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| author | Ebru Akagunduz <ebru.akagunduz@gmail.com> | 2016-09-19 14:44:04 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-09-19 15:36:16 -0700 |
| commit | 982785c6b05a82c01e90687b7e25ee87c8970b2e (patch) | |
| tree | d855120e0185c802dcb3c222fc94abe31a279b3c /mm | |
| parent | c131f751ab1a852d4dd4b490b3a7fbba7d738de5 (diff) | |
| download | linux-0-day-982785c6b05a82c01e90687b7e25ee87c8970b2e.tar.gz linux-0-day-982785c6b05a82c01e90687b7e25ee87c8970b2e.tar.xz | |
mm, thp: fix leaking mapped pte in __collapse_huge_page_swapin()
Currently, khugepaged does not permit swapin if there are enough young
pages in a THP. The problem is when a THP does not have enough young
pages, khugepaged leaks mapped ptes.
This patch prohibits leaking mapped ptes.
Link: http://lkml.kernel.org/r/1472820276-7831-1-git-send-email-ebru.akagunduz@gmail.com
Signed-off-by: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Suggested-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/khugepaged.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 62339bf3c726d..728d7790dc2da 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -882,6 +882,11 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm, .pmd = pmd, }; + /* we only decide to swapin, if there is enough young ptes */ + if (referenced < HPAGE_PMD_NR/2) { + trace_mm_collapse_huge_page_swapin(mm, swapped_in, referenced, 0); + return false; + } fe.pte = pte_offset_map(pmd, address); for (; fe.address < address + HPAGE_PMD_NR*PAGE_SIZE; fe.pte++, fe.address += PAGE_SIZE) { @@ -889,11 +894,6 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm, if (!is_swap_pte(pteval)) continue; swapped_in++; - /* we only decide to swapin, if there is enough young ptes */ - if (referenced < HPAGE_PMD_NR/2) { - trace_mm_collapse_huge_page_swapin(mm, swapped_in, referenced, 0); - return false; - } ret = do_swap_page(&fe, pteval); /* do_swap_page returns VM_FAULT_RETRY with released mmap_sem */ |