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Message-Id: <20210628143004.32596-62-sashal@kernel.org>
Date: Mon, 28 Jun 2021 10:29:54 -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 61/71] mm: page_vma_mapped_walk(): add a level of indentation
From: Hugh Dickins <hughd@...gle.com>
page_vma_mapped_walk() cleanup: add a level of indentation to much of
the body, making no functional change in this commit, but reducing the
later diff when this is all converted to a loop.
[hughd@...gle.com: : page_vma_mapped_walk(): add a level of indentation fix]
Link: https://lkml.kernel.org/r/7f817555-3ce1-c785-e438-87d8efdcaf26@google.com
Link: https://lkml.kernel.org/r/efde211-f3e2-fe54-977-ef481419e7f3@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 | 105 ++++++++++++++++++++++---------------------
1 file changed, 55 insertions(+), 50 deletions(-)
diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index bf17f93f162c..b71058fcfde9 100644
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -168,62 +168,67 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
if (pvmw->pte)
goto next_pte;
restart:
- pgd = pgd_offset(mm, pvmw->address);
- if (!pgd_present(*pgd))
- return false;
- p4d = p4d_offset(pgd, pvmw->address);
- if (!p4d_present(*p4d))
- return false;
- pud = pud_offset(p4d, pvmw->address);
- if (!pud_present(*pud))
- return false;
- pvmw->pmd = pmd_offset(pud, pvmw->address);
- /*
- * Make sure the pmd value isn't cached in a register by the
- * compiler and used as a stale value after we've observed a
- * subsequent update.
- */
- pmde = READ_ONCE(*pvmw->pmd);
- if (pmd_trans_huge(pmde) || is_pmd_migration_entry(pmde)) {
- pvmw->ptl = pmd_lock(mm, pvmw->pmd);
- pmde = *pvmw->pmd;
- if (likely(pmd_trans_huge(pmde))) {
- if (pvmw->flags & PVMW_MIGRATION)
- return not_found(pvmw);
- if (pmd_page(pmde) != page)
- return not_found(pvmw);
- return true;
- }
- if (!pmd_present(pmde)) {
- swp_entry_t entry;
+ {
+ pgd = pgd_offset(mm, pvmw->address);
+ if (!pgd_present(*pgd))
+ return false;
+ p4d = p4d_offset(pgd, pvmw->address);
+ if (!p4d_present(*p4d))
+ return false;
+ pud = pud_offset(p4d, pvmw->address);
+ if (!pud_present(*pud))
+ return false;
- if (!thp_migration_supported() ||
- !(pvmw->flags & PVMW_MIGRATION))
- return not_found(pvmw);
- entry = pmd_to_swp_entry(pmde);
- if (!is_migration_entry(entry) ||
- migration_entry_to_page(entry) != page)
- return not_found(pvmw);
- return true;
- }
- /* THP pmd was split under us: handle on pte level */
- spin_unlock(pvmw->ptl);
- pvmw->ptl = NULL;
- } else if (!pmd_present(pmde)) {
+ pvmw->pmd = pmd_offset(pud, pvmw->address);
/*
- * If PVMW_SYNC, take and drop THP pmd lock so that we
- * cannot return prematurely, while zap_huge_pmd() has
- * cleared *pmd but not decremented compound_mapcount().
+ * Make sure the pmd value isn't cached in a register by the
+ * compiler and used as a stale value after we've observed a
+ * subsequent update.
*/
- if ((pvmw->flags & PVMW_SYNC) && PageTransCompound(page)) {
- spinlock_t *ptl = pmd_lock(mm, pvmw->pmd);
+ pmde = READ_ONCE(*pvmw->pmd);
- spin_unlock(ptl);
+ if (pmd_trans_huge(pmde) || is_pmd_migration_entry(pmde)) {
+ pvmw->ptl = pmd_lock(mm, pvmw->pmd);
+ pmde = *pvmw->pmd;
+ if (likely(pmd_trans_huge(pmde))) {
+ if (pvmw->flags & PVMW_MIGRATION)
+ return not_found(pvmw);
+ if (pmd_page(pmde) != page)
+ return not_found(pvmw);
+ return true;
+ }
+ if (!pmd_present(pmde)) {
+ swp_entry_t entry;
+
+ if (!thp_migration_supported() ||
+ !(pvmw->flags & PVMW_MIGRATION))
+ return not_found(pvmw);
+ entry = pmd_to_swp_entry(pmde);
+ if (!is_migration_entry(entry) ||
+ migration_entry_to_page(entry) != page)
+ return not_found(pvmw);
+ return true;
+ }
+ /* THP pmd was split under us: handle on pte level */
+ spin_unlock(pvmw->ptl);
+ pvmw->ptl = NULL;
+ } else if (!pmd_present(pmde)) {
+ /*
+ * If PVMW_SYNC, take and drop THP pmd lock so that we
+ * cannot return prematurely, while zap_huge_pmd() has
+ * cleared *pmd but not decremented compound_mapcount().
+ */
+ if ((pvmw->flags & PVMW_SYNC) &&
+ PageTransCompound(page)) {
+ spinlock_t *ptl = pmd_lock(mm, pvmw->pmd);
+
+ spin_unlock(ptl);
+ }
+ return false;
}
- return false;
+ if (!map_pte(pvmw))
+ goto next_pte;
}
- if (!map_pte(pvmw))
- goto next_pte;
while (1) {
unsigned long end;
--
2.30.2
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