From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756808Ab1CHCGm (ORCPT ); Mon, 7 Mar 2011 21:06:42 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.123]:56132 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750754Ab1CHCGl (ORCPT ); Mon, 7 Mar 2011 21:06:41 -0500 X-Authority-Analysis: v=1.1 cv=dquaJDitHqzHCdqWSoZ6IgapSuTzW/4TaRYx9N9k4W8= c=1 sm=0 a=ABoCb2N1DRQA:10 a=Q9fys5e9bTEA:10 a=OPBmh+XkhLl+Enan7BmTLg==:17 a=20KFwNOVAAAA:8 a=VwQbUJbxAAAA:8 a=W0vUJOdyAAAA:8 a=zb5_ILVmYcTN2S5kA3MA:9 a=LQj4ebXQw0seyOYTyXAA:7 a=imCJT4yra4hDmiEL_nYp63LZxhwA:4 a=PUjeQqilurYA:10 a=x8gzFH9gYPwA:10 a=jEp0ucaQiEUA:10 a=OPBmh+XkhLl+Enan7BmTLg==:117 X-Cloudmark-Score: 0 X-Originating-IP: 67.242.120.143 Subject: Re: [PATCHv2] trace: adding unstable sched clock note to the warning From: Steven Rostedt To: Jiri Olsa Cc: linux-kernel@vger.kernel.org, fweisbec@gmail.com, mingo@elte.hu In-Reply-To: <20110307104513.GB3661@jolsa.redhat.com> References: <1296649698-6003-1-git-send-email-jolsa@redhat.com> <20110218145219.GD2604@jolsa.brq.redhat.com> <20110307104513.GB3661@jolsa.redhat.com> Content-Type: text/plain; charset="ISO-8859-15" Date: Mon, 07 Mar 2011 21:06:38 -0500 Message-ID: <1299549998.20306.48.camel@gandalf.stny.rr.com> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2011-03-07 at 11:45 +0100, Jiri Olsa wrote: > hi, > any feedback? I could pull it in. Thanks, -- Steve > > thanks, > jirka > > On Fri, Feb 18, 2011 at 03:52:19PM +0100, Jiri Olsa wrote: > > hi, > > > > warning "Delta way too big" warning might appear on a system with > > unstable shed clock right after the system is resumed and tracing > > was enabled during the suspend. > > > > Since it's not realy bug, and the unstable sched clock is working > > fast and reliable otherwise, Steven suggested to keep using the > > sched clock in any case and just to make note in the warning itself. > > > > v2 changes: > > - added CONFIG_HAVE_UNSTABLE_SCHED_CLOCK dependency > > > > wbr, > > jirka > > > > > > Signed-off-by: Jiri Olsa > > --- > > kernel/trace/ring_buffer.c | 12 ++++++++++-- > > 1 files changed, 10 insertions(+), 2 deletions(-) > > > > diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c > > index bd1c35a..37c4d3e 100644 > > --- a/kernel/trace/ring_buffer.c > > +++ b/kernel/trace/ring_buffer.c > > @@ -2162,11 +2162,19 @@ rb_reserve_next_event(struct ring_buffer *buffer, > > if (likely(ts >= cpu_buffer->write_stamp)) { > > delta = diff; > > if (unlikely(test_time_stamp(delta))) { > > + int local_clock_stable = 1; > > +#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK > > + local_clock_stable = sched_clock_stable; > > +#endif > > WARN_ONCE(delta > (1ULL << 59), > > - KERN_WARNING "Delta way too big! %llu ts=%llu write stamp = %llu\n", > > + KERN_WARNING "Delta way too big! %llu ts=%llu write stamp = %llu\n%s", > > (unsigned long long)delta, > > (unsigned long long)ts, > > - (unsigned long long)cpu_buffer->write_stamp); > > + (unsigned long long)cpu_buffer->write_stamp, > > + local_clock_stable ? "" : > > + "If you just came from a suspend/resume,\n" > > + "please switch to the trace global clock:\n" > > + " echo global > /sys/kernel/debug/tracing/trace_clock\n"); > > add_timestamp = 1; > > } > > } > > -- > > 1.7.1 > > -- > > 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/