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

Commit Message

Miaohe Lin Oct. 12, 2020, 1:16 p.m. UTC

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

Comments

Johannes Weiner Oct. 12, 2020, 1:58 p.m. UTC | #1

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 <[e-mail]>
> Signed-off-by: Miaohe Lin <[e-mail]>

Looks good to me.

Acked-by: Johannes Weiner <[e-mail]>

Patch

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)