[withdrawn] mm-page_vma_mapped_walk-use-pmd_read_atomic.patch removed from -mm tree
From: akpm@linux-foundation.org
Date: 2021-06-15 02:26:04
Also in:
mm-commits
The patch titled
Subject: mm: page_vma_mapped_walk(): use pmd_read_atomic()
has been removed from the -mm tree. Its filename was
mm-page_vma_mapped_walk-use-pmd_read_atomic.patch
This patch was dropped because it was withdrawn
------------------------------------------------------
From: Hugh Dickins <hughd@google.com>
Subject: mm: page_vma_mapped_walk(): use pmd_read_atomic()
page_vma_mapped_walk() cleanup: use pmd_read_atomic() with barrier()
instead of READ_ONCE() for pmde: some architectures (e.g. i386 with PAE)
have a multi-word pmd entry, for which READ_ONCE() is not good enough.
Link: https://lkml.kernel.org/r/594c1f0-d396-5346-1f36-606872cddb18@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: "Kirill A. Shutemov" <redacted>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ralph Campbell <redacted>
Cc: Wang Yugui <redacted>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <redacted>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <redacted>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/page_vma_mapped.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/mm/page_vma_mapped.c~mm-page_vma_mapped_walk-use-pmd_read_atomic
+++ a/mm/page_vma_mapped.c@@ -182,13 +182,16 @@ restart: 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); + pmde = pmd_read_atomic(pvmw->pmd); + barrier(); + if (pmd_trans_huge(pmde) || is_pmd_migration_entry(pmde)) { pvmw->ptl = pmd_lock(mm, pvmw->pmd); if (likely(pmd_trans_huge(*pvmw->pmd))) {
_ Patches currently in -mm which might be from hughd@google.com are mm-thp-fix-__split_huge_pmd_locked-on-shmem-migration-entry.patch mm-thp-make-is_huge_zero_pmd-safe-and-quicker.patch mm-thp-try_to_unmap-use-ttu_sync-for-safe-splitting.patch mm-thp-fix-vma_address-if-virtual-address-below-file-offset.patch mm-thp-unmap_mapping_page-to-fix-thp-truncate_cleanup_page.patch mm-page_vma_mapped_walk-use-page-for-pvmw-page.patch mm-page_vma_mapped_walk-settle-pagehuge-on-entry.patch mm-page_vma_mapped_walk-use-pmde-for-pvmw-pmd.patch mm-page_vma_mapped_walk-prettify-pvmw_migration-block.patch mm-page_vma_mapped_walk-crossing-page-table-boundary.patch mm-page_vma_mapped_walk-add-a-level-of-indentation.patch mm-page_vma_mapped_walk-use-goto-instead-of-while-1.patch mm-page_vma_mapped_walk-get-vma_address_end-earlier.patch mm-thp-fix-page_vma_mapped_walk-if-thp-mapped-by-ptes.patch mm-thp-another-pvmw_sync-fix-in-page_vma_mapped_walk.patch mm-futex-fix-shared-futex-pgoff-on-shmem-huge-page.patch mm-thp-remap_page-is-only-needed-on-anonymous-thp.patch mm-hwpoison_user_mappings-try_to_unmap-with-ttu_sync.patch