The patch titled
Subject: mm: thp: fix wrong cache flush in remove_migration_pmd()
has been added to the -mm tree. Its filename is
mm-thp-fix-wrong-cache-flush-in-remove_migration_pmd.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-thp-fix-wrong-cache-flush-in-remove_migration_pmd.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-thp-fix-wrong-cache-flush-in-remove_migration_pmd.patch
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------------------------------------------------------
From: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Subject: mm: thp: fix wrong cache flush in remove_migration_pmd()
The flush_cache_range() is supposed to be justified only if the page is
already placed in process page table, and that is done right after
flush_cache_range(). So using this interface is wrong. And there is no
need to invalite cache since it was non-present before in
remove_migration_pmd(). So just to remove it.
Link: https://lkml.kernel.org/r/20220208073617.70342-2-songmuchun@xxxxxxxxxxxxx
Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Reviewed-by: Zi Yan <ziy@xxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Lars Persson <lars.persson@xxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Xiongchun Duan <duanxiongchun@xxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Mina Almasry <almasrymina@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/mm/huge_memory.c~mm-thp-fix-wrong-cache-flush-in-remove_migration_pmd
+++ a/mm/huge_memory.c
@@ -3124,7 +3124,6 @@ void remove_migration_pmd(struct page_vm
if (pmd_swp_uffd_wp(*pvmw->pmd))
pmde = pmd_wrprotect(pmd_mkuffd_wp(pmde));
- flush_cache_range(vma, mmun_start, mmun_start + HPAGE_PMD_SIZE);
if (PageAnon(new))
page_add_anon_rmap(new, vma, mmun_start, true);
else
@@ -3132,6 +3131,8 @@ void remove_migration_pmd(struct page_vm
set_pmd_at(mm, mmun_start, pvmw->pmd, pmde);
if ((vma->vm_flags & VM_LOCKED) && !PageDoubleMap(new))
mlock_vma_page(new);
+
+ /* No need to invalidate - it was non-present before */
update_mmu_cache_pmd(vma, address, pvmw->pmd);
}
#endif
_
Patches currently in -mm which might be from songmuchun@xxxxxxxxxxxxx are
mm-thp-fix-wrong-cache-flush-in-remove_migration_pmd.patch
mm-fix-missing-cache-flush-for-all-tail-pages-of-compound-page.patch
mm-hugetlb-fix-missing-cache-flush-in-copy_huge_page_from_user.patch
mm-hugetlb-fix-missing-cache-flush-in-hugetlb_mcopy_atomic_pte.patch
mm-replace-multiple-dcache-flush-with-flush_dcache_folio.patch
mm-hugetlb-free-the-2nd-vmemmap-page-associated-with-each-hugetlb-page.patch
mm-hugetlb-replace-hugetlb_free_vmemmap_enabled-with-a-static_key.patch
mm-sparsemem-use-page-table-lock-to-protect-kernel-pmd-operations.patch
selftests-vm-add-a-hugetlb-test-case.patch
mm-sparsemem-move-vmemmap-related-to-hugetlb-to-config_hugetlb_page_free_vmemmap.patch
