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From: Benjamin King <benjaminking@web.de>
To: Andi Kleen <andi@firstfloor.org>
Cc: Milian Wolff <milian.wolff@kdab.com>, linux-perf-users@vger.kernel.org
Subject: Re: Failure to parallelize
Date: Tue, 23 Aug 2016 08:10:25 +0200	[thread overview]
Message-ID: <20160823061025.GA3208@localhost> (raw)
In-Reply-To: <8737lw1p7j.fsf@tassilo.jf.intel.com>

Hi Andi,

On Mon, Aug 22, 2016 at 02:14:08PM -0700, Andi Kleen wrote:
>Benjamin King <benjaminking@web.de> writes:
>> Still, I dabbled a bit with "perf record -s ...; perf report -T", but I find the
>> output a little confusing. To wit:
>
>I would rather use perf report --sort cpu,sym
>This reports all samples separated by CPUs, but sorted in the same view.

Thanks! 'perf record ...; perf report --sort pid,sym'
did the job for me. Here I can clearly see a difference between a function
being called in parallel vs one that is not via the thread id.

With 'perf report --sort cpu,sym' I get '-001' for the CPU number. 'perf
script -Fcpu,ip' tells me that:

Samples for 'cycles:pp' event do not have CPU attribute set. Cannot print 'cpu' field.

This was with perf 4.4.0 on an i7-3537U. I stripped off the ':pp', tried
recording instructions rather than cycles, and also tested with perf 4.2.3 on
an i7-3770, but had no luck with per CPU display.

Cheers,
  Benjamin

      reply	other threads:[~2016-08-23  6:10 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-17 13:55 Failure to parallelize Benjamin King
2016-08-18  9:56 ` Milian Wolff
2016-08-18 18:50   ` Benjamin King
2016-08-22 21:14     ` Andi Kleen
2016-08-23  6:10       ` Benjamin King [this message]

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