linux-kernel - Re: [RFC PATCH] x86:Use cpu_khz for loops_per

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Message-ID: <20080604141714.GA6140@ucw.cz>
Date:	Wed, 4 Jun 2008 16:17:15 +0200
From:	Pavel Machek <pavel@...e.cz>
To:	Alok Kataria <akataria@...are.com>
Cc:	Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...e.hu>,
	LKML <linux-kernel@...r.kernel.org>,
	Dan Hecht <dhecht@...are.com>, Tim Mann <mann@...are.com>,
	Zachary Amsden <zach@...are.com>,
	Sahil Rihan <srihan@...are.com>
Subject: Re: [RFC PATCH] x86:Use cpu_khz for loops_per_jiffy calculation

Hi!

> @@ -123,6 +123,8 @@
>  		(boot_cpu_data.x86_vendor == X86_VENDOR_AMD))
>  		cpu_khz = calculate_cpu_khz();
>  
> +	lpj_tsc = ((unsigned long)cpu_khz * 1000)/HZ;
> +

No. Some cpus do one loop per tick, some do two loops per tick, and
there are probably weird cpus, too.

							Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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