From: Ingo Molnar <mingo@kernel.org>
To: Waiman Long <waiman.long@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Arnd Bergmann <arnd@arndb.de>,
linux-arch@vger.kernel.org, x86@kernel.org,
linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Steven Rostedt <rostedt@goodmis.org>,
Andrew Morton <akpm@linux-foundation.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Matt Fleming <matt.fleming@intel.com>,
Michel Lespinasse <walken@google.com>,
Andi Kleen <andi@firstfloor.org>, Rik van Riel <riel@redhat.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>,
George Spelvin <linux@horizon.com>,
Harvey Harrison <harvey.harrison@gmail.com>,
"Chandramouleeswaran, Aswin" <aswin@hp.com>,
"Norton, Scott J" <scott.norton@hp.com>
Subject: Re: [PATCH v3 0/3] qrwlock: Introducing a queue read/write lock implementation
Date: Wed, 14 Aug 2013 17:57:51 +0200 [thread overview]
Message-ID: <20130814155751.GA17821@gmail.com> (raw)
In-Reply-To: <520BA109.1000501@hp.com>
* Waiman Long <waiman.long@hp.com> wrote:
> On 08/14/2013 06:20 AM, Ingo Molnar wrote:
> >* Waiman Long<waiman.long@hp.com> wrote:
> >
> >>
> >>I would like to share with you a rwlock related system crash that I
> >>encountered during my testing with hackbench on an 80-core DL980. The
> >>kernel crash because of a "watchdog detected hard lockup on cpu 79". The
> >>crashing CPU was running "write_lock_irq(&tasklist_lock)" in
> >>forget_original_parent() of the exit code path when I interrupted the
> >>hackbench which was spawning thousands of processes. Apparently, the
> >>remote CPU was not able to get the lock for a sufficient long time due
> >>to the unfairness of the rwlock which I think my version of queue rwlock
> >>will be able to alleviate this issue.
> >>
> >>So far, I was not able to reproduce the crash. I will try to see if I
> >>could more consistently reproduce it.
> >Was it an actual crash/lockup, or a longish hang followed by a lock
> >detector splat followed by the system eventually recovering back to
> >working order?
> >
> >Thanks,
> >
> > Ingo
>
> It was an actual crash initiated by the NMI handler. I think the
> system was in a halt state after that.
Could be a CONFIG_BOOTPARAM_HARDLOCKUP_PANIC_VALUE=1 kernel?
Thanks,
Ingo
next prev parent reply other threads:[~2013-08-14 15:57 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-01 0:00 [PATCH v3 0/3] qrwlock: Introducing a queue read/write lock implementation Waiman Long
2013-08-01 0:00 ` Waiman Long
2013-08-01 0:00 ` Waiman Long
2013-08-01 0:00 ` [PATCH v3 1/3] qrwlock: A " Waiman Long
2013-08-01 0:00 ` Waiman Long
2013-08-01 0:00 ` Waiman Long
2013-08-01 0:00 ` [PATCH v3 2/3] qrwlock x86: Enable x86 to use queue read/write lock Waiman Long
2013-08-01 0:00 ` Waiman Long
2013-08-01 0:00 ` Waiman Long
2013-08-01 0:00 ` [PATCH v3 3/3] qrwlock: Enable fair queue read/write lock behavior Waiman Long
2013-08-01 0:00 ` Waiman Long
2013-08-01 0:00 ` Waiman Long
2013-08-13 18:55 ` [PATCH v3 0/3] qrwlock: Introducing a queue read/write lock implementation Waiman Long
2013-08-14 10:20 ` Ingo Molnar
2013-08-14 15:23 ` Waiman Long
2013-08-14 15:57 ` Ingo Molnar [this message]
2013-08-16 22:47 ` Waiman Long
2013-08-19 10:57 ` Ingo Molnar
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