+ mm-damon-use-set_huge_pte_at-to-make-huge-pte-old.patch added to mm-hotfixes-unstable branch

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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/mm-damon-use-set_huge_pte_at-to-make-huge-pte-old.patch

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@xxxxxxxxxxxxxxxxx>
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@xxxxxxx/

Link: https://lkml.kernel.org/r/1655692482-28797-1-git-send-email-baolin.wang@xxxxxxxxxxxxxxxxx
Fixes: 49f4203aae06 ("mm/damon: add access checking for hugetlb pages")
Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Reviewed-by: SeongJae Park <sj@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 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@xxxxxxxxxxxxxxxxx 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




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