From owner-freebsd-current@FreeBSD.ORG  Fri Jul  9 16:26:58 2004
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To: Chuck Swiger <cswiger@mac.com>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Fri, 09 Jul 2004 12:23:01 EDT."
             <40EEC665.5010608@mac.com> 
Date: Fri, 09 Jul 2004 18:26:50 +0200
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Sender: phk@critter.freebsd.dk
cc: Chris Stenton <jacs@gnome.co.uk>
cc: current@freebsd.org
Subject: Re: default HZ value in 5.2.1 
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In message <40EEC665.5010608@mac.com>, Chuck Swiger writes:
>Chris Stenton wrote:
>> Any reason why the default value for HZ is still set at 100?
>
>Sure.  Timer interrupts and context switching aren't free, you know: the 
>faster the HZ, the more time the system spends on overhead rather than doing 
>useful work.
>
>> Would not 1000 be better for finer granularity?
>
>Certainly it would, but tradeoffs exist....

Most of my systems run with HZ=1000 already, but that is hardly
ground for changes to the default.  What we need is some pro et
contra arguments, including benchmarks.



-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.