linux-kernel - Re: [PATCH] powernow-k6: set transition latency value so ondemand governor can be used

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Message-ID: <20091026064101.GB17984@elte.hu>
Date:	Mon, 26 Oct 2009 07:41:01 +0100
From:	Ingo Molnar <mingo@...e.hu>
To:	Krzysztof Helt <krzysztof.h1@...zta.fm>
Cc:	Dave Jones <davej@...hat.com>, cpufreq@...r.kernel.org,
	LKLM <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] powernow-k6: set transition latency value so ondemand
	governor can be used


* Krzysztof Helt <krzysztof.h1@...zta.fm> wrote:

> From: Krzysztof Helt <krzysztof.h1@...pl>
> 
> Set the transition latency to value smaller than CPUFREQ_ETERNAL so
> governors other than "performance" work (like the "ondemand" one).
> 
> The value is found in "AMD PowerNow! Technology Platform Design Guide for 
> Embedded Processors" dated December 2000 (AMD doc #24267A). There is the 
> answer to one of FAQs on page 40 which states that suggested complete transition 
> period is 200 us.

Btw., would be nice to put this paragraph between '/* .. */' signs and 
put it into the source code - seems highly relevant when someone comes 
across that wonders what the magic number '200000' is.

	Ingo
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