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From:   Yang Shi <shy828301@gmail.com>
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        linmiaohe@huawei.com, songliubraving@fb.com, riel@surriel.com,
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        linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org,
        linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [v2 PATCH 2/8] mm: khugepaged: remove redundant check for VM_NO_KHUGEPAGED
Date:   Thu, 17 Mar 2022 16:48:21 -0700
Message-Id: <20220317234827.447799-3-shy828301@gmail.com>
In-Reply-To: <20220317234827.447799-1-shy828301@gmail.com>
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The hugepage_vma_check() called by khugepaged_enter_vma_merge() does
check VM_NO_KHUGEPAGED. Remove the check from caller and move the check
in hugepage_vma_check() up.

More checks may be run for VM_NO_KHUGEPAGED vmas, but MADV_HUGEPAGE is
definitely not a hot path, so cleaner code does outweigh.

Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Yang Shi <shy828301@gmail.com>
---
 mm/khugepaged.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 131492fd1148..82c71c6da9ce 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -366,8 +366,7 @@ int hugepage_madvise(struct vm_area_struct *vma,
 		 * register it here without waiting a page fault that
 		 * may not happen any time soon.
 		 */
-		if (!(*vm_flags & VM_NO_KHUGEPAGED) &&
-				khugepaged_enter_vma_merge(vma, *vm_flags))
+		if (khugepaged_enter_vma_merge(vma, *vm_flags))
 			return -ENOMEM;
 		break;
 	case MADV_NOHUGEPAGE:
@@ -446,6 +445,9 @@ static bool hugepage_vma_check(struct vm_area_struct *vma,
 	if (!transhuge_vma_enabled(vma, vm_flags))
 		return false;
 
+	if (vm_flags & VM_NO_KHUGEPAGED)
+		return false;
+
 	if (vma->vm_file && !IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) -
 				vma->vm_pgoff, HPAGE_PMD_NR))
 		return false;
@@ -471,7 +473,8 @@ static bool hugepage_vma_check(struct vm_area_struct *vma,
 		return false;
 	if (vma_is_temporary_stack(vma))
 		return false;
-	return !(vm_flags & VM_NO_KHUGEPAGED);
+
+	return true;
 }
 
 int __khugepaged_enter(struct mm_struct *mm)
-- 
2.26.3