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Date: Tue, 8 Jan 2013 07:56:10 -0800
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Subject: Re: To SMP or not to SMP
From: Adrian Chadd <adrian@freebsd.org>
To: Barney Cordoba <barney_cordoba@yahoo.com>
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Cc: freebsd-net@freebsd.org, Erich Dollansky <erichsfreebsdlist@alogt.com>
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The only weird crap I've seen with SMP versus non-SMP these days is
some assumptions that it's cheap to alternate between two tasks in a
preemptive kernel.

That behaviour sucks on MIPS.

On SMP machines with enough CPUs/hardware threads, you don't see the
context switch overhead because you have enough CPUs to run them
concurrently. But on single core MIPS boards, things aren't quite as
shiny.

(Yes, I'm working towards making net80211 and some of the wifi drivers
enforce better behaviour in this regard. The network stack doesn't
really "help" me here.)



Adrian