From: Ingo Molnar <mingo@kernel.org>
To: Waiman Long <Waiman.Long@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Darren Hart <dvhart@linux.intel.com>,
Davidlohr Bueso <davidlohr@hp.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
linux-doc@vger.kernel.org, Jason Low <jason.low2@hp.com>,
Scott J Norton <scott.norton@hp.com>
Subject: Re: [RFC PATCH 0/5] futex: introduce an optimistic spinning futex
Date: Mon, 21 Jul 2014 23:18:01 +0200 [thread overview]
Message-ID: <20140721211801.GA12149@gmail.com> (raw)
In-Reply-To: <1405956271-34339-1-git-send-email-Waiman.Long@hp.com>
* Waiman Long <Waiman.Long@hp.com> wrote:
> Testing done on a 4-socket Westmere-EX boxes with 40 cores (HT off)
> showed the following performance data (average kops/s) with various
> load factor (number of pause instructions) used in the critical
> section using an userspace mutex microbenchmark.
>
> Threads Load Waiting Futex Spinning Futex %Change
> ------- ---- ------------- -------------- -------
> 256 1 6894 8883 +29%
> 256 10 3656 4912 +34%
> 256 50 1332 4358 +227%
> 256 100 792 2753 +248%
> 10 1 6382 4838 -24%
> 10 10 3614 4748 +31%
> 10 50 1319 3900 +196%
> 10 100 782 2459 +214%
> 2 1 7905 7194 -9.0%
> 2 10 4556 4717 +3.5%
> 2 50 2191 4167 +90%
> 2 100 1767 2407 +36%
So the numbers look interesting - but it would be _really_ important
to provide noise/sttdev figures in a sixth column as well (denoted in
percentage units, not in benchmark units), so that we know how
significant a particular speedup (or slowdown) is.
Thanks,
Ingo
next prev parent reply other threads:[~2014-07-21 21:18 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-21 15:24 [RFC PATCH 0/5] futex: introduce an optimistic spinning futex Waiman Long
2014-07-21 15:24 ` [RFC PATCH 1/5] futex: add new exclusive lock & unlock command codes Waiman Long
2014-07-21 16:42 ` Thomas Gleixner
2014-07-22 18:22 ` Waiman Long
[not found] ` <53CEABD7.3030509-VXdhtT5mjnY@public.gmane.org>
2014-07-22 21:00 ` Thomas Gleixner
2014-07-22 21:00 ` Thomas Gleixner
[not found] ` <1405956271-34339-1-git-send-email-Waiman.Long-VXdhtT5mjnY@public.gmane.org>
2014-07-21 15:24 ` [RFC PATCH 2/5] futex: add optimistic spinning to FUTEX_SPIN_LOCK Waiman Long
2014-07-21 15:24 ` Waiman Long
[not found] ` <1405956271-34339-3-git-send-email-Waiman.Long-VXdhtT5mjnY@public.gmane.org>
2014-07-21 17:15 ` Davidlohr Bueso
2014-07-21 17:15 ` Davidlohr Bueso
[not found] ` <1405962929.11927.19.camel-5JQ4ckphU/8SZAcGdq5asR6epYMZPwEe5NbjCUgZEJk@public.gmane.org>
2014-07-22 18:46 ` Waiman Long
2014-07-22 18:46 ` Waiman Long
2014-07-21 20:17 ` Jason Low
2014-07-22 19:34 ` Waiman Long
2014-07-21 15:24 ` [RFC PATCH 3/5] spinning futex: move a wakened task to spinning Waiman Long
2014-07-21 15:24 ` [RFC PATCH 4/5] spinning futex: put waiting tasks in a sorted rbtree Waiman Long
2014-07-21 15:24 ` [RFC PATCH 5/5] futex, doc: add a document on how to use the spinning futexes Waiman Long
2014-07-21 15:45 ` Randy Dunlap
2014-07-22 3:19 ` Waiman Long
2014-07-21 16:42 ` [RFC PATCH 0/5] futex: introduce an optimistic spinning futex Andi Kleen
2014-07-21 16:45 ` Andi Kleen
[not found] ` <871tte3bjw.fsf-KWJ+5VKanrL29G5dvP0v1laTQe2KTcn/@public.gmane.org>
2014-07-21 17:20 ` Darren Hart
2014-07-21 17:20 ` Darren Hart
[not found] ` <CFF29A00.9D44A%dvhart@linux.intel.com>
[not found] ` <CFF29A00.9D44A%dvhart-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2014-07-21 17:41 ` Darren Hart
2014-07-21 17:41 ` Darren Hart
[not found] ` <CFF29E4A.9D44E%dvhart-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2014-07-21 20:16 ` Thomas Gleixner
2014-07-21 20:16 ` Thomas Gleixner
2014-07-21 21:27 ` Peter Zijlstra
2014-07-21 21:27 ` Peter Zijlstra
2014-07-21 21:31 ` Andy Lutomirski
2014-07-21 21:47 ` Thomas Gleixner
2014-07-21 22:41 ` Darren Hart
2014-07-22 1:01 ` Thomas Gleixner
2014-07-22 1:34 ` Steven Rostedt
2014-07-22 2:31 ` Mike Galbraith
2014-07-22 3:06 ` Davidlohr Bueso
[not found] ` <20140721213457.46623e2f-f9ZlEuEWxVcJvu8Pb33WZ0EMvNT87kid@public.gmane.org>
2014-07-22 7:47 ` Peter Zijlstra
2014-07-22 7:47 ` Peter Zijlstra
2014-07-22 8:39 ` Thomas Gleixner
2014-07-22 8:39 ` Thomas Gleixner
2014-07-22 8:48 ` Peter Zijlstra
2014-07-22 9:59 ` Thomas Gleixner
2014-07-22 9:59 ` Thomas Gleixner
2014-07-22 20:25 ` Waiman Long
2014-07-22 20:52 ` Thomas Gleixner
2014-07-22 20:21 ` Waiman Long
2014-07-22 21:03 ` Thomas Gleixner
2014-07-22 0:32 ` Davidlohr Bueso
2014-07-22 7:35 ` Peter Zijlstra
2014-07-21 21:43 ` Thomas Gleixner
2014-07-21 18:24 ` Thomas Gleixner
2014-07-22 18:35 ` Waiman Long
2014-07-22 18:28 ` Waiman Long
[not found] ` <8761iq3bp3.fsf-KWJ+5VKanrL29G5dvP0v1laTQe2KTcn/@public.gmane.org>
2014-07-23 4:55 ` Mike Galbraith
2014-07-23 4:55 ` Mike Galbraith
2014-07-23 6:57 ` Peter Zijlstra
2014-07-23 7:25 ` Mike Galbraith
2014-07-23 7:25 ` Mike Galbraith
2014-07-23 7:35 ` Peter Zijlstra
2014-07-23 7:39 ` Mike Galbraith
2014-07-23 7:39 ` Mike Galbraith
2014-07-23 7:52 ` Peter Zijlstra
2014-07-21 21:18 ` Ingo Molnar [this message]
2014-07-21 21:41 ` Thomas Gleixner
[not found] ` <20140721211801.GA12149-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2014-07-22 19:36 ` Waiman Long
2014-07-22 19:36 ` Waiman Long
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