Date: Thu, 10 Dec 1998 22:03:44 +0100 (MET) From: Mats Lofkvist <mal@algonet.se> To: tlambert@primenet.com Cc: alk@pobox.com, tlambert@primenet.com, peter@netplex.com.au, gpalmer@FreeBSD.ORG, marcelk@stack.nl, smp@FreeBSD.ORG Subject: Re: Pthreads and SMP Message-ID: <199812102103.WAA24473@kairos.algonet.se> In-Reply-To: <199812082132.OAA25044@usr09.primenet.com> (message from Terry Lambert on Tue, 8 Dec 1998 21:32:43 %2B0000 (GMT)) References: <199812082132.OAA25044@usr09.primenet.com>
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Terry Lambert <tlambert@primenet.com> wrote:
The problem with kernel threads is that, barring everything else,
the threads will migrate randomly between processors, cache-busting
as they go, and you won't get significant benefit from having
multiple processors at all. Only multiple processes really gain
benefit from SMP given the current scheduler.
(Sorry for the delay, but I have been thinking about this
on and off for a few days now and I still don't get it :-)
Are you saying that processes migrating randomly between processors,
cache busting as they go, is less of a problem for a given parallell
application than kernel threads doing the same? Or that the scheduler
is able to keep processes mostly on the same processor but would not
easily be made able to do the same for kernel threads?
_
Mats Lofkvist
mal@algonet.se
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