From 037a1d67d236f922d6a31279995c7be69ae57131 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Thu, 24 Jun 2021 18:39:23 -0700 Subject: [PATCH] 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/4542b34d-862f-7cb4-bb22-e0df6ce830a2@google.com Signed-off-by: Hugh Dickins Acked-by: Kirill A. Shutemov Cc: Alistair Popple Cc: Matthew Wilcox Cc: Peter Xu Cc: Ralph Campbell Cc: Wang Yugui Cc: Will Deacon Cc: Yang Shi Cc: Zi Yan Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- 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 fc68ab2d3ea1..93dd79ba9969 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -166,6 +166,15 @@ 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: @@ -233,10 +242,6 @@ 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)