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Subject: Re: Why HZ on i386 is 100 ?
To: george@mvista.com (george anzinger)
Date: Tue, 23 Apr 2002 08:08:31 +0100 (BST)
Cc: jalvo@mbay.net (John Alvord), pavel@suse.cz (Pavel Machek),
        davidm@hpl.hp.com, davidel@xmailserver.org (Davide Libenzi),
        torvalds@transmeta.com (Linus Torvalds), linux-kernel@vger.kernel.org
In-Reply-To: <3CC4861C.F21859A6@mvista.com> from "george anzinger" at Apr 22, 2002 02:52:28 PM
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From: Alan Cox <alan@lxorguk.ukuu.org.uk>
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> The problem is in accounting (or time slicing if you prefer) where we
> need to start a timer each time a task is context switched to, and stop
> it when the task is switched away.  The overhead is purely in the set up
> and tear down.  MOST of these never expire.

Done properly on many platforms a variable tick is very very easy and also
very efficient to handle. X86 is a paticular problem case because the timer
is so expensive to fiddle with
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