[PATCH v13 46/70] acct: use VMA iterator instead of linked list

From: Liam Howlett
Date: Mon Aug 22 2022 - 11:37:01 EST


From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>

The VMA iterator is faster than the linked list.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
---
kernel/acct.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/kernel/acct.c b/kernel/acct.c
index 13706356ec54..62200d799b9b 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -555,15 +555,14 @@ void acct_collect(long exitcode, int group_dead)
unsigned long vsize = 0;

if (group_dead && current->mm) {
+ struct mm_struct *mm = current->mm;
+ VMA_ITERATOR(vmi, mm, 0);
struct vm_area_struct *vma;

- mmap_read_lock(current->mm);
- vma = current->mm->mmap;
- while (vma) {
+ mmap_read_lock(mm);
+ for_each_vma(vmi, vma)
vsize += vma->vm_end - vma->vm_start;
- vma = vma->vm_next;
- }
- mmap_read_unlock(current->mm);
+ mmap_read_unlock(mm);
}

spin_lock_irq(&current->sighand->siglock);
--
2.35.1