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From: Mike Galbraith <umgwanakikbuti@gmail.com>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-rt-users <linux-rt-users@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	rostedt@goodmis.org, John Kacur <jkacur@redhat.com>
Subject: Re: [rfc patch v2] rt,nohz_full: fix nohz_full for PREEMPT_RT_FULL
Date: Tue, 17 Mar 2015 05:45:22 +0100	[thread overview]
Message-ID: <1426567522.12107.8.camel@gmail.com> (raw)
In-Reply-To: <1426557233.20938.8.camel@gmail.com>

On Tue, 2015-03-17 at 02:53 +0100, Mike Galbraith wrote:
> On Mon, 2015-03-16 at 21:24 +0100, Sebastian Andrzej Siewior wrote:

> > What you do is that you accept the fact that the timer-softirq is
> > scheduled for no reason and then you try to disable the tick from within
> > the timer-softirq. I assumed that it would work get the "expired timer"
> > somehow.
> 
> Yup, it works around that otherwise crippling wakeup.  If I re-apply..
> 
>      timers-do-not-raise-softirq-unconditionally.patch
> 
> ..the workaround is not needed of course, but the livelock fix still is.
> I haven't yet tested that in 3.18-rt though, only 4.0-rt, but I presume
> it'll be the same deal there when I do.

Did that, and it is.  Fire up tbench 4 + make -j4 on my i7-4790+smt box
booted nohz_full=2,3,6,7, death spiral begins shortly thereafter.

	-Mike


  reply	other threads:[~2015-03-17  4:45 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-16 11:18 [ANNOUNCE] 3.18.7-rt1 Sebastian Andrzej Siewior
2015-02-16 18:13 ` Sebastian Andrzej Siewior
2015-02-16 20:12 ` Richard Cochran
2015-02-16 20:21   ` Steven Rostedt
2015-02-17  8:37 ` Daniel Wagner
2015-02-19  9:36   ` Joakim Hernberg
2015-02-25 13:55     ` Sebastian Andrzej Siewior
2015-02-26  8:48       ` Sebastian Andrzej Siewior
2015-02-27  6:40         ` Daniel Wagner
2015-02-27  7:58           ` Sebastian Andrzej Siewior
2015-02-18 11:21 ` [patch-3.18.7-rt1] sched/context-tracking: fix PREEMPT_LAZY explosions Mike Galbraith
2015-02-18 11:27   ` [rfc patch-3.18.7-rt1] rt/nohz_full: Fix can_stop_full_tick() gripe within softirq Mike Galbraith
2015-02-19  4:50     ` Mike Galbraith
2015-02-19  6:30   ` [patch-3.18.7-rt1] sched/context-tracking: fix PREEMPT_LAZY explosions Mike Galbraith
2015-03-09 13:45   ` Sebastian Andrzej Siewior
2015-03-09 14:36     ` Mike Galbraith
2015-03-09 14:45       ` Sebastian Andrzej Siewior
2015-03-10  9:35       ` Mike Galbraith
2015-03-11  6:18         ` Mike Galbraith
2015-03-12  9:38         ` [rfc patch] rt,nohz_full: fix nohz_full for PREEMPT_RT_FULL Mike Galbraith
2015-03-12 15:09           ` Steven Rostedt
2015-03-13  2:13             ` Mike Galbraith
2015-03-13  3:03               ` Steven Rostedt
2015-03-13  4:53           ` [rfc patch v2] " Mike Galbraith
2015-03-16 20:24             ` Sebastian Andrzej Siewior
2015-03-17  1:53               ` Mike Galbraith
2015-03-17  4:45                 ` Mike Galbraith [this message]
2015-04-10 14:15             ` Sebastian Andrzej Siewior
2015-04-10 14:24               ` Mike Galbraith
2015-04-10 14:28               ` Mike Galbraith
2015-04-11 13:15               ` Mike Galbraith
2015-04-11 13:36                 ` Mike Galbraith
2015-04-11 14:22                   ` Mike Galbraith
2015-04-13  9:43                   ` Sebastian Andrzej Siewior
2015-04-13  9:41                 ` Sebastian Andrzej Siewior
2015-02-18 14:09 ` [patch-3.18.7-rt1] snd/pcm: fix snd_pcm_stream_lock*() irqs_disabled() splats Mike Galbraith
2015-02-25 14:08   ` Sebastian Andrzej Siewior
2015-02-18 15:05 ` [patch-3.18.7-rt1]sunrpc: make svc_xprt_do_enqueue() use get_cpu_light() Mike Galbraith
2015-02-25 14:14   ` Sebastian Andrzej Siewior

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