[PATCHv9-rebased2 03/37] mm, thp: fix locking inconsistency in collapse_huge_page
From: Kirill A. Shutemov <hidden>
Date: 2016-06-15 20:06:08
Also in:
linux-fsdevel, lkml
Subsystem:
memory management, memory management - thp (transparent huge page), the rest · Maintainers:
Andrew Morton, David Hildenbrand, Lorenzo Stoakes, Linus Torvalds
From: Ebru Akagunduz <redacted> After creating revalidate vma function, locking inconsistency occured due to directing the code path to wrong label. This patch directs to correct label and fix the inconsistency. Related commit that caused inconsistency: http://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=da4360877094368f6dfe75bbe804b0f0a5d575b0 Link: http://lkml.kernel.org/r/1464956884-4644-1-git-send-email-ebru.akagunduz@gmail.com Signed-off-by: Ebru Akagunduz <redacted> Cc: Vlastimil Babka <redacted> Cc: Sergey Senozhatsky <redacted> Cc: Kirill A. Shutemov <redacted> Cc: Stephen Rothwell <redacted> Cc: Rik van Riel <redacted> Cc: Andrea Arcangeli <redacted> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- mm/huge_memory.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 7bb30e853335..1777b806de96 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c@@ -2487,13 +2487,18 @@ static void collapse_huge_page(struct mm_struct *mm, down_read(&mm->mmap_sem); result = hugepage_vma_revalidate(mm, address); - if (result) - goto out; + if (result) { + mem_cgroup_cancel_charge(new_page, memcg, true); + up_read(&mm->mmap_sem); + goto out_nolock; + } pmd = mm_find_pmd(mm, address); if (!pmd) { result = SCAN_PMD_NULL; - goto out; + mem_cgroup_cancel_charge(new_page, memcg, true); + up_read(&mm->mmap_sem); + goto out_nolock; } /*
@@ -2502,8 +2507,9 @@ static void collapse_huge_page(struct mm_struct *mm, * label out. Continuing to collapse causes inconsistency. */ if (!__collapse_huge_page_swapin(mm, vma, address, pmd)) { + mem_cgroup_cancel_charge(new_page, memcg, true); up_read(&mm->mmap_sem); - goto out; + goto out_nolock; } up_read(&mm->mmap_sem);
--
2.8.1
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