Messages in this thread | | | Date | Mon, 19 Dec 2011 03:01:49 +0100 | From | Frederic Weisbecker <> | Subject | Re: [PATCH] cgroup: remove redundate get/put of old css_set from migrate |
| |
On Fri, Dec 16, 2011 at 08:38:31AM -0800, Mandeep Singh Baines wrote: > We can now assume that the css_set reference held by the task > will not go away for an exiting task. PF_EXITING state can be > trusted throughout migration by checking it after locking > threadgroup. > > This patch depends on: > > commit cd3d095275374220921fcf0d4e0c16584b26ddbc > Author: Tejun Heo <tj@kernel.org> > Date: Mon Dec 12 18:12:21 2011 -0800 > > cgroup: always lock threadgroup during migration > > Signed-off-by: Mandeep Singh Baines <msb@chromium.org> > Cc: Tejun Heo <tj@kernel.org> > Cc: Li Zefan <lizf@cn.fujitsu.com> > Cc: containers@lists.linux-foundation.org > Cc: cgroups@vger.kernel.org > Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> > Cc: Frederic Weisbecker <fweisbec@gmail.com> > Cc: Oleg Nesterov <oleg@redhat.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Paul Menage <paul@paulmenage.org> > --- > kernel/cgroup.c | 25 ++++++------------------- > 1 files changed, 6 insertions(+), 19 deletions(-) > > diff --git a/kernel/cgroup.c b/kernel/cgroup.c > index 1b3b841..eb95e32 100644 > --- a/kernel/cgroup.c > +++ b/kernel/cgroup.c > @@ -1856,7 +1856,6 @@ static int cgroup_task_migrate(struct cgroup *cgrp, struct cgroup *oldcgrp, > */ > task_lock(tsk); > oldcg = tsk->cgroups; > - get_css_set(oldcg); > task_unlock(tsk);
Seems we don't need these task_lock() anymore. I'm cooking a patch to clean that up.
| |