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To: Robert Watson <rwatson@FreeBSD.org>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Sun, 02 Dec 2007 12:35:12 GMT."
	<20071202123231.G74097@fledge.watson.org> 
Date: Sun, 02 Dec 2007 12:50:22 +0000
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Sender: phk@critter.freebsd.dk
Cc: Attilio Rao <attilio@FreeBSD.org>, arch@FreeBSD.org,
	Andre Oppermann <andre@FreeBSD.org>
Subject: Re: New "timeout" api, to replace callout 
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In message <20071202123231.G74097@fledge.watson.org>, Robert Watson writes:
>On Sun, 2 Dec 2007, Poul-Henning Kamp wrote:

>The reason affinity is getting raised in particular is that quite a few people 
>are running around thinking that affinity is something that they do want and 
>plan to use.

That's fine and good and all.

But before we can play with that sort of stuff, we need some kind
of instance handle on the timeout to express cpu affinity to/with.

We also need to losse Hz from this API, for a large number of reasons,
from efficiency to precision.

And we need to get rid of the 20+ lines of "cleanup my callout" code
that is infecting more and more code.

This API redesign tries to address those three major problems, and
getting that right is important because there are 444 sourcefiles
to visit.

If we find later on that we need to add timeout_fiddle_cpu_affinity(),
we can add that, touching only two or three files, so that is two
orders of magnitude less interesting right now.

The important thing to look at this API, is that it should be able
to express our intent, so that we should never need to visit all
the 444 files ever again.

-- 
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.