linux-kernel - [PATCH v2] mm/hugetlb: Remove unnecessary huge_ptep_set_access_flags() in hugetlb_mcopy_atomic

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Message-Id: <f3e28b897b53a69967a8b98a6fdcda3be80c9229.1653616175.git.baolin.wang@linux.alibaba.com>
Date:   Fri, 27 May 2022 10:01:35 +0800
From:   Baolin Wang <baolin.wang@...ux.alibaba.com>
To:     mike.kravetz@...cle.com, akpm@...ux-foundation.org,
        songmuchun@...edance.com
Cc:     anshuman.khandual@....com, baolin.wang@...ux.alibaba.com,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: [PATCH v2] mm/hugetlb: Remove unnecessary huge_ptep_set_access_flags() in hugetlb_mcopy_atomic_pte()

There is no need to update the hugetlb access flags after just setting the
hugetlb page table entry by set_huge_pte_at(), since the page table entry
value has no changes.

Thus remove the unnecessary huge_ptep_set_access_flags() in
hugetlb_mcopy_atomic_pte().

Signed-off-by: Baolin Wang <baolin.wang@...ux.alibaba.com>
Reviewed-by: Muchun Song <songmuchun@...edance.com>
Reviewed-by: Mike Kravetz <mike.kravetz@...cle.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@....com>
---
Changes from v1:
 - Update commit message to remove checkpatch.pl complaint.
 - Collect reviewed-by tags.
---
 mm/hugetlb.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 7c468ac..3ad49bf 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6032,8 +6032,6 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 
 	set_huge_pte_at(dst_mm, dst_addr, dst_pte, _dst_pte);
 
-	(void)huge_ptep_set_access_flags(dst_vma, dst_addr, dst_pte, _dst_pte,
-					dst_vma->vm_flags & VM_WRITE);
 	hugetlb_count_add(pages_per_huge_page(h), dst_mm);
 
 	/* No need to invalidate - it was non-present before */
-- 
1.8.3.1