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Message-Id: <20210628143004.32596-64-sashal@kernel.org>
Date: Mon, 28 Jun 2021 10:29:56 -0400
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc: Hugh Dickins <hughd@...gle.com>,
"Kirill A . Shutemov" <kirill.shutemov@...ux.intel.com>,
Alistair Popple <apopple@...dia.com>,
Matthew Wilcox <willy@...radead.org>,
Peter Xu <peterx@...hat.com>,
Ralph Campbell <rcampbell@...dia.com>,
Wang Yugui <wangyugui@...-tech.com>,
Will Deacon <will@...nel.org>, Yang Shi <shy828301@...il.com>,
Zi Yan <ziy@...dia.com>,
Andrew Morton <akpm@...ux-foundation.org>,
Linus Torvalds <torvalds@...ux-foundation.org>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: [PATCH 5.4 63/71] mm: page_vma_mapped_walk(): get vma_address_end() earlier
From: Hugh Dickins <hughd@...gle.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@...gle.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
Cc: Alistair Popple <apopple@...dia.com>
Cc: Matthew Wilcox <willy@...radead.org>
Cc: Peter Xu <peterx@...hat.com>
Cc: Ralph Campbell <rcampbell@...dia.com>
Cc: Wang Yugui <wangyugui@...-tech.com>
Cc: Will Deacon <will@...nel.org>
Cc: Yang Shi <shy828301@...il.com>
Cc: Zi Yan <ziy@...dia.com>
Cc: <stable@...r.kernel.org>
Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@...ux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.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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