From: Kirill Tkhai <tkhai@yandex.ru>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@gmail.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"mingo@redhat.com" <mingo@redhat.com>,
"stable@vger.kernel.org" <stable@vger.kernel.org>
Subject: Re: [PATCH] sched/dl: Fix race between dl_task_timer() and sched_setaffinity()
Date: Tue, 20 May 2014 10:07:18 +0400 [thread overview]
Message-ID: <1694921400566038@web28j.yandex.ru> (raw)
In-Reply-To: <1413311400562533@web30m.yandex.ru>
20.05.2014, 09:08, "Kirill Tkhai" <tkhai@yandex.ru>:
> 20.05.2014, 04:00, "Peter Zijlstra" <peterz@infradead.org>:
>
>> О©╫On Mon, May 19, 2014 at 11:31:19PM +0400, Kirill Tkhai wrote:
>>> О©╫О©╫@@ -513,9 +513,17 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer)
>>> О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫struct sched_dl_entity,
>>> О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫dl_timer);
>>> О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫struct task_struct *p = dl_task_of(dl_se);
>>> О©╫О©╫- struct rq *rq = task_rq(p);
>>> О©╫О©╫+ struct rq *rq;
>>> О©╫О©╫+again:
>>> О©╫О©╫+ rq = task_rq(p);
>>> О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫О©╫raw_spin_lock(&rq->lock);
>>>
>>> О©╫О©╫+ if (unlikely(rq != task_rq(p))) {
>>> О©╫О©╫+ /* Task was moved, retrying. */
>>> О©╫О©╫+ raw_spin_unlock(&rq->lock);
>>> О©╫О©╫+ goto again;
>>> О©╫О©╫+ }
>>> О©╫О©╫+
>> О©╫That thing is called: rq = __task_rq_lock(p);
>
> But p->pi_lock is not held. The problem is __task_rq_lock() has lockdep assert.
> Should we change it?
Or make something like this?
static inline struct rq *_task_rq_lock(struct task_struct *p)
{
lockdep_assert_held(&p->pi_lock);
return __task_rq_lock(p);
}
Thanks!
next prev parent reply other threads:[~2014-05-20 6:07 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-16 21:30 [PATCH] sched/dl: Fix race between dl_task_timer() and sched_setaffinity() Kirill Tkhai
2014-05-19 13:12 ` Juri Lelli
2014-05-19 19:31 ` Kirill Tkhai
2014-05-20 0:00 ` Peter Zijlstra
2014-05-20 5:08 ` Kirill Tkhai
2014-05-20 6:07 ` Kirill Tkhai [this message]
2014-05-20 7:53 ` Peter Zijlstra
2014-05-20 8:17 ` Juri Lelli
2014-05-20 9:33 ` Kirill Tkhai
2014-05-21 7:29 ` Peter Zijlstra
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=1694921400566038@web28j.yandex.ru \
--to=tkhai@yandex.ru \
--cc=juri.lelli@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=stable@vger.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