The patch titled Subject: mm/damon: use set_huge_pte_at() to make huge pte old has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-damon-use-set_huge_pte_at-to-make-huge-pte-old.patch
This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...
This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------ From: Baolin Wang baolin.wang@linux.alibaba.com Subject: mm/damon: use set_huge_pte_at() to make huge pte old Date: Mon, 20 Jun 2022 10:34:42 +0800
The huge_ptep_set_access_flags() can not make the huge pte old according to the discussion [1], that means we will always mornitor the young state of the hugetlb though we stopped accessing the hugetlb, as a result DAMON will get inaccurate accessing statistics.
So changing to use set_huge_pte_at() to make the huge pte old to fix this issue.
[1] https://lore.kernel.org/all/Yqy97gXI4Nqb7dYo@arm.com/
Link: https://lkml.kernel.org/r/1655692482-28797-1-git-send-email-baolin.wang@linu... Fixes: 49f4203aae06 ("mm/damon: add access checking for hugetlb pages") Signed-off-by: Baolin Wang baolin.wang@linux.alibaba.com Reviewed-by: SeongJae Park sj@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
mm/damon/vaddr.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/mm/damon/vaddr.c~mm-damon-use-set_huge_pte_at-to-make-huge-pte-old +++ a/mm/damon/vaddr.c @@ -336,8 +336,7 @@ static void damon_hugetlb_mkold(pte_t *p if (pte_young(entry)) { referenced = true; entry = pte_mkold(entry); - huge_ptep_set_access_flags(vma, addr, pte, entry, - vma->vm_flags & VM_WRITE); + set_huge_pte_at(mm, addr, pte, entry); }
#ifdef CONFIG_MMU_NOTIFIER _
Patches currently in -mm which might be from baolin.wang@linux.alibaba.com are
mm-damon-use-set_huge_pte_at-to-make-huge-pte-old.patch mm-hugetlb-remove-unnecessary-huge_ptep_set_access_flags-in-hugetlb_mcopy_atomic_pte.patch mm-rmap-simplify-the-hugetlb-handling-when-unmapping-or-migration.patch