From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753031Ab0HTOSl (ORCPT ); Fri, 20 Aug 2010 10:18:41 -0400 Received: from hera.kernel.org ([140.211.167.34]:55785 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752790Ab0HTOSj (ORCPT ); Fri, 20 Aug 2010 10:18:39 -0400 Date: Fri, 20 Aug 2010 14:18:08 GMT From: tip-bot for Peter Zijlstra Cc: linux-kernel@vger.kernel.org, eranian@google.com, hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl, fweisbec@gmail.com, tglx@linutronix.de, mingo@elte.hu, dzickus@redhat.com Reply-To: mingo@redhat.com, hpa@zytor.com, eranian@google.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, fweisbec@gmail.com, tglx@linutronix.de, mingo@elte.hu, dzickus@redhat.com In-Reply-To: <1282215916.1926.4696.camel@laptop> References: <1282215916.1926.4696.camel@laptop> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] watchdog: Don't throttle the watchdog Message-ID: Git-Commit-ID: b847b94fe2caff0f28a99af6353e9a27282e771a X-Mailer: tip-git-log-daemon 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]); Fri, 20 Aug 2010 14:18:09 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: b847b94fe2caff0f28a99af6353e9a27282e771a Gitweb: http://git.kernel.org/tip/b847b94fe2caff0f28a99af6353e9a27282e771a Author: Peter Zijlstra AuthorDate: Fri, 20 Aug 2010 11:49:15 +0200 Committer: Ingo Molnar CommitDate: Fri, 20 Aug 2010 15:00:06 +0200 watchdog: Don't throttle the watchdog Stephane reported that when the machine locks up, the regular ticks, which are responsible to resetting the throttle count, stop too. Hence the NMI watchdog can end up being throttled before it reports on the locked up state, and we end up being sad.. Cure this by having the watchdog overflow reset its own throttle count. Reported-by: Stephane Eranian Tested-by: Stephane Eranian Cc: Don Zickus Cc: Frederic Weisbecker Signed-off-by: Peter Zijlstra LKML-Reference: <1282215916.1926.4696.camel@laptop> Signed-off-by: Ingo Molnar --- kernel/watchdog.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 613bc1f..0d53c8e 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -206,6 +206,9 @@ void watchdog_overflow_callback(struct perf_event *event, int nmi, struct perf_sample_data *data, struct pt_regs *regs) { + /* Ensure the watchdog never gets throttled */ + event->hw.interrupts = 0; + if (__get_cpu_var(watchdog_nmi_touch) == true) { __get_cpu_var(watchdog_nmi_touch) = false; return;