From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755689AbcFHNNa (ORCPT ); Wed, 8 Jun 2016 09:13:30 -0400 Received: from mail-wm0-f67.google.com ([74.125.82.67]:33022 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754210AbcFHNN2 (ORCPT ); Wed, 8 Jun 2016 09:13:28 -0400 Date: Wed, 8 Jun 2016 15:13:24 +0200 From: Ingo Molnar To: Andrey Ryabinin Cc: Ingo Molnar , Peter Zijlstra , linux-kernel@vger.kernel.org Subject: Re: [PATCH] kernel/sysrq: reset watchdog on all CPUs while processing sysrq-w Message-ID: <20160608131324.GA15193@gmail.com> References: <1464353394-30528-1-git-send-email-aryabinin@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1464353394-30528-1-git-send-email-aryabinin@virtuozzo.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andrey Ryabinin wrote: > Lengthy output of sysrq-w may take a lot of time on slow serial console. > Currently we reset NMI-watchdog on the current CPU to avoid softlockup. > Sometimes this doesn't work since watchdog might trigger on the other > CPU which is waiting for an IPI to proceed. > > Reset watchdog on all CPUs to prevent spurious softlockup messages. > > Signed-off-by: Andrey Ryabinin > --- > kernel/sched/core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index 7f2cae4..c135eee 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -5134,7 +5134,7 @@ void show_state_filter(unsigned long state_filter) > * reset the NMI-timeout, listing all files on a slow > * console might take a lot of time: > */ > - touch_nmi_watchdog(); > + touch_all_softlockup_watchdogs(); So don't we want both? Thanks, Ingo