From 32665f2bbfed2e325d37236d9b0071a11a69124e Mon Sep 17 00:00:00 2001 From: Joonsoo Kim Date: Tue, 21 Jan 2014 15:51:15 -0800 Subject: [PATCH] mm/migrate: correct failure handling if !hugepage_migration_support() We should remove the page from the list if we fail with ENOSYS, since migrate_pages() consider error cases except -ENOMEM and -EAGAIN as permanent failure and it assumes that the page would be removed from the list. Without this patch, we could overcount number of failure. In addition, we should put back the new hugepage if !hugepage_migration_support(). If not, we would leak hugepage memory. Signed-off-by: Joonsoo Kim Acked-by: Christoph Lameter Reviewed-by: Wanpeng Li Reviewed-by: Naoya Horiguchi Cc: Rafael Aquini Cc: Vlastimil Babka Cc: Wanpeng Li Cc: Mel Gorman Cc: Rik van Riel Cc: Vlastimil Babka Cc: Zhang Yanfei Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/migrate.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/mm/migrate.c b/mm/migrate.c index 626ca3c..13bedcc 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1013,7 +1013,7 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, { int rc = 0; int *result = NULL; - struct page *new_hpage = get_new_page(hpage, private, &result); + struct page *new_hpage; struct anon_vma *anon_vma = NULL; /* @@ -1023,9 +1023,12 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, * tables or check whether the hugepage is pmd-based or not before * kicking migration. */ - if (!hugepage_migration_support(page_hstate(hpage))) + if (!hugepage_migration_support(page_hstate(hpage))) { + putback_active_hugepage(hpage); return -ENOSYS; + } + new_hpage = get_new_page(hpage, private, &result); if (!new_hpage) return -ENOMEM; -- 2.7.4