Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH 5.4 63/71] mm: page_vma_mapped_walk(): get vma_address_end() earlier | Date | Mon, 28 Jun 2021 10:29:56 -0400 |
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From: Hugh Dickins <hughd@google.com>
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 <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Xu <peterx@redhat.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Wang Yugui <wangyugui@e16-tech.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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 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 @@ 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) -- 2.30.2
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