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Date: Thu, 04 Nov 2004 11:42:53 -0800
From: Julian Elischer <julian@elischer.org>
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To: Poul-Henning Kamp <phk@phk.freebsd.dk>
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cc: arch@freebsd.org
Subject: Re: HEADSUP:  HZ=1000 by default on i386
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I've been using 1000 by default for a long time..
seems to work fine..

Interstingly, 600 or 1200 are a really good speeds for video

Common multiple of 25 Hz (europe TV) 30HZ (North American TV) and 24HZ 
(cinema film)
If we wanted to do good video handling, I'd suggest 1200 as a good option.

I've been lookign a bit into a FreeBSD kernel video framework that 
allows teh clocking in and out of frames at various
rates and conversions, and having a 1200 Hz internal clock would be 
really cool for that..
Of course we could use a dedicated timer if we have one avaliable.. I 
was playing with the
acquire_timer2() (etc) interface to do that but it would be cool to have 
the default rate
be useable :-)



Poul-Henning Kamp wrote:

>We increasingly need better granularity in our sleep/wakeup calls and
>things like device polling and trafic shaping needs higher granularity
>in particular.
>
>So pending any really good arguments to the contrary I plan to increase
>HZ to 1000 on i386 this weekend.
>
>You can still define any HZ value you like in your kernel config file
>or even set it from the loader.
>
>  
>