Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761299AbYAKJvv (ORCPT ); Fri, 11 Jan 2008 04:51:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756772AbYAKJvn (ORCPT ); Fri, 11 Jan 2008 04:51:43 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:38797 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754473AbYAKJvl (ORCPT ); Fri, 11 Jan 2008 04:51:41 -0500 Date: Fri, 11 Jan 2008 10:51:24 +0100 From: Ingo Molnar To: David Dillow Cc: Guillaume Chazarain , linux-kernel@vger.kernel.org, linux-btrace@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de Subject: Re: CONFIG_NO_HZ breaks blktrace timestamps Message-ID: <20080111095121.GG8143@elte.hu> References: <1199918912.8388.13.camel@lap75545.ornl.gov> <1199996752.9159.46.camel@lap75545.ornl.gov> <20080110234438.4826f658@inria.fr> <1200020661.5099.3.camel@obelisk.thedillows.org> <20080111094441.GF8143@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080111094441.GF8143@elte.hu> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1873 Lines: 55 * Ingo Molnar wrote: > > With those patches, CONFIG_NO_HZ works just fine. > > could you please try the two patches below, do they fix the problem as > well? They got a ton of testing in x86.git in the past ~2 months and > we could perhaps still push them into v2.6.24. plus, if needed, perhaps this patch below from Guillaume ontop of it. Ingo ----------------> Subject: sched: fix rq->clock warps on frequency changes From: Guillaume Chazarain sched: fix rq->clock warps on frequency changes Fix 2bacec8c318ca0418c0ee9ac662ee44207765dd4 (sched: touch softlockup watchdog after idling) that reintroduced warps on frequency changes. touch_softlockup_watchdog() calls __update_rq_clock that checks rq->clock for warps, so call it after adjusting rq->clock. Signed-off-by: Guillaume Chazarain Signed-off-by: Ingo Molnar --- kernel/sched.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux-x86.q/kernel/sched.c =================================================================== --- linux-x86.q.orig/kernel/sched.c +++ linux-x86.q/kernel/sched.c @@ -668,7 +668,6 @@ void sched_clock_idle_wakeup_event(u64 d struct rq *rq = cpu_rq(smp_processor_id()); u64 now = sched_clock(); - touch_softlockup_watchdog(); rq->idle_clock += delta_ns; /* * Override the previous timestamp and ignore all @@ -680,6 +679,7 @@ void sched_clock_idle_wakeup_event(u64 d rq->prev_clock_raw = now; rq->clock += delta_ns; spin_unlock(&rq->lock); + touch_softlockup_watchdog(); } EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event); -- 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/