Messages in this thread Patch in this message | | | Date | Wed, 10 May 2017 14:27:23 -0700 (PDT) | From | David Rientjes <> | Subject | [patch] mm, thp: copying user pages must schedule on collapse |
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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.
Signed-off-by: David Rientjes <rientjes@google.com> --- mm/khugepaged.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c --- 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(); } }
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