From: Kaixu Xia <kaixuxia@tencent.com>
Date: Tue, 2 Jun 2020 04:49:36 +0000 (-0700)
Subject: mm: memcontrol: simplify value comparison between count and limit
X-Git-Tag: v5.8-rc1~201^2~51
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=1c4448edb71ab9da35a938244602cdd75809de2b;p=users%2Fjedix%2Flinux-maple.git

mm: memcontrol: simplify value comparison between count and limit

When the variables count and limit have the same value(count == limit),
the result of min(margin, limit - count) statement should be 0 and the
variable margin is set to 0.  So in this case, the min() statement is
not necessary and we can directly set the variable margin to 0.

Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Link: http://lkml.kernel.org/r/1587479661-27237-1-git-send-email-kaixuxia@tencent.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 4bb922c02521..2243230befd2 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1314,7 +1314,7 @@ static unsigned long mem_cgroup_margin(struct mem_cgroup *memcg)
 	if (do_memsw_account()) {
 		count = page_counter_read(&memcg->memsw);
 		limit = READ_ONCE(memcg->memsw.max);
-		if (count <= limit)
+		if (count < limit)
 			margin = min(margin, limit - count);
 		else
 			margin = 0;