[PATCH v7 47/70] acct: Use VMA iterator instead of linked list

[Liam Howlett]

From: "Liam R. Howlett" <Liam.Howlett at Oracle.com>

The VMA iterator is faster than the linked list.

Signed-off-by: Matthew Wilcox (Oracle) <willy at infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett at Oracle.com>
Acked-by: Vlastimil Babka <vbabka at suse.cz>
---
 kernel/acct.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/kernel/acct.c b/kernel/acct.c
index 3df53cf1dcd5..2e7bf8d41f04 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -535,15 +535,14 @@ 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);
-- 
2.34.1