From: Li Zefan <lizefan@huawei.com>
To: Tejun Heo <tj@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>, cgroups <cgroups@vger.kernel.org>
Subject: [PATCH 2/2] cpuset: remove redundant checks in file write functions
Date: Tue, 13 Aug 2013 09:17:53 +0800 [thread overview]
Message-ID: <52098941.4070600@huawei.com> (raw)
In-Reply-To: <5209892D.8070502@huawei.com>
Now cgroup core gets a reference to the css when a cgroup file is
opened(), and the reference is dropped at file release. so it's
guaranteed the cpuset is online during the write function.
Signed-off-by: Li Zefan <lizefan@huawei.com>
---
kernel/cpuset.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 9d8d637..8c4b3c4 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1589,8 +1589,6 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft,
int retval = -ENODEV;
mutex_lock(&cpuset_mutex);
- if (!is_cpuset_online(cs))
- goto out_unlock;
switch (type) {
case FILE_CPU_EXCLUSIVE:
@@ -1624,7 +1622,7 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft,
retval = -EINVAL;
break;
}
-out_unlock:
+
mutex_unlock(&cpuset_mutex);
return retval;
}
@@ -1637,8 +1635,6 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
int retval = -ENODEV;
mutex_lock(&cpuset_mutex);
- if (!is_cpuset_online(cs))
- goto out_unlock;
switch (type) {
case FILE_SCHED_RELAX_DOMAIN_LEVEL:
@@ -1648,7 +1644,7 @@ static int cpuset_write_s64(struct cgroup_subsys_state *css, struct cftype *cft,
retval = -EINVAL;
break;
}
-out_unlock:
+
mutex_unlock(&cpuset_mutex);
return retval;
}
@@ -1677,8 +1673,6 @@ static int cpuset_write_resmask(struct cgroup_subsys_state *css,
flush_work(&cpuset_hotplug_work);
mutex_lock(&cpuset_mutex);
- if (!is_cpuset_online(cs))
- goto out_unlock;
trialcs = alloc_trial_cpuset(cs);
if (!trialcs) {
--
1.8.0.2
next prev parent reply other threads:[~2013-08-13 1:17 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-13 1:17 [PATCH 1/2] cpuset: remove an unncessary forward declaration Li Zefan
2013-08-13 1:17 ` Li Zefan [this message]
2013-08-13 2:07 ` [PATCH 2/2] cpuset: remove redundant checks in file write functions Li Zefan
2013-08-13 15:05 ` Tejun Heo
2013-08-14 2:01 ` Li Zefan
2013-08-14 13:30 ` Tejun Heo
2013-08-16 6:48 ` Li Zefan
2013-08-13 14:53 ` [PATCH 1/2] cpuset: remove an unncessary forward declaration Tejun Heo
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