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From: fche@redhat.com (Frank Ch. Eigler)
To: Arjan van de Ven <arjan@infradead.org>
Cc: linux-kernel@vger.kernel.org, mingo@elte.hu,
	peterz@infradead.org, Frederic Weisbecker <fweisbec@gmail.com>
Subject: Re: [RFC PATCH] perf_core: provide a kernel-internal interface to get to performance counters
Date: Sat, 26 Sep 2009 12:03:28 -0400	[thread overview]
Message-ID: <y0mhbuplmlr.fsf@fche.csb> (raw)
In-Reply-To: <20090925122556.2f8bd939@infradead.org> (Arjan van de Ven's message of "Fri, 25 Sep 2009 12:25:56 +0200")


Arjan van de Ven <arjan@infradead.org> writes:

> [...]
> There are reasons for kernel code to ask for, and use, performance counters.
> For example, in CPU freq governors this tends to be a good idea, but there
> are other examples possible as well of course.
> 
> This patch adds the needed bits to do enable this functionality; they have been
> tested in an experimental cpufreq driver that I'm working on, and the changes
> are all that I needed to access counters properly.
> [...]

For what it's worth, this sort of thing also looks useful from
systemtap's point of view.

It appears that the patch assumes that a perf counter instance is to
be associated with the "current" task.  How do you use this from your
prototype scheduler?  Do you create/attach a new one for each thread?


- FChE

  parent reply	other threads:[~2009-09-26 16:03 UTC|newest]

Thread overview: 30+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-09-25 10:25 [RFC PATCH] perf_core: provide a kernel-internal interface to get to performance counters Arjan van de Ven
2009-09-25 10:44 ` Frederic Weisbecker
2009-09-25 11:42 ` Peter Zijlstra
2009-09-26 16:03 ` Frank Ch. Eigler [this message]
2009-09-26 16:11   ` Arjan van de Ven
2009-09-26 16:20     ` Frank Ch. Eigler
2009-09-26 18:32   ` K.Prasad
2009-09-26 18:48     ` Arjan van de Ven
2009-10-01  7:25       ` Ingo Molnar
2009-10-01  8:16         ` K.Prasad
2009-10-01  8:53           ` Ingo Molnar
2009-10-01 10:01             ` K.Prasad
2009-10-01 10:28               ` Ingo Molnar
2009-10-04 22:28             ` Frederic Weisbecker
2009-10-05  9:55               ` Ingo Molnar
2009-10-05 10:13                 ` Frédéric Weisbecker
2009-10-05  7:53             ` Peter Zijlstra
2009-10-05  8:55               ` Ingo Molnar
2009-10-05  9:24                 ` Frédéric Weisbecker
2009-10-05  9:48                   ` Ingo Molnar
2009-10-05 10:08                     ` Frédéric Weisbecker
2009-11-21 13:36 ` [tip:perf/core] perf/core: Provide " tip-bot for Arjan van de Ven
2010-02-05 15:47 ` [RFC PATCH] perf_core: provide " Christoph Hellwig
2010-02-05 17:59   ` john smith
2010-02-06  6:24   ` Arjan van de Ven
2010-02-06 11:46     ` Frederic Weisbecker
2010-02-06 14:18       ` Peter Zijlstra
2010-02-06 16:08         ` Frederic Weisbecker
2010-02-07 17:01   ` Ingo Molnar
  -- strict thread matches above, loose matches on Subject: below --
2010-01-25  5:10 john smith

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