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| author | David Rientjes <rientjes@google.com> | 2017-05-12 15:47:03 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-05-12 15:57:16 -0700 |
| commit | 338a16ba154959b049458d4f507d60f694550b68 (patch) | |
| tree | 1c70e3bc5d6a1692874e9f569d944aeac684522a /mm/khugepaged.c | |
| parent | 876f29460cbd4086b43475890c1bf2488fa11d40 (diff) | |
| download | lwn-338a16ba154959b049458d4f507d60f694550b68.tar.gz lwn-338a16ba154959b049458d4f507d60f694550b68.zip | |
mm, thp: copying user pages must schedule on collapse
We have encountered need_resched warnings in __collapse_huge_page_copy()
while doing {clear,copy}_user_highpage() over HPAGE_PMD_NR source pages.
mm->mmap_sem is held for write, but the iteration is well bounded.
Reschedule as needed.
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1705101426380.109808@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/khugepaged.c')
| -rw-r--r-- | mm/khugepaged.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index d1943e54ba95..945fd1ca49b5 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -612,7 +612,8 @@ static void __collapse_huge_page_copy(pte_t *pte, struct page *page, spinlock_t *ptl) { pte_t *_pte; - for (_pte = pte; _pte < pte+HPAGE_PMD_NR; _pte++) { + for (_pte = pte; _pte < pte + HPAGE_PMD_NR; + _pte++, page++, address += PAGE_SIZE) { pte_t pteval = *_pte; struct page *src_page; @@ -651,9 +652,7 @@ static void __collapse_huge_page_copy(pte_t *pte, struct page *page, spin_unlock(ptl); free_page_and_swap_cache(src_page); } - - address += PAGE_SIZE; - page++; + cond_resched(); } } |