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To: Mike Silbersack <silby@silby.com>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Tue, 01 Apr 2003 10:50:22 MDT."
             <20030401104630.T1612@odysseus.silby.com> 
Date: Tue, 01 Apr 2003 19:57:17 +0200
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cc: Yar Tikhiy <yar@freebsd.org>
cc: hackers@freebsd.org
Subject: Re: "Expensive timeout(9) function..." 
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In message <20030401104630.T1612@odysseus.silby.com>, Mike Silbersack writes:


>Yeah, I suppose limiting it to one mii_tick routine per second would help
>somewhat... but it's still a bad situation.

I wasn't advocating slowing it down that much, merely trying to run it
sequentially out of timeout()'s hair.

>Actually, we could improve it quite a bit if someone adds NANODELAY()
>(hint, hint...)  Couldn't we have a first-run nanodelay that just used
>nanotime to do the counting for it?

It should probably be called either nanosleep() or nanospin().

It is not a trivial task to do it.

Writing the short end calibration code to be sufficiently robust
and precise will take some time and a lot of experiments.

There used to be a crumbled note with this somewhere in my stack
of TODO items, but by now I suspect that it is ironed perfectly
flat from the weight of all the stuff on top of it.

But to add to my knowledge-base:  What length of delays are you
looking for ?

-- 
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.