From: Hugh Dickins <hughd@google.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
Yang Shi <shy828301@gmail.com>,
Wang Yugui <wangyugui@e16-tech.com>,
Matthew Wilcox <willy@infradead.org>,
Alistair Popple <apopple@nvidia.com>,
Ralph Campbell <rcampbell@nvidia.com>, Zi Yan <ziy@nvidia.com>,
Peter Xu <peterx@redhat.com>, Will Deacon <will@kernel.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: [PATCH 04/11] mm: page_vma_mapped_walk(): use pmde for *pvmw->pmd
Date: Wed, 9 Jun 2021 23:40:08 -0700 (PDT) [thread overview]
Message-ID: <53fbc9d-891e-46b2-cb4b-468c3b19238e@google.com> (raw)
In-Reply-To: <589b358c-febc-c88e-d4c2-7834b37fa7bf@google.com>
page_vma_mapped_walk() cleanup: re-evaluate pmde after taking lock, then
use it in subsequent tests, instead of repeatedly dereferencing pointer.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
---
mm/page_vma_mapped.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index 973c3c4e72cc..81000dd0b5da 100644
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -194,18 +194,19 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
if (pmd_trans_huge(pmde) || is_pmd_migration_entry(pmde)) {
pvmw->ptl = pmd_lock(mm, pvmw->pmd);
- if (likely(pmd_trans_huge(*pvmw->pmd))) {
+ pmde = *pvmw->pmd;
+ if (likely(pmd_trans_huge(pmde))) {
if (pvmw->flags & PVMW_MIGRATION)
return not_found(pvmw);
- if (pmd_page(*pvmw->pmd) != page)
+ if (pmd_page(pmde) != page)
return not_found(pvmw);
return true;
- } else if (!pmd_present(*pvmw->pmd)) {
+ } else if (!pmd_present(pmde)) {
if (thp_migration_supported()) {
if (!(pvmw->flags & PVMW_MIGRATION))
return not_found(pvmw);
- if (is_migration_entry(pmd_to_swp_entry(*pvmw->pmd))) {
- swp_entry_t entry = pmd_to_swp_entry(*pvmw->pmd);
+ if (is_migration_entry(pmd_to_swp_entry(pmde))) {
+ swp_entry_t entry = pmd_to_swp_entry(pmde);
if (migration_entry_to_page(entry) != page)
return not_found(pvmw);
--
2.26.2
next prev parent reply other threads:[~2021-06-10 6:40 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-10 6:31 [PATCH 00/11] mm: page_vma_mapped_walk() cleanup and THP fixes Hugh Dickins
2021-06-10 6:34 ` [PATCH 01/11] mm: page_vma_mapped_walk(): use page for pvmw->page Hugh Dickins
2021-06-10 8:12 ` Alistair Popple
2021-06-10 8:55 ` Kirill A. Shutemov
2021-06-10 14:14 ` Peter Xu
2021-06-10 6:36 ` [PATCH 02/11] mm: page_vma_mapped_walk(): settle PageHuge on entry Hugh Dickins
2021-06-10 8:57 ` Kirill A. Shutemov
2021-06-10 14:17 ` Peter Xu
2021-06-10 6:38 ` [PATCH 03/11] mm: page_vma_mapped_walk(): use pmd_read_atomic() Hugh Dickins
2021-06-10 9:06 ` Kirill A. Shutemov
2021-06-10 12:15 ` Jason Gunthorpe
[not found] ` <aebb6b96-153e-7d7-59da-f6bad4337aa7@google.com>
2021-06-11 15:36 ` Jason Gunthorpe
2021-06-11 19:05 ` Hugh Dickins
2021-06-11 19:42 ` Jason Gunthorpe
2021-06-15 9:46 ` Will Deacon
2021-06-16 0:42 ` Jason Gunthorpe
2021-06-16 10:27 ` Will Deacon
2021-06-11 19:33 ` Hugh Dickins
2021-06-10 6:40 ` Hugh Dickins [this message]
2021-06-10 9:10 ` [PATCH 04/11] mm: page_vma_mapped_walk(): use pmde for *pvmw->pmd Kirill A. Shutemov
2021-06-10 14:31 ` Peter Xu
2021-06-10 6:42 ` [PATCH 05/11] mm: page_vma_mapped_walk(): prettify PVMW_MIGRATION block Hugh Dickins
2021-06-10 9:16 ` Kirill A. Shutemov
2021-06-10 14:48 ` Peter Xu
2021-06-10 6:44 ` [PATCH 06/11] mm: page_vma_mapped_walk(): crossing page table boundary Hugh Dickins
2021-06-10 9:32 ` Kirill A. Shutemov
2021-06-10 6:46 ` [PATCH 07/11] mm: page_vma_mapped_walk(): add a level of indentation Hugh Dickins
2021-06-10 9:34 ` Kirill A. Shutemov
2021-06-10 6:48 ` [PATCH 08/11] mm: page_vma_mapped_walk(): use goto instead of while (1) Hugh Dickins
2021-06-10 9:39 ` Kirill A. Shutemov
2021-06-10 6:50 ` [PATCH 09/11] mm: page_vma_mapped_walk(): get vma_address_end() earlier Hugh Dickins
2021-06-10 9:40 ` Kirill A. Shutemov
2021-06-10 6:52 ` [PATCH 10/11] mm/thp: fix page_vma_mapped_walk() if THP mapped by ptes Hugh Dickins
2021-06-10 9:42 ` Kirill A. Shutemov
2021-06-10 6:54 ` [PATCH 11/11] mm/thp: another PVMW_SYNC fix in page_vma_mapped_walk() Hugh Dickins
2021-06-10 9:43 ` Kirill A. Shutemov
2021-06-11 18:29 ` Hugh Dickins
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