From: Mel Gorman <mgorman@techsingularity.net>
To: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
Davidlohr Bueso <dave@stgolabs.net>,
manfred@colorfullife.com, Waiman.Long@hpe.com,
torvalds@linux-foundation.org, ggherdovich@suse.com,
linux-kernel@vger.kernel.org
Subject: Re: sem_lock() vs qspinlocks
Date: Fri, 20 May 2016 11:45:00 +0100 [thread overview]
Message-ID: <20160520104500.GL2527@techsingularity.net> (raw)
In-Reply-To: <20160520100901.GA20016@gmail.com>
On Fri, May 20, 2016 at 12:09:01PM +0200, Ingo Molnar wrote:
>
> * Peter Zijlstra <peterz@infradead.org> wrote:
>
> > On Fri, May 20, 2016 at 10:30:08AM +0200, Peter Zijlstra wrote:
> > > On Thu, May 19, 2016 at 10:39:26PM -0700, Davidlohr Bueso wrote:
> > > > Specifically
> > > > for the 'cascade_cond' and 'cascade_flock' programs, which exhibit hangs in libc's
> > > > semop() blocked waiting for zero.
> > >
> > > OK; so I've been running:
> > >
> > > while :; do
> > > bin/cascade_cond -E -C 200 -L -S -W -T 200 -I 2000000 ;
> > > bin/cascade_flock -E -C 200 -L -S -W -P 200 -I 5000000 ;
> > > done
> > >
> > > for a few minutes now and its not stuck and my machine didn't splat.
> > >
> > > Am I not doing it right?
> >
> > Hooray, it went *bang*..
>
> I suspect a required step was to post about failure to reproduce!
>
It is known that the bug is both intermittent and not all machines can
reproduce the problem. If it fails to reproduce, it's not necessarily a
methodology error and can simply be a function of luck.
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2016-05-20 10:45 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-20 5:39 sem_lock() vs qspinlocks Davidlohr Bueso
2016-05-20 7:49 ` Peter Zijlstra
2016-05-20 15:00 ` Davidlohr Bueso
2016-05-20 15:05 ` Peter Zijlstra
2016-05-20 15:25 ` Davidlohr Bueso
2016-05-20 15:28 ` Peter Zijlstra
2016-05-20 20:47 ` Waiman Long
2016-05-20 20:52 ` Peter Zijlstra
2016-05-21 0:59 ` Davidlohr Bueso
2016-05-21 4:01 ` Waiman Long
2016-05-21 7:40 ` Peter Zijlstra
2016-05-20 7:53 ` Peter Zijlstra
2016-05-20 8:13 ` Peter Zijlstra
2016-05-20 8:18 ` Peter Zijlstra
2016-05-20 9:07 ` Giovanni Gherdovich
2016-05-20 9:34 ` Peter Zijlstra
2016-05-20 8:30 ` Peter Zijlstra
2016-05-20 9:00 ` Peter Zijlstra
2016-05-20 10:09 ` Ingo Molnar
2016-05-20 10:45 ` Mel Gorman [this message]
2016-05-20 11:58 ` Peter Zijlstra
2016-05-20 14:05 ` Boqun Feng
2016-05-20 15:21 ` Peter Zijlstra
2016-05-20 16:04 ` Peter Zijlstra
2016-05-20 17:00 ` Linus Torvalds
2016-05-20 21:06 ` Peter Zijlstra
2016-05-20 21:44 ` Linus Torvalds
2016-05-21 0:48 ` Davidlohr Bueso
2016-05-21 2:30 ` Linus Torvalds
2016-05-21 7:37 ` Peter Zijlstra
2016-05-21 13:49 ` Manfred Spraul
2016-05-24 10:57 ` Peter Zijlstra
2016-05-21 17:14 ` Davidlohr Bueso
2016-05-23 12:25 ` Peter Zijlstra
2016-05-23 17:52 ` Linus Torvalds
2016-05-25 6:37 ` Boqun Feng
2016-05-22 8:43 ` Manfred Spraul
2016-05-22 9:38 ` Peter Zijlstra
2016-05-20 16:20 ` Davidlohr Bueso
2016-05-20 20:44 ` Waiman Long
2016-05-20 20:53 ` Peter Zijlstra
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