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From: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
To: Nicholas Piggin <npiggin@gmail.com>
Cc: sachinp <sachinp@linux.vnet.ibm.com>,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	linux-next <linux-next@vger.kernel.org>,
	linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [next-20180517][ppc] watchdog: CPU 88 self-detected hard LOCKUP @ update_cfs_group+0x30/0x150
Date: Tue, 29 May 2018 18:39:40 +0530	[thread overview]
Message-ID: <1527599380.3777.3.camel@abdul> (raw)
In-Reply-To: <20180521165056.5f3dceeb@roar.ozlabs.ibm.com>

On Mon, 2018-05-21 at 16:50 +1000, Nicholas Piggin wrote:
> Ah, it's POWER8.
> 
> I'm betting we have a bug with nohz timer offloading somewhere.
> 
> I *think* we may have seen similar on P9 as well, but that may be
> related to problems with stop states.
> 
> Can you reproduce it easily? I'm thinking maybe adding some
> tracepoints that track decrementer settings and interrupts, and
> nohz offload activity might show something up.

Yes, the problem is reproducible consistently on our CI setup and today
It triggered on 4.17.0-rc6 (mainline) too.

-- 
Regard's

Abdul Haleem
IBM Linux Technology Centre

      reply	other threads:[~2018-05-29 13:11 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-21  6:15 [next-20180517][ppc] watchdog: CPU 88 self-detected hard LOCKUP @ update_cfs_group+0x30/0x150 Abdul Haleem
2018-05-21  6:50 ` Nicholas Piggin
2018-05-29 13:09   ` Abdul Haleem [this message]

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