From: Oleg Nesterov <oleg@redhat.com>
To: Tejun Heo <htejun@gmail.com>
Cc: rjw@sisk.pl, paul@paulmenage.org, lizf@cn.fujitsu.com,
linux-pm@lists.linux-foundation.org,
linux-kernel@vger.kernel.org,
containers@lists.linux-foundation.org, fweisbec@gmail.com,
matthltc@us.ibm.com, akpm@linux-foundation.org,
Tejun Heo <tj@kernel.org>, Paul Menage <menage@google.com>
Subject: Re: [PATCH 1/4] cgroup: change locking order in attach_task_by_pid()
Date: Sun, 18 Sep 2011 20:56:21 +0200 [thread overview]
Message-ID: <20110918185621.GB6159@redhat.com> (raw)
In-Reply-To: <1315159280-25032-2-git-send-email-htejun@gmail.com>
On 09/05, Tejun Heo wrote:
>
> cgroup_mutex is updated to nest inside threadgroup_fork_lock instead
> of the other way around. threadgroup locking is scheduled to be
> updated to cover all threadgroup altering operations and nesting it
> inside cgroup_mutex complicates locking dependency unnecessarily.
Could you please explain this change?
I can't understand why threadgroup_lock() under cgroup_mutex is bad.
Do you mean we can deadlock otherwise?
And, this means we can't change cpuset_do_move_task() to do
threadgroup_lock().
Oleg.
next prev parent reply other threads:[~2011-09-18 19:00 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-04 18:01 [PATCHSET cgroup] extend threadgroup locking Tejun Heo
2011-09-04 18:01 ` [PATCH 1/4] cgroup: change locking order in attach_task_by_pid() Tejun Heo
2011-09-18 18:56 ` Oleg Nesterov [this message]
2011-10-10 17:34 ` Tejun Heo
2011-10-10 17:43 ` Tejun Heo
2011-09-04 18:01 ` Tejun Heo
2011-09-04 18:01 ` [PATCH 2/4] threadgroup: rename signal->threadgroup_fork_lock to ->group_rwsem Tejun Heo
2011-09-04 18:01 ` Tejun Heo
2011-09-04 18:01 ` [PATCH 3/4] threadgroup: extend threadgroup_lock() to cover exit and exec Tejun Heo
2011-09-04 18:01 ` Tejun Heo
2011-09-12 4:04 ` Paul Menage
2011-09-13 7:54 ` Tejun Heo
2011-09-18 17:37 ` Oleg Nesterov
2011-09-18 18:46 ` Oleg Nesterov
2011-10-08 18:37 ` Ben Blum
2011-10-10 17:11 ` Tejun Heo
2011-10-12 17:51 ` Oleg Nesterov
2011-10-12 18:05 ` Ben Blum
2011-10-12 18:29 ` Oleg Nesterov
2011-10-12 18:44 ` Ben Blum
2011-10-12 19:07 ` Oleg Nesterov
2011-09-04 18:01 ` [PATCH 4/4] cgroup: always lock threadgroup during migration Tejun Heo
2011-09-18 17:41 ` Oleg Nesterov
2011-10-10 17:31 ` Tejun Heo
2011-09-04 18:01 ` Tejun Heo
[not found] ` <1315159280-25032-1-git-send-email-htejun-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2011-09-04 18:01 ` [PATCH 1/4] cgroup: change locking order in attach_task_by_pid() Tejun Heo
2011-09-04 18:01 ` [PATCH 2/4] threadgroup: rename signal->threadgroup_fork_lock to ->group_rwsem Tejun Heo
2011-09-04 18:01 ` [PATCH 3/4] threadgroup: extend threadgroup_lock() to cover exit and exec Tejun Heo
2011-09-04 18:01 ` [PATCH 4/4] cgroup: always lock threadgroup during migration Tejun Heo
2011-09-05 4:05 ` [PATCHSET cgroup] extend threadgroup locking Rafael J. Wysocki
2011-09-06 9:00 ` Li Zefan
2011-09-11 3:35 ` Tejun Heo
2011-09-05 4:05 ` Rafael J. Wysocki
2011-09-05 4:05 ` Rafael J. Wysocki
2011-09-05 8:43 ` Tejun Heo
[not found] ` <201109050605.57360.rjw-KKrjLPT3xs0@public.gmane.org>
2011-09-05 8:43 ` Tejun Heo
2011-09-05 8:43 ` Tejun Heo
2011-09-06 9:00 ` Li Zefan
2011-09-06 9:00 ` Li Zefan
2011-09-11 3:35 ` Tejun Heo
2011-09-14 18:33 ` Oleg Nesterov
2011-09-14 23:33 ` Tejun Heo
2011-09-11 3:35 ` Tejun Heo
2011-09-12 4:11 ` Paul Menage
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