From: Peter Zijlstra <peterz@infradead.org>
To: John Stultz <john.stultz@linaro.org>
Cc: lkml <linux-kernel@vger.kernel.org>, Mike Chan <mike@android.com>,
Ingo Molnar <mingo@elte.hu>
Subject: Re: [PATCH 3/5] scheduler: cpuacct: Enable platform hooks to track cpuusage for CPU frequencies
Date: Sat, 20 Nov 2010 11:48:24 +0100 [thread overview]
Message-ID: <1290250104.2118.4.camel@laptop> (raw)
In-Reply-To: <1290218934-8544-4-git-send-email-john.stultz@linaro.org>
On Fri, 2010-11-19 at 18:08 -0800, John Stultz wrote:
> From: Mike Chan <mike@android.com>
>
> Introduce new platform callback hooks for cpuacct for tracking CPU frequencies
>
> Not all platforms / architectures have a set CPU_FREQ_TABLE defined
> for CPU transition speeds. In order to track time spent in at various
> CPU frequencies, we enable platform callbacks from cpuacct for this accounting.
>
> Architectures that support overclock boosting, or don't have pre-defined
> frequency tables can implement their own bucketing system that makes sense
> given their cpufreq scaling abilities.
>
> New file:
> cpuacct.cpufreq reports the CPU time (in nanoseconds) spent at each CPU
> frequency.
I utterly detest all such accounting crap.. it adds ABI constraints it
add runtime overhead. etc..
Can't you get the same information by using the various perf bits? If
you trace the cpufreq changes you can compute the time spend in each
power state, if you additionally trace the sched_switch you can compute
it for each task.
next prev parent reply other threads:[~2010-11-20 10:48 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-20 2:08 [PATCH 0/5] [RFC] Trivial scheduler related Android patches John Stultz
2010-11-20 2:08 ` [PATCH 1/5] sched: Enable might_sleep before initializing drivers John Stultz
2010-11-20 10:42 ` Peter Zijlstra
2010-11-20 2:08 ` [PATCH 2/5] sched: make task dump print all 15 chars of proc comm John Stultz
2010-11-23 10:21 ` [tip:sched/core] sched: Make " tip-bot for Erik Gilling
2010-11-20 2:08 ` [PATCH 3/5] scheduler: cpuacct: Enable platform hooks to track cpuusage for CPU frequencies John Stultz
2010-11-20 10:48 ` Peter Zijlstra [this message]
2010-11-22 5:51 ` Florian Mickler
2010-11-22 10:43 ` Peter Zijlstra
2010-11-22 12:23 ` Florian Mickler
2010-11-23 2:05 ` Mike Chan
2010-11-23 11:35 ` Peter Zijlstra
2010-11-20 2:08 ` [PATCH 4/5] scheduler: cpuacct: Enable platform callbacks for cpuacct power tracking John Stultz
2010-11-20 2:08 ` [PATCH 5/5] sched: use the old min_vruntime when normalizing on dequeue John Stultz
2010-11-20 10:55 ` Peter Zijlstra
2010-11-20 12:33 ` Peter Zijlstra
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