Messages in this thread Patch in this message | | | Date | Wed, 9 Jun 2021 23:50:23 -0700 (PDT) | From | Hugh Dickins <> | Subject | [PATCH 09/11] mm: page_vma_mapped_walk(): get vma_address_end() earlier |
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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.
Signed-off-by: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> --- mm/page_vma_mapped.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index 006f4814abbc..f6839f536645 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: @@ -239,10 +248,6 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) 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) -- 2.26.2
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