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: 28+ 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 ` [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
2011-09-12 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
2011-09-05 4:05 ` [PATCHSET cgroup] extend threadgroup locking Rafael J. Wysocki
2011-09-05 8:43 ` Tejun Heo
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
2011-09-12 4:11 ` Paul Menage
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20110918185621.GB6159@redhat.com \
--to=oleg@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=containers@lists.linux-foundation.org \
--cc=fweisbec@gmail.com \
--cc=htejun@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@lists.linux-foundation.org \
--cc=lizf@cn.fujitsu.com \
--cc=matthltc@us.ibm.com \
--cc=menage@google.com \
--cc=paul@paulmenage.org \
--cc=rjw@sisk.pl \
--cc=tj@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Powered by JetHome