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author | Li Zefan <lizefan@huawei.com> | 2013-03-13 02:35:59 +0400 |
---|---|---|
committer | Tejun Heo <tj@kernel.org> | 2013-03-13 02:35:59 +0400 |
commit | d7eeac1913ff86a17f891cb4b73f03d4b94907d0 (patch) | |
tree | 1e44fde86b626dbeb7c27f007eeebce7d47ef206 | |
parent | 6dc01181eac16192dc4a5d1b310b78e2e97c003c (diff) | |
download | linux-d7eeac1913ff86a17f891cb4b73f03d4b94907d0.tar.xz |
cgroup: hold cgroup_mutex before calling css_offline()
cpuset no longer nests cgroup_mutex inside cpu_hotplug lock, so
we don't have to release cgroup_mutex before calling css_offline().
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
-rw-r--r-- | Documentation/cgroups/cgroups.txt | 1 | ||||
-rw-r--r-- | kernel/cgroup.c | 11 |
2 files changed, 2 insertions, 10 deletions
diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt index bcf1a00b06a1..0028e888828c 100644 --- a/Documentation/cgroups/cgroups.txt +++ b/Documentation/cgroups/cgroups.txt @@ -580,6 +580,7 @@ propagation along the hierarchy. See the comment on cgroup_for_each_descendant_pre() for details. void css_offline(struct cgroup *cgrp); +(cgroup_mutex held by caller) This is the counterpart of css_online() and called iff css_online() has succeeded on @cgrp. This signifies the beginning of the end of diff --git a/kernel/cgroup.c b/kernel/cgroup.c index fd0b056d8da5..49297cbc134d 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -4169,17 +4169,8 @@ static void offline_css(struct cgroup_subsys *ss, struct cgroup *cgrp) if (!(css->flags & CSS_ONLINE)) return; - /* - * css_offline() should be called with cgroup_mutex unlocked. See - * 3fa59dfbc3 ("cgroup: fix potential deadlock in pre_destroy") for - * details. This temporary unlocking should go away once - * cgroup_mutex is unexported from controllers. - */ - if (ss->css_offline) { - mutex_unlock(&cgroup_mutex); + if (ss->css_offline) ss->css_offline(cgrp); - mutex_lock(&cgroup_mutex); - } cgrp->subsys[ss->subsys_id]->flags &= ~CSS_ONLINE; } |