[PATCH 46/49] mm/mempolicy: replace nodes_weight with nodes_weight_eq

From: Yury Norov
Date: Thu Feb 10 2022 - 19:33:36 EST


do_migrate_pages() calls nodes_weight() to compare the weight
of nodemask with a given number. We can do it more efficiently with
nodes_weight_eq() because conditional nodes_weight() may stop
traversing the nodemask earlier, as soon as condition is (or is not)
met.

Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>
---
mm/mempolicy.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 7c852793d9e8..56efd00b1b6e 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1154,7 +1154,7 @@ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
* [0-7] - > [3,4,5] moves only 0,1,2,6,7.
*/

- if ((nodes_weight(*from) != nodes_weight(*to)) &&
+ if (!nodes_weight_eq(*from, nodes_weight(*to)) &&
(node_isset(s, *to)))
continue;

--
2.32.0