From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754693Ab1BHWRX (ORCPT ); Tue, 8 Feb 2011 17:17:23 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:43765 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752983Ab1BHWRV (ORCPT ); Tue, 8 Feb 2011 17:17:21 -0500 X-Authority-Analysis: v=1.1 cv=dquaJDitHqzHCdqWSoZ6IgapSuTzW/4TaRYx9N9k4W8= c=1 sm=0 a=0nNWrt12pMMA:10 a=bbbx4UPp9XUA:10 a=OPBmh+XkhLl+Enan7BmTLg==:17 a=20KFwNOVAAAA:8 a=meVymXHHAAAA:8 a=7ZQwqa3CbsZe9ahqxigA:9 a=KDKU3mU6SBf8FTlU5Yk9qCSajpwA:4 a=DHQQ7jDAcw4A:10 a=jEp0ucaQiEUA:10 a=jeBq3FmKZ4MA:10 a=OPBmh+XkhLl+Enan7BmTLg==:117 X-Cloudmark-Score: 0 X-Originating-IP: 67.242.120.143 Message-Id: <20110208221720.339784840@goodmis.org> User-Agent: quilt/0.48-1 Date: Tue, 08 Feb 2011 17:16:18 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Frederic Weisbecker , Jiri Olsa Subject: [PATCH 06/10] tracing: Add unstable sched clock note to the warning References: <20110208221612.084294240@goodmis.org> Content-Disposition: inline; filename=0006-tracing-Add-unstable-sched-clock-note-to-the-warning.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jiri Olsa The 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. Signed-off-by: Jiri Olsa LKML-Reference: <1296649698-6003-1-git-send-email-jolsa@redhat.com> Signed-off-by: Steven Rostedt --- kernel/trace/ring_buffer.c | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index bd1c35a..7739893 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2163,10 +2163,14 @@ rb_reserve_next_event(struct ring_buffer *buffer, delta = diff; if (unlikely(test_time_stamp(delta))) { 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, + sched_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; } } -- 1.7.2.3