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From: Andi Kleen <ak@linux.intel.com>
To: Prarit Bhargava <prarit@redhat.com>
Cc: kan.liang@intel.com, linux-kernel@vger.kernel.org,
	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,
	stable@vger.kernel.org
Subject: Re: [PATCH] kernel/watchdog: fix spurious hard lockups
Date: Tue, 20 Jun 2017 16:00:02 -0700	[thread overview]
Message-ID: <20170620230002.GE23705@tassilo.jf.intel.com> (raw)
In-Reply-To: <4718a252-9515-626e-a69f-565f1c2bc589@redhat.com>

On Tue, Jun 20, 2017 at 06:34:23PM -0400, Prarit Bhargava wrote:
> 
> 
> 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.

It only happens on a few specific CPU SKUs with a very wide Turbo range.
Reproducer is typically some stress workload that turbos very high.

-Andi

  reply	other threads:[~2017-06-20 23:00 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-06-20 21:33 [PATCH] kernel/watchdog: fix spurious hard lockups kan.liang
2017-06-20 22:03 ` Andrew Morton
2017-06-21 12:40   ` Liang, Kan
2017-06-21 13:47     ` Don Zickus
2017-06-21 14:10       ` Liang, Kan
2017-06-20 22:34 ` Prarit Bhargava
2017-06-20 23:00   ` Andi Kleen [this message]
2017-06-21  0:12     ` Prarit Bhargava
2017-06-21 21:02       ` Marc Herbert
2017-06-21 13:40 ` Don Zickus
2017-06-21 14:02   ` Liang, Kan
2017-06-28 11:40 ` Michal Hocko
2017-06-28 13:24   ` Liang, Kan
2017-06-28 14:29     ` Michal Hocko
2017-06-28 14:32       ` Liang, Kan

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