2020-10-12 13:36:10

by Miaohe Lin

Subject: [PATCH v2] mm: memcontrol: eliminate redundant check in __mem_cgroup_insert_exceeded()

The mz->usage_in_excess >= mz_node->usage_in_excess check is exactly the
else case of mz->usage_in_excess < mz_node->usage_in_excess. So we could
replace else if (mz->usage_in_excess >= mz_node->usage_in_excess) with else
equally. Also drop the comment which doesn't really explain much.

Acked-by: Michal Hocko <[email protected]>
Signed-off-by: Miaohe Lin <[email protected]>
---
mm/memcontrol.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 2636f8bad908..b080a9434b9e 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -623,14 +623,9 @@ static void __mem_cgroup_insert_exceeded(struct mem_cgroup_per_node *mz,
if (mz->usage_in_excess < mz_node->usage_in_excess) {
p = &(*p)->rb_left;
rightmost = false;
- }
-
- /*
- * We can't avoid mem cgroups that are over their soft
- * limit by the same amount
- */
- else if (mz->usage_in_excess >= mz_node->usage_in_excess)
+ } else {
p = &(*p)->rb_right;
+ }
}

if (rightmost)
--
2.19.1

2020-10-12 14:04:06

by Johannes Weiner

Subject: Re: [PATCH v2] mm: memcontrol: eliminate redundant check in __mem_cgroup_insert_exceeded()

On Mon, Oct 12, 2020 at 09:16:07AM -0400, Miaohe Lin wrote:
> The mz->usage_in_excess >= mz_node->usage_in_excess check is exactly the
> else case of mz->usage_in_excess < mz_node->usage_in_excess. So we could
> replace else if (mz->usage_in_excess >= mz_node->usage_in_excess) with else
> equally. Also drop the comment which doesn't really explain much.
>
> Acked-by: Michal Hocko <[email protected]>
> Signed-off-by: Miaohe Lin <[email protected]>

Looks good to me.

Acked-by: Johannes Weiner <[email protected]>