From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Andrzej Siewior Subject: Re: [patch-3.18.7-rt1] sched/context-tracking: fix PREEMPT_LAZY explosions Date: Mon, 09 Mar 2015 15:45:41 +0100 Message-ID: <54FDB215.1090205@linutronix.de> References: <20150216111822.GA21649@linutronix.de> <1424258514.3819.39.camel@gmail.com> <20150309134535.GA13768@linutronix.de> <1425911771.30469.8.camel@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: linux-rt-users , LKML , Thomas Gleixner , rostedt@goodmis.org, John Kacur To: Mike Galbraith Return-path: In-Reply-To: <1425911771.30469.8.camel@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-rt-users.vger.kernel.org On 03/09/2015 03:36 PM, Mike Galbraith wrote: > On Mon, 2015-03-09 at 14:45 +0100, Sebastian Andrzej Siewior wrote: >> * Mike Galbraith | 2015-02-18 12:21:54 [+0100]: >> >>> On Mon, 2015-02-16 at 12:18 +0100, Sebastian Andrzej Siewior wrote: >>> >>>> Known issues: >>>> >>>> - lazy preempt on x86_64 leads to a crash with some load. >>> >>> The below still works for me. (it doesn't make nohz_full actually work >>> in rt, but at least folks who want to tinker with it can do so) >> So your box still crashes without it? >> >> The thing is I tried to reproduce it and it does not occur anymore. >> Neither in KVM nor on real HW. > > Heh, well that's interesting, I just presumed it would still explode > because you said it would. I'll beat on it any let you know if I'm > carrying a placebo patch or not :) Hehe. By the time I did 3.18-rt1 I was surprised that the disable- lazy-preempt-on-x8664 was still there because I assumed it has been fixed in the v3.14 series. So I left it as-is (including the broken message) and wanted to drop later an eye on it. And after you dropped a few patches to fix it I assumed (even more) that it is still broken :) > > -Mike > Sebastian