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From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: There is a Tasks RCU stall warning
Date: Tue, 11 Apr 2017 14:32:08 -0700	[thread overview]
Message-ID: <20170411213208.GG1600@linux.vnet.ibm.com> (raw)
In-Reply-To: <20170411172107.59030e32@gandalf.local.home>

On Tue, Apr 11, 2017 at 05:21:07PM -0400, Steven Rostedt wrote:
> On Tue, 11 Apr 2017 14:18:02 -0700
> "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> wrote:
> 
> > Hello, Steve,
> > 
> > Network connectivity issues...  :-/
> 
> ug
> 
> > There is already a Tasks RCU stall warning, but it waits for
> > ten -minutes- before complaining.  You can change this with the
> > rcupdate.rcu_task_stall_timeout kernel boot parameter, if you wish.
> > 
> > Or did you wait longer than ten minutes?
> 
> Hmm, I may have waited longer. But I can try again and shorten the
> timeout.

Failing that, you might try carefully placed printk() calls in
rcu_tasks_kthread().  The loop spinning on non-empty rcu_tasks_holdouts()
should loop at most once per second, so you can get away with quite a
bit of instrumentation.  Unlike much of the rest of RCU.  ;-)

							Thanx, Paul

  reply	other threads:[~2017-04-11 21:32 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-11 21:18 There is a Tasks RCU stall warning Paul E. McKenney
2017-04-11 21:21 ` Steven Rostedt
2017-04-11 21:32   ` Paul E. McKenney [this message]
2017-04-11 21:31 ` Steven Rostedt
2017-04-11 21:34   ` Steven Rostedt
2017-04-11 21:39     ` Steven Rostedt
2017-04-11 21:44       ` Paul E. McKenney
2017-04-11 21:49         ` Steven Rostedt
2017-04-11 21:56           ` Paul E. McKenney
2017-04-11 22:15             ` Steven Rostedt
2017-04-11 23:01               ` Paul E. McKenney
2017-04-11 23:04                 ` Paul E. McKenney
2017-04-11 23:11                   ` Paul E. McKenney
2017-04-12  3:23                     ` Paul E. McKenney
2017-04-12 13:18                       ` Steven Rostedt
2017-04-12 14:19                         ` Paul E. McKenney
2017-04-12 14:42                           ` Steven Rostedt
2017-04-12 15:18                             ` Paul E. McKenney
2017-04-12 15:53                               ` Steven Rostedt
2017-04-12 16:26                                 ` Paul E. McKenney
2017-04-12 16:49                                   ` Steven Rostedt
2017-04-12 14:48                     ` Paul E. McKenney
2017-04-12 14:59                       ` Steven Rostedt
2017-04-12 16:27                         ` Paul E. McKenney
2017-04-12 16:57                           ` Steven Rostedt
2017-04-12 17:07                             ` Paul E. McKenney
2017-04-12 17:13                               ` Steven Rostedt
2017-04-12 20:02                                 ` Paul E. McKenney

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