From: Ingo Molnar <mingo@kernel.org>
To: Neil Horman <nhorman@tuxdriver.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
linux-kernel@vger.kernel.org, sebastien.dugue@bull.net,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH] x86: Run checksumming in parallel accross multiple alu's
Date: Mon, 28 Oct 2013 17:24:38 +0100 [thread overview]
Message-ID: <20131028162438.GB14350@gmail.com> (raw)
In-Reply-To: <20131028160131.GA31048@hmsreliant.think-freely.org>
* Neil Horman <nhorman@tuxdriver.com> wrote:
> Looking at the specific cpu counters we get this:
>
> Base:
> Total time: 0.179 [sec]
>
> Performance counter stats for 'perf bench sched messaging -- bash -c echo 1 > /sys/module/csum_test/parameters/test_fire' (20 runs):
>
> 1571.304618 task-clock # 5.213 CPUs utilized ( +- 0.45% )
> 14,423 context-switches # 0.009 M/sec ( +- 4.28% )
> 2,710 cpu-migrations # 0.002 M/sec ( +- 2.83% )
Hm, for these second round of measurements were you using 'perf stat
-a -C ...'?
The most accurate method of measurement for such single-threaded
workloads is something like:
taskset 0x1 perf stat -a -C 1 --repeat 20 ...
this will bind your workload to CPU#0, and will do PMU measurements
only there - without mixing in other CPUs or workloads.
Thanks,
Ingo
next prev parent reply other threads:[~2013-10-28 16:24 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1381510298-20572-1-git-send-email-nhorman@tuxdriver.com>
[not found] ` <20131012172124.GA18241@gmail.com>
[not found] ` <20131014202854.GH26880@hmsreliant.think-freely.org>
[not found] ` <1381785560.2045.11.camel@edumazet-glaptop.roam.corp.google.com>
[not found] ` <1381789127.2045.22.camel@edumazet-glaptop.roam.corp.google.com>
[not found] ` <20131017003421.GA31470@hmsreliant.think-freely.org>
2013-10-17 8:41 ` [PATCH] x86: Run checksumming in parallel accross multiple alu's Ingo Molnar
2013-10-17 18:19 ` H. Peter Anvin
2013-10-17 18:48 ` Eric Dumazet
2013-10-18 6:43 ` Ingo Molnar
2013-10-28 16:01 ` Neil Horman
2013-10-28 16:20 ` Ingo Molnar
2013-10-28 17:49 ` Neil Horman
2013-10-28 16:24 ` Ingo Molnar [this message]
2013-10-28 16:49 ` David Ahern
2013-10-28 17:46 ` Neil Horman
2013-10-28 18:29 ` Neil Horman
2013-10-29 8:25 ` Ingo Molnar
2013-10-29 11:20 ` Neil Horman
2013-10-29 11:30 ` Ingo Molnar
2013-10-29 11:49 ` Neil Horman
2013-10-29 12:52 ` Ingo Molnar
2013-10-29 13:07 ` Neil Horman
2013-10-29 13:11 ` Ingo Molnar
2013-10-29 13:20 ` Neil Horman
2013-10-29 14:17 ` Neil Horman
2013-10-29 14:27 ` Ingo Molnar
2013-10-29 20:26 ` Neil Horman
2013-10-31 10:22 ` Ingo Molnar
2013-10-31 14:33 ` Neil Horman
2013-11-01 9:13 ` Ingo Molnar
2013-11-01 14:06 ` Neil Horman
2013-10-29 14:12 ` David Ahern
[not found] ` <1383751399-10298-1-git-send-email-nhorman@tuxdriver.com>
[not found] ` <1383751399-10298-3-git-send-email-nhorman@tuxdriver.com>
[not found] ` <87iow58eqf.fsf@tassilo.jf.intel.com>
2013-11-07 21:23 ` [PATCH v2 2/2] x86: add prefetching to do_csum Neil Horman
2013-10-30 5:25 [PATCH] x86: Run checksumming in parallel accross multiple alu's Doug Ledford
2013-10-30 10:27 ` David Laight
2013-10-30 11:02 ` Neil Horman
2013-10-30 12:18 ` David Laight
2013-10-30 13:22 ` Doug Ledford
2013-10-30 13:35 ` Doug Ledford
2013-10-30 14:04 ` David Laight
2013-10-30 14:52 ` Neil Horman
2013-10-31 18:30 ` Neil Horman
2013-11-01 9:21 ` Ingo Molnar
2013-11-01 15:42 ` Ben Hutchings
2013-11-01 16:08 ` Neil Horman
2013-11-01 16:16 ` Ben Hutchings
2013-11-01 16:18 ` David Laight
2013-11-01 17:37 ` Neil Horman
2013-11-01 19:45 ` Joe Perches
2013-11-01 19:58 ` Neil Horman
2013-11-01 20:26 ` Joe Perches
2013-11-02 2:07 ` Neil Horman
2013-11-04 9:47 ` David Laight
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