From 9818b8cde6221fe7a52aad816425f67d4439b14e Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Thu, 14 Jul 2016 12:07:12 -0700 Subject: [PATCH] madvise_free, thp: fix madvise_free_huge_pmd return value after splitting madvise_free_huge_pmd should return 0 if the fallback PTE operations are required. In madvise_free_huge_pmd, if part pages of THP are discarded, the THP will be split and fallback PTE operations should be used if splitting succeeds. But the original code will make fallback PTE operations skipped, after splitting succeeds. Fix that via make madvise_free_huge_pmd return 0 after splitting successfully, so that the fallback PTE operations will be done. Link: http://lkml.kernel.org/r/1467135452-16688-1-git-send-email-ying.huang@intel.com Signed-off-by: "Huang, Ying" Acked-by: Minchan Kim Cc: "Kirill A. Shutemov" Cc: Vlastimil Babka Cc: Jerome Marchand Cc: Andrea Arcangeli Cc: Ebru Akagunduz Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/huge_memory.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 9ed58530f695..55940d173318 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1624,14 +1624,9 @@ int madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, if (next - addr != HPAGE_PMD_SIZE) { get_page(page); spin_unlock(ptl); - if (split_huge_page(page)) { - put_page(page); - unlock_page(page); - goto out_unlocked; - } + split_huge_page(page); put_page(page); unlock_page(page); - ret = 1; goto out_unlocked; } -- 2.20.1