Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754479Ab3EMTkc (ORCPT ); Mon, 13 May 2013 15:40:32 -0400 Received: from www.linutronix.de ([62.245.132.108]:48996 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751229Ab3EMTkb (ORCPT ); Mon, 13 May 2013 15:40:31 -0400 Date: Mon, 13 May 2013 21:40:27 +0200 (CEST) From: Thomas Gleixner To: Jiri Kosina cc: Frederic Weisbecker , Borislav Petkov , Tony Luck , linux-kernel@vger.kernel.org, x86@kernel.org Subject: Re: NOHZ: WARNING: at arch/x86/kernel/smp.c:123 native_smp_send_reschedule In-Reply-To: Message-ID: References: <20130510002930.GB2394@somewhere> <20130510152102.GD22942@pd.tnic> <20130510154349.GB9358@somewhere> <20130510162340.GE22942@pd.tnic> <20130510213851.GC9358@somewhere> User-Agent: Alpine 2.02 (LFD 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1305 Lines: 40 On Mon, 13 May 2013, Jiri Kosina wrote: > > --- a/kernel/time/tick-sched.c > > +++ b/kernel/time/tick-sched.c > > @@ -650,6 +650,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, > > > > ts->last_tick = hrtimer_get_expires(&ts->sched_timer); > > ts->tick_stopped = 1; > > + WARN_ON_ONCE(!cpu_online(cpu)); So that warning triggers. > WARNING: at kernel/time/tick-sched.c:653 tick_nohz_stop_sched_tick+0x38e/0x3a0() The pre full dyntick idle code bailed out when a cpu was offline. The new fangled can_stop_idle_tick() function dropped that. Does the patch below fix the issue? Thanks, tglx diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index bc67d42..00a9a97 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -717,6 +717,7 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts) if (unlikely(!cpu_online(cpu))) { if (cpu == tick_do_timer_cpu) tick_do_timer_cpu = TICK_DO_TIMER_NONE; + return false; } if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE)) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/