From: Ingo Molnar <mingo@elte.hu>
To: Mark_H_Johnson@raytheon.com
Cc: Amit Shah <amit.shah@codito.com>,
Karsten Wiese <annabellesgarden@yahoo.de>,
Bill Huey <bhuey@lnxw.com>, Adam Heath <doogie@debian.org>,
emann@mrv.com, Gunther Persoons <gunther_persoons@spymac.com>,
"K.R. Foley" <kr@cybsft.com>,
linux-kernel@vger.kernel.org,
Florian Schmidt <mista.tapas@gmx.net>,
Fernando Pablo Lopez-Lezcano <nando@ccrma.Stanford.EDU>,
Lee Revell <rlrevell@joe-job.com>,
Rui Nuno Capela <rncbc@rncbc.org>,
Shane Shrybman <shrybman@aei.ca>,
Esben Nielsen <simlo@phys.au.dk>,
Thomas Gleixner <tglx@linutronix.de>,
Michal Schmidt <xschmi00@stud.feec.vutbr.cz>
Subject: Re: [patch] Real-Time Preemption, -RT-2.6.10-rc2-mm2-V0.7.30-2
Date: Tue, 23 Nov 2004 12:46:39 +0100 [thread overview]
Message-ID: <20041123114639.GA23730@elte.hu> (raw)
In-Reply-To: <20041122221224.GA13799@elte.hu>
* Ingo Molnar <mingo@elte.hu> wrote:
> * Mark_H_Johnson@raytheon.com <Mark_H_Johnson@raytheon.com> wrote:
>
> > - echo 0 > /proc/sys/kernel/preempt_wakeup_timing [entered, but
> > display was frozen at this point and did not see newline nor any
> > further output]
>
> managed to reproduce this on an SMP box but not on an UP box, so i
> think this is SMP related. It definitely happens almost immediately
> after preempt_wakeup_timing is reset - or after preempt_max_timing is
> reset. (Perhaps a dump_stack() from the wrong place, or something
> like that.)
The lockup was caused by the mutex wakeup being done under the PI lock,
and if a new critical-section latency is reported within try_to_wake_up
then the trylock done there deadlocked. The NMI watchdog triggered but
the printks done there deadlocked as well.
I fixed both the deadlock scenario, and made the NMI printout path more
robust to get the messages out to the console in even such a case.
The fixes are in the latest (-30-4) patch which can be found at the
usual place:
http://redhat.com/~mingo/realtime-preempt/
Ingo
next prev parent reply other threads:[~2004-11-23 10:46 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-11-22 16:06 [patch] Real-Time Preemption, -RT-2.6.10-rc2-mm2-V0.7.30-2 Mark_H_Johnson
2004-11-22 22:12 ` Ingo Molnar
2004-11-22 21:21 ` K.R. Foley
2004-11-23 11:46 ` Ingo Molnar [this message]
2004-11-23 4:43 ` Adam Heath
2004-11-23 11:52 ` Ingo Molnar
2004-11-23 18:07 ` Adam Heath
2004-11-23 19:17 ` [patch] Real-Time Preemption, -RT-2.6.10-rc2-mm2-V0.7.29-0, and 30-9 Adam Heath
2004-11-23 21:22 ` Steven Rostedt
2004-11-23 21:47 ` Lee Revell
2004-11-23 22:22 ` Steven Rostedt
2004-11-24 3:27 ` Ingo Molnar
2004-11-24 4:06 ` [patch] Real-Time Preemption, -RT-2.6.10-rc2-mm2-V0.7.30-2 Ingo Molnar
2004-11-24 9:00 ` Adam Heath
2004-11-25 3:22 ` Adam Heath
2004-11-25 17:02 ` Ingo Molnar
2004-11-25 17:13 ` Adam Heath
-- strict thread matches above, loose matches on Subject: below --
2004-11-22 19:12 Mark_H_Johnson
2004-11-22 19:00 Mark_H_Johnson
2004-11-22 17:12 Mark_H_Johnson
2004-11-22 16:44 Mark_H_Johnson
2004-11-08 16:57 [patch] Real-Time Preemption, -RT-2.6.10-rc1-mm3-V0.7.21 Ingo Molnar
2004-11-09 16:05 ` [patch] Real-Time Preemption, -RT-2.6.10-rc1-mm3-V0.7.23 Ingo Molnar
2004-11-11 14:44 ` [patch] Real-Time Preemption, -RT-2.6.10-rc1-mm3-V0.7.25-0 Ingo Molnar
2004-11-11 21:51 ` [patch] Real-Time Preemption, -RT-2.6.10-rc1-mm3-V0.7.25-1 Ingo Molnar
2004-11-16 12:54 ` [patch] Real-Time Preemption, -RT-2.6.10-rc2-mm1-V0.7.27-0 Ingo Molnar
2004-11-16 13:09 ` [patch] Real-Time Preemption, -RT-2.6.10-rc2-mm1-V0.7.27-1 Ingo Molnar
2004-11-16 13:40 ` [patch] Real-Time Preemption, -RT-2.6.10-rc2-mm1-V0.7.27-3 Ingo Molnar
2004-11-17 12:42 ` [patch] Real-Time Preemption, -RT-2.6.10-rc2-mm1-V0.7.28-0 Ingo Molnar
2004-11-18 12:35 ` [patch] Real-Time Preemption, -RT-2.6.10-rc2-mm1-V0.7.28-1 Ingo Molnar
2004-11-18 16:46 ` [patch] Real-Time Preemption, -RT-2.6.10-rc2-mm2-V0.7.29-0 Ingo Molnar
2004-11-22 0:54 ` [patch] Real-Time Preemption, -RT-2.6.10-rc2-mm2-V0.7.30-2 Ingo Molnar
2004-11-22 1:07 ` Florian Schmidt
2004-11-22 9:46 ` Ingo Molnar
2004-11-22 10:36 ` Rui Nuno Capela
2004-11-22 13:24 ` Ingo Molnar
2004-11-22 12:56 ` Rui Nuno Capela
2004-11-22 15:00 ` Ingo Molnar
2004-11-22 15:10 ` Ingo Molnar
2004-11-22 15:20 ` Ingo Molnar
2004-11-22 13:27 ` Florian Schmidt
2004-11-22 14:18 ` Rui Nuno Capela
2004-11-22 15:41 ` Ingo Molnar
2004-11-22 15:45 ` Ingo Molnar
2004-11-22 16:53 ` Rui Nuno Capela
2004-11-23 13:55 ` Ingo Molnar
2004-11-23 13:56 ` Ingo Molnar
2004-11-23 13:58 ` Ingo Molnar
2004-11-23 14:11 ` Ingo Molnar
2004-11-23 14:32 ` Ingo Molnar
2004-11-23 14:41 ` Ingo Molnar
2004-11-23 14:00 ` Rui Nuno Capela
2004-11-23 15:41 ` Ingo Molnar
2004-11-23 16:53 ` Rui Nuno Capela
2004-11-23 18:00 ` Ingo Molnar
2004-11-23 14:46 ` Ingo Molnar
2004-11-23 13:57 ` Florian Schmidt
2004-11-23 15:05 ` Ingo Molnar
2004-11-23 15:21 ` Ingo Molnar
2004-11-23 14:41 ` Florian Schmidt
2004-12-01 13:57 ` Paul Davis
2004-12-01 14:37 ` Ingo Molnar
2004-12-01 14:56 ` Paul Davis
2004-12-01 15:53 ` Ingo Molnar
2004-12-01 16:05 ` Paul Davis
2004-12-01 16:16 ` Esben Nielsen
2004-12-01 21:24 ` Ingo Molnar
2004-12-01 21:40 ` Chris Friesen
2004-12-01 16:08 ` Esben Nielsen
2004-11-23 14:53 ` Ingo Molnar
2004-11-22 8:44 ` Eran Mann
2004-11-22 10:01 ` Ingo Molnar
2004-11-22 13:34 ` Eran Mann
2004-11-22 14:42 ` Ingo Molnar
2004-11-23 8:24 ` Eran Mann
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