linux-kernel - [PATCH v2] mm: memcontrol: eliminate redundant check in __mem_cgroup_insert

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Message-ID: <20201012131607.10656-1-linmiaohe@huawei.com>
Date:   Mon, 12 Oct 2020 09:16:07 -0400
From:   Miaohe Lin <linmiaohe@...wei.com>
To:     <akpm@...ux-foundation.org>, <hannes@...xchg.org>,
        <mhocko@...nel.org>, <vdavydov.dev@...il.com>
CC:     <cgroups@...r.kernel.org>, <linux-mm@...ck.org>,
        <linux-kernel@...r.kernel.org>, <linmiaohe@...wei.com>
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 <mhocko@...e.com>
Signed-off-by: Miaohe Lin <linmiaohe@...wei.com>
---
 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