From: Johannes Weiner <hannes@cmpxchg.org>
To: Tejun Heo <tj@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Vladimir Davydov <vdavydov@virtuozzo.com>,
Michal Hocko <mhocko@suse.cz>, Li Zefan <lizefan@huawei.com>,
linux-mm@kvack.org, cgroups@vger.kernel.org,
linux-kernel@vger.kernel.org, kernel-team@fb.com
Subject: [PATCH 2/3] cgroup: remove unnecessary 0 check from css_from_id()
Date: Fri, 17 Jun 2016 12:24:27 -0400 [thread overview]
Message-ID: <20160617162427.GC19084@cmpxchg.org> (raw)
In-Reply-To: <20160617162310.GA19084@cmpxchg.org>
css_idr allocation starts at 1, so index 0 will never point to an
item. css_from_id() currently filters that before asking idr_find(),
but idr_find() would also just return NULL, so this is not needed.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
---
kernel/cgroup.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 36fc0ff506c3..78f6d18ff0af 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -6162,7 +6162,7 @@ struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry,
struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss)
{
WARN_ON_ONCE(!rcu_read_lock_held());
- return id > 0 ? idr_find(&ss->css_idr, id) : NULL;
+ return idr_find(&ss->css_idr, id);
}
/**
--
2.8.3
--
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next prev parent reply other threads:[~2016-06-17 16:26 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-16 3:42 [PATCH] mm: memcontrol: fix cgroup creation failure after many small jobs Johannes Weiner
2016-06-16 20:06 ` Tejun Heo
2016-06-17 16:23 ` Johannes Weiner
2016-06-17 16:23 ` [PATCH 1/3] cgroup: fix idr leak for the first cgroup root Johannes Weiner
2016-06-17 16:24 ` Johannes Weiner [this message]
2016-06-17 18:17 ` [PATCH 2/3] cgroup: remove unnecessary 0 check from css_from_id() Tejun Heo
2016-06-17 16:25 ` [PATCH 3/3] mm: memcontrol: fix cgroup creation failure after many small jobs Johannes Weiner
2016-06-17 18:18 ` Tejun Heo
2016-06-20 6:14 ` Nikolay Borisov
2016-06-21 10:16 ` Vladimir Davydov
2016-06-21 15:46 ` Johannes Weiner
2016-06-17 9:06 ` [PATCH] " Vladimir Davydov
2016-06-17 16:40 ` Johannes Weiner
2016-07-14 15:37 ` Johannes Weiner
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