Subject: Re: [PATCH] sched: Provide iowait counters
From: Peter Zijlstra <peterz@infradead.org>
To: Arjan van de Ven <arjan@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
       Ingo Molnar <mingo@elte.hu>,
       "Kok, Auke-jan H" <auke-jan.h.kok@intel.com>
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Date: Sat, 25 Jul 2009 19:41:14 +0200
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On Sat, 2009-07-25 at 09:42 -0700, Arjan van de Ven wrote:
> 
> In case you wonder why you need both tools, and can't just use one: we
> wondered the same, but it turns out that if you only build
> Tool Two, you don't get a good overview of what is going on on a
> higher level. It's like looking at the world via a microscope all the
> time,

I'd be thinking you could compose your ms based picture on the sample
data. For instance, if you sample on cpu-clock at 100kHz, then a 100
samples get you a full blue slice, 50 get you a 50% blue slice, etc.

Of course, since its sample based, you can miss some detail, but I think
you're looking at the large picture anyway.

Would this work?

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