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| author | Yang Shi <shy828301@gmail.com> | 2022-05-13 12:17:05 -0700 |
|---|---|---|
| committer | akpm <akpm@linux-foundation.org> | 2022-07-03 18:08:37 -0700 |
| commit | c453d8c7d1384d7e1d7f26d3ec0d527092edf801 (patch) | |
| tree | e9002d90743acd58901113b8a5af798343e83ba2 /mm/page_vma_mapped.c | |
| parent | 507db7927cd181d409dd495c8384b8e14c21c600 (diff) | |
| download | lwn-c453d8c7d1384d7e1d7f26d3ec0d527092edf801.tar.gz lwn-c453d8c7d1384d7e1d7f26d3ec0d527092edf801.zip | |
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 <shy828301@gmail.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/page_vma_mapped.c')
| -rw-r--r-- | mm/page_vma_mapped.c | 2 |
1 files changed, 1 insertions, 1 deletions
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); |