Skip to content
Commit c453d8c7 authored by Yang Shi's avatar Yang Shi Committed by akpm
Browse files

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: default avatarYang Shi <shy828301@gmail.com>
Reviewed-by: default avatarMuchun Song <songmuchun@bytedance.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 507db792
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment