Commit 5ac95884 authored by Yang Shi's avatar Yang Shi Committed by Linus Torvalds
Browse files

mm/migrate: enable returning precise migrate_pages() success count 

Under normal circumstances, migrate_pages() returns the number of pages
migrated.  In error conditions, it returns an error code.  When returning
an error code, there is no way to know how many pages were migrated or not
migrated.

Make migrate_pages() return how many pages are demoted successfully for
all cases, including when encountering errors.  Page reclaim behavior will
depend on this in subsequent patches.

Link: https://lkml.kernel.org/r/20210721063926.3024591-3-ying.huang@intel.com
Link: https://lkml.kernel.org/r/20210715055145.195411-4-ying.huang@intel.com


Signed-off-by: default avatarYang Shi <yang.shi@linux.alibaba.com>
Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: default avatar"Huang, Ying" <ying.huang@intel.com>
Suggested-by: Oscar Salvador <osalvador@suse.de> [optional parameter]
Reviewed-by: default avatarYang Shi <shy828301@gmail.com>
Reviewed-by: default avatarZi Yan <ziy@nvidia.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Keith Busch <kbusch@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 884a6e5d

include/linux/migrate.h

+3 −2
Original line number Diff line number Diff line
@@ -41,7 +41,8 @@ extern int migrate_page(struct address_space *mapping, 
			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);
@@ -56,7 +57,7 @@ extern int migrate_page_move_mapping(struct address_space *mapping, 
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)

mm/compaction.c

+1 −1
Original line number Diff line number Diff line
@@ -2398,7 +2398,7 @@ compact_zone(struct compact_control *cc, struct capture_control *capc) 


		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);

mm/gup.c

+1 −1
Original line number Diff line number Diff line
@@ -1772,7 +1772,7 @@ static long check_and_migrate_movable_pages(unsigned long nr_pages, 
	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);

	}

mm/memory-failure.c

+1 −1
Original line number Diff line number Diff line
@@ -2099,7 +2099,7 @@ static int __soft_offline_page(struct page *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;

mm/memory_hotplug.c

+1 −1
Original line number Diff line number Diff line
@@ -1469,7 +1469,7 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) 
		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)) {