From c453d8c7d1384d7e1d7f26d3ec0d527092edf801 Mon Sep 17 00:00:00 2001 From: Yang Shi Date: Fri, 13 May 2022 12:17:05 -0700 Subject: mm/page_vma_mapped.c: check possible huge PMD map with transhuge_vma_suitable() IIUC page_vma_mapped_walk() checks if the vma is possibly huge PMD mapped with transparent_hugepage_active() and "pvmw->nr_pages >= HPAGE_PMD_NR". Actually pvmw->nr_pages is returned by compound_nr() or folio_nr_pages(), so the page should be THP as long as "pvmw->nr_pages >= HPAGE_PMD_NR". And it is guaranteed THP is allocated for valid VMA in the first place. But it may be not PMD mapped if the VMA is file VMA and it is not properly aligned. The transhuge_vma_suitable() is used to do such check, so replace transparent_hugepage_active() to it, which is too heavy and overkilling. Link: https://lkml.kernel.org/r/20220513191705.457775-1-shy828301@gmail.com Signed-off-by: Yang Shi Reviewed-by: Muchun Song Cc: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton --- mm/page_vma_mapped.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/page_vma_mapped.c') diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index c10f839fc410..e971a467fcdf 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -243,7 +243,7 @@ restart: * cleared *pmd but not decremented compound_mapcount(). */ if ((pvmw->flags & PVMW_SYNC) && - transparent_hugepage_active(vma) && + transhuge_vma_suitable(vma, pvmw->address) && (pvmw->nr_pages >= HPAGE_PMD_NR)) { spinlock_t *ptl = pmd_lock(mm, pvmw->pmd); -- cgit v1.2.3