During testing, I found ksm_pages_scanned is unchanged although the
scan_get_next_rmap_item() did return valid rmap_item that is not NULL.
The reason is the scan_get_next_rmap_item() will return NULL after
a full scan, so ksm_do_scan() just return without accounting of the
ksm_pages_scanned.
Fix it by just putting ksm_pages_scanned accounting in that loop,
and it will be accounted more timely if that loop would last for
a long time.
Fixes: b348b5fe2b5f ("mm/ksm: add pages scanned metric")
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: xu xin <xu.xin16@xxxxxxxxxx>
Signed-off-by: Chengming Zhou <chengming.zhou@xxxxxxxxx>
---
mm/ksm.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/mm/ksm.c b/mm/ksm.c
index 452ac8346e6e..9e99cb12d330 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -2754,18 +2754,16 @@ static void ksm_do_scan(unsigned int scan_npages)
{
struct ksm_rmap_item *rmap_item;
struct page *page;
- unsigned int npages = scan_npages;
- while (npages-- && likely(!freezing(current))) {
+ while (scan_npages-- && likely(!freezing(current))) {
cond_resched();
rmap_item = scan_get_next_rmap_item(&page);
if (!rmap_item)
return;
cmp_and_merge_page(page, rmap_item);
put_page(page);
+ ksm_pages_scanned++;
}
-
- ksm_pages_scanned += scan_npages - npages;
}
static int ksmd_should_run(void)
--
2.45.1
