From: Ingo Molnar <mingo@kernel.org>
To: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: Leo Yan <leo.yan@linaro.org>,
Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] sched: fix tsk->pi_lock isn't held when do_set_cpus_allowed()
Date: Tue, 25 Aug 2015 10:30:59 +0200 [thread overview]
Message-ID: <20150825083059.GA20801@gmail.com> (raw)
In-Reply-To: <BLU436-SMTP1299386265B1F48065C898780610@phx.gbl>
* Wanpeng Li <wanpeng.li@hotmail.com> wrote:
> >>--- a/kernel/cpuset.c
> >>+++ b/kernel/cpuset.c
> >>@@ -2376,8 +2376,12 @@ void cpuset_cpus_allowed(struct task_struct *tsk, struct cpumask *pmask)
> >> void cpuset_cpus_allowed_fallback(struct task_struct *tsk)
> >> {
> >>+ unsigned long flags;
> >>+
> >> rcu_read_lock();
> >>+ raw_spin_lock_irqsave(&tsk->pi_lock, flags);
> >> do_set_cpus_allowed(tsk, task_cs(tsk)->effective_cpus);
> >>+ raw_spin_lock_irqsave(&tsk->pi_lock, flags);
> >Just curious, Will introduce deadlock after acquire lock twice? ;)
>
> Could you point out where acquires lock twice?
In the code you quote?
Thanks,
Ingo
next prev parent reply other threads:[~2015-08-25 8:31 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-25 7:59 [PATCH] sched: fix tsk->pi_lock isn't held when do_set_cpus_allowed() Wanpeng Li
2015-08-25 8:13 ` Leo Yan
2015-08-25 8:24 ` Wanpeng Li
2015-08-25 8:30 ` Ingo Molnar [this message]
2015-08-25 8:38 ` Wanpeng Li
2015-08-25 10:05 ` Peter Zijlstra
2015-08-25 10:10 ` Peter Zijlstra
2015-08-25 10:32 ` Peter Zijlstra
[not found] ` <BLU437-SMTP7261DF7A82716F49242C7B80610@phx.gbl>
2015-08-27 22:18 ` Peter Zijlstra
2015-08-28 1:49 ` Wanpeng Li
2015-08-25 10:18 ` Wanpeng Li
2015-08-27 13:47 ` T. Zhou
-- strict thread matches above, loose matches on Subject: below --
2015-08-25 7:56 Wanpeng Li
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