From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756585Ab1BQPA7 (ORCPT ); Thu, 17 Feb 2011 10:00:59 -0500 Received: from hera.kernel.org ([140.211.167.34]:37971 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754174Ab1BQPA5 (ORCPT ); Thu, 17 Feb 2011 10:00:57 -0500 Date: Thu, 17 Feb 2011 15:00:43 GMT From: tip-bot for Jiri Olsa Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, rostedt@goodmis.org, tglx@linutronix.de, jolsa@redhat.com Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, rostedt@goodmis.org, tglx@linutronix.de, jolsa@redhat.com In-Reply-To: <1296649698-6003-1-git-send-email-jolsa@redhat.com> References: <1296649698-6003-1-git-send-email-jolsa@redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] tracing: Add unstable sched clock note to the warning Message-ID: Git-Commit-ID: 5e38ca8f3ea423442eaafe1b7e206084aa38120a X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Thu, 17 Feb 2011 15:00:43 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 5e38ca8f3ea423442eaafe1b7e206084aa38120a Gitweb: http://git.kernel.org/tip/5e38ca8f3ea423442eaafe1b7e206084aa38120a Author: Jiri Olsa AuthorDate: Wed, 2 Feb 2011 13:28:18 +0100 Committer: Steven Rostedt CommitDate: Tue, 8 Feb 2011 11:57:22 -0500 tracing: Add unstable sched clock note to the warning 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; } }