Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761962AbYFEXxd (ORCPT ); Thu, 5 Jun 2008 19:53:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752850AbYFEXx0 (ORCPT ); Thu, 5 Jun 2008 19:53:26 -0400 Received: from hs-out-0708.google.com ([64.233.178.241]:33495 "EHLO hs-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752519AbYFEXxZ (ORCPT ); Thu, 5 Jun 2008 19:53:25 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=N3c7u9F/dPg5wcLsu0PK0Kq1CWM0L5Uh6ONXbD0HwvaMITKuld/RO526g7B/zEP6SZ ylVP1B1qa65lkdk0hxN1i8QpFZnaDnFZAj1a3RQcttJ0FwQ8EhXXD/m+xeRCPEbufpis dcokC9nuLgZQPmj8Ac+cPpnBxb++dD3XnKRFQ= Message-ID: <48487C69.7000202@gmail.com> Date: Thu, 05 Jun 2008 20:53:13 -0300 From: Kevin Winchester User-Agent: Thunderbird 2.0.0.14 (X11/20080505) MIME-Version: 1.0 To: Ingo Molnar CC: Sitsofe Wheeler , Thomas Gleixner , Linux Kernel Mailing List Subject: Re: [X86][BISECTED] WARNING: at kernel/lockdep.c:2680 References: <4844868F.20104@gmail.com> <1212483192.6304.8.camel@twins> <20080605130823.GD6332@elte.hu> In-Reply-To: <20080605130823.GD6332@elte.hu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2666 Lines: 84 Ingo Molnar wrote: > * Sitsofe Wheeler wrote: > >> OK I've managed to bisect this down to commit >> [c6531cce6e6e4b99bcda46b6268d6f2d9e30aea4] (sched: do not trace >> sched_clock): >> >> commit c6531cce6e6e4b99bcda46b6268d6f2d9e30aea4 >> Author: Ingo Molnar >> Date: Mon May 12 21:21:14 2008 +0200 >> >> sched: do not trace sched_clock >> >> The tracer uses sched_clock, so do not trace it. >> >> Signed-off-by: Ingo Molnar >> Signed-off-by: Thomas Gleixner >> >> Reverting this made the lockdep warning go away. Here is the bisection log: > > ah, good find! Does the patch below (instead of the full revert) fix it > as well? I've queued the fix up into tip/tracing/ftrace. > > Ingo > > ----------------> > Subject: sched: sched_clock() lockdep fix > From: Ingo Molnar > Date: Thu Jun 05 15:04:17 CEST 2008 > > Sitsofe Wheeler reported a lockdep warning and bisected it down to: > >> commit c6531cce6e6e4b99bcda46b6268d6f2d9e30aea4 >> Author: Ingo Molnar >> Date: Mon May 12 21:21:14 2008 +0200 >> >> sched: do not trace sched_clock > > do not use raw irq flags in cpu_clock() as it causes lockdep to lose > track of the true state of the IRQ flag. > > Reported-and-bisected-by: Sitsofe Wheeler > Signed-off-by: Ingo Molnar > --- > kernel/sched.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > Index: linux/kernel/sched.c > =================================================================== > --- linux.orig/kernel/sched.c > +++ linux/kernel/sched.c > @@ -862,7 +862,7 @@ unsigned long long notrace cpu_clock(int > unsigned long long prev_cpu_time, time, delta_time; > unsigned long flags; > > - raw_local_irq_save(flags); > + local_irq_save(flags); > prev_cpu_time = per_cpu(prev_cpu_time, cpu); > time = __cpu_clock(cpu) + per_cpu(time_offset, cpu); > delta_time = time-prev_cpu_time; > @@ -871,7 +871,7 @@ unsigned long long notrace cpu_clock(int > time = __sync_cpu_clock(time, cpu); > per_cpu(prev_cpu_time, cpu) = time; > } > - raw_local_irq_restore(flags); > + local_irq_restore(flags); > > return time; > } > I didn't manage to get through a bisection run for the warning - thanks to Sitsofe for doing it. The patch does eliminate the warning for me. Thanks, -- Kevin Winchester -- 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/