From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>,
LKML <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@elte.hu>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: Lockup in tracepoint unregister in sched switch ftrace plugin
Date: Tue, 21 Oct 2008 09:18:12 -0700 [thread overview]
Message-ID: <20081021161812.GC6853@linux.vnet.ibm.com> (raw)
In-Reply-To: <alpine.DEB.1.10.0810210012440.25193@gandalf.stny.rr.com>
On Tue, Oct 21, 2008 at 12:14:03AM -0400, Steven Rostedt wrote:
>
>
> [ Paul, Thomas, wake up ]
I am awake, but fortunately for me, Ingo woke up before I did. ;-)
(Sorry, couldn't resist...)
Thanx, Paul
> On Mon, 20 Oct 2008, Steven Rostedt wrote:
> >
> > which calls unregister_trace_sched_switch define as macro to:
> >
> > kernel/tracepoint.c: tracepoint_probe_unregister
> > " " : remove_tracepoint
> > kernel/rcupdate.c: rcu_barrier_sched
> > " " : _rcu_barrier
> >
> > where it gets stuck at that "wait_for_completion".
> >
> > I'm not sure if, because this is a scheduler trace point that we are
> > hitting some kind of race that is preventing the wait_for_completion to
> > finish, or what.
>
> Note, I just booted this kernel with CONFIG_NOHZ=n and it booted fine.
> This looks like a bug somewhere in tracepoints/RCU/dynamic-ticks
>
> -- Steve
>
prev parent reply other threads:[~2008-10-21 16:18 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-21 3:48 Lockup in tracepoint unregister in sched switch ftrace plugin Steven Rostedt
2008-10-21 4:11 ` Mathieu Desnoyers
2008-10-21 4:14 ` Steven Rostedt
2008-10-21 12:08 ` Ingo Molnar
2008-10-21 13:03 ` Steven Rostedt
2008-10-21 16:18 ` Paul E. McKenney [this message]
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