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Date: Sun, 30 Jan 2005 15:06:10 -0600 (CST)
From: Mike Silbersack <silby@silby.com>
To: Robert Watson <rwatson@FreeBSD.org>
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cc: Poul-Henning Kamp <phk@phk.freebsd.dk>
cc: current@freebsd.org
cc: cperciva@FreeBSD.org
Subject: Re: tcp_isn_tick() / dummynet() callout madness ?
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On Sun, 30 Jan 2005, Robert Watson wrote:

> Note that the remainder run 1/100th as often, presumably because they do
> hz/10 or hz/100 or the like.  I've talked to both Colin Percival and Mike
> Silby about the problem -- since the callout_reset() is one of the more
> expensive parts of this code, Colin has been looking at some locking
> optimizations to lower the cost.  I attempted to convince Mike that if we
> thought the ISN sequencing was "sufficiently secure" with HZ of 100, then
> we should be able to still run it at hz/100 now instead of 1000 times per
> second, but he seems resistant.  I'll CC him so he's forced to reconsider
> :-).

You're right, reducing tcp_isn_tick to 100 hz won't really hurt anything. 
However, I'd still like an efficient way to run sometime once per tick. 
Is there a better place to hook in instead of callouts?

Mike "Silby" Silbersack