[v3 PATCH 2/8] mm: khugepaged: remove redundant check for VM_NO_KHUGEPAGED

From: Yang Shi
Date: Mon Apr 04 2022 - 17:39:01 EST


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@xxxxxxxxxx>
Acked-by: Song Liu <song@xxxxxxxxxx>
Signed-off-by: Yang Shi <shy828301@xxxxxxxxx>
---
mm/khugepaged.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index a4e5eaf3eb01..7d197d9e3258 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -365,8 +365,7 @@ 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:
@@ -445,6 +444,9 @@ 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;
@@ -470,7 +472,8 @@ 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