

···
 		if (nodes_empty(nmask))
 			node_set(mtc.nid, nmask);
 		ret = migrate_pages(&source, alloc_migration_target, NULL,
-			(unsigned long)&mtc, MIGRATE_SYNC, MR_MEMORY_HOTPLUG);
+			(unsigned long)&mtc, MIGRATE_SYNC, MR_MEMORY_HOTPLUG, NULL);
 		if (ret) {
 			list_for_each_entry(page, &source, lru) {
 				if (__ratelimit(&migrate_rs)) {

mm/mempolicy.c

···
  *                but useful to set in a VMA when you have a non default
  *                process policy.
  *
+ * preferred many Try a set of nodes first before normal fallback. This is
+ *                similar to preferred without the special case.
+ *
  * default        Allocate on the local node first, or when on a VMA
  *                use the process policy. This is what Linux always did
  *		  in a NUMA aware kernel and still does by, ahem, default.
···
 	nodes_onto(*ret, tmp, *rel);
 }
 
-static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes)
+static int mpol_new_nodemask(struct mempolicy *pol, const nodemask_t *nodes)
 {
 	if (nodes_empty(*nodes))
 		return -EINVAL;
···
 
 	nodes_clear(pol->nodes);
 	node_set(first_node(*nodes), pol->nodes);
-	return 0;
-}
-
-static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes)
-{
-	if (nodes_empty(*nodes))
-		return -EINVAL;
-	pol->nodes = *nodes;
 	return 0;
 }
 
···
 		.rebind = mpol_rebind_default,
 	},
 	[MPOL_INTERLEAVE] = {
-		.create = mpol_new_interleave,
+		.create = mpol_new_nodemask,
 		.rebind = mpol_rebind_nodemask,
 	},
 	[MPOL_PREFERRED] = {
···
 		.rebind = mpol_rebind_preferred,
 	},
 	[MPOL_BIND] = {
-		.create = mpol_new_bind,
+		.create = mpol_new_nodemask,
 		.rebind = mpol_rebind_nodemask,
 	},
 	[MPOL_LOCAL] = {
 		.rebind = mpol_rebind_default,
+	},
+	[MPOL_PREFERRED_MANY] = {
+		.create = mpol_new_nodemask,
+		.rebind = mpol_rebind_preferred,
 	},
 };
 
···
 	case MPOL_BIND:
 	case MPOL_INTERLEAVE:
 	case MPOL_PREFERRED:
+	case MPOL_PREFERRED_MANY:
 		*nodes = p->nodes;
 		break;
 	case MPOL_LOCAL:
···
 
 	if (!list_empty(&pagelist)) {
 		err = migrate_pages(&pagelist, alloc_migration_target, NULL,
-				(unsigned long)&mtc, MIGRATE_SYNC, MR_SYSCALL);
+				(unsigned long)&mtc, MIGRATE_SYNC, MR_SYSCALL, NULL);
 		if (err)
 			putback_movable_pages(&pagelist);
 	}
···
 		if (!list_empty(&pagelist)) {
 			WARN_ON_ONCE(flags & MPOL_MF_LAZY);
 			nr_failed = migrate_pages(&pagelist, new_page, NULL,
-				start, MIGRATE_SYNC, MR_MEMPOLICY_MBIND);
+				start, MIGRATE_SYNC, MR_MEMPOLICY_MBIND, NULL);
 			if (nr_failed)
 				putback_movable_pages(&pagelist);
 		}
···
 {
 	*flags = *mode & MPOL_MODE_FLAGS;
 	*mode &= ~MPOL_MODE_FLAGS;
-	if ((unsigned int)(*mode) >= MPOL_MAX)
+
+	if ((unsigned int)(*mode) >=  MPOL_MAX)
 		return -EINVAL;
 	if ((*flags & MPOL_F_STATIC_NODES) && (*flags & MPOL_F_RELATIVE_NODES))
 		return -EINVAL;
···
  */
 nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
 {
+	int mode = policy->mode;
+
 	/* Lower zones don't get a nodemask applied for MPOL_BIND */
-	if (unlikely(policy->mode == MPOL_BIND) &&
-			apply_policy_zone(policy, gfp_zone(gfp)) &&
-			cpuset_nodemask_valid_mems_allowed(&policy->nodes))
+	if (unlikely(mode == MPOL_BIND) &&
+		apply_policy_zone(policy, gfp_zone(gfp)) &&
+		cpuset_nodemask_valid_mems_allowed(&policy->nodes))
+		return &policy->nodes;
+
+	if (mode == MPOL_PREFERRED_MANY)
 		return &policy->nodes;
 
 	return NULL;
 }
 
-/* Return the node id preferred by the given mempolicy, or the given id */
+/*
+ * Return the  preferred node id for 'prefer' mempolicy, and return
+ * the given id for all other policies.
+ *
+ * policy_node() is always coupled with policy_nodemask(), which
+ * secures the nodemask limit for 'bind' and 'prefer-many' policy.
+ */
 static int policy_node(gfp_t gfp, struct mempolicy *policy, int nd)
 {
 	if (policy->mode == MPOL_PREFERRED) {
···
 	struct mempolicy *policy;
 	int node = numa_mem_id();
 
-	if (in_interrupt())
+	if (!in_task())
 		return node;
 
 	policy = current->mempolicy;
···
 	case MPOL_INTERLEAVE:
 		return interleave_nodes(policy);
 
-	case MPOL_BIND: {
+	case MPOL_BIND:
+	case MPOL_PREFERRED_MANY:
+	{
 		struct zoneref *z;
 
 		/*
···
  * @addr: address in @vma for shared policy lookup and interleave policy
  * @gfp_flags: for requested zone
  * @mpol: pointer to mempolicy pointer for reference counted mempolicy
- * @nodemask: pointer to nodemask pointer for MPOL_BIND nodemask
+ * @nodemask: pointer to nodemask pointer for 'bind' and 'prefer-many' policy
  *
  * Returns a nid suitable for a huge page allocation and a pointer
  * to the struct mempolicy for conditional unref after allocation.
- * If the effective policy is 'BIND, returns a pointer to the mempolicy's
- * @nodemask for filtering the zonelist.
+ * If the effective policy is 'bind' or 'prefer-many', returns a pointer
+ * to the mempolicy's @nodemask for filtering the zonelist.
  *
  * Must be protected by read_mems_allowed_begin()
  */
···
 				struct mempolicy **mpol, nodemask_t **nodemask)
 {
 	int nid;
+	int mode;
 
 	*mpol = get_vma_policy(vma, addr);
-	*nodemask = NULL;	/* assume !MPOL_BIND */
+	*nodemask = NULL;
+	mode = (*mpol)->mode;
 
-	if (unlikely((*mpol)->mode == MPOL_INTERLEAVE)) {
+	if (unlikely(mode == MPOL_INTERLEAVE)) {
 		nid = interleave_nid(*mpol, vma, addr,
 					huge_page_shift(hstate_vma(vma)));
 	} else {
 		nid = policy_node(gfp_flags, *mpol, numa_node_id());
-		if ((*mpol)->mode == MPOL_BIND)
+		if (mode == MPOL_BIND || mode == MPOL_PREFERRED_MANY)
 			*nodemask = &(*mpol)->nodes;
 	}
 	return nid;
···
 	mempolicy = current->mempolicy;
 	switch (mempolicy->mode) {
 	case MPOL_PREFERRED:
+	case MPOL_PREFERRED_MANY:
 	case MPOL_BIND:
 	case MPOL_INTERLEAVE:
 		*mask = mempolicy->nodes;
···
 	return page;
 }
 
+static struct page *alloc_pages_preferred_many(gfp_t gfp, unsigned int order,
+						int nid, struct mempolicy *pol)
+{
+	struct page *page;
+	gfp_t preferred_gfp;
+
+	/*
+	 * This is a two pass approach. The first pass will only try the
+	 * preferred nodes but skip the direct reclaim and allow the
+	 * allocation to fail, while the second pass will try all the
+	 * nodes in system.
+	 */
+	preferred_gfp = gfp | __GFP_NOWARN;
+	preferred_gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL);
+	page = __alloc_pages(preferred_gfp, order, nid, &pol->nodes);
+	if (!page)
+		page = __alloc_pages(gfp, order, numa_node_id(), NULL);
+
+	return page;
+}
+
 /**
  * alloc_pages_vma - Allocate a page for a VMA.
  * @gfp: GFP flags.
···
 		goto out;
 	}
 
+	if (pol->mode == MPOL_PREFERRED_MANY) {
+		page = alloc_pages_preferred_many(gfp, order, node, pol);
+		mpol_cond_put(pol);
+		goto out;
+	}
+
 	if (unlikely(IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && hugepage)) {
 		int hpage_node = node;
 
···
 		 * node and don't fall back to other nodes, as the cost of
 		 * remote accesses would likely offset THP benefits.
 		 *
-		 * If the policy is interleave, or does not allow the current
+		 * If the policy is interleave or does not allow the current
 		 * node in its nodemask, we allocate the standard way.
 		 */
 		if (pol->mode == MPOL_PREFERRED)
···
 	 */
 	if (pol->mode == MPOL_INTERLEAVE)
 		page = alloc_page_interleave(gfp, order, interleave_nodes(pol));
+	else if (pol->mode == MPOL_PREFERRED_MANY)
+		page = alloc_pages_preferred_many(gfp, order,
+				numa_node_id(), pol);
 	else
 		page = __alloc_pages(gfp, order,
 				policy_node(gfp, pol, numa_node_id()),
···
 	case MPOL_BIND:
 	case MPOL_INTERLEAVE:
 	case MPOL_PREFERRED:
+	case MPOL_PREFERRED_MANY:
 		return !!nodes_equal(a->nodes, b->nodes);
 	case MPOL_LOCAL:
 		return true;
···
  * node id.  Policy determination "mimics" alloc_page_vma().
  * Called from fault path where we know the vma and faulting address.
  *
- * Return: -1 if the page is in a node that is valid for this policy, or a
- * suitable node ID to allocate a replacement page from.
+ * Return: NUMA_NO_NODE if the page is in a node that is valid for this
+ * policy, or a suitable node ID to allocate a replacement page from.
  */
 int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long addr)
 {
···
 	int thiscpu = raw_smp_processor_id();
 	int thisnid = cpu_to_node(thiscpu);
 	int polnid = NUMA_NO_NODE;
-	int ret = -1;
+	int ret = NUMA_NO_NODE;
 
 	pol = get_vma_policy(vma, addr);
 	if (!(pol->flags & MPOL_F_MOF))
···
 		break;
 
 	case MPOL_PREFERRED:
+		if (node_isset(curnid, pol->nodes))
+			goto out;
 		polnid = first_node(pol->nodes);
 		break;
 
···
 				break;
 			goto out;
 		}
+		fallthrough;
 
+	case MPOL_PREFERRED_MANY:
 		/*
-		 * allows binding to multiple nodes.
 		 * use current page if in policy nodemask,
 		 * else select nearest allowed node, if any.
 		 * If no allowed nodes, use current [!misplaced].
···
 	[MPOL_BIND]       = "bind",
 	[MPOL_INTERLEAVE] = "interleave",
 	[MPOL_LOCAL]      = "local",
+	[MPOL_PREFERRED_MANY]  = "prefer (many)",
 };
 
 
···
 		if (!nodelist)
 			err = 0;
 		goto out;
+	case MPOL_PREFERRED_MANY:
 	case MPOL_BIND:
 		/*
 		 * Insist on a nodelist
···
 	case MPOL_LOCAL:
 		break;
 	case MPOL_PREFERRED:
+	case MPOL_PREFERRED_MANY:
 	case MPOL_BIND:
 	case MPOL_INTERLEAVE:
 		nodes = pol->nodes;
···
 		p += scnprintf(p, buffer + maxlen - p, ":%*pbl",
 			       nodemask_pr_args(&nodes));
 }
+
+bool numa_demotion_enabled = false;
+
+#ifdef CONFIG_SYSFS
+static ssize_t numa_demotion_enabled_show(struct kobject *kobj,
+					  struct kobj_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%s\n",
+			  numa_demotion_enabled? "true" : "false");
+}
+
+static ssize_t numa_demotion_enabled_store(struct kobject *kobj,
+					   struct kobj_attribute *attr,
+					   const char *buf, size_t count)
+{
+	if (!strncmp(buf, "true", 4) || !strncmp(buf, "1", 1))
+		numa_demotion_enabled = true;
+	else if (!strncmp(buf, "false", 5) || !strncmp(buf, "0", 1))
+		numa_demotion_enabled = false;
+	else
+		return -EINVAL;
+
+	return count;
+}
+
+static struct kobj_attribute numa_demotion_enabled_attr =
+	__ATTR(demotion_enabled, 0644, numa_demotion_enabled_show,
+	       numa_demotion_enabled_store);
+
+static struct attribute *numa_attrs[] = {
+	&numa_demotion_enabled_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group numa_attr_group = {
+	.attrs = numa_attrs,
+};
+
+static int __init numa_init_sysfs(void)
+{
+	int err;
+	struct kobject *numa_kobj;
+
+	numa_kobj = kobject_create_and_add("numa", mm_kobj);
+	if (!numa_kobj) {
+		pr_err("failed to create numa kobject\n");
+		return -ENOMEM;
+	}
+	err = sysfs_create_group(numa_kobj, &numa_attr_group);
+	if (err) {
+		pr_err("failed to register numa group\n");
+		goto delete_obj;
+	}
+	return 0;
+
+delete_obj:
+	kobject_put(numa_kobj);
+	return err;
+}
+subsys_initcall(numa_init_sysfs);
+#endif

mm/migrate.c

···
 #include <linux/sched/mm.h>
 #include <linux/ptrace.h>
 #include <linux/oom.h>
+#include <linux/memory.h>
 
 #include <asm/tlbflush.h>
 
···
 	return rc;
 }
 
+
+/*
+ * node_demotion[] example:
+ *
+ * Consider a system with two sockets.  Each socket has
+ * three classes of memory attached: fast, medium and slow.
+ * Each memory class is placed in its own NUMA node.  The
+ * CPUs are placed in the node with the "fast" memory.  The
+ * 6 NUMA nodes (0-5) might be split among the sockets like
+ * this:
+ *
+ *	Socket A: 0, 1, 2
+ *	Socket B: 3, 4, 5
+ *
+ * When Node 0 fills up, its memory should be migrated to
+ * Node 1.  When Node 1 fills up, it should be migrated to
+ * Node 2.  The migration path start on the nodes with the
+ * processors (since allocations default to this node) and
+ * fast memory, progress through medium and end with the
+ * slow memory:
+ *
+ *	0 -> 1 -> 2 -> stop
+ *	3 -> 4 -> 5 -> stop
+ *
+ * This is represented in the node_demotion[] like this:
+ *
+ *	{  1, // Node 0 migrates to 1
+ *	   2, // Node 1 migrates to 2
+ *	  -1, // Node 2 does not migrate
+ *	   4, // Node 3 migrates to 4
+ *	   5, // Node 4 migrates to 5
+ *	  -1} // Node 5 does not migrate
+ */
+
+/*
+ * Writes to this array occur without locking.  Cycles are
+ * not allowed: Node X demotes to Y which demotes to X...
+ *
+ * If multiple reads are performed, a single rcu_read_lock()
+ * must be held over all reads to ensure that no cycles are
+ * observed.
+ */
+static int node_demotion[MAX_NUMNODES] __read_mostly =
+	{[0 ...  MAX_NUMNODES - 1] = NUMA_NO_NODE};
+
+/**
+ * next_demotion_node() - Get the next node in the demotion path
+ * @node: The starting node to lookup the next node
+ *
+ * Return: node id for next memory node in the demotion path hierarchy
+ * from @node; NUMA_NO_NODE if @node is terminal.  This does not keep
+ * @node online or guarantee that it *continues* to be the next demotion
+ * target.
+ */
+int next_demotion_node(int node)
+{
+	int target;
+
+	/*
+	 * node_demotion[] is updated without excluding this
+	 * function from running.  RCU doesn't provide any
+	 * compiler barriers, so the READ_ONCE() is required
+	 * to avoid compiler reordering or read merging.
+	 *
+	 * Make sure to use RCU over entire code blocks if
+	 * node_demotion[] reads need to be consistent.
+	 */
+	rcu_read_lock();
+	target = READ_ONCE(node_demotion[node]);
+	rcu_read_unlock();
+
+	return target;
+}
+
 /*
  * Obtain the lock on page, remove all ptes and migrate the page
  * to the newly allocated page in newpage.
···
  * @mode:		The migration mode that specifies the constraints for
  *			page migration, if any.
  * @reason:		The reason for page migration.
+ * @ret_succeeded:	Set to the number of pages migrated successfully if
+ *			the caller passes a non-NULL pointer.
  *
  * The function returns after 10 attempts or if no pages are movable any more
  * because the list has become empty or no retryable pages exist any more.
···
  */
 int migrate_pages(struct list_head *from, new_page_t get_new_page,
 		free_page_t put_new_page, unsigned long private,
-		enum migrate_mode mode, int reason)
+		enum migrate_mode mode, int reason, unsigned int *ret_succeeded)
 {
 	int retry = 1;
 	int thp_retry = 1;
···
 	if (!swapwrite)
 		current->flags &= ~PF_SWAPWRITE;
 
+	if (ret_succeeded)
+		*ret_succeeded = nr_succeeded;
+
 	return rc;
 }
 
···
 	};
 
 	err = migrate_pages(pagelist, alloc_migration_target, NULL,
-			(unsigned long)&mtc, MIGRATE_SYNC, MR_SYSCALL);
+		(unsigned long)&mtc, MIGRATE_SYNC, MR_SYSCALL, NULL);
 	if (err)
 		putback_movable_pages(pagelist);
 	return err;
···
 
 	list_add(&page->lru, &migratepages);
 	nr_remaining = migrate_pages(&migratepages, *new, NULL, node,
-				     MIGRATE_ASYNC, MR_NUMA_MISPLACED);
+				     MIGRATE_ASYNC, MR_NUMA_MISPLACED, NULL);
 	if (nr_remaining) {
 		if (!list_empty(&migratepages)) {
 			list_del(&page->lru);
···
 }
 EXPORT_SYMBOL(migrate_vma_finalize);
 #endif /* CONFIG_DEVICE_PRIVATE */
+
+#if defined(CONFIG_MEMORY_HOTPLUG)
+/* Disable reclaim-based migration. */
+static void __disable_all_migrate_targets(void)
+{
+	int node;
+
+	for_each_online_node(node)
+		node_demotion[node] = NUMA_NO_NODE;
+}
+
+static void disable_all_migrate_targets(void)
+{
+	__disable_all_migrate_targets();
+
+	/*
+	 * Ensure that the "disable" is visible across the system.
+	 * Readers will see either a combination of before+disable
+	 * state or disable+after.  They will never see before and
+	 * after state together.
+	 *
+	 * The before+after state together might have cycles and
+	 * could cause readers to do things like loop until this
+	 * function finishes.  This ensures they can only see a
+	 * single "bad" read and would, for instance, only loop
+	 * once.
+	 */
+	synchronize_rcu();
+}
+
+/*
+ * Find an automatic demotion target for 'node'.
+ * Failing here is OK.  It might just indicate
+ * being at the end of a chain.
+ */
+static int establish_migrate_target(int node, nodemask_t *used)
+{
+	int migration_target;
+
+	/*
+	 * Can not set a migration target on a
+	 * node with it already set.
+	 *
+	 * No need for READ_ONCE() here since this
+	 * in the write path for node_demotion[].
+	 * This should be the only thread writing.
+	 */
+	if (node_demotion[node] != NUMA_NO_NODE)
+		return NUMA_NO_NODE;
+
+	migration_target = find_next_best_node(node, used);
+	if (migration_target == NUMA_NO_NODE)
+		return NUMA_NO_NODE;
+
+	node_demotion[node] = migration_target;
+
+	return migration_target;
+}
+
+/*
+ * When memory fills up on a node, memory contents can be
+ * automatically migrated to another node instead of
+ * discarded at reclaim.
+ *
+ * Establish a "migration path" which will start at nodes
+ * with CPUs and will follow the priorities used to build the
+ * page allocator zonelists.
+ *
+ * The difference here is that cycles must be avoided.  If
+ * node0 migrates to node1, then neither node1, nor anything
+ * node1 migrates to can migrate to node0.
+ *
+ * This function can run simultaneously with readers of
+ * node_demotion[].  However, it can not run simultaneously
+ * with itself.  Exclusion is provided by memory hotplug events
+ * being single-threaded.
+ */
+static void __set_migration_target_nodes(void)
+{
+	nodemask_t next_pass	= NODE_MASK_NONE;
+	nodemask_t this_pass	= NODE_MASK_NONE;
+	nodemask_t used_targets = NODE_MASK_NONE;
+	int node;
+
+	/*
+	 * Avoid any oddities like cycles that could occur
+	 * from changes in the topology.  This will leave
+	 * a momentary gap when migration is disabled.
+	 */
+	disable_all_migrate_targets();
+
+	/*
+	 * Allocations go close to CPUs, first.  Assume that
+	 * the migration path starts at the nodes with CPUs.
+	 */
+	next_pass = node_states[N_CPU];
+again:
+	this_pass = next_pass;
+	next_pass = NODE_MASK_NONE;
+	/*
+	 * To avoid cycles in the migration "graph", ensure
+	 * that migration sources are not future targets by
+	 * setting them in 'used_targets'.  Do this only
+	 * once per pass so that multiple source nodes can
+	 * share a target node.
+	 *
+	 * 'used_targets' will become unavailable in future
+	 * passes.  This limits some opportunities for
+	 * multiple source nodes to share a destination.
+	 */
+	nodes_or(used_targets, used_targets, this_pass);
+	for_each_node_mask(node, this_pass) {
+		int target_node = establish_migrate_target(node, &used_targets);
+
+		if (target_node == NUMA_NO_NODE)
+			continue;
+
+		/*
+		 * Visit targets from this pass in the next pass.
+		 * Eventually, every node will have been part of
+		 * a pass, and will become set in 'used_targets'.
+		 */
+		node_set(target_node, next_pass);
+	}
+	/*
+	 * 'next_pass' contains nodes which became migration
+	 * targets in this pass.  Make additional passes until
+	 * no more migrations targets are available.
+	 */
+	if (!nodes_empty(next_pass))
+		goto again;
+}
+
+/*
+ * For callers that do not hold get_online_mems() already.
+ */
+static void set_migration_target_nodes(void)
+{
+	get_online_mems();
+	__set_migration_target_nodes();
+	put_online_mems();
+}
+
+/*
+ * React to hotplug events that might affect the migration targets
+ * like events that online or offline NUMA nodes.
+ *
+ * The ordering is also currently dependent on which nodes have
+ * CPUs.  That means we need CPU on/offline notification too.
+ */
+static int migration_online_cpu(unsigned int cpu)
+{
+	set_migration_target_nodes();
+	return 0;
+}
+
+static int migration_offline_cpu(unsigned int cpu)
+{
+	set_migration_target_nodes();
+	return 0;
+}
+
+/*
+ * This leaves migrate-on-reclaim transiently disabled between
+ * the MEM_GOING_OFFLINE and MEM_OFFLINE events.  This runs
+ * whether reclaim-based migration is enabled or not, which
+ * ensures that the user can turn reclaim-based migration at
+ * any time without needing to recalculate migration targets.
+ *
+ * These callbacks already hold get_online_mems().  That is why
+ * __set_migration_target_nodes() can be used as opposed to
+ * set_migration_target_nodes().
+ */
+static int __meminit migrate_on_reclaim_callback(struct notifier_block *self,
+						 unsigned long action, void *arg)
+{
+	switch (action) {
+	case MEM_GOING_OFFLINE:
+		/*
+		 * Make sure there are not transient states where
+		 * an offline node is a migration target.  This
+		 * will leave migration disabled until the offline
+		 * completes and the MEM_OFFLINE case below runs.
+		 */
+		disable_all_migrate_targets();
+		break;
+	case MEM_OFFLINE:
+	case MEM_ONLINE:
+		/*
+		 * Recalculate the target nodes once the node
+		 * reaches its final state (online or offline).
+		 */
+		__set_migration_target_nodes();
+		break;
+	case MEM_CANCEL_OFFLINE:
+		/*
+		 * MEM_GOING_OFFLINE disabled all the migration
+		 * targets.  Reenable them.
+		 */
+		__set_migration_target_nodes();
+		break;
+	case MEM_GOING_ONLINE:
+	case MEM_CANCEL_ONLINE:
+		break;
+	}
+
+	return notifier_from_errno(0);
+}
+
+static int __init migrate_on_reclaim_init(void)
+{
+	int ret;
+
+	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "migrate on reclaim",
+				migration_online_cpu,
+				migration_offline_cpu);
+	/*
+	 * In the unlikely case that this fails, the automatic
+	 * migration targets may become suboptimal for nodes
+	 * where N_CPU changes.  With such a small impact in a
+	 * rare case, do not bother trying to do anything special.
+	 */
+	WARN_ON(ret < 0);
+
+	hotplug_memory_notifier(migrate_on_reclaim_callback, 100);
+	return 0;
+}
+late_initcall(migrate_on_reclaim_init);
+#endif /* CONFIG_MEMORY_HOTPLUG */

mm/mmap.c

···
 {
 	struct rb_node **__rb_link, *__rb_parent, *rb_prev;
 
+	mmap_assert_locked(mm);
 	__rb_link = &mm->mm_rb.rb_node;
 	rb_prev = __rb_parent = NULL;
 
···
 	struct rb_node *rb_node;
 	struct vm_area_struct *vma;
 
+	mmap_assert_locked(mm);
 	/* Check the cache first. */
 	vma = vmacache_find(mm, addr);
 	if (likely(vma))
···
 	if (mmap_write_lock_killable(mm))
 		return -EINTR;
 
-	vma = find_vma(mm, start);
+	vma = vma_lookup(mm, start);
 
 	if (!vma || !(vma->vm_flags & VM_SHARED))
-		goto out;
-
-	if (start < vma->vm_start)
 		goto out;
 
 	if (start + size > vma->vm_end) {

mm/mremap.c

···
 	if (do_munmap(mm, old_addr, old_len, uf_unmap) < 0) {
 		/* OOM: unable to split vma, just get accounts right */
 		if (vm_flags & VM_ACCOUNT && !(flags & MREMAP_DONTUNMAP))
-			vm_acct_memory(new_len >> PAGE_SHIFT);
+			vm_acct_memory(old_len >> PAGE_SHIFT);
 		excess = 0;
 	}
 

mm/oom_kill.c

···
 #include <linux/sched/task.h>
 #include <linux/sched/debug.h>
 #include <linux/swap.h>
+#include <linux/syscalls.h>
 #include <linux/timex.h>
 #include <linux/jiffies.h>
 #include <linux/cpuset.h>
···
 		return;
 	out_of_memory(&oc);
 	mutex_unlock(&oom_lock);
+}
+
+SYSCALL_DEFINE2(process_mrelease, int, pidfd, unsigned int, flags)
+{
+#ifdef CONFIG_MMU
+	struct mm_struct *mm = NULL;
+	struct task_struct *task;
+	struct task_struct *p;
+	unsigned int f_flags;
+	bool reap = true;
+	struct pid *pid;
+	long ret = 0;
+
+	if (flags)
+		return -EINVAL;
+
+	pid = pidfd_get_pid(pidfd, &f_flags);
+	if (IS_ERR(pid))
+		return PTR_ERR(pid);
+
+	task = get_pid_task(pid, PIDTYPE_TGID);
+	if (!task) {
+		ret = -ESRCH;
+		goto put_pid;
+	}
+
+	/*
+	 * Make sure to choose a thread which still has a reference to mm
+	 * during the group exit
+	 */
+	p = find_lock_task_mm(task);
+	if (!p) {
+		ret = -ESRCH;
+		goto put_task;
+	}
+
+	mm = p->mm;
+	mmgrab(mm);
+
+	/* If the work has been done already, just exit with success */
+	if (test_bit(MMF_OOM_SKIP, &mm->flags))
+		reap = false;
+	else if (!task_will_free_mem(p)) {
+		reap = false;
+		ret = -EINVAL;
+	}
+	task_unlock(p);
+
+	if (!reap)
+		goto drop_mm;
+
+	if (mmap_read_lock_killable(mm)) {
+		ret = -EINTR;
+		goto drop_mm;
+	}
+	if (!__oom_reap_task_mm(mm))
+		ret = -EAGAIN;
+	mmap_read_unlock(mm);
+
+drop_mm:
+	mmdrop(mm);
+put_task:
+	put_task_struct(task);
+put_pid:
+	put_pid(pid);
+	return ret;
+#else
+	return -ENOSYS;
+#endif /* CONFIG_MMU */
 }

mm/page-writeback.c

···
 static void wb_min_max_ratio(struct bdi_writeback *wb,
 			     unsigned long *minp, unsigned long *maxp)
 {
-	unsigned long this_bw = wb->avg_write_bandwidth;
+	unsigned long this_bw = READ_ONCE(wb->avg_write_bandwidth);
 	unsigned long tot_bw = atomic_long_read(&wb->bdi->tot_write_bandwidth);
 	unsigned long long min = wb->bdi->min_ratio;
 	unsigned long long max = wb->bdi->max_ratio;
···
 static void wb_position_ratio(struct dirty_throttle_control *dtc)
 {
 	struct bdi_writeback *wb = dtc->wb;
-	unsigned long write_bw = wb->avg_write_bandwidth;
+	unsigned long write_bw = READ_ONCE(wb->avg_write_bandwidth);
 	unsigned long freerun = dirty_freerun_ceiling(dtc->thresh, dtc->bg_thresh);
 	unsigned long limit = hard_dirty_limit(dtc_dom(dtc), dtc->thresh);
 	unsigned long wb_thresh = dtc->wb_thresh;
···
 					&wb->bdi->tot_write_bandwidth) <= 0);
 	}
 	wb->write_bandwidth = bw;
-	wb->avg_write_bandwidth = avg;
+	WRITE_ONCE(wb->avg_write_bandwidth, avg);
 }
 
 static void update_dirty_limit(struct dirty_throttle_control *dtc)
···
 	dom->dirty_limit = limit;
 }
 
-static void domain_update_bandwidth(struct dirty_throttle_control *dtc,
-				    unsigned long now)
+static void domain_update_dirty_limit(struct dirty_throttle_control *dtc,
+				      unsigned long now)
 {
 	struct wb_domain *dom = dtc_dom(dtc);
 
···
 	else
 		dirty_ratelimit -= step;
 
-	wb->dirty_ratelimit = max(dirty_ratelimit, 1UL);
+	WRITE_ONCE(wb->dirty_ratelimit, max(dirty_ratelimit, 1UL));
 	wb->balanced_dirty_ratelimit = balanced_dirty_ratelimit;
 
 	trace_bdi_dirty_ratelimit(wb, dirty_rate, task_ratelimit);
···
 
 static void __wb_update_bandwidth(struct dirty_throttle_control *gdtc,
 				  struct dirty_throttle_control *mdtc,
-				  unsigned long start_time,
 				  bool update_ratelimit)
 {
 	struct bdi_writeback *wb = gdtc->wb;
 	unsigned long now = jiffies;
-	unsigned long elapsed = now - wb->bw_time_stamp;
+	unsigned long elapsed;
 	unsigned long dirtied;
 	unsigned long written;
 
-	lockdep_assert_held(&wb->list_lock);
+	spin_lock(&wb->list_lock);
 
 	/*
-	 * rate-limit, only update once every 200ms.
+	 * Lockless checks for elapsed time are racy and delayed update after
+	 * IO completion doesn't do it at all (to make sure written pages are
+	 * accounted reasonably quickly). Make sure elapsed >= 1 to avoid
+	 * division errors.
 	 */
-	if (elapsed < BANDWIDTH_INTERVAL)
-		return;
-
+	elapsed = max(now - wb->bw_time_stamp, 1UL);
 	dirtied = percpu_counter_read(&wb->stat[WB_DIRTIED]);
 	written = percpu_counter_read(&wb->stat[WB_WRITTEN]);
 
-	/*
-	 * Skip quiet periods when disk bandwidth is under-utilized.
-	 * (at least 1s idle time between two flusher runs)
-	 */
-	if (elapsed > HZ && time_before(wb->bw_time_stamp, start_time))
-		goto snapshot;
-
 	if (update_ratelimit) {
-		domain_update_bandwidth(gdtc, now);
+		domain_update_dirty_limit(gdtc, now);
 		wb_update_dirty_ratelimit(gdtc, dirtied, elapsed);
 
 		/*
···
 		 * compiler has no way to figure that out.  Help it.
 		 */
 		if (IS_ENABLED(CONFIG_CGROUP_WRITEBACK) && mdtc) {
-			domain_update_bandwidth(mdtc, now);
+			domain_update_dirty_limit(mdtc, now);
 			wb_update_dirty_ratelimit(mdtc, dirtied, elapsed);
 		}
 	}
 	wb_update_write_bandwidth(wb, elapsed, written);
 
-snapshot:
 	wb->dirtied_stamp = dirtied;
 	wb->written_stamp = written;
-	wb->bw_time_stamp = now;
+	WRITE_ONCE(wb->bw_time_stamp, now);
+	spin_unlock(&wb->list_lock);
 }
 
-void wb_update_bandwidth(struct bdi_writeback *wb, unsigned long start_time)
+void wb_update_bandwidth(struct bdi_writeback *wb)
 {
 	struct dirty_throttle_control gdtc = { GDTC_INIT(wb) };
 
-	__wb_update_bandwidth(&gdtc, NULL, start_time, false);
+	__wb_update_bandwidth(&gdtc, NULL, false);
+}
+
+/* Interval after which we consider wb idle and don't estimate bandwidth */
+#define WB_BANDWIDTH_IDLE_JIF (HZ)
+
+static void wb_bandwidth_estimate_start(struct bdi_writeback *wb)
+{
+	unsigned long now = jiffies;
+	unsigned long elapsed = now - READ_ONCE(wb->bw_time_stamp);
+
+	if (elapsed > WB_BANDWIDTH_IDLE_JIF &&
+	    !atomic_read(&wb->writeback_inodes)) {
+		spin_lock(&wb->list_lock);
+		wb->dirtied_stamp = wb_stat(wb, WB_DIRTIED);
+		wb->written_stamp = wb_stat(wb, WB_WRITTEN);
+		WRITE_ONCE(wb->bw_time_stamp, now);
+		spin_unlock(&wb->list_lock);
+	}
 }
 
 /*
···
 static unsigned long wb_max_pause(struct bdi_writeback *wb,
 				  unsigned long wb_dirty)
 {
-	unsigned long bw = wb->avg_write_bandwidth;
+	unsigned long bw = READ_ONCE(wb->avg_write_bandwidth);
 	unsigned long t;
 
 	/*
···
 			 unsigned long dirty_ratelimit,
 			 int *nr_dirtied_pause)
 {
-	long hi = ilog2(wb->avg_write_bandwidth);
-	long lo = ilog2(wb->dirty_ratelimit);
+	long hi = ilog2(READ_ONCE(wb->avg_write_bandwidth));
+	long lo = ilog2(READ_ONCE(wb->dirty_ratelimit));
 	long t;		/* target pause */
 	long pause;	/* estimated next pause */
 	int pages;	/* target nr_dirtied_pause */
···
 		if (dirty_exceeded && !wb->dirty_exceeded)
 			wb->dirty_exceeded = 1;
 
-		if (time_is_before_jiffies(wb->bw_time_stamp +
-					   BANDWIDTH_INTERVAL)) {
-			spin_lock(&wb->list_lock);
-			__wb_update_bandwidth(gdtc, mdtc, start_time, true);
-			spin_unlock(&wb->list_lock);
-		}
+		if (time_is_before_jiffies(READ_ONCE(wb->bw_time_stamp) +
+					   BANDWIDTH_INTERVAL))
+			__wb_update_bandwidth(gdtc, mdtc, true);
 
 		/* throttle according to the chosen dtc */
-		dirty_ratelimit = wb->dirty_ratelimit;
+		dirty_ratelimit = READ_ONCE(wb->dirty_ratelimit);
 		task_ratelimit = ((u64)dirty_ratelimit * sdtc->pos_ratio) >>
 							RATELIMIT_CALC_SHIFT;
 		max_pause = wb_max_pause(wb, sdtc->wb_dirty);
···
 int do_writepages(struct address_space *mapping, struct writeback_control *wbc)
 {
 	int ret;
+	struct bdi_writeback *wb;
 
 	if (wbc->nr_to_write <= 0)
 		return 0;
+	wb = inode_to_wb_wbc(mapping->host, wbc);
+	wb_bandwidth_estimate_start(wb);
 	while (1) {
 		if (mapping->a_ops->writepages)
 			ret = mapping->a_ops->writepages(mapping, wbc);
···
 		cond_resched();
 		congestion_wait(BLK_RW_ASYNC, HZ/50);
 	}
+	/*
+	 * Usually few pages are written by now from those we've just submitted
+	 * but if there's constant writeback being submitted, this makes sure
+	 * writeback bandwidth is updated once in a while.
+	 */
+	if (time_is_before_jiffies(READ_ONCE(wb->bw_time_stamp) +
+				   BANDWIDTH_INTERVAL))
+		wb_update_bandwidth(wb);
 	return ret;
 }
 
···
 }
 EXPORT_SYMBOL(clear_page_dirty_for_io);
 
+static void wb_inode_writeback_start(struct bdi_writeback *wb)
+{
+	atomic_inc(&wb->writeback_inodes);
+}
+
+static void wb_inode_writeback_end(struct bdi_writeback *wb)
+{
+	atomic_dec(&wb->writeback_inodes);
+	/*
+	 * Make sure estimate of writeback throughput gets updated after
+	 * writeback completed. We delay the update by BANDWIDTH_INTERVAL
+	 * (which is the interval other bandwidth updates use for batching) so
+	 * that if multiple inodes end writeback at a similar time, they get
+	 * batched into one bandwidth update.
+	 */
+	queue_delayed_work(bdi_wq, &wb->bw_dwork, BANDWIDTH_INTERVAL);
+}
+
 int test_clear_page_writeback(struct page *page)
 {
 	struct address_space *mapping = page_mapping(page);
···
 
 				dec_wb_stat(wb, WB_WRITEBACK);
 				__wb_writeout_inc(wb);
+				if (!mapping_tagged(mapping,
+						    PAGECACHE_TAG_WRITEBACK))
+					wb_inode_writeback_end(wb);
 			}
 		}
 
···
 						   PAGECACHE_TAG_WRITEBACK);
 
 			xas_set_mark(&xas, PAGECACHE_TAG_WRITEBACK);
-			if (bdi->capabilities & BDI_CAP_WRITEBACK_ACCT)
-				inc_wb_stat(inode_to_wb(inode), WB_WRITEBACK);
+			if (bdi->capabilities & BDI_CAP_WRITEBACK_ACCT) {
+				struct bdi_writeback *wb = inode_to_wb(inode);
+
+				inc_wb_stat(wb, WB_WRITEBACK);
+				if (!on_wblist)
+					wb_inode_writeback_start(wb);
+			}
 
 			/*
 			 * We can come through here when swapping anonymous

mm/page_alloc.c

···
 		if (tsk_is_oom_victim(current) ||
 		    (current->flags & (PF_MEMALLOC | PF_EXITING)))
 			filter &= ~SHOW_MEM_FILTER_NODES;
-	if (in_interrupt() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
+	if (!in_task() || !(gfp_mask & __GFP_DIRECT_RECLAIM))
 		filter &= ~SHOW_MEM_FILTER_NODES;
 
 	show_mem(filter, nodemask);
···
 	return true;
 }
 
-void __fs_reclaim_acquire(void)
+void __fs_reclaim_acquire(unsigned long ip)
 {
-	lock_map_acquire(&__fs_reclaim_map);
+	lock_acquire_exclusive(&__fs_reclaim_map, 0, 0, NULL, ip);
 }
 
-void __fs_reclaim_release(void)
+void __fs_reclaim_release(unsigned long ip)
 {
-	lock_map_release(&__fs_reclaim_map);
+	lock_release(&__fs_reclaim_map, ip);
 }
 
 void fs_reclaim_acquire(gfp_t gfp_mask)
···
 
 	if (__need_reclaim(gfp_mask)) {
 		if (gfp_mask & __GFP_FS)
-			__fs_reclaim_acquire();
+			__fs_reclaim_acquire(_RET_IP_);
 
 #ifdef CONFIG_MMU_NOTIFIER
 		lock_map_acquire(&__mmu_notifier_invalidate_range_start_map);
···
 
 	if (__need_reclaim(gfp_mask)) {
 		if (gfp_mask & __GFP_FS)
-			__fs_reclaim_release();
+			__fs_reclaim_release(_RET_IP_);
 	}
 }
 EXPORT_SYMBOL_GPL(fs_reclaim_release);
···
 		 * comment for __cpuset_node_allowed().
 		 */
 		alloc_flags &= ~ALLOC_CPUSET;
-	} else if (unlikely(rt_task(current)) && !in_interrupt())
+	} else if (unlikely(rt_task(current)) && in_task())
 		alloc_flags |= ALLOC_HARDER;
 
 	alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, alloc_flags);
···
 		 * When we are in the interrupt context, it is irrelevant
 		 * to the current task context. It means that any node ok.
 		 */
-		if (!in_interrupt() && !ac->nodemask)
+		if (in_task() && !ac->nodemask)
 			ac->nodemask = &cpuset_current_mems_allowed;
 		else
 			*alloc_flags |= ALLOC_CPUSET;
···
 		" unevictable:%lu dirty:%lu writeback:%lu\n"
 		" slab_reclaimable:%lu slab_unreclaimable:%lu\n"
 		" mapped:%lu shmem:%lu pagetables:%lu bounce:%lu\n"
+		" kernel_misc_reclaimable:%lu\n"
 		" free:%lu free_pcp:%lu free_cma:%lu\n",
 		global_node_page_state(NR_ACTIVE_ANON),
 		global_node_page_state(NR_INACTIVE_ANON),
···
 		global_node_page_state(NR_SHMEM),
 		global_node_page_state(NR_PAGETABLE),
 		global_zone_page_state(NR_BOUNCE),
+		global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE),
 		global_zone_page_state(NR_FREE_PAGES),
 		free_pcp,
 		global_zone_page_state(NR_FREE_CMA_PAGES));
···
  *
  * 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)
+int find_next_best_node(int node, nodemask_t *used_node_mask)
 {
 	int n, val;
 	int min_val = INT_MAX;
···
 	}
 }
 
-#if !defined(CONFIG_FLATMEM)
 /*
  * Only struct pages that correspond to ranges defined by memblock.memory
  * are zeroed and initialized by going through __init_single_page() during
···
 		pr_info("On node %d, zone %s: %lld pages in unavailable ranges",
 			node, zone_names[zone], pgcnt);
 }
-#else
-static inline void init_unavailable_range(unsigned long spfn,
-					  unsigned long epfn,
-					  int zone, int node)
-{
-}
-#endif
 
 static void __init memmap_init_zone_range(struct zone *zone,
 					  unsigned long start_pfn,
···
 {
 	unsigned long start_pfn, end_pfn;
 	unsigned long hole_pfn = 0;
-	int i, j, zone_id, nid;
+	int i, j, zone_id = 0, nid;
 
 	for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, &nid) {
 		struct pglist_data *node = NODE_DATA(nid);
···
 	if (hole_pfn < end_pfn)
 #endif
 		init_unavailable_range(hole_pfn, end_pfn, zone_id, nid);
+}
+
+void __init *memmap_alloc(phys_addr_t size, phys_addr_t align,
+			  phys_addr_t min_addr, int nid, bool exact_nid)
+{
+	void *ptr;
+
+	if (exact_nid)
+		ptr = memblock_alloc_exact_nid_raw(size, align, min_addr,
+						   MEMBLOCK_ALLOC_ACCESSIBLE,
+						   nid);
+	else
+		ptr = memblock_alloc_try_nid_raw(size, align, min_addr,
+						 MEMBLOCK_ALLOC_ACCESSIBLE,
+						 nid);
+
+	if (ptr && size > 0)
+		page_init_poison(ptr, size);
+
+	return ptr;
 }
 
 static int zone_batchsize(struct zone *zone)
···
 }
 
 #ifdef CONFIG_FLATMEM
-static void __ref alloc_node_mem_map(struct pglist_data *pgdat)
+static void __init alloc_node_mem_map(struct pglist_data *pgdat)
 {
 	unsigned long __maybe_unused start = 0;
 	unsigned long __maybe_unused offset = 0;
···
 		end = pgdat_end_pfn(pgdat);
 		end = ALIGN(end, MAX_ORDER_NR_PAGES);
 		size =  (end - start) * sizeof(struct page);
-		map = memblock_alloc_node(size, SMP_CACHE_BYTES,
-					  pgdat->node_id);
+		map = memmap_alloc(size, SMP_CACHE_BYTES, MEMBLOCK_LOW_LIMIT,
+				   pgdat->node_id, false);
 		if (!map)
 			panic("Failed to allocate %ld bytes for node %d memory map\n",
 			      size, pgdat->node_id);
···
 #endif
 }
 #else
-static void __ref alloc_node_mem_map(struct pglist_data *pgdat) { }
+static inline void alloc_node_mem_map(struct pglist_data *pgdat) { }
 #endif /* CONFIG_FLATMEM */
 
 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
···
 		cc->nr_migratepages -= nr_reclaimed;
 
 		ret = migrate_pages(&cc->migratepages, alloc_migration_target,
-				NULL, (unsigned long)&mtc, cc->mode, MR_CONTIG_RANGE);
+			NULL, (unsigned long)&mtc, cc->mode, MR_CONTIG_RANGE, NULL);
 
 		/*
 		 * On -ENOMEM, migrate_pages() bails out right away. It is pointless

mm/page_isolation.c

···
 	unsigned long pfn, flags;
 	struct page *page;
 	struct zone *zone;
+	int ret;
 
 	/*
 	 * Note: pageblock_nr_pages != MAX_ORDER. Then, chunks of free pages
···
 			break;
 	}
 	page = __first_valid_page(start_pfn, end_pfn - start_pfn);
-	if ((pfn < end_pfn) || !page)
-		return -EBUSY;
+	if ((pfn < end_pfn) || !page) {
+		ret = -EBUSY;
+		goto out;
+	}
+
 	/* Check all pages are free or marked as ISOLATED */
 	zone = page_zone(page);
 	spin_lock_irqsave(&zone->lock, flags);
 	pfn = __test_page_isolated_in_pageblock(start_pfn, end_pfn, isol_flags);
 	spin_unlock_irqrestore(&zone->lock, flags);
 
+	ret = pfn < end_pfn ? -EBUSY : 0;
+
+out:
 	trace_test_pages_isolated(start_pfn, end_pfn, pfn);
 
-	return pfn < end_pfn ? -EBUSY : 0;
+	return ret;
 }

mm/percpu.c

···
  * Pages in [@page_start,@page_end) have been populated to @chunk.  Update
  * the bookkeeping information accordingly.  Must be called after each
  * successful population.
- *
- * If this is @for_alloc, do not increment pcpu_nr_empty_pop_pages because it
- * is to serve an allocation in that area.
  */
 static void pcpu_chunk_populated(struct pcpu_chunk *chunk, int page_start,
 				 int page_end)

mm/shmem.c

···
 #include <linux/hugetlb.h>
 #include <linux/frontswap.h>
 #include <linux/fs_parser.h>
-
-#include <asm/tlbflush.h> /* for arch/microblaze update_mmu_cache() */
+#include <linux/swapfile.h>
 
 static struct vfsmount *shm_mnt;
 
···
 }
 #endif
 
-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,
···
 	ino_t ino;
 
 	if (!(sb->s_flags & SB_KERNMOUNT)) {
-		spin_lock(&sbinfo->stat_lock);
+		raw_spin_lock(&sbinfo->stat_lock);
 		if (sbinfo->max_inodes) {
 			if (!sbinfo->free_inodes) {
-				spin_unlock(&sbinfo->stat_lock);
+				raw_spin_unlock(&sbinfo->stat_lock);
 				return -ENOSPC;
 			}
 			sbinfo->free_inodes--;
···
 			}
 			*inop = ino;
 		}
-		spin_unlock(&sbinfo->stat_lock);
+		raw_spin_unlock(&sbinfo->stat_lock);
 	} else if (inop) {
 		/*
 		 * __shmem_file_setup, one of our callers, is lock-free: it
···
 		 * to worry about things like glibc compatibility.
 		 */
 		ino_t *next_ino;
+
 		next_ino = per_cpu_ptr(sbinfo->ino_batch, get_cpu());
 		ino = *next_ino;
 		if (unlikely(ino % SHMEM_INO_BATCH == 0)) {
-			spin_lock(&sbinfo->stat_lock);
+			raw_spin_lock(&sbinfo->stat_lock);
 			ino = sbinfo->next_ino;
 			sbinfo->next_ino += SHMEM_INO_BATCH;
-			spin_unlock(&sbinfo->stat_lock);
+			raw_spin_unlock(&sbinfo->stat_lock);
 			if (unlikely(is_zero_ino(ino)))
 				ino++;
 		}
···
 {
 	struct shmem_sb_info *sbinfo = SHMEM_SB(sb);
 	if (sbinfo->max_inodes) {
-		spin_lock(&sbinfo->stat_lock);
+		raw_spin_lock(&sbinfo->stat_lock);
 		sbinfo->free_inodes++;
-		spin_unlock(&sbinfo->stat_lock);
+		raw_spin_unlock(&sbinfo->stat_lock);
 	}
 }
 
···
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 /* ifdef here to avoid bloating shmem.o when not necessary */
 
-static int shmem_huge __read_mostly;
+static int shmem_huge __read_mostly = SHMEM_HUGE_NEVER;
+
+bool shmem_is_huge(struct vm_area_struct *vma,
+		   struct inode *inode, pgoff_t index)
+{
+	loff_t i_size;
+
+	if (shmem_huge == SHMEM_HUGE_DENY)
+		return false;
+	if (vma && ((vma->vm_flags & VM_NOHUGEPAGE) ||
+	    test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)))
+		return false;
+	if (shmem_huge == SHMEM_HUGE_FORCE)
+		return true;
+
+	switch (SHMEM_SB(inode->i_sb)->huge) {
+	case SHMEM_HUGE_ALWAYS:
+		return true;
+	case SHMEM_HUGE_WITHIN_SIZE:
+		index = 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) >= index)
+			return true;
+		fallthrough;
+	case SHMEM_HUGE_ADVISE:
+		if (vma && (vma->vm_flags & VM_HUGEPAGE))
+			return true;
+		fallthrough;
+	default:
+		return false;
+	}
+}
 
 #if defined(CONFIG_SYSFS)
 static int shmem_parse_huge(const char *str)
···
 
 #define shmem_huge SHMEM_HUGE_DENY
 
+bool shmem_is_huge(struct vm_area_struct *vma,
+		   struct inode *inode, pgoff_t index)
+{
+	return false;
+}
+
 static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo,
 		struct shrink_control *sc, unsigned long nr_to_split)
 {
 	return 0;
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
-
-static inline bool is_huge_enabled(struct shmem_sb_info *sbinfo)
-{
-	if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
-	    (shmem_huge == SHMEM_HUGE_FORCE || sbinfo->huge) &&
-	    shmem_huge != SHMEM_HUGE_DENY)
-		return true;
-	return false;
-}
 
 /*
  * Like add_to_page_cache_locked, but error if expected item has gone.
···
 	if (lend == -1)
 		end = -1;	/* unsigned, so actually very big */
 
+	if (info->fallocend > start && info->fallocend <= end && !unfalloc)
+		info->fallocend = start;
+
 	pagevec_init(&pvec);
 	index = start;
 	while (index < end && find_lock_entries(mapping, index, end - 1,
···
 {
 	struct inode *inode = path->dentry->d_inode;
 	struct shmem_inode_info *info = SHMEM_I(inode);
-	struct shmem_sb_info *sb_info = SHMEM_SB(inode->i_sb);
 
 	if (info->alloced - info->swapped != inode->i_mapping->nrpages) {
 		spin_lock_irq(&info->lock);
···
 	}
 	generic_fillattr(&init_user_ns, inode, stat);
 
-	if (is_huge_enabled(sb_info))
+	if (shmem_is_huge(NULL, inode, 0))
 		stat->blksize = HPAGE_PMD_SIZE;
 
 	return 0;
···
 {
 	struct inode *inode = d_inode(dentry);
 	struct shmem_inode_info *info = SHMEM_I(inode);
-	struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
 	int error;
 
 	error = setattr_prepare(&init_user_ns, dentry, attr);
···
 			if (oldsize > holebegin)
 				unmap_mapping_range(inode->i_mapping,
 							holebegin, 0, 1);
-
-			/*
-			 * Part of the huge page can be beyond i_size: subject
-			 * to shrink under memory pressure.
-			 */
-			if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) {
-				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);
-			}
 		}
 	}
 
···
 	shmem_free_inode(inode->i_sb);
 	clear_inode(inode);
 }
-
-extern struct swap_info_struct *swap_info[];
 
 static int shmem_find_swap_entries(struct address_space *mapping,
 				   pgoff_t start, unsigned int nr_entries,
···
 	swp_entry_t swap;
 	pgoff_t index;
 
-	VM_BUG_ON_PAGE(PageCompound(page), page);
+	/*
+	 * If /sys/kernel/mm/transparent_hugepage/shmem_enabled is "always" or
+	 * "force", drivers/gpu/drm/i915/gem/i915_gem_shmem.c gets huge pages,
+	 * and its shmem_writeback() needs them to be split when swapping.
+	 */
+	if (PageTransCompound(page)) {
+		/* Ensure the subpages are still dirty */
+		SetPageDirty(page);
+		if (split_huge_page(page) < 0)
+			goto redirty;
+		ClearPageDirty(page);
+	}
+
 	BUG_ON(!PageLocked(page));
 	mapping = page->mapping;
 	index = page->index;
···
 {
 	struct mempolicy *mpol = NULL;
 	if (sbinfo->mpol) {
-		spin_lock(&sbinfo->stat_lock);	/* prevent replace/use races */
+		raw_spin_lock(&sbinfo->stat_lock);	/* prevent replace/use races */
 		mpol = sbinfo->mpol;
 		mpol_get(mpol);
-		spin_unlock(&sbinfo->stat_lock);
+		raw_spin_unlock(&sbinfo->stat_lock);
 	}
 	return mpol;
 }
···
 	struct shmem_sb_info *sbinfo;
 	struct mm_struct *charge_mm;
 	struct page *page;
-	enum sgp_type sgp_huge = sgp;
 	pgoff_t hindex = index;
 	gfp_t huge_gfp;
 	int error;
···
 
 	if (index > (MAX_LFS_FILESIZE >> PAGE_SHIFT))
 		return -EFBIG;
-	if (sgp == SGP_NOHUGE || sgp == SGP_HUGE)
-		sgp = SGP_CACHE;
 repeat:
 	if (sgp <= SGP_CACHE &&
 	    ((loff_t)index << PAGE_SHIFT) >= i_size_read(inode)) {
···
 		return error;
 	}
 
-	if (page)
+	if (page) {
 		hindex = page->index;
-	if (page && sgp == SGP_WRITE)
-		mark_page_accessed(page);
-
-	/* fallocated page? */
-	if (page && !PageUptodate(page)) {
+		if (sgp == SGP_WRITE)
+			mark_page_accessed(page);
+		if (PageUptodate(page))
+			goto out;
+		/* fallocated page */
 		if (sgp != SGP_READ)
 			goto clear;
 		unlock_page(page);
 		put_page(page);
-		page = NULL;
-		hindex = index;
 	}
-	if (page || sgp == SGP_READ)
-		goto out;
 
 	/*
-	 * Fast cache lookup did not find it:
-	 * bring it back from swap or allocate.
+	 * SGP_READ: succeed on hole, with NULL page, letting caller zero.
+	 * SGP_NOALLOC: fail on hole, with NULL page, letting caller fail.
+	 */
+	*pagep = NULL;
+	if (sgp == SGP_READ)
+		return 0;
+	if (sgp == SGP_NOALLOC)
+		return -ENOENT;
+
+	/*
+	 * Fast cache lookup and swap lookup did not find it: allocate.
 	 */
 
 	if (vma && userfaultfd_missing(vma)) {
···
 		return 0;
 	}
 
-	/* shmem_symlink() */
-	if (!shmem_mapping(mapping))
+	/* Never use a huge page for shmem_symlink() */
+	if (S_ISLNK(inode->i_mode))
 		goto alloc_nohuge;
-	if (shmem_huge == SHMEM_HUGE_DENY || sgp_huge == SGP_NOHUGE)
+	if (!shmem_is_huge(vma, inode, index))
 		goto alloc_nohuge;
-	if (shmem_huge == SHMEM_HUGE_FORCE)
-		goto alloc_huge;
-	switch (sbinfo->huge) {
-	case SHMEM_HUGE_NEVER:
-		goto alloc_nohuge;
-	case SHMEM_HUGE_WITHIN_SIZE: {
-		loff_t i_size;
-		pgoff_t off;
 
-		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;
-	}
-
-alloc_huge:
 	huge_gfp = vma_thp_gfp_mask(vma);
 	huge_gfp = limit_gfp_mask(huge_gfp, gfp);
 	page = shmem_alloc_and_acct_page(huge_gfp, inode, index, true);
···
 	struct vm_area_struct *vma = vmf->vma;
 	struct inode *inode = file_inode(vma->vm_file);
 	gfp_t gfp = mapping_gfp_mask(inode->i_mapping);
-	enum sgp_type sgp;
 	int err;
 	vm_fault_t ret = VM_FAULT_LOCKED;
 
···
 		spin_unlock(&inode->i_lock);
 	}
 
-	sgp = SGP_CACHE;
-
-	if ((vma->vm_flags & VM_NOHUGEPAGE) ||
-	    test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
-		sgp = SGP_NOHUGE;
-	else if (vma->vm_flags & VM_HUGEPAGE)
-		sgp = SGP_HUGE;
-
-	err = shmem_getpage_gfp(inode, vmf->pgoff, &vmf->page, sgp,
+	err = shmem_getpage_gfp(inode, vmf->pgoff, &vmf->page, SGP_CACHE,
 				  gfp, vma, vmf, &ret);
 	if (err)
 		return vmf_error(err);
···
 	struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
 	struct shmem_inode_info *info = SHMEM_I(inode);
 	struct shmem_falloc shmem_falloc;
-	pgoff_t start, index, end;
+	pgoff_t start, index, end, undo_fallocend;
 	int error;
 
 	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
···
 	inode->i_private = &shmem_falloc;
 	spin_unlock(&inode->i_lock);
 
-	for (index = start; index < end; index++) {
+	/*
+	 * info->fallocend is only relevant when huge pages might be
+	 * involved: to prevent split_huge_page() freeing fallocated
+	 * pages when FALLOC_FL_KEEP_SIZE committed beyond i_size.
+	 */
+	undo_fallocend = info->fallocend;
+	if (info->fallocend < end)
+		info->fallocend = end;
+
+	for (index = start; index < end; ) {
 		struct page *page;
 
 		/*
···
 		else
 			error = shmem_getpage(inode, index, &page, SGP_FALLOC);
 		if (error) {
+			info->fallocend = undo_fallocend;
 			/* Remove the !PageUptodate pages we added */
 			if (index > start) {
 				shmem_undo_range(inode,
···
 			goto undone;
 		}
 
+		index++;
+		/*
+		 * Here is a more important optimization than it appears:
+		 * a second SGP_FALLOC on the same huge page will clear it,
+		 * making it PageUptodate and un-undoable if we fail later.
+		 */
+		if (PageTransCompound(page)) {
+			index = round_up(index, HPAGE_PMD_NR);
+			/* Beware 32-bit wraparound */
+			if (!index)
+				index--;
+		}
+
 		/*
 		 * Inform shmem_writepage() how far we have reached.
 		 * No need for lock or barrier: we have the page lock.
 		 */
-		shmem_falloc.next++;
 		if (!PageUptodate(page))
-			shmem_falloc.nr_falloced++;
+			shmem_falloc.nr_falloced += index - shmem_falloc.next;
+		shmem_falloc.next = index;
 
 		/*
 		 * If !PageUptodate, leave it that way so that freeable pages
···
 	struct shmem_options *ctx = fc->fs_private;
 	struct shmem_sb_info *sbinfo = SHMEM_SB(fc->root->d_sb);
 	unsigned long inodes;
+	struct mempolicy *mpol = NULL;
 	const char *err;
 
-	spin_lock(&sbinfo->stat_lock);
+	raw_spin_lock(&sbinfo->stat_lock);
 	inodes = sbinfo->max_inodes - sbinfo->free_inodes;
 	if ((ctx->seen & SHMEM_SEEN_BLOCKS) && ctx->blocks) {
 		if (!sbinfo->max_blocks) {
···
 	 * Preserve previous mempolicy unless mpol remount option was specified.
 	 */
 	if (ctx->mpol) {
-		mpol_put(sbinfo->mpol);
+		mpol = sbinfo->mpol;
 		sbinfo->mpol = ctx->mpol;	/* transfers initial ref */
 		ctx->mpol = NULL;
 	}
-	spin_unlock(&sbinfo->stat_lock);
+	raw_spin_unlock(&sbinfo->stat_lock);
+	mpol_put(mpol);
 	return 0;
 out:
-	spin_unlock(&sbinfo->stat_lock);
+	raw_spin_unlock(&sbinfo->stat_lock);
 	return invalfc(fc, "%s", err);
 }
 
···
 	struct shmem_options *ctx = fc->fs_private;
 	struct inode *inode;
 	struct shmem_sb_info *sbinfo;
-	int err = -ENOMEM;
 
 	/* Round up to L1_CACHE_BYTES to resist false sharing */
 	sbinfo = kzalloc(max((int)sizeof(struct shmem_sb_info),
···
 	sbinfo->mpol = ctx->mpol;
 	ctx->mpol = NULL;
 
-	spin_lock_init(&sbinfo->stat_lock);
+	raw_spin_lock_init(&sbinfo->stat_lock);
 	if (percpu_counter_init(&sbinfo->used_blocks, 0, GFP_KERNEL))
 		goto failed;
 	spin_lock_init(&sbinfo->shrinklist_lock);
···
 
 failed:
 	shmem_put_super(sb);
-	return err;
+	return -ENOMEM;
 }
 
 static int shmem_get_tree(struct fs_context *fc)
···
 	if (has_transparent_hugepage() && shmem_huge > SHMEM_HUGE_DENY)
 		SHMEM_SB(shm_mnt->mnt_sb)->huge = shmem_huge;
 	else
-		shmem_huge = 0; /* just in case it was patched */
+		shmem_huge = SHMEM_HUGE_NEVER; /* just in case it was patched */
 #endif
 	return 0;
 
···
 struct kobj_attribute shmem_enabled_attr =
 	__ATTR(shmem_enabled, 0644, shmem_enabled_show, shmem_enabled_store);
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE && CONFIG_SYSFS */
-
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-bool shmem_huge_enabled(struct vm_area_struct *vma)
-{
-	struct inode *inode = file_inode(vma->vm_file);
-	struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb);
-	loff_t i_size;
-	pgoff_t off;
-
-	if (!transhuge_vma_enabled(vma, vma->vm_flags))
-		return false;
-	if (shmem_huge == SHMEM_HUGE_FORCE)
-		return true;
-	if (shmem_huge == SHMEM_HUGE_DENY)
-		return false;
-	switch (sbinfo->huge) {
-		case SHMEM_HUGE_NEVER:
-			return false;
-		case SHMEM_HUGE_ALWAYS:
-			return true;
-		case SHMEM_HUGE_WITHIN_SIZE:
-			off = round_up(vma->vm_pgoff, HPAGE_PMD_NR);
-			i_size = round_up(i_size_read(inode), PAGE_SIZE);
-			if (i_size >= HPAGE_PMD_SIZE &&
-					i_size >> PAGE_SHIFT >= off)
-				return true;
-			fallthrough;
-		case SHMEM_HUGE_ADVISE:
-			/* TODO: implement fadvise() hints */
-			return (vma->vm_flags & VM_HUGEPAGE);
-		default:
-			VM_BUG_ON(1);
-			return false;
-	}
-}
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 #else /* !CONFIG_SHMEM */
 

mm/sparse.c

···
 }
 #endif
 
-#ifdef CONFIG_SPARSEMEM_EXTREME
-unsigned long __section_nr(struct mem_section *ms)
-{
-	unsigned long root_nr;
-	struct mem_section *root = NULL;
-
-	for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) {
-		root = __nr_to_section(root_nr * SECTIONS_PER_ROOT);
-		if (!root)
-			continue;
-
-		if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT)))
-		     break;
-	}
-
-	VM_BUG_ON(!root);
-
-	return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
-}
-#else
-unsigned long __section_nr(struct mem_section *ms)
-{
-	return (unsigned long)(ms - mem_section[0]);
-}
-#endif
-
 /*
  * During early boot, before section_mem_map is used for an actual
  * mem_map, we use section_mem_map to store the section's NUMA
···
  */
 static inline unsigned long sparse_encode_early_nid(int nid)
 {
-	return (nid << SECTION_NID_SHIFT);
+	return ((unsigned long)nid << SECTION_NID_SHIFT);
 }
 
 static inline int sparse_early_nid(struct mem_section *section)
···
  * those loops early.
  */
 unsigned long __highest_present_section_nr;
-static void section_mark_present(struct mem_section *ms)
+static void __section_mark_present(struct mem_section *ms,
+		unsigned long section_nr)
 {
-	unsigned long section_nr = __section_nr(ms);
-
 	if (section_nr > __highest_present_section_nr)
 		__highest_present_section_nr = section_nr;
 
···
 		if (!ms->section_mem_map) {
 			ms->section_mem_map = sparse_encode_early_nid(nid) |
 							SECTION_IS_ONLINE;
-			section_mark_present(ms);
+			__section_mark_present(ms, section);
 		}
 	}
 }
···
 static inline phys_addr_t pgdat_to_phys(struct pglist_data *pgdat)
 {
 #ifndef CONFIG_NUMA
-	return __pa_symbol(pgdat);
+	VM_BUG_ON(pgdat != &contig_page_data);
+	return __pa_symbol(&contig_page_data);
 #else
 	return __pa(pgdat);
 #endif
···
 	if (map)
 		return map;
 
-	map = memblock_alloc_try_nid_raw(size, size, addr,
-					  MEMBLOCK_ALLOC_ACCESSIBLE, nid);
+	map = memmap_alloc(size, size, addr, nid, false);
 	if (!map)
 		panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%pa\n",
 		      __func__, size, PAGE_SIZE, nid, &addr);
···
 	 * and we want it to be properly aligned to the section size - this is
 	 * especially the case for VMEMMAP which maps memmap to PMDs
 	 */
-	sparsemap_buf = memblock_alloc_exact_nid_raw(size, section_map_size(),
-					addr, MEMBLOCK_ALLOC_ACCESSIBLE, nid);
+	sparsemap_buf = memmap_alloc(size, section_map_size(), addr, nid, true);
 	sparsemap_buf_end = sparsemap_buf + size;
 }
 
···
 
 	ms = __nr_to_section(section_nr);
 	set_section_nid(section_nr, nid);
-	section_mark_present(ms);
+	__section_mark_present(ms, section_nr);
 
 	/* Align memmap to section boundary in the subsection case */
 	if (section_nr_to_pfn(section_nr) != start_pfn)

mm/swap.c

···
 }
 EXPORT_SYMBOL_GPL(get_kernel_pages);
 
-/*
- * get_kernel_page() - pin a kernel page in memory
- * @start:	starting kernel address
- * @write:	pinning for read/write, currently ignored
- * @pages:	array that receives pointer to the page pinned.
- *		Must be at least nr_segs long.
- *
- * Returns 1 if page is pinned. If the page was not pinned, returns
- * -errno. The page returned must be released with a put_page() call
- * when it is finished with.
- */
-int get_kernel_page(unsigned long start, int write, struct page **pages)
-{
-	const struct kvec kiov = {
-		.iov_base = (void *)start,
-		.iov_len = PAGE_SIZE
-	};
-
-	return get_kernel_pages(&kiov, 1, write, pages);
-}
-EXPORT_SYMBOL_GPL(get_kernel_page);
-
 static void pagevec_lru_move_fn(struct pagevec *pvec,
 	void (*move_fn)(struct page *page, struct lruvec *lruvec))
 {

mm/swapfile.c

···
 	struct filename *name;
 	struct file *swap_file = NULL;
 	struct address_space *mapping;
+	struct dentry *dentry;
 	int prio;
 	int error;
 	union swap_header *swap_header;
···
 
 	p->swap_file = swap_file;
 	mapping = swap_file->f_mapping;
+	dentry = swap_file->f_path.dentry;
 	inode = mapping->host;
 
 	error = claim_swapfile(p, inode);
···
 		goto bad_swap;
 
 	inode_lock(inode);
+	if (d_unlinked(dentry) || cant_mount(dentry)) {
+		error = -ENOENT;
+		goto bad_swap_unlock_inode;
+	}
 	if (IS_SWAPFILE(inode)) {
 		error = -EBUSY;
 		goto bad_swap_unlock_inode;
···
 }
 
 #if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
-void cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)
+void __cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)
 {
 	struct swap_info_struct *si, *next;
 	int nid = page_to_nid(page);

mm/truncate.c

···
 			index = indices[i];
 
 			if (xa_is_value(page)) {
-				invalidate_exceptional_entry(mapping, index,
-							     page);
+				count += invalidate_exceptional_entry(mapping,
+								      index,
+								      page);
 				continue;
 			}
 			index += thp_nr_pages(page) - 1;
···
 }
 
 /**
- * invalidate_mapping_pages - Invalidate all the unlocked pages of one inode
- * @mapping: the address_space which holds the pages to invalidate
+ * invalidate_mapping_pages - Invalidate all clean, unlocked cache of one inode
+ * @mapping: the address_space which holds the cache to invalidate
  * @start: the offset 'from' which to invalidate
  * @end: the offset 'to' which to invalidate (inclusive)
  *
- * This function only removes the unlocked pages, if you want to
- * remove all the pages of one inode, you must call truncate_inode_pages.
+ * This function removes pages that are clean, unmapped and unlocked,
+ * as well as shadow entries. It will not block on IO activity.
  *
- * invalidate_mapping_pages() will not block on IO activity. It will not
- * invalidate pages which are dirty, locked, under writeback or mapped into
- * pagetables.
+ * If you want to remove all the pages of one inode, regardless of
+ * their use and writeback state, use truncate_inode_pages().
  *
- * Return: the number of the pages that were invalidated
+ * Return: the number of the cache entries that were invalidated
  */
 unsigned long invalidate_mapping_pages(struct address_space *mapping,
 		pgoff_t start, pgoff_t end)
···
 static int
 invalidate_complete_page2(struct address_space *mapping, struct page *page)
 {
-	unsigned long flags;
-
 	if (page->mapping != mapping)
 		return 0;
 
 	if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL))
 		return 0;
 
-	xa_lock_irqsave(&mapping->i_pages, flags);
+	xa_lock_irq(&mapping->i_pages);
 	if (PageDirty(page))
 		goto failed;
 
 	BUG_ON(page_has_private(page));
 	__delete_from_page_cache(page, NULL);
-	xa_unlock_irqrestore(&mapping->i_pages, flags);
+	xa_unlock_irq(&mapping->i_pages);
 
 	if (mapping->a_ops->freepage)
 		mapping->a_ops->freepage(page);
···
 	put_page(page);	/* pagecache ref */
 	return 1;
 failed:
-	xa_unlock_irqrestore(&mapping->i_pages, flags);
+	xa_unlock_irq(&mapping->i_pages);
 	return 0;
 }
 

mm/userfaultfd.c

···
 					      unsigned long src_start,
 					      unsigned long len,
 					      enum mcopy_atomic_mode mcopy_mode,
-					      bool *mmap_changing,
+					      atomic_t *mmap_changing,
 					      __u64 mode)
 {
 	struct vm_area_struct *dst_vma;
···
 	 * request the user to retry later
 	 */
 	err = -EAGAIN;
-	if (mmap_changing && READ_ONCE(*mmap_changing))
+	if (mmap_changing && atomic_read(mmap_changing))
 		goto out_unlock;
 
 	/*
···
 
 ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
 		     unsigned long src_start, unsigned long len,
-		     bool *mmap_changing, __u64 mode)
+		     atomic_t *mmap_changing, __u64 mode)
 {
 	return __mcopy_atomic(dst_mm, dst_start, src_start, len,
 			      MCOPY_ATOMIC_NORMAL, mmap_changing, mode);
 }
 
 ssize_t mfill_zeropage(struct mm_struct *dst_mm, unsigned long start,
-		       unsigned long len, bool *mmap_changing)
+		       unsigned long len, atomic_t *mmap_changing)
 {
 	return __mcopy_atomic(dst_mm, start, 0, len, MCOPY_ATOMIC_ZEROPAGE,
 			      mmap_changing, 0);
 }
 
 ssize_t mcopy_continue(struct mm_struct *dst_mm, unsigned long start,
-		       unsigned long len, bool *mmap_changing)
+		       unsigned long len, atomic_t *mmap_changing)
 {
 	return __mcopy_atomic(dst_mm, start, 0, len, MCOPY_ATOMIC_CONTINUE,
 			      mmap_changing, 0);
 }
 
 int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start,
-			unsigned long len, bool enable_wp, bool *mmap_changing)
+			unsigned long len, bool enable_wp,
+			atomic_t *mmap_changing)
 {
 	struct vm_area_struct *dst_vma;
 	pgprot_t newprot;
···
 	 * request the user to retry later
 	 */
 	err = -EAGAIN;
-	if (mmap_changing && READ_ONCE(*mmap_changing))
+	if (mmap_changing && atomic_read(mmap_changing))
 		goto out_unlock;
 
 	err = -ENOENT;

mm/vmalloc.c

···
 	return atomic_long_read(&nr_vmalloc_pages);
 }
 
+static struct vmap_area *find_vmap_area_exceed_addr(unsigned long addr)
+{
+	struct vmap_area *va = NULL;
+	struct rb_node *n = vmap_area_root.rb_node;
+
+	while (n) {
+		struct vmap_area *tmp;
+
+		tmp = rb_entry(n, struct vmap_area, rb_node);
+		if (tmp->va_end > addr) {
+			va = tmp;
+			if (tmp->va_start <= addr)
+				break;
+
+			n = n->rb_left;
+		} else
+			n = n->rb_right;
+	}
+
+	return va;
+}
+
 static struct vmap_area *__find_vmap_area(unsigned long addr)
 {
 	struct rb_node *n = vmap_area_root.rb_node;
···
 				int node, gfp_t gfp_mask)
 {
 	struct vmap_area *va;
+	unsigned long freed;
 	unsigned long addr;
 	int purged = 0;
 	int ret;
···
 		goto retry;
 	}
 
-	if (gfpflags_allow_blocking(gfp_mask)) {
-		unsigned long freed = 0;
-		blocking_notifier_call_chain(&vmap_notify_list, 0, &freed);
-		if (freed > 0) {
-			purged = 0;
-			goto retry;
-		}
+	freed = 0;
+	blocking_notifier_call_chain(&vmap_notify_list, 0, &freed);
+
+	if (freed > 0) {
+		purged = 0;
+		goto retry;
 	}
 
 	if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit())
···
 
 static inline unsigned int
 vm_area_alloc_pages(gfp_t gfp, int nid,
-		unsigned int order, unsigned long nr_pages, struct page **pages)
+		unsigned int order, unsigned int nr_pages, struct page **pages)
 {
 	unsigned int nr_allocated = 0;
 
···
 	 * to fails, fallback to a single page allocator that is
 	 * more permissive.
 	 */
-	if (!order)
-		nr_allocated = alloc_pages_bulk_array_node(
-			gfp, nid, nr_pages, pages);
-	else
+	if (!order) {
+		while (nr_allocated < nr_pages) {
+			unsigned int nr, nr_pages_request;
+
+			/*
+			 * A maximum allowed request is hard-coded and is 100
+			 * pages per call. That is done in order to prevent a
+			 * long preemption off scenario in the bulk-allocator
+			 * so the range is [1:100].
+			 */
+			nr_pages_request = min(100U, nr_pages - nr_allocated);
+
+			nr = alloc_pages_bulk_array_node(gfp, nid,
+				nr_pages_request, pages + nr_allocated);
+
+			nr_allocated += nr;
+			cond_resched();
+
+			/*
+			 * If zero or pages were obtained partly,
+			 * fallback to a single page allocator.
+			 */
+			if (nr != nr_pages_request)
+				break;
+		}
+	} else
 		/*
 		 * Compound pages required for remap_vmalloc_page if
 		 * high-order pages.
···
 		for (i = 0; i < (1U << order); i++)
 			pages[nr_allocated + i] = page + i;
 
-		if (gfpflags_allow_blocking(gfp))
-			cond_resched();
-
+		cond_resched();
 		nr_allocated += 1U << order;
 	}
 
···
 		count = -(unsigned long) addr;
 
 	spin_lock(&vmap_area_lock);
-	va = __find_vmap_area((unsigned long)addr);
+	va = find_vmap_area_exceed_addr((unsigned long)addr);
 	if (!va)
 		goto finished;
+
+	/* no intersects with alive vmap_area */
+	if ((unsigned long)addr + count <= va->va_start)
+		goto finished;
+
 	list_for_each_entry_from(va, &vmap_area_list, list) {
 		if (!count)
 			break;

mm/vmpressure.c

···
 
 static struct vmpressure *vmpressure_parent(struct vmpressure *vmpr)
 {
-	struct cgroup_subsys_state *css = vmpressure_to_css(vmpr);
-	struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+	struct mem_cgroup *memcg = vmpressure_to_memcg(vmpr);
 
 	memcg = parent_mem_cgroup(memcg);
 	if (!memcg)
···
 void vmpressure(gfp_t gfp, struct mem_cgroup *memcg, bool tree,
 		unsigned long scanned, unsigned long reclaimed)
 {
-	struct vmpressure *vmpr = memcg_to_vmpressure(memcg);
+	struct vmpressure *vmpr;
+
+	if (mem_cgroup_disabled())
+		return;
+
+	vmpr = memcg_to_vmpressure(memcg);
 
 	/*
 	 * Here we only want to account pressure that userland is able to

mm/vmscan.c

···
 #include <linux/kthread.h>
 #include <linux/freezer.h>
 #include <linux/memcontrol.h>
+#include <linux/migrate.h>
 #include <linux/delayacct.h>
 #include <linux/sysctl.h>
 #include <linux/oom.h>
···
 
 	/* The file pages on the current node are dangerously low */
 	unsigned int file_is_tiny:1;
+
+	/* Always discard instead of demoting to lower tier memory */
+	unsigned int no_demotion:1;
 
 	/* Allocation order */
 	s8 order;
···
 	return atomic_long_add_return(nr, &shrinker->nr_deferred[nid]);
 }
 
+static bool can_demote(int nid, struct scan_control *sc)
+{
+	if (!numa_demotion_enabled)
+		return false;
+	if (sc) {
+		if (sc->no_demotion)
+			return false;
+		/* It is pointless to do demotion in memcg reclaim */
+		if (cgroup_reclaim(sc))
+			return false;
+	}
+	if (next_demotion_node(nid) == NUMA_NO_NODE)
+		return false;
+
+	return true;
+}
+
+static inline bool can_reclaim_anon_pages(struct mem_cgroup *memcg,
+					  int nid,
+					  struct scan_control *sc)
+{
+	if (memcg == NULL) {
+		/*
+		 * For non-memcg reclaim, is there
+		 * space in any swap device?
+		 */
+		if (get_nr_swap_pages() > 0)
+			return true;
+	} else {
+		/* Is the memcg below its swap limit? */
+		if (mem_cgroup_get_nr_swap_pages(memcg) > 0)
+			return true;
+	}
+
+	/*
+	 * The page can not be swapped.
+	 *
+	 * Can it be reclaimed from this node via demotion?
+	 */
+	return can_demote(nid, sc);
+}
+
 /*
  * This misses isolated pages which are not accounted for to save counters.
  * As the data only determines if reclaim or compaction continues, it is
···
 
 	nr = zone_page_state_snapshot(zone, NR_ZONE_INACTIVE_FILE) +
 		zone_page_state_snapshot(zone, NR_ZONE_ACTIVE_FILE);
-	if (get_nr_swap_pages() > 0)
+	if (can_reclaim_anon_pages(NULL, zone_to_nid(zone), NULL))
 		nr += zone_page_state_snapshot(zone, NR_ZONE_INACTIVE_ANON) +
 			zone_page_state_snapshot(zone, NR_ZONE_ACTIVE_ANON);
 
···
 void drop_slab_node(int nid)
 {
 	unsigned long freed;
+	int shift = 0;
 
 	do {
 		struct mem_cgroup *memcg = NULL;
···
 		do {
 			freed += shrink_slab(GFP_KERNEL, nid, memcg, 0);
 		} while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL);
-	} while (freed > 10);
+	} while ((freed >> shift++) > 1);
 }
 
 void drop_slab(void)
···
 static int __remove_mapping(struct address_space *mapping, struct page *page,
 			    bool reclaimed, struct mem_cgroup *target_memcg)
 {
-	unsigned long flags;
 	int refcount;
 	void *shadow = NULL;
 
 	BUG_ON(!PageLocked(page));
 	BUG_ON(mapping != page_mapping(page));
 
-	xa_lock_irqsave(&mapping->i_pages, flags);
+	xa_lock_irq(&mapping->i_pages);
 	/*
 	 * The non racy check for a busy page.
 	 *
···
 		if (reclaimed && !mapping_exiting(mapping))
 			shadow = workingset_eviction(page, target_memcg);
 		__delete_from_swap_cache(page, swap, shadow);
-		xa_unlock_irqrestore(&mapping->i_pages, flags);
+		xa_unlock_irq(&mapping->i_pages);
 		put_swap_page(page, swap);
 	} else {
 		void (*freepage)(struct page *);
···
 		    !mapping_exiting(mapping) && !dax_mapping(mapping))
 			shadow = workingset_eviction(page, target_memcg);
 		__delete_from_page_cache(page, shadow);
-		xa_unlock_irqrestore(&mapping->i_pages, flags);
+		xa_unlock_irq(&mapping->i_pages);
 
 		if (freepage != NULL)
 			freepage(page);
···
 	return 1;
 
 cannot_free:
-	xa_unlock_irqrestore(&mapping->i_pages, flags);
+	xa_unlock_irq(&mapping->i_pages);
 	return 0;
 }
 
···
 		mapping->a_ops->is_dirty_writeback(page, dirty, writeback);
 }
 
+static struct page *alloc_demote_page(struct page *page, unsigned long node)
+{
+	struct migration_target_control mtc = {
+		/*
+		 * Allocate from 'node', or fail quickly and quietly.
+		 * When this happens, 'page' will likely just be discarded
+		 * instead of migrated.
+		 */
+		.gfp_mask = (GFP_HIGHUSER_MOVABLE & ~__GFP_RECLAIM) |
+			    __GFP_THISNODE  | __GFP_NOWARN |
+			    __GFP_NOMEMALLOC | GFP_NOWAIT,
+		.nid = node
+	};
+
+	return alloc_migration_target(page, (unsigned long)&mtc);
+}
+
+/*
+ * Take pages on @demote_list and attempt to demote them to
+ * another node.  Pages which are not demoted are left on
+ * @demote_pages.
+ */
+static unsigned int demote_page_list(struct list_head *demote_pages,
+				     struct pglist_data *pgdat)
+{
+	int target_nid = next_demotion_node(pgdat->node_id);
+	unsigned int nr_succeeded;
+	int err;
+
+	if (list_empty(demote_pages))
+		return 0;
+
+	if (target_nid == NUMA_NO_NODE)
+		return 0;
+
+	/* Demotion ignores all cpuset and mempolicy settings */
+	err = migrate_pages(demote_pages, alloc_demote_page, NULL,
+			    target_nid, MIGRATE_ASYNC, MR_DEMOTION,
+			    &nr_succeeded);
+
+	if (current_is_kswapd())
+		__count_vm_events(PGDEMOTE_KSWAPD, nr_succeeded);
+	else
+		__count_vm_events(PGDEMOTE_DIRECT, nr_succeeded);
+
+	return nr_succeeded;
+}
+
 /*
  * shrink_page_list() returns the number of reclaimed pages
  */
···
 {
 	LIST_HEAD(ret_pages);
 	LIST_HEAD(free_pages);
+	LIST_HEAD(demote_pages);
 	unsigned int nr_reclaimed = 0;
 	unsigned int pgactivate = 0;
+	bool do_demote_pass;
 
 	memset(stat, 0, sizeof(*stat));
 	cond_resched();
+	do_demote_pass = can_demote(pgdat->node_id, sc);
 
+retry:
 	while (!list_empty(page_list)) {
 		struct address_space *mapping;
 		struct page *page;
···
 		case PAGEREF_RECLAIM:
 		case PAGEREF_RECLAIM_CLEAN:
 			; /* try to reclaim the page below */
+		}
+
+		/*
+		 * Before reclaiming the page, try to relocate
+		 * its contents to another node.
+		 */
+		if (do_demote_pass &&
+		    (thp_migration_supported() || !PageTransHuge(page))) {
+			list_add(&page->lru, &demote_pages);
+			unlock_page(page);
+			continue;
 		}
 
 		/*
···
 			/* follow __remove_mapping for reference */
 			if (!page_ref_freeze(page, 1))
 				goto keep_locked;
-			if (PageDirty(page)) {
-				page_ref_unfreeze(page, 1);
-				goto keep_locked;
-			}
-
+			/*
+			 * The page has only one reference left, which is
+			 * from the isolation. After the caller puts the
+			 * page back on lru and drops the reference, the
+			 * page will be freed anyway. It doesn't matter
+			 * which lru it goes. So we don't bother checking
+			 * PageDirty here.
+			 */
 			count_vm_event(PGLAZYFREED);
 			count_memcg_page_event(page, PGLAZYFREED);
 		} else if (!mapping || !__remove_mapping(mapping, page, true,
···
 		list_add(&page->lru, &ret_pages);
 		VM_BUG_ON_PAGE(PageLRU(page) || PageUnevictable(page), page);
 	}
+	/* 'page_list' is always empty here */
+
+	/* Migrate pages selected for demotion */
+	nr_reclaimed += demote_page_list(&demote_pages, pgdat);
+	/* Pages that could not be demoted are still in @demote_pages */
+	if (!list_empty(&demote_pages)) {
+		/* Pages which failed to demoted go back on @page_list for retry: */
+		list_splice_init(&demote_pages, page_list);
+		do_demote_pass = false;
+		goto retry;
+	}
 
 	pgactivate = stat->nr_activate[0] + stat->nr_activate[1];
 
···
 {
 	struct scan_control sc = {
 		.gfp_mask = GFP_KERNEL,
-		.priority = DEF_PRIORITY,
 		.may_unmap = 1,
 	};
 	struct reclaim_stat stat;
···
 	unsigned int noreclaim_flag;
 	struct scan_control sc = {
 		.gfp_mask = GFP_KERNEL,
-		.priority = DEF_PRIORITY,
 		.may_writepage = 1,
 		.may_unmap = 1,
 		.may_swap = 1,
+		.no_demotion = 1,
 	};
 
 	noreclaim_flag = memalloc_noreclaim_save();
···
 static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc,
 			   unsigned long *nr)
 {
+	struct pglist_data *pgdat = lruvec_pgdat(lruvec);
 	struct mem_cgroup *memcg = lruvec_memcg(lruvec);
 	unsigned long anon_cost, file_cost, total_cost;
 	int swappiness = mem_cgroup_swappiness(memcg);
···
 	enum lru_list lru;
 
 	/* If we have no swap space, do not bother scanning anon pages. */
-	if (!sc->may_swap || mem_cgroup_get_nr_swap_pages(memcg) <= 0) {
+	if (!sc->may_swap || !can_reclaim_anon_pages(memcg, pgdat->node_id, sc)) {
 		scan_balance = SCAN_FILE;
 		goto out;
 	}
···
 	}
 }
 
+/*
+ * Anonymous LRU management is a waste if there is
+ * ultimately no way to reclaim the memory.
+ */
+static bool can_age_anon_pages(struct pglist_data *pgdat,
+			       struct scan_control *sc)
+{
+	/* Aging the anon LRU is valuable if swap is present: */
+	if (total_swap_pages > 0)
+		return true;
+
+	/* Also valuable if anon pages can be demoted: */
+	return can_demote(pgdat->node_id, sc);
+}
+
 static void shrink_lruvec(struct lruvec *lruvec, struct scan_control *sc)
 {
 	unsigned long nr[NR_LRU_LISTS];
···
 	 * Even if we did not try to evict anon pages at all, we want to
 	 * rebalance the anon lru active/inactive ratio.
 	 */
-	if (total_swap_pages && inactive_is_low(lruvec, LRU_INACTIVE_ANON))
+	if (can_age_anon_pages(lruvec_pgdat(lruvec), sc) &&
+	    inactive_is_low(lruvec, LRU_INACTIVE_ANON))
 		shrink_active_list(SWAP_CLUSTER_MAX, lruvec,
 				   sc, LRU_ACTIVE_ANON);
 }
···
 	 */
 	pages_for_compaction = compact_gap(sc->order);
 	inactive_lru_pages = node_page_state(pgdat, NR_INACTIVE_FILE);
-	if (get_nr_swap_pages() > 0)
+	if (can_reclaim_anon_pages(NULL, pgdat->node_id, sc))
 		inactive_lru_pages += node_page_state(pgdat, NR_INACTIVE_ANON);
 
 	return inactive_lru_pages > pages_for_compaction;
···
 	target_lruvec = mem_cgroup_lruvec(sc->target_mem_cgroup, pgdat);
 
 again:
+	/*
+	 * Flush the memory cgroup stats, so that we read accurate per-memcg
+	 * lruvec stats for heuristics.
+	 */
+	mem_cgroup_flush_stats();
+
 	memset(&sc->nr, 0, sizeof(sc->nr));
 
 	nr_reclaimed = sc->nr_reclaimed;
···
 	 * blocked waiting on the same lock. Instead, throttle for up to a
 	 * second before continuing.
 	 */
-	if (!(gfp_mask & __GFP_FS)) {
+	if (!(gfp_mask & __GFP_FS))
 		wait_event_interruptible_timeout(pgdat->pfmemalloc_wait,
 			allow_direct_reclaim(pgdat), HZ);
+	else
+		/* Throttle until kswapd wakes the process */
+		wait_event_killable(zone->zone_pgdat->pfmemalloc_wait,
+			allow_direct_reclaim(pgdat));
 
-		goto check_pending;
-	}
-
-	/* Throttle until kswapd wakes the process */
-	wait_event_killable(zone->zone_pgdat->pfmemalloc_wait,
-		allow_direct_reclaim(pgdat));
-
-check_pending:
 	if (fatal_signal_pending(current))
 		return true;
 
···
 	struct mem_cgroup *memcg;
 	struct lruvec *lruvec;
 
-	if (!total_swap_pages)
+	if (!can_age_anon_pages(pgdat, sc))
 		return;
 
 	lruvec = mem_cgroup_lruvec(NULL, pgdat);
···
 
 	set_task_reclaim_state(current, &sc.reclaim_state);
 	psi_memstall_enter(&pflags);
-	__fs_reclaim_acquire();
+	__fs_reclaim_acquire(_THIS_IP_);
 
 	count_vm_event(PAGEOUTRUN);
 
···
 			wake_up_all(&pgdat->pfmemalloc_wait);
 
 		/* Check if kswapd should be suspending */
-		__fs_reclaim_release();
+		__fs_reclaim_release(_THIS_IP_);
 		ret = try_to_freeze();
-		__fs_reclaim_acquire();
+		__fs_reclaim_acquire(_THIS_IP_);
 		if (ret || kthread_should_stop())
 			break;
 
···
 	}
 
 	snapshot_refaults(NULL, pgdat);
-	__fs_reclaim_release();
+	__fs_reclaim_release(_THIS_IP_);
 	psi_memstall_leave(&pflags);
 	set_task_reclaim_state(current, NULL);
 
···
  * This kswapd start function will be called by init and node-hot-add.
  * On node-hot-add, kswapd will moved to proper cpus if cpus are hot-added.
  */
-int kswapd_run(int nid)
+void kswapd_run(int nid)
 {
 	pg_data_t *pgdat = NODE_DATA(nid);
-	int ret = 0;
 
 	if (pgdat->kswapd)
-		return 0;
+		return;
 
 	pgdat->kswapd = kthread_run(kswapd, pgdat, "kswapd%d", nid);
 	if (IS_ERR(pgdat->kswapd)) {
 		/* failure at boot is fatal */
 		BUG_ON(system_state < SYSTEM_RUNNING);
 		pr_err("Failed to start kswapd on node %d\n", nid);
-		ret = PTR_ERR(pgdat->kswapd);
 		pgdat->kswapd = NULL;
 	}
-	return ret;
 }
 
 /*

mm/vmstat.c

···
 	 *
 	 * Some sample thresholds:
 	 *
-	 * Threshold	Processors	(fls)	Zonesize	fls(mem+1)
+	 * Threshold	Processors	(fls)	Zonesize	fls(mem)+1
 	 * ------------------------------------------------------------------
 	 * 8		1		1	0.9-1 GB	4
 	 * 16		2		2	0.9-1 GB	4
···
 	"pgreuse",
 	"pgsteal_kswapd",
 	"pgsteal_direct",
+	"pgdemote_kswapd",
+	"pgdemote_direct",
 	"pgscan_kswapd",
 	"pgscan_direct",
 	"pgscan_direct_throttle",
···
 }
 
 /* Print out the free pages at each order for each migatetype */
-static int pagetypeinfo_showfree(struct seq_file *m, void *arg)
+static void pagetypeinfo_showfree(struct seq_file *m, void *arg)
 {
 	int order;
 	pg_data_t *pgdat = (pg_data_t *)arg;
···
 	seq_putc(m, '\n');
 
 	walk_zones_in_node(m, pgdat, true, false, pagetypeinfo_showfree_print);
-
-	return 0;
 }
 
 static void pagetypeinfo_showblockcount_print(struct seq_file *m,
···
 }
 
 /* Print out the number of pageblocks for each migratetype */
-static int pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
+static void pagetypeinfo_showblockcount(struct seq_file *m, void *arg)
 {
 	int mtype;
 	pg_data_t *pgdat = (pg_data_t *)arg;
···
 	seq_putc(m, '\n');
 	walk_zones_in_node(m, pgdat, true, false,
 		pagetypeinfo_showblockcount_print);
-
-	return 0;
 }
 
 /*
···
 }
 
 /*
- * Switch off vmstat processing and then fold all the remaining differentials
- * until the diffs stay at zero. The function is used by NOHZ and can only be
- * invoked when tick processing is not active.
- */
-/*
  * Check if the diffs for a certain cpu indicate that
  * an update is needed.
  */
···
 		/*
 		 * The fast way of checking if there are any vmstat diffs.
 		 */
-		if (memchr_inv(pzstats->vm_stat_diff, 0, NR_VM_ZONE_STAT_ITEMS *
-			       sizeof(pzstats->vm_stat_diff[0])))
+		if (memchr_inv(pzstats->vm_stat_diff, 0, sizeof(pzstats->vm_stat_diff)))
 			return true;
 
 		if (last_pgdat == zone->zone_pgdat)
 			continue;
 		last_pgdat = zone->zone_pgdat;
 		n = per_cpu_ptr(zone->zone_pgdat->per_cpu_nodestats, cpu);
-		if (memchr_inv(n->vm_node_stat_diff, 0, NR_VM_NODE_STAT_ITEMS *
-			       sizeof(n->vm_node_stat_diff[0])))
-		    return true;
+		if (memchr_inv(n->vm_node_stat_diff, 0, sizeof(n->vm_node_stat_diff)))
+			return true;
 	}
 	return false;
 }

security/tomoyo/domain.c

···
 		      struct tomoyo_page_dump *dump)
 {
 	struct page *page;
+#ifdef CONFIG_MMU
+	int ret;
+#endif
 
 	/* dump->data is released by tomoyo_find_next_domain(). */
 	if (!dump->data) {
···
 	/*
 	 * This is called at execve() time in order to dig around
 	 * in the argv/environment of the new proceess
-	 * (represented by bprm).  'current' is the process doing
-	 * the execve().
+	 * (represented by bprm).
 	 */
-	if (get_user_pages_remote(bprm->mm, pos, 1,
-				FOLL_FORCE, &page, NULL, NULL) <= 0)
+	mmap_read_lock(bprm->mm);
+	ret = get_user_pages_remote(bprm->mm, pos, 1,
+				    FOLL_FORCE, &page, NULL, NULL);
+	mmap_read_unlock(bprm->mm);
+	if (ret <= 0)
 		return false;
 #else
 	page = bprm->page[pos / PAGE_SIZE];

tools/testing/scatterlist/linux/mm.h

···
 #define kmemleak_free(a)
 
 #define PageSlab(p) (0)
-#define flush_kernel_dcache_page(p)
 
 #define MAX_ERRNO	4095
 

tools/testing/selftests/vm/.gitignore

···
 memfd_secret
 local_config.*
 split_huge_page_test
+ksm_tests

tools/testing/selftests/vm/Makefile

···
 TEST_GEN_FILES += transhuge-stress
 TEST_GEN_FILES += userfaultfd
 TEST_GEN_FILES += split_huge_page_test
+TEST_GEN_FILES += ksm_tests
 
 ifeq ($(MACHINE),x86_64)
 CAN_BUILD_I386 := $(shell ./../x86/check_cc.sh $(CC) ../x86/trivial_32bit_program.c -m32)
···
 
 # HMM_EXTRA_LIBS may get set in local_config.mk, or it may be left empty.
 $(OUTPUT)/hmm-tests: LDLIBS += $(HMM_EXTRA_LIBS)
+
+$(OUTPUT)/ksm_tests: LDLIBS += -lnuma
 
 local_config.mk local_config.h: check_config.sh
 	/bin/sh ./check_config.sh $(CC)

tools/testing/selftests/vm/charge_reserved_hugetlb.sh

···
 #!/bin/sh
 # SPDX-License-Identifier: GPL-2.0
 
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+
 set -e
 
 if [[ $(id -u) -ne 0 ]]; then
   echo "This test must be run as root. Skipping..."
-  exit 0
+  exit $ksft_skip
 fi
 
 fault_limit_file=limit_in_bytes

tools/testing/selftests/vm/hugetlb_reparenting_test.sh

···
 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0
 
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+
 set -e
 
 if [[ $(id -u) -ne 0 ]]; then
   echo "This test must be run as root. Skipping..."
-  exit 0
+  exit $ksft_skip
 fi
 
 usage_file=usage_in_bytes

tools/testing/selftests/vm/ksm_tests.c

···
+// SPDX-License-Identifier: GPL-2.0
+
+#include <sys/mman.h>
+#include <stdbool.h>
+#include <time.h>
+#include <string.h>
+#include <numa.h>
+
+#include "../kselftest.h"
+#include "../../../../include/vdso/time64.h"
+
+#define KSM_SYSFS_PATH "/sys/kernel/mm/ksm/"
+#define KSM_FP(s) (KSM_SYSFS_PATH s)
+#define KSM_SCAN_LIMIT_SEC_DEFAULT 120
+#define KSM_PAGE_COUNT_DEFAULT 10l
+#define KSM_PROT_STR_DEFAULT "rw"
+#define KSM_USE_ZERO_PAGES_DEFAULT false
+#define KSM_MERGE_ACROSS_NODES_DEFAULT true
+#define MB (1ul << 20)
+
+struct ksm_sysfs {
+	unsigned long max_page_sharing;
+	unsigned long merge_across_nodes;
+	unsigned long pages_to_scan;
+	unsigned long run;
+	unsigned long sleep_millisecs;
+	unsigned long stable_node_chains_prune_millisecs;
+	unsigned long use_zero_pages;
+};
+
+enum ksm_test_name {
+	CHECK_KSM_MERGE,
+	CHECK_KSM_UNMERGE,
+	CHECK_KSM_ZERO_PAGE_MERGE,
+	CHECK_KSM_NUMA_MERGE,
+	KSM_MERGE_TIME,
+	KSM_COW_TIME
+};
+
+static int ksm_write_sysfs(const char *file_path, unsigned long val)
+{
+	FILE *f = fopen(file_path, "w");
+
+	if (!f) {
+		fprintf(stderr, "f %s\n", file_path);
+		perror("fopen");
+		return 1;
+	}
+	if (fprintf(f, "%lu", val) < 0) {
+		perror("fprintf");
+		return 1;
+	}
+	fclose(f);
+
+	return 0;
+}
+
+static int ksm_read_sysfs(const char *file_path, unsigned long *val)
+{
+	FILE *f = fopen(file_path, "r");
+
+	if (!f) {
+		fprintf(stderr, "f %s\n", file_path);
+		perror("fopen");
+		return 1;
+	}
+	if (fscanf(f, "%lu", val) != 1) {
+		perror("fscanf");
+		return 1;
+	}
+	fclose(f);
+
+	return 0;
+}
+
+static int str_to_prot(char *prot_str)
+{
+	int prot = 0;
+
+	if ((strchr(prot_str, 'r')) != NULL)
+		prot |= PROT_READ;
+	if ((strchr(prot_str, 'w')) != NULL)
+		prot |= PROT_WRITE;
+	if ((strchr(prot_str, 'x')) != NULL)
+		prot |= PROT_EXEC;
+
+	return prot;
+}
+
+static void print_help(void)
+{
+	printf("usage: ksm_tests [-h] <test type> [-a prot] [-p page_count] [-l timeout]\n"
+	       "[-z use_zero_pages] [-m merge_across_nodes] [-s size]\n");
+
+	printf("Supported <test type>:\n"
+	       " -M (page merging)\n"
+	       " -Z (zero pages merging)\n"
+	       " -N (merging of pages in different NUMA nodes)\n"
+	       " -U (page unmerging)\n"
+	       " -P evaluate merging time and speed.\n"
+	       "    For this test, the size of duplicated memory area (in MiB)\n"
+	       "    must be provided using -s option\n"
+	       " -C evaluate the time required to break COW of merged pages.\n\n");
+
+	printf(" -a: specify the access protections of pages.\n"
+	       "     <prot> must be of the form [rwx].\n"
+	       "     Default: %s\n", KSM_PROT_STR_DEFAULT);
+	printf(" -p: specify the number of pages to test.\n"
+	       "     Default: %ld\n", KSM_PAGE_COUNT_DEFAULT);
+	printf(" -l: limit the maximum running time (in seconds) for a test.\n"
+	       "     Default: %d seconds\n", KSM_SCAN_LIMIT_SEC_DEFAULT);
+	printf(" -z: change use_zero_pages tunable\n"
+	       "     Default: %d\n", KSM_USE_ZERO_PAGES_DEFAULT);
+	printf(" -m: change merge_across_nodes tunable\n"
+	       "     Default: %d\n", KSM_MERGE_ACROSS_NODES_DEFAULT);
+	printf(" -s: the size of duplicated memory area (in MiB)\n");
+
+	exit(0);
+}
+
+static void  *allocate_memory(void *ptr, int prot, int mapping, char data, size_t map_size)
+{
+	void *map_ptr = mmap(ptr, map_size, PROT_WRITE, mapping, -1, 0);
+
+	if (!map_ptr) {
+		perror("mmap");
+		return NULL;
+	}
+	memset(map_ptr, data, map_size);
+	if (mprotect(map_ptr, map_size, prot)) {
+		perror("mprotect");
+		munmap(map_ptr, map_size);
+		return NULL;
+	}
+
+	return map_ptr;
+}
+
+static int ksm_do_scan(int scan_count, struct timespec start_time, int timeout)
+{
+	struct timespec cur_time;
+	unsigned long cur_scan, init_scan;
+
+	if (ksm_read_sysfs(KSM_FP("full_scans"), &init_scan))
+		return 1;
+	cur_scan = init_scan;
+
+	while (cur_scan < init_scan + scan_count) {
+		if (ksm_read_sysfs(KSM_FP("full_scans"), &cur_scan))
+			return 1;
+		if (clock_gettime(CLOCK_MONOTONIC_RAW, &cur_time)) {
+			perror("clock_gettime");
+			return 1;
+		}
+		if ((cur_time.tv_sec - start_time.tv_sec) > timeout) {
+			printf("Scan time limit exceeded\n");
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+static int ksm_merge_pages(void *addr, size_t size, struct timespec start_time, int timeout)
+{
+	if (madvise(addr, size, MADV_MERGEABLE)) {
+		perror("madvise");
+		return 1;
+	}
+	if (ksm_write_sysfs(KSM_FP("run"), 1))
+		return 1;
+
+	/* Since merging occurs only after 2 scans, make sure to get at least 2 full scans */
+	if (ksm_do_scan(2, start_time, timeout))
+		return 1;
+
+	return 0;
+}
+
+static bool assert_ksm_pages_count(long dupl_page_count)
+{
+	unsigned long max_page_sharing, pages_sharing, pages_shared;
+
+	if (ksm_read_sysfs(KSM_FP("pages_shared"), &pages_shared) ||
+	    ksm_read_sysfs(KSM_FP("pages_sharing"), &pages_sharing) ||
+	    ksm_read_sysfs(KSM_FP("max_page_sharing"), &max_page_sharing))
+		return false;
+
+	/*
+	 * Since there must be at least 2 pages for merging and 1 page can be
+	 * shared with the limited number of pages (max_page_sharing), sometimes
+	 * there are 'leftover' pages that cannot be merged. For example, if there
+	 * are 11 pages and max_page_sharing = 10, then only 10 pages will be
+	 * merged and the 11th page won't be affected. As a result, when the number
+	 * of duplicate pages is divided by max_page_sharing and the remainder is 1,
+	 * pages_shared and pages_sharing values will be equal between dupl_page_count
+	 * and dupl_page_count - 1.
+	 */
+	if (dupl_page_count % max_page_sharing == 1 || dupl_page_count % max_page_sharing == 0) {
+		if (pages_shared == dupl_page_count / max_page_sharing &&
+		    pages_sharing == pages_shared * (max_page_sharing - 1))
+			return true;
+	} else {
+		if (pages_shared == (dupl_page_count / max_page_sharing + 1) &&
+		    pages_sharing == dupl_page_count - pages_shared)
+			return true;
+	}
+
+	return false;
+}
+
+static int ksm_save_def(struct ksm_sysfs *ksm_sysfs)
+{
+	if (ksm_read_sysfs(KSM_FP("max_page_sharing"), &ksm_sysfs->max_page_sharing) ||
+	    ksm_read_sysfs(KSM_FP("merge_across_nodes"), &ksm_sysfs->merge_across_nodes) ||
+	    ksm_read_sysfs(KSM_FP("sleep_millisecs"), &ksm_sysfs->sleep_millisecs) ||
+	    ksm_read_sysfs(KSM_FP("pages_to_scan"), &ksm_sysfs->pages_to_scan) ||
+	    ksm_read_sysfs(KSM_FP("run"), &ksm_sysfs->run) ||
+	    ksm_read_sysfs(KSM_FP("stable_node_chains_prune_millisecs"),
+			   &ksm_sysfs->stable_node_chains_prune_millisecs) ||
+	    ksm_read_sysfs(KSM_FP("use_zero_pages"), &ksm_sysfs->use_zero_pages))
+		return 1;
+
+	return 0;
+}
+
+static int ksm_restore(struct ksm_sysfs *ksm_sysfs)
+{
+	if (ksm_write_sysfs(KSM_FP("max_page_sharing"), ksm_sysfs->max_page_sharing) ||
+	    ksm_write_sysfs(KSM_FP("merge_across_nodes"), ksm_sysfs->merge_across_nodes) ||
+	    ksm_write_sysfs(KSM_FP("pages_to_scan"), ksm_sysfs->pages_to_scan) ||
+	    ksm_write_sysfs(KSM_FP("run"), ksm_sysfs->run) ||
+	    ksm_write_sysfs(KSM_FP("sleep_millisecs"), ksm_sysfs->sleep_millisecs) ||
+	    ksm_write_sysfs(KSM_FP("stable_node_chains_prune_millisecs"),
+			    ksm_sysfs->stable_node_chains_prune_millisecs) ||
+	    ksm_write_sysfs(KSM_FP("use_zero_pages"), ksm_sysfs->use_zero_pages))
+		return 1;
+
+	return 0;
+}
+
+static int check_ksm_merge(int mapping, int prot, long page_count, int timeout, size_t page_size)
+{
+	void *map_ptr;
+	struct timespec start_time;
+
+	if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
+		perror("clock_gettime");
+		return KSFT_FAIL;
+	}
+
+	/* fill pages with the same data and merge them */
+	map_ptr = allocate_memory(NULL, prot, mapping, '*', page_size * page_count);
+	if (!map_ptr)
+		return KSFT_FAIL;
+
+	if (ksm_merge_pages(map_ptr, page_size * page_count, start_time, timeout))
+		goto err_out;
+
+	/* verify that the right number of pages are merged */
+	if (assert_ksm_pages_count(page_count)) {
+		printf("OK\n");
+		munmap(map_ptr, page_size * page_count);
+		return KSFT_PASS;
+	}
+
+err_out:
+	printf("Not OK\n");
+	munmap(map_ptr, page_size * page_count);
+	return KSFT_FAIL;
+}
+
+static int check_ksm_unmerge(int mapping, int prot, int timeout, size_t page_size)
+{
+	void *map_ptr;
+	struct timespec start_time;
+	int page_count = 2;
+
+	if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
+		perror("clock_gettime");
+		return KSFT_FAIL;
+	}
+
+	/* fill pages with the same data and merge them */
+	map_ptr = allocate_memory(NULL, prot, mapping, '*', page_size * page_count);
+	if (!map_ptr)
+		return KSFT_FAIL;
+
+	if (ksm_merge_pages(map_ptr, page_size * page_count, start_time, timeout))
+		goto err_out;
+
+	/* change 1 byte in each of the 2 pages -- KSM must automatically unmerge them */
+	memset(map_ptr, '-', 1);
+	memset(map_ptr + page_size, '+', 1);
+
+	/* get at least 1 scan, so KSM can detect that the pages were modified */
+	if (ksm_do_scan(1, start_time, timeout))
+		goto err_out;
+
+	/* check that unmerging was successful and 0 pages are currently merged */
+	if (assert_ksm_pages_count(0)) {
+		printf("OK\n");
+		munmap(map_ptr, page_size * page_count);
+		return KSFT_PASS;
+	}
+
+err_out:
+	printf("Not OK\n");
+	munmap(map_ptr, page_size * page_count);
+	return KSFT_FAIL;
+}
+
+static int check_ksm_zero_page_merge(int mapping, int prot, long page_count, int timeout,
+				     bool use_zero_pages, size_t page_size)
+{
+	void *map_ptr;
+	struct timespec start_time;
+
+	if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
+		perror("clock_gettime");
+		return KSFT_FAIL;
+	}
+
+	if (ksm_write_sysfs(KSM_FP("use_zero_pages"), use_zero_pages))
+		return KSFT_FAIL;
+
+	/* fill pages with zero and try to merge them */
+	map_ptr = allocate_memory(NULL, prot, mapping, 0, page_size * page_count);
+	if (!map_ptr)
+		return KSFT_FAIL;
+
+	if (ksm_merge_pages(map_ptr, page_size * page_count, start_time, timeout))
+		goto err_out;
+
+       /*
+	* verify that the right number of pages are merged:
+	* 1) if use_zero_pages is set to 1, empty pages are merged
+	*    with the kernel zero page instead of with each other;
+	* 2) if use_zero_pages is set to 0, empty pages are not treated specially
+	*    and merged as usual.
+	*/
+	if (use_zero_pages && !assert_ksm_pages_count(0))
+		goto err_out;
+	else if (!use_zero_pages && !assert_ksm_pages_count(page_count))
+		goto err_out;
+
+	printf("OK\n");
+	munmap(map_ptr, page_size * page_count);
+	return KSFT_PASS;
+
+err_out:
+	printf("Not OK\n");
+	munmap(map_ptr, page_size * page_count);
+	return KSFT_FAIL;
+}
+
+static int check_ksm_numa_merge(int mapping, int prot, int timeout, bool merge_across_nodes,
+				size_t page_size)
+{
+	void *numa1_map_ptr, *numa2_map_ptr;
+	struct timespec start_time;
+	int page_count = 2;
+
+	if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
+		perror("clock_gettime");
+		return KSFT_FAIL;
+	}
+
+	if (numa_available() < 0) {
+		perror("NUMA support not enabled");
+		return KSFT_SKIP;
+	}
+	if (numa_max_node() < 1) {
+		printf("At least 2 NUMA nodes must be available\n");
+		return KSFT_SKIP;
+	}
+	if (ksm_write_sysfs(KSM_FP("merge_across_nodes"), merge_across_nodes))
+		return KSFT_FAIL;
+
+	/* allocate 2 pages in 2 different NUMA nodes and fill them with the same data */
+	numa1_map_ptr = numa_alloc_onnode(page_size, 0);
+	numa2_map_ptr = numa_alloc_onnode(page_size, 1);
+	if (!numa1_map_ptr || !numa2_map_ptr) {
+		perror("numa_alloc_onnode");
+		return KSFT_FAIL;
+	}
+
+	memset(numa1_map_ptr, '*', page_size);
+	memset(numa2_map_ptr, '*', page_size);
+
+	/* try to merge the pages */
+	if (ksm_merge_pages(numa1_map_ptr, page_size, start_time, timeout) ||
+	    ksm_merge_pages(numa2_map_ptr, page_size, start_time, timeout))
+		goto err_out;
+
+       /*
+	* verify that the right number of pages are merged:
+	* 1) if merge_across_nodes was enabled, 2 duplicate pages will be merged;
+	* 2) if merge_across_nodes = 0, there must be 0 merged pages, since there is
+	*    only 1 unique page in each node and they can't be shared.
+	*/
+	if (merge_across_nodes && !assert_ksm_pages_count(page_count))
+		goto err_out;
+	else if (!merge_across_nodes && !assert_ksm_pages_count(0))
+		goto err_out;
+
+	numa_free(numa1_map_ptr, page_size);
+	numa_free(numa2_map_ptr, page_size);
+	printf("OK\n");
+	return KSFT_PASS;
+
+err_out:
+	numa_free(numa1_map_ptr, page_size);
+	numa_free(numa2_map_ptr, page_size);
+	printf("Not OK\n");
+	return KSFT_FAIL;
+}
+
+static int ksm_merge_time(int mapping, int prot, int timeout, size_t map_size)
+{
+	void *map_ptr;
+	struct timespec start_time, end_time;
+	unsigned long scan_time_ns;
+
+	map_size *= MB;
+
+	map_ptr = allocate_memory(NULL, prot, mapping, '*', map_size);
+	if (!map_ptr)
+		return KSFT_FAIL;
+
+	if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
+		perror("clock_gettime");
+		goto err_out;
+	}
+	if (ksm_merge_pages(map_ptr, map_size, start_time, timeout))
+		goto err_out;
+	if (clock_gettime(CLOCK_MONOTONIC_RAW, &end_time)) {
+		perror("clock_gettime");
+		goto err_out;
+	}
+
+	scan_time_ns = (end_time.tv_sec - start_time.tv_sec) * NSEC_PER_SEC +
+		       (end_time.tv_nsec - start_time.tv_nsec);
+
+	printf("Total size:    %lu MiB\n", map_size / MB);
+	printf("Total time:    %ld.%09ld s\n", scan_time_ns / NSEC_PER_SEC,
+	       scan_time_ns % NSEC_PER_SEC);
+	printf("Average speed:  %.3f MiB/s\n", (map_size / MB) /
+					       ((double)scan_time_ns / NSEC_PER_SEC));
+
+	munmap(map_ptr, map_size);
+	return KSFT_PASS;
+
+err_out:
+	printf("Not OK\n");
+	munmap(map_ptr, map_size);
+	return KSFT_FAIL;
+}
+
+static int ksm_cow_time(int mapping, int prot, int timeout, size_t page_size)
+{
+	void *map_ptr;
+	struct timespec start_time, end_time;
+	unsigned long cow_time_ns;
+
+	/* page_count must be less than 2*page_size */
+	size_t page_count = 4000;
+
+	map_ptr = allocate_memory(NULL, prot, mapping, '*', page_size * page_count);
+	if (!map_ptr)
+		return KSFT_FAIL;
+
+	if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
+		perror("clock_gettime");
+		return KSFT_FAIL;
+	}
+	for (size_t i = 0; i < page_count - 1; i = i + 2)
+		memset(map_ptr + page_size * i, '-', 1);
+	if (clock_gettime(CLOCK_MONOTONIC_RAW, &end_time)) {
+		perror("clock_gettime");
+		return KSFT_FAIL;
+	}
+
+	cow_time_ns = (end_time.tv_sec - start_time.tv_sec) * NSEC_PER_SEC +
+		       (end_time.tv_nsec - start_time.tv_nsec);
+
+	printf("Total size:    %lu MiB\n\n", (page_size * page_count) / MB);
+	printf("Not merged pages:\n");
+	printf("Total time:     %ld.%09ld s\n", cow_time_ns / NSEC_PER_SEC,
+	       cow_time_ns % NSEC_PER_SEC);
+	printf("Average speed:  %.3f MiB/s\n\n", ((page_size * (page_count / 2)) / MB) /
+					       ((double)cow_time_ns / NSEC_PER_SEC));
+
+	/* Create 2000 pairs of duplicate pages */
+	for (size_t i = 0; i < page_count - 1; i = i + 2) {
+		memset(map_ptr + page_size * i, '+', i / 2 + 1);
+		memset(map_ptr + page_size * (i + 1), '+', i / 2 + 1);
+	}
+	if (ksm_merge_pages(map_ptr, page_size * page_count, start_time, timeout))
+		goto err_out;
+
+	if (clock_gettime(CLOCK_MONOTONIC_RAW, &start_time)) {
+		perror("clock_gettime");
+		goto err_out;
+	}
+	for (size_t i = 0; i < page_count - 1; i = i + 2)
+		memset(map_ptr + page_size * i, '-', 1);
+	if (clock_gettime(CLOCK_MONOTONIC_RAW, &end_time)) {
+		perror("clock_gettime");
+		goto err_out;
+	}
+
+	cow_time_ns = (end_time.tv_sec - start_time.tv_sec) * NSEC_PER_SEC +
+		       (end_time.tv_nsec - start_time.tv_nsec);
+
+	printf("Merged pages:\n");
+	printf("Total time:     %ld.%09ld s\n", cow_time_ns / NSEC_PER_SEC,
+	       cow_time_ns % NSEC_PER_SEC);
+	printf("Average speed:  %.3f MiB/s\n", ((page_size * (page_count / 2)) / MB) /
+					       ((double)cow_time_ns / NSEC_PER_SEC));
+
+	munmap(map_ptr, page_size * page_count);
+	return KSFT_PASS;
+
+err_out:
+	printf("Not OK\n");
+	munmap(map_ptr, page_size * page_count);
+	return KSFT_FAIL;
+}
+
+int main(int argc, char *argv[])
+{
+	int ret, opt;
+	int prot = 0;
+	int ksm_scan_limit_sec = KSM_SCAN_LIMIT_SEC_DEFAULT;
+	long page_count = KSM_PAGE_COUNT_DEFAULT;
+	size_t page_size = sysconf(_SC_PAGESIZE);
+	struct ksm_sysfs ksm_sysfs_old;
+	int test_name = CHECK_KSM_MERGE;
+	bool use_zero_pages = KSM_USE_ZERO_PAGES_DEFAULT;
+	bool merge_across_nodes = KSM_MERGE_ACROSS_NODES_DEFAULT;
+	long size_MB = 0;
+
+	while ((opt = getopt(argc, argv, "ha:p:l:z:m:s:MUZNPC")) != -1) {
+		switch (opt) {
+		case 'a':
+			prot = str_to_prot(optarg);
+			break;
+		case 'p':
+			page_count = atol(optarg);
+			if (page_count <= 0) {
+				printf("The number of pages must be greater than 0\n");
+				return KSFT_FAIL;
+			}
+			break;
+		case 'l':
+			ksm_scan_limit_sec = atoi(optarg);
+			if (ksm_scan_limit_sec <= 0) {
+				printf("Timeout value must be greater than 0\n");
+				return KSFT_FAIL;
+			}
+			break;
+		case 'h':
+			print_help();
+			break;
+		case 'z':
+			if (strcmp(optarg, "0") == 0)
+				use_zero_pages = 0;
+			else
+				use_zero_pages = 1;
+			break;
+		case 'm':
+			if (strcmp(optarg, "0") == 0)
+				merge_across_nodes = 0;
+			else
+				merge_across_nodes = 1;
+			break;
+		case 's':
+			size_MB = atoi(optarg);
+			if (size_MB <= 0) {
+				printf("Size must be greater than 0\n");
+				return KSFT_FAIL;
+			}
+		case 'M':
+			break;
+		case 'U':
+			test_name = CHECK_KSM_UNMERGE;
+			break;
+		case 'Z':
+			test_name = CHECK_KSM_ZERO_PAGE_MERGE;
+			break;
+		case 'N':
+			test_name = CHECK_KSM_NUMA_MERGE;
+			break;
+		case 'P':
+			test_name = KSM_MERGE_TIME;
+			break;
+		case 'C':
+			test_name = KSM_COW_TIME;
+			break;
+		default:
+			return KSFT_FAIL;
+		}
+	}
+
+	if (prot == 0)
+		prot = str_to_prot(KSM_PROT_STR_DEFAULT);
+
+	if (access(KSM_SYSFS_PATH, F_OK)) {
+		printf("Config KSM not enabled\n");
+		return KSFT_SKIP;
+	}
+
+	if (ksm_save_def(&ksm_sysfs_old)) {
+		printf("Cannot save default tunables\n");
+		return KSFT_FAIL;
+	}
+
+	if (ksm_write_sysfs(KSM_FP("run"), 2) ||
+	    ksm_write_sysfs(KSM_FP("sleep_millisecs"), 0) ||
+	    ksm_write_sysfs(KSM_FP("merge_across_nodes"), 1) ||
+	    ksm_write_sysfs(KSM_FP("pages_to_scan"), page_count))
+		return KSFT_FAIL;
+
+	switch (test_name) {
+	case CHECK_KSM_MERGE:
+		ret = check_ksm_merge(MAP_PRIVATE | MAP_ANONYMOUS, prot, page_count,
+				      ksm_scan_limit_sec, page_size);
+		break;
+	case CHECK_KSM_UNMERGE:
+		ret = check_ksm_unmerge(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec,
+					page_size);
+		break;
+	case CHECK_KSM_ZERO_PAGE_MERGE:
+		ret = check_ksm_zero_page_merge(MAP_PRIVATE | MAP_ANONYMOUS, prot, page_count,
+						ksm_scan_limit_sec, use_zero_pages, page_size);
+		break;
+	case CHECK_KSM_NUMA_MERGE:
+		ret = check_ksm_numa_merge(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec,
+					   merge_across_nodes, page_size);
+		break;
+	case KSM_MERGE_TIME:
+		if (size_MB == 0) {
+			printf("Option '-s' is required.\n");
+			return KSFT_FAIL;
+		}
+		ret = ksm_merge_time(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec,
+				     size_MB);
+		break;
+	case KSM_COW_TIME:
+		ret = ksm_cow_time(MAP_PRIVATE | MAP_ANONYMOUS, prot, ksm_scan_limit_sec,
+				   page_size);
+		break;
+	}
+
+	if (ksm_restore(&ksm_sysfs_old)) {
+		printf("Cannot restore default tunables\n");
+		return KSFT_FAIL;
+	}
+
+	return ret;
+}

tools/testing/selftests/vm/mlock-random-test.c

···
 		}
 	}
 
-	perror("cann't parse VmLck in /proc/self/status\n");
+	perror("cannot parse VmLck in /proc/self/status\n");
 	fclose(f);
 	return -1;
 }

tools/testing/selftests/vm/run_vmtests.sh

···
 	exitcode=1
 fi
 
+echo "-------------------------------------------------------"
+echo "running KSM MADV_MERGEABLE test with 10 identical pages"
+echo "-------------------------------------------------------"
+./ksm_tests -M -p 10
+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
+
+echo "------------------------"
+echo "running KSM unmerge test"
+echo "------------------------"
+./ksm_tests -U
+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
+
+echo "----------------------------------------------------------"
+echo "running KSM test with 10 zero pages and use_zero_pages = 0"
+echo "----------------------------------------------------------"
+./ksm_tests -Z -p 10 -z 0
+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
+
+echo "----------------------------------------------------------"
+echo "running KSM test with 10 zero pages and use_zero_pages = 1"
+echo "----------------------------------------------------------"
+./ksm_tests -Z -p 10 -z 1
+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
+
+echo "-------------------------------------------------------------"
+echo "running KSM test with 2 NUMA nodes and merge_across_nodes = 1"
+echo "-------------------------------------------------------------"
+./ksm_tests -N -m 1
+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
+
+echo "-------------------------------------------------------------"
+echo "running KSM test with 2 NUMA nodes and merge_across_nodes = 0"
+echo "-------------------------------------------------------------"
+./ksm_tests -N -m 0
+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
 
 exit $exitcode

tools/testing/selftests/vm/userfaultfd.c

···
 	}
 }
 
+static void wake_range(int ufd, unsigned long addr, unsigned long len)
+{
+	struct uffdio_range uffdio_wake;
+
+	uffdio_wake.start = addr;
+	uffdio_wake.len = len;
+
+	if (ioctl(ufd, UFFDIO_WAKE, &uffdio_wake))
+		fprintf(stderr, "error waking %lu\n",
+			addr), exit(1);
+}
+
 static int __copy_page(int ufd, unsigned long offset, bool retry)
 {
 	struct uffdio_copy uffdio_copy;
···
 		if (uffdio_copy.copy != -EEXIST)
 			err("UFFDIO_COPY error: %"PRId64,
 			    (int64_t)uffdio_copy.copy);
+		wake_range(ufd, uffdio_copy.dst, page_size);
 	} else if (uffdio_copy.copy != page_size) {
 		err("UFFDIO_COPY error: %"PRId64, (int64_t)uffdio_copy.copy);
 	} else {