From: Oleg Nesterov <oleg@redhat.com>
To: Amerigo Wang <amwang@redhat.com>
Cc: linux-kernel@vger.kernel.org, Tejun Heo <tj@kernel.org>,
Rusty Russell <rusty@rustcorp.com.au>,
akpm@linux-foundation.org, Ingo Molnar <mingo@elte.hu>
Subject: Re: [Patch] workqueue: move lockdep annotations up to destroy_workqueue()
Date: Wed, 31 Mar 2010 13:25:59 +0200 [thread overview]
Message-ID: <20100331112559.GA17747@redhat.com> (raw)
In-Reply-To: <20100331105534.5601.50813.sendpatchset@localhost.localdomain>
On 03/31, Amerigo Wang wrote:
>
> This fixes a lockdep warning when invoking destroy_workqueue(),
> because the lockdep annotations are invoked under cpu_add_remove_lock.
Confused. Why does lockdep complains?
> So, move the lockdep annotations before taking cpu_add_remove_lock
> in destroy_workqueue(), this will not affect the original purpose
> of adding them for destroy_workqueue() etc.
>
> However, it will affect another caller of cleanup_workqueue_thread(),
> that is, workqueue_cpu_callback(). This should be fine, because there
> are no other cases than cpu hotplug could call it.
OK, but nobody should take cpu_maps_update_begin() under wq->lockdep_map,
in particular work->func() must not.
I must have missed something, but it seems to me this patch tries to
supress the valid warning.
Could you please clarify?
Oleg.
next prev parent reply other threads:[~2010-03-31 11:28 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-31 10:51 [Patch] workqueue: move lockdep annotations up to destroy_workqueue() Amerigo Wang
2010-03-31 11:25 ` Oleg Nesterov [this message]
2010-04-01 2:45 ` Cong Wang
2010-04-01 3:56 ` Tejun Heo
2010-04-01 4:09 ` Cong Wang
2010-04-01 4:14 ` Tejun Heo
2010-04-01 4:28 ` Cong Wang
2010-04-01 4:59 ` Tejun Heo
2010-04-01 5:20 ` Cong Wang
2010-04-01 6:05 ` Cong Wang
2010-04-01 6:07 ` Cong Wang
2010-04-01 6:28 ` Tejun Heo
2010-04-01 16:36 ` Oleg Nesterov
2010-04-02 5:00 ` Cong Wang
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=20100331112559.GA17747@redhat.com \
--to=oleg@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=amwang@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=rusty@rustcorp.com.au \
--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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.