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Date: Wed, 26 Dec 2012 00:21:27 +0100
From: Marius Strobl <marius@alchemy.franken.de>
To: Alexander Motin <mav@freebsd.org>
Subject: Re: [RFC/RFT] calloutng
Message-ID: <20121225232126.GA47692@alchemy.franken.de>
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Cc: Davide Italiano <davide@freebsd.org>,
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On Tue, Dec 18, 2012 at 11:03:47AM +0200, Alexander Motin wrote:
> Experiments with dummynet shown ineffective support for very short 
> tick-based callouts. New version fixes that, allowing to get as many 
> tick-based callout events as hz value permits, while still be able to 
> aggregate events and generating minimum of interrupts.
> 
> Also this version modifies system load average calculation to fix some 
> cases existing in HEAD and 9 branches, that could be fixed with new 
> direct callout functionality.
> 
> http://people.freebsd.org/~mav/calloutng_12_17.patch
> 
> With several important changes made last time I am going to delay commit 
> to HEAD for another week to do more testing. Comments and new test cases 
> are welcome. Thanks for staying tuned and commenting.

FYI, I gave both calloutng_12_15_1.patch and calloutng_12_17.patch a
try on sparc64 and it at least survives a buildworld there. However,
with the patched kernels, buildworld times seem to increase slightly but
reproducible by 1-2% (I only did four runs but typically buildworld
times are rather stable and don't vary more than a minute for the
same kernel and source here). Is this an expected trade-off (system
time as such doesn't seem to increase)?
Is there anything specific to test?

Marius