From: Tejun Heo <tj@kernel.org>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>,
Mandeep Singh Baines <msb@chromium.org>,
linux-kernel@vger.kernel.org,
containers@lists.linux-foundation.org, cgroups@vger.kernel.org,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Oleg Nesterov <oleg@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Paul Menage <paul@paulmenage.org>
Subject: Re: [PATCH 4/4] cgroup: remove extra calls to find_existing_css_set
Date: Thu, 22 Dec 2011 07:40:37 -0800 [thread overview]
Message-ID: <20111222154037.GC17084@google.com> (raw)
In-Reply-To: <20111222094437.GO17668@somewhere>
On Thu, Dec 22, 2011 at 10:44:39AM +0100, Frederic Weisbecker wrote:
> > > if (ent.cgrp == cgrp)
> > > continue;
> > > + ent.cg = find_css_set(tsk->cgroups, cgrp);
> >
> > unfortunately This won't work, because we are holding tasklist_lock.
>
> I believe we can remove tasklist_lock now (in a seperate patch).
>
> It was there in order to protect while_each_thread() against exec but
> now we have threadgroup_lock().
>
> I think we only need to use rcu_read_lock() to protect against concurrent
> removal in exit.
Yeah, that should work and I really like this patch.
kernel/cgroup.c | 152 ++++++++++++-------------------------------------------
1 files changed, 32 insertions(+), 120 deletions(-)
Let's get it working. :)
Thanks.
--
tejun
next prev parent reply other threads:[~2011-12-22 15:40 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-22 4:18 [PATCH 1/4] cgroup: remove redundant get/put of old css_set from migrate Mandeep Singh Baines
2011-12-22 4:18 ` [PATCH 2/4] cgroup: remove redundant get/put of task struct Mandeep Singh Baines
2011-12-22 5:36 ` Li Zefan
2011-12-22 4:18 ` [PATCH 3/4] cgroup: only need to check oldcgrp==newgrp once Mandeep Singh Baines
2011-12-22 15:38 ` Tejun Heo
2011-12-22 4:18 ` [PATCH 4/4] cgroup: remove extra calls to find_existing_css_set Mandeep Singh Baines
2011-12-22 5:50 ` Li Zefan
2011-12-22 9:44 ` Frederic Weisbecker
2011-12-22 15:40 ` Tejun Heo [this message]
2011-12-22 5:11 ` [PATCH 1/4] cgroup: remove redundant get/put of old css_set from migrate Li Zefan
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