mm/page_isolation: remove migratetype parameter from more functions

migratetype is no longer overwritten during pageblock isolation,
start_isolate_page_range(), has_unmovable_pages(), and
set_migratetype_isolate() no longer need which migratetype to restore
during isolation failure.

For has_unmoable_pages(), it needs to know if the isolation is for CMA
allocation, so adding PB_ISOLATE_MODE_CMA_ALLOC provide the information.
At the same time change isolation flags to enum pb_isolate_mode
(PB_ISOLATE_MODE_MEM_OFFLINE, PB_ISOLATE_MODE_CMA_ALLOC,
PB_ISOLATE_MODE_OTHER). Remove REPORT_FAILURE and check
PB_ISOLATE_MODE_MEM_OFFLINE, since only PB_ISOLATE_MODE_MEM_OFFLINE
reports isolation failures.

alloc_contig_range() no longer needs migratetype. Replace it with a newly
defined acr_flags_t to tell if an allocation is for CMA. So does
__alloc_contig_migrate_range(). Add ACR_FLAGS_NONE (set to 0) to indicate
ordinary allocations.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Zi Yan <[e-mail]>
Reviewed-by: Vlastimil Babka <[e-mail]>
Acked-by: David Hildenbrand <[e-mail]>
Cc: Baolin Wang <[e-mail]>
Cc: Brendan Jackman <[e-mail]>
Cc: Johannes Weiner <[e-mail]>
Cc: Kirill A. Shuemov <[e-mail]>
Cc: Mel Gorman <[e-mail]>
Cc: Michal Hocko <[e-mail]>
Cc: Oscar Salvador <[e-mail]>
Cc: Richard Chang <[e-mail]>
Cc: Suren Baghdasaryan <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

drivers/virtio/virtio_mem.c

···
 		if (atomic_read(&vm->config_changed))
 			return -EAGAIN;
 
-		rc = alloc_contig_range(pfn, pfn + nr_pages, MIGRATE_MOVABLE,
+		rc = alloc_contig_range(pfn, pfn + nr_pages, ACR_FLAGS_NONE,
 					GFP_KERNEL);
 		if (rc == -ENOMEM)
 			/* whoops, out of memory */

include/linux/gfp.h

···
 extern gfp_t vma_thp_gfp_mask(struct vm_area_struct *vma);
 
 #ifdef CONFIG_CONTIG_ALLOC
+
+typedef unsigned int __bitwise acr_flags_t;
+#define ACR_FLAGS_NONE ((__force acr_flags_t)0) // ordinary allocation request
+#define ACR_FLAGS_CMA ((__force acr_flags_t)BIT(0)) // allocate for CMA
+
 /* The below functions must be run on a range from a single zone. */
 extern int alloc_contig_range_noprof(unsigned long start, unsigned long end,
-			      unsigned migratetype, gfp_t gfp_mask);
+				     acr_flags_t alloc_flags, gfp_t gfp_mask);
 #define alloc_contig_range(...)			alloc_hooks(alloc_contig_range_noprof(__VA_ARGS__))
 
 extern struct page *alloc_contig_pages_noprof(unsigned long nr_pages, gfp_t gfp_mask,

include/linux/page-isolation.h

···
 }
 #endif
 
-#define MEMORY_OFFLINE	0x1
-#define REPORT_FAILURE	0x2
+/*
+ * Pageblock isolation modes:
+ * PB_ISOLATE_MODE_MEM_OFFLINE - isolate to offline (!allocate) memory
+ *				 e.g., skip over PageHWPoison() pages and
+ *				 PageOffline() pages. Unmovable pages will be
+ *				 reported in this mode.
+ * PB_ISOLATE_MODE_CMA_ALLOC   - isolate for CMA allocations
+ * PB_ISOLATE_MODE_OTHER       - isolate for other purposes
+ */
+enum pb_isolate_mode {
+	PB_ISOLATE_MODE_MEM_OFFLINE,
+	PB_ISOLATE_MODE_CMA_ALLOC,
+	PB_ISOLATE_MODE_OTHER,
+};
 
 void __meminit init_pageblock_migratetype(struct page *page,
 					  enum migratetype migratetype,
···
 bool pageblock_unisolate_and_move_free_pages(struct zone *zone, struct page *page);
 
 int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
-			     int migratetype, int flags);
+			     enum pb_isolate_mode mode);
 
 void undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn);
 
 int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
-			int isol_flags);
+			enum pb_isolate_mode mode);
 #endif

include/trace/events/kmem.h

···
 		__entry->change_ownership)
 );
 
+#ifdef CONFIG_CONTIG_ALLOC
 TRACE_EVENT(mm_alloc_contig_migrate_range_info,
 
 	TP_PROTO(unsigned long start,
···
 		 unsigned long nr_migrated,
 		 unsigned long nr_reclaimed,
 		 unsigned long nr_mapped,
-		 int migratetype),
+		 acr_flags_t alloc_flags),
 
-	TP_ARGS(start, end, nr_migrated, nr_reclaimed, nr_mapped, migratetype),
+	TP_ARGS(start, end, nr_migrated, nr_reclaimed, nr_mapped, alloc_flags),
 
 	TP_STRUCT__entry(
 		__field(unsigned long, start)
···
 		__field(unsigned long, nr_migrated)
 		__field(unsigned long, nr_reclaimed)
 		__field(unsigned long, nr_mapped)
-		__field(int, migratetype)
+		__field(acr_flags_t, alloc_flags)
 	),
 
 	TP_fast_assign(
···
 		__entry->nr_migrated = nr_migrated;
 		__entry->nr_reclaimed = nr_reclaimed;
 		__entry->nr_mapped = nr_mapped;
-		__entry->migratetype = migratetype;
+		__entry->alloc_flags = alloc_flags;
 	),
 
-	TP_printk("start=0x%lx end=0x%lx migratetype=%d nr_migrated=%lu nr_reclaimed=%lu nr_mapped=%lu",
+	TP_printk("start=0x%lx end=0x%lx alloc_flags=%d nr_migrated=%lu nr_reclaimed=%lu nr_mapped=%lu",
 		  __entry->start,
 		  __entry->end,
-		  __entry->migratetype,
+		  __entry->alloc_flags,
 		  __entry->nr_migrated,
 		  __entry->nr_reclaimed,
 		  __entry->nr_mapped)
 );
+#endif
 
 TRACE_EVENT(mm_setup_per_zone_wmarks,
 

mm/cma.c

···
 
 		pfn = cmr->base_pfn + (bitmap_no << cma->order_per_bit);
 		mutex_lock(&cma->alloc_mutex);
-		ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA, gfp);
+		ret = alloc_contig_range(pfn, pfn + count, ACR_FLAGS_CMA, gfp);
 		mutex_unlock(&cma->alloc_mutex);
 		if (ret == 0) {
 			page = pfn_to_page(pfn);

mm/memory_hotplug.c

···
 
 	/* set above range as isolated */
 	ret = start_isolate_page_range(start_pfn, end_pfn,
-				       MIGRATE_MOVABLE,
-				       MEMORY_OFFLINE | REPORT_FAILURE);
+				       PB_ISOLATE_MODE_MEM_OFFLINE);
 	if (ret) {
 		reason = "failure to isolate range";
 		goto failed_removal_pcplists_disabled;
···
 			goto failed_removal_isolated;
 		}
 
-		ret = test_pages_isolated(start_pfn, end_pfn, MEMORY_OFFLINE);
+		ret = test_pages_isolated(start_pfn, end_pfn,
+					  PB_ISOLATE_MODE_MEM_OFFLINE);
 
 	} while (ret);
 

mm/page_alloc.c

···
 
 /*
  * [start, end) must belong to a single zone.
- * @migratetype: using migratetype to filter the type of migration in
+ * @alloc_flags: using acr_flags_t to filter the type of migration in
  *		trace_mm_alloc_contig_migrate_range_info.
  */
 static int __alloc_contig_migrate_range(struct compact_control *cc,
-		unsigned long start, unsigned long end, int migratetype)
+					unsigned long start, unsigned long end,
+					acr_flags_t alloc_flags)
 {
 	/* This function is based on compact_zone() from compaction.c. */
 	unsigned int nr_reclaimed;
···
 		putback_movable_pages(&cc->migratepages);
 	}
 
-	trace_mm_alloc_contig_migrate_range_info(start, end, migratetype,
+	trace_mm_alloc_contig_migrate_range_info(start, end, alloc_flags,
 						 total_migrated,
 						 total_reclaimed,
 						 total_mapped);
···
  * alloc_contig_range() -- tries to allocate given range of pages
  * @start:	start PFN to allocate
  * @end:	one-past-the-last PFN to allocate
- * @migratetype:	migratetype of the underlying pageblocks (either
- *			#MIGRATE_MOVABLE or #MIGRATE_CMA).  All pageblocks
- *			in range must have the same migratetype and it must
- *			be either of the two.
+ * @alloc_flags:	allocation information
  * @gfp_mask:	GFP mask. Node/zone/placement hints are ignored; only some
  *		action and reclaim modifiers are supported. Reclaim modifiers
  *		control allocation behavior during compaction/migration/reclaim.
···
  * need to be freed with free_contig_range().
  */
 int alloc_contig_range_noprof(unsigned long start, unsigned long end,
-		       unsigned migratetype, gfp_t gfp_mask)
+			      acr_flags_t alloc_flags, gfp_t gfp_mask)
 {
 	unsigned long outer_start, outer_end;
 	int ret = 0;
···
 		.alloc_contig = true,
 	};
 	INIT_LIST_HEAD(&cc.migratepages);
+	enum pb_isolate_mode mode = (alloc_flags & ACR_FLAGS_CMA) ?
+					    PB_ISOLATE_MODE_CMA_ALLOC :
+					    PB_ISOLATE_MODE_OTHER;
 
 	gfp_mask = current_gfp_context(gfp_mask);
 	if (__alloc_contig_verify_gfp_mask(gfp_mask, (gfp_t *)&cc.gfp_mask))
···
 	 * put back to page allocator so that buddy can use them.
 	 */
 
-	ret = start_isolate_page_range(start, end, migratetype, 0);
+	ret = start_isolate_page_range(start, end, mode);
 	if (ret)
 		goto done;
 
···
 	 * allocated.  So, if we fall through be sure to clear ret so that
 	 * -EBUSY is not accidentally used or returned to caller.
 	 */
-	ret = __alloc_contig_migrate_range(&cc, start, end, migratetype);
+	ret = __alloc_contig_migrate_range(&cc, start, end, alloc_flags);
 	if (ret && ret != -EBUSY)
 		goto done;
 
···
 	outer_start = find_large_buddy(start);
 
 	/* Make sure the range is really isolated. */
-	if (test_pages_isolated(outer_start, end, 0)) {
+	if (test_pages_isolated(outer_start, end, mode)) {
 		ret = -EBUSY;
 		goto done;
 	}
···
 {
 	unsigned long end_pfn = start_pfn + nr_pages;
 
-	return alloc_contig_range_noprof(start_pfn, end_pfn, MIGRATE_MOVABLE,
-				   gfp_mask);
+	return alloc_contig_range_noprof(start_pfn, end_pfn, ACR_FLAGS_NONE,
+					 gfp_mask);
 }
 
 static bool pfn_range_valid_contig(struct zone *z, unsigned long start_pfn,

mm/page_isolation.c

···
  *
  */
 static struct page *has_unmovable_pages(unsigned long start_pfn, unsigned long end_pfn,
-				int migratetype, int flags)
+				enum pb_isolate_mode mode)
 {
 	struct page *page = pfn_to_page(start_pfn);
 	struct zone *zone = page_zone(page);
···
 		 * isolate CMA pageblocks even when they are not movable in fact
 		 * so consider them movable here.
 		 */
-		if (is_migrate_cma(migratetype))
+		if (mode == PB_ISOLATE_MODE_CMA_ALLOC)
 			return NULL;
 
 		return page;
···
 		 * The HWPoisoned page may be not in buddy system, and
 		 * page_count() is not 0.
 		 */
-		if ((flags & MEMORY_OFFLINE) && PageHWPoison(page))
+		if ((mode == PB_ISOLATE_MODE_MEM_OFFLINE) && PageHWPoison(page))
 			continue;
 
 		/*
···
 		 * move these pages that still have a reference count > 0.
 		 * (false negatives in this function only)
 		 */
-		if ((flags & MEMORY_OFFLINE) && PageOffline(page))
+		if ((mode == PB_ISOLATE_MODE_MEM_OFFLINE) && PageOffline(page))
 			continue;
 
 		if (__PageMovable(page) || PageLRU(page))
···
  * present in [start_pfn, end_pfn). The pageblock must intersect with
  * [start_pfn, end_pfn).
  */
-static int set_migratetype_isolate(struct page *page, int migratetype, int isol_flags,
+static int set_migratetype_isolate(struct page *page, enum pb_isolate_mode mode,
 			unsigned long start_pfn, unsigned long end_pfn)
 {
 	struct zone *zone = page_zone(page);
···
 				  end_pfn);
 
 	unmovable = has_unmovable_pages(check_unmovable_start, check_unmovable_end,
-			migratetype, isol_flags);
+			mode);
 	if (!unmovable) {
 		if (!pageblock_isolate_and_move_free_pages(zone, page)) {
 			spin_unlock_irqrestore(&zone->lock, flags);
···
 	}
 
 	spin_unlock_irqrestore(&zone->lock, flags);
-	if (isol_flags & REPORT_FAILURE) {
+	if (mode == PB_ISOLATE_MODE_MEM_OFFLINE) {
 		/*
 		 * printk() with zone->lock held will likely trigger a
 		 * lockdep splat, so defer it here.
···
  * isolate_single_pageblock() -- tries to isolate a pageblock that might be
  * within a free or in-use page.
  * @boundary_pfn:		pageblock-aligned pfn that a page might cross
- * @flags:			isolation flags
+ * @mode:			isolation mode
  * @isolate_before:	isolate the pageblock before the boundary_pfn
  * @skip_isolation:	the flag to skip the pageblock isolation in second
  *			isolate_single_pageblock()
- * @migratetype:	migrate type to set in error recovery.
  *
  * Free and in-use pages can be as big as MAX_PAGE_ORDER and contain more than one
  * pageblock. When not all pageblocks within a page are isolated at the same
···
  * either. The function handles this by splitting the free page or migrating
  * the in-use page then splitting the free page.
  */
-static int isolate_single_pageblock(unsigned long boundary_pfn, int flags,
-		bool isolate_before, bool skip_isolation, int migratetype)
+static int isolate_single_pageblock(unsigned long boundary_pfn,
+			enum pb_isolate_mode mode, bool isolate_before,
+			bool skip_isolation)
 {
 	unsigned long start_pfn;
 	unsigned long isolate_pageblock;
···
 				      zone->zone_start_pfn);
 
 	if (skip_isolation) {
-		int mt __maybe_unused = get_pageblock_migratetype(pfn_to_page(isolate_pageblock));
-
-		VM_BUG_ON(!is_migrate_isolate(mt));
+		VM_BUG_ON(!get_pageblock_isolate(pfn_to_page(isolate_pageblock)));
 	} else {
-		ret = set_migratetype_isolate(pfn_to_page(isolate_pageblock), migratetype,
-				flags, isolate_pageblock, isolate_pageblock + pageblock_nr_pages);
+		ret = set_migratetype_isolate(pfn_to_page(isolate_pageblock),
+				mode, isolate_pageblock,
+				isolate_pageblock + pageblock_nr_pages);
 
 		if (ret)
 			return ret;
···
  * start_isolate_page_range() - mark page range MIGRATE_ISOLATE
  * @start_pfn:		The first PFN of the range to be isolated.
  * @end_pfn:		The last PFN of the range to be isolated.
- * @migratetype:	Migrate type to set in error recovery.
- * @flags:		The following flags are allowed (they can be combined in
- *			a bit mask)
- *			MEMORY_OFFLINE - isolate to offline (!allocate) memory
- *					 e.g., skip over PageHWPoison() pages
- *					 and PageOffline() pages.
- *			REPORT_FAILURE - report details about the failure to
- *			isolate the range
+ * @mode:		isolation mode
  *
  * Making page-allocation-type to be MIGRATE_ISOLATE means free pages in
  * the range will never be allocated. Any free pages and pages freed in the
···
  * Return: 0 on success and -EBUSY if any part of range cannot be isolated.
  */
 int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
-			     int migratetype, int flags)
+			     enum pb_isolate_mode mode)
 {
 	unsigned long pfn;
 	struct page *page;
···
 	bool skip_isolation = false;
 
 	/* isolate [isolate_start, isolate_start + pageblock_nr_pages) pageblock */
-	ret = isolate_single_pageblock(isolate_start, flags, false,
-			skip_isolation, migratetype);
+	ret = isolate_single_pageblock(isolate_start, mode, false,
+			skip_isolation);
 	if (ret)
 		return ret;
 
···
 		skip_isolation = true;
 
 	/* isolate [isolate_end - pageblock_nr_pages, isolate_end) pageblock */
-	ret = isolate_single_pageblock(isolate_end, flags, true,
-			skip_isolation, migratetype);
+	ret = isolate_single_pageblock(isolate_end, mode, true, skip_isolation);
 	if (ret) {
 		unset_migratetype_isolate(pfn_to_page(isolate_start));
 		return ret;
···
 	     pfn < isolate_end - pageblock_nr_pages;
 	     pfn += pageblock_nr_pages) {
 		page = __first_valid_page(pfn, pageblock_nr_pages);
-		if (page && set_migratetype_isolate(page, migratetype, flags,
-					start_pfn, end_pfn)) {
+		if (page && set_migratetype_isolate(page, mode, start_pfn,
+					end_pfn)) {
 			undo_isolate_page_range(isolate_start, pfn);
 			unset_migratetype_isolate(
 				pfn_to_page(isolate_end - pageblock_nr_pages));
···
  */
 static unsigned long
 __test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn,
-				  int flags)
+				  enum pb_isolate_mode mode)
 {
 	struct page *page;
 
···
 			 * simple way to verify that as VM_BUG_ON(), though.
 			 */
 			pfn += 1 << buddy_order(page);
-		else if ((flags & MEMORY_OFFLINE) && PageHWPoison(page))
+		else if ((mode == PB_ISOLATE_MODE_MEM_OFFLINE) &&
+			 PageHWPoison(page))
 			/* A HWPoisoned page cannot be also PageBuddy */
 			pfn++;
-		else if ((flags & MEMORY_OFFLINE) && PageOffline(page) &&
-			 !page_count(page))
+		else if ((mode == PB_ISOLATE_MODE_MEM_OFFLINE) &&
+			 PageOffline(page) && !page_count(page))
 			/*
 			 * The responsible driver agreed to skip PageOffline()
 			 * pages when offlining memory by dropping its
···
  * test_pages_isolated - check if pageblocks in range are isolated
  * @start_pfn:		The first PFN of the isolated range
  * @end_pfn:		The first PFN *after* the isolated range
- * @isol_flags:		Testing mode flags
+ * @mode:		Testing mode
  *
  * This tests if all in the specified range are free.
  *
- * If %MEMORY_OFFLINE is specified in @flags, it will consider
+ * If %PB_ISOLATE_MODE_MEM_OFFLINE specified in @mode, it will consider
  * poisoned and offlined pages free as well.
  *
  * Caller must ensure the requested range doesn't span zones.
···
  * Returns 0 if true, -EBUSY if one or more pages are in use.
  */
 int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
-			int isol_flags)
+			enum pb_isolate_mode mode)
 {
 	unsigned long pfn, flags;
 	struct page *page;
···
 	/* 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);
+	pfn = __test_page_isolated_in_pageblock(start_pfn, end_pfn, mode);
 	spin_unlock_irqrestore(&zone->lock, flags);
 
 	ret = pfn < end_pfn ? -EBUSY : 0;