From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S1752516AbdJCNU2 (ORCPT <rfc822;w@1wt.eu>);
        Tue, 3 Oct 2017 09:20:28 -0400
Received: from Galois.linutronix.de ([146.0.238.70]:53386 "EHLO
        Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S1752289AbdJCNU0 (ORCPT
        <rfc822;linux-kernel@vger.kernel.org>);
        Tue, 3 Oct 2017 09:20:26 -0400
Date: Tue, 3 Oct 2017 15:20:21 +0200 (CEST)
From: Thomas Gleixner <tglx@linutronix.de>
To: Michael Ellerman <mpe@ellerman.id.au>
cc: LKML <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>, Borislav Petkov <bp@alien8.de>,
        Andrew Morton <akpm@linux-foundation.org>,
        Sebastian Siewior <bigeasy@linutronix.de>,
        Nicholas Piggin <npiggin@gmail.com>, Don Zickus <dzickus@redhat.com>,
        Chris Metcalf <cmetcalf@mellanox.com>,
        Ulrich Obergfell <uobergfe@redhat.com>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        linuxppc-dev@lists.ozlabs.org
Subject: Re: [patch V2 22/29] lockup_detector: Make watchdog_nmi_reconfigure()
 two stage
In-Reply-To: <alpine.DEB.2.20.1710031411440.2281@nanos>
Message-ID: <alpine.DEB.2.20.1710031451590.2281@nanos>
References: <20170912193654.321505854@linutronix.de> <20170912194147.862865570@linutronix.de> <87d165dqew.fsf@concordia.ellerman.id.au> <alpine.DEB.2.20.1710030848210.2281@nanos> <87o9pocvjq.fsf@concordia.ellerman.id.au>
 <alpine.DEB.2.20.1710031411440.2281@nanos>
User-Agent: Alpine 2.20 (DEB 67 2015-01-07)
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
X-Linutronix-Spam-Score: -1.0
X-Linutronix-Spam-Level: -
X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required,  ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Tue, 3 Oct 2017, Thomas Gleixner wrote:
> On Tue, 3 Oct 2017, Michael Ellerman wrote:
> > Hmm, I tried that patch, it makes the warning go away. But then I
> > triggered a deliberate hard lockup and got nothing.
> > 
> > Then I went back to the existing code (in linux-next), and I still get
> > no warning from a deliberate hard lockup.
> > 
> > So seems there may be some more gremlins. Will test more in the morning.
> 
> Hrm. That's weird. I'll have a look and send a proper patch series on top
> of next.

The major difference is that the reworked code utilizes
watchdog_nmi_reconfigure() for both init and the sysctl updates, but I
can't for my life figure out why that doesn't work.

Thanks,

	tglx