DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com A589D80460
Subject: Re: [PATCH] kernel/watchdog: fix spurious hard lockups
To: kan.liang@intel.com, linux-kernel@vger.kernel.org
References: <20170620213309.30051-1-kan.liang@intel.com>
Cc: dzickus@redhat.com, mingo@kernel.org, akpm@linux-foundation.org,
        babu.moger@oracle.com, atomlin@redhat.com,
        torvalds@linux-foundation.org, peterz@infradead.org,
        tglx@linutronix.de, eranian@google.com, acme@redhat.com,
        ak@linux.intel.com, stable@vger.kernel.org
From: Prarit Bhargava <prarit@redhat.com>
Message-ID: <4718a252-9515-626e-a69f-565f1c2bc589@redhat.com>
Date: Tue, 20 Jun 2017 18:34:23 -0400
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101
 Thunderbird/45.7.0
MIME-Version: 1.0
In-Reply-To: <20170620213309.30051-1-kan.liang@intel.com>
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 529
Lines: 17


On 06/20/2017 05:33 PM, kan.liang@intel.com wrote:
> From: Kan Liang <Kan.liang@intel.com>
> 
> Some users reported spurious NMI watchdog timeouts.
> 
> We now have more and more systems where the Turbo range is wide enough
> that the NMI watchdog expires faster than the soft watchdog timer that
> updates the interrupt tick the NMI watchdog relies on.
> 

Hmm ... odd that I haven't seen this.  We're running a pretty wide
variety of systems here.  Do you have a reproducer?  I'd like to see
this occur on production HW.

P.