diff mbox series

+ mm-page_vma_mapped_walk-use-pmde-for-pvmw-pmd.patch added to -mm tree

Message ID 20210610222513.HLpHBh8Tk%akpm@linux-foundation.org
State Superseded
Headers show
Series + mm-page_vma_mapped_walk-use-pmde-for-pvmw-pmd.patch added to -mm tree | expand

Commit Message

Andrew Morton June 10, 2021, 10:25 p.m. UTC
The patch titled
     Subject: mm: page_vma_mapped_walk(): use pmde for *pvmw->pmd
has been added to the -mm tree.  Its filename is
     mm-page_vma_mapped_walk-use-pmde-for-pvmw-pmd.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-page_vma_mapped_walk-use-pmde-for-pvmw-pmd.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-page_vma_mapped_walk-use-pmde-for-pvmw-pmd.patch

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------------------------------------------------------
From: Hugh Dickins <hughd@google.com>
Subject: mm: page_vma_mapped_walk(): use pmde for *pvmw->pmd

page_vma_mapped_walk() cleanup: re-evaluate pmde after taking lock, then
use it in subsequent tests, instead of repeatedly dereferencing pointer.

Link: https://lkml.kernel.org/r/53fbc9d-891e-46b2-cb4b-468c3b19238e@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
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>
---

 mm/page_vma_mapped.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)
diff mbox series

Patch

--- a/mm/page_vma_mapped.c~mm-page_vma_mapped_walk-use-pmde-for-pvmw-pmd
+++ a/mm/page_vma_mapped.c
@@ -194,18 +194,19 @@  restart:
 
 	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);