From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751415AbdINNqn (ORCPT ); Thu, 14 Sep 2017 09:46:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59664 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751133AbdINNqm (ORCPT ); Thu, 14 Sep 2017 09:46:42 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com EDEE781DE4 Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx01.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=dzickus@redhat.com Date: Thu, 14 Sep 2017 09:46:39 -0400 From: Don Zickus To: Helge Deller Cc: Thomas Gleixner , LKML , Ingo Molnar , Peter Zijlstra , Borislav Petkov , Andrew Morton , Sebastian Siewior , Nicholas Piggin , Chris Metcalf , Ulrich Obergfell , linux-parisc@vger.kernel.org Subject: Re: [patch V2 04/29] parisc: Use lockup_detector_stop() Message-ID: <20170914134639.2f2yz3o66igau6xq@redhat.com> References: <20170912193654.321505854@linutronix.de> <20170912194146.407385557@linutronix.de> <20170914085917.GA24723@ls3530> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170914085917.GA24723@ls3530> User-Agent: NeoMutt/20170428-dirty (1.8.2) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Thu, 14 Sep 2017 13:46:42 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 14, 2017 at 10:59:17AM +0200, Helge Deller wrote: > * Thomas Gleixner : > > The broken lockup_detector_suspend/resume() interface is going away. Use > > the new lockup_detector_soft_poweroff() interface to stop the watchdog from > > the busy looping power off routine. > > > > Signed-off-by: Thomas Gleixner > > Cc: Don Zickus > > Cc: Chris Metcalf > > Cc: linux-parisc@vger.kernel.org > > Cc: Peter Zijlstra > > Cc: Sebastian Siewior > > Cc: Nicholas Piggin > > Cc: Ulrich Obergfell > > Cc: Borislav Petkov > > Cc: Andrew Morton > > Cc: Helge Deller > > Link: http://lkml.kernel.org/r/20170831073053.281414373@linutronix.de > > > > --- > > arch/parisc/kernel/process.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > --- a/arch/parisc/kernel/process.c > > +++ b/arch/parisc/kernel/process.c > > @@ -146,7 +146,7 @@ void machine_power_off(void) > > > > /* prevent soft lockup/stalled CPU messages for endless loop. */ > > rcu_sysrq_start(); > > - lockup_detector_suspend(); > > + lockup_detector_soft_poweroff(); > > for (;;); > > } > > Thomas, thanks for cleaning that up. > You may add to patches 03/04: > Acked-by: Helge Deller > > > On a side-note, there is sadly no general function like > turn_off_all_kind_of_runtime_hang_detectors() > which turns off *all* detectors at once (including soft lockup detector). > I've seen another detector complaing at runtime that we were hanging > here. I would need to dig up more info if you are interested... There are numerous detectors I have seen over the years: rcu, clocksource, hard/soft, hang, fs, network, wq?, etc.. I am not sure it is easy to put them all in one place or makes sense. I know working with the kvm folks, when they swap back in, the real clock can do a massive jump forward and causes a flood of warnings such that they had to 'touch' all of them before running the vm again. Cheers, Don