[PATCH v2 1/6] mm: migrate: do not migrate HugeTLB page whose refcount is one
From: Muchun Song <hidden>
Date: 2021-01-06 08:50:25
Also in:
lkml
Subsystem:
memory management, memory management - memory policy and migration, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
If the refcount is one when it is migrated, it means that the page was freed from under us. So we are done and do not need to migrate. Signed-off-by: Muchun Song <redacted> Reviewed-by: Mike Kravetz <redacted> Acked-by: Yang Shi <redacted> --- mm/migrate.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/mm/migrate.c b/mm/migrate.c
index 4385f2fb5d18..a6631c4eb6a6 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c@@ -1279,6 +1279,12 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, return -ENOSYS; } + if (page_count(hpage) == 1) { + /* page was freed from under us. So we are done. */ + putback_active_hugepage(hpage); + return MIGRATEPAGE_SUCCESS; + } + new_hpage = get_new_page(hpage, private); if (!new_hpage) return -ENOMEM;
--
2.11.0