Date: Wed, 8 Mar 2017 12:13:12 +0000
From: Chris Wilson <chris@chris-wilson.co.uk>
To: kernel test robot <xiaolong.ye@intel.com>
Cc: Boqun Feng <boqun.feng@gmail.com>, Ingo Molnar <mingo@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Fengguang Wu <fengguang.wu@intel.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Nicolai =?iso-8859-1?Q?H=E4hnle?= <Nicolai.Haehnle@amd.com>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        LKML <linux-kernel@vger.kernel.org>, lkp@01.org
Subject: Re: [lkp-robot] [locking/ww_mutex]  857811a371:
 INFO:task_blocked_for_more_than#seconds
Message-ID: <20170308121312.GL25284@nuc-i3427.alporthouse.com>
References: <20170308010854.GA17420@yexl-desktop>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20170308010854.GA17420@yexl-desktop>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 764
Lines: 23

On Wed, Mar 08, 2017 at 09:08:54AM +0800, kernel test robot wrote:
> 
> FYI, we noticed the following commit:
> 
> commit: 857811a37129f5d2ba162d7be3986eff44724014 ("locking/ww_mutex: Adjust the lock number for stress test")
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
> 
> in testcase: boot
> 
> on test machine: qemu-system-i386 -enable-kvm -m 320M
> 
> caused below changes (please refer to attached dmesg/kmsg for entire log/backtrace):

Now the test is running, it takes too long. :)

wait_for_completion_interruptible() would stop the hung task check? That
leaves NMI watchdog to check if we hit a deadlock between the workers.

And add a timeout to the stress test.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre