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authorHugh Dickins <[email protected]>2021-06-24 18:39:23 -0700
committerLinus Torvalds <[email protected]>2021-06-24 19:40:53 -0700
commita765c417d876cc635f628365ec9aa6f09470069a (patch)
tree7b213a4aac5f5b8c8c5b80189007049054764586
parent474466301dfd8b39a10c01db740645f3f7ae9a28 (diff)
mm: page_vma_mapped_walk(): get vma_address_end() earlier
page_vma_mapped_walk() cleanup: get THP's vma_address_end() at the start, rather than later at next_pte. It's a little unnecessary overhead on the first call, but makes for a simpler loop in the following commit. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Hugh Dickins <[email protected]> Acked-by: Kirill A. Shutemov <[email protected]> Cc: Alistair Popple <[email protected]> Cc: Matthew Wilcox <[email protected]> Cc: Peter Xu <[email protected]> Cc: Ralph Campbell <[email protected]> Cc: Wang Yugui <[email protected]> Cc: Will Deacon <[email protected]> Cc: Yang Shi <[email protected]> Cc: Zi Yan <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
-rw-r--r--mm/page_vma_mapped.c13
1 files changed, 9 insertions, 4 deletions
diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index 6b9320340f1b..df89ea3df4f4 100644
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -171,6 +171,15 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
return true;
}
+ /*
+ * Seek to next pte only makes sense for THP.
+ * But more important than that optimization, is to filter out
+ * any PageKsm page: whose page->index misleads vma_address()
+ * and vma_address_end() to disaster.
+ */
+ end = PageTransCompound(page) ?
+ vma_address_end(page, pvmw->vma) :
+ pvmw->address + PAGE_SIZE;
if (pvmw->pte)
goto next_pte;
restart:
@@ -238,10 +247,6 @@ this_pte:
if (check_pte(pvmw))
return true;
next_pte:
- /* Seek to next pte only makes sense for THP */
- if (!PageTransHuge(page))
- return not_found(pvmw);
- end = vma_address_end(page, pvmw->vma);
do {
pvmw->address += PAGE_SIZE;
if (pvmw->address >= end)