From owner-freebsd-smp Thu Dec 10 13:04:08 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id NAA16028 for freebsd-smp-outgoing; Thu, 10 Dec 1998 13:04:08 -0800 (PST) (envelope-from owner-freebsd-smp@FreeBSD.ORG) Received: from hromeo.algonet.se (hromeo.algonet.se [194.213.74.10]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id NAA16017 for ; Thu, 10 Dec 1998 13:04:05 -0800 (PST) (envelope-from mal@algonet.se) Received: (qmail 24269 invoked from network); 10 Dec 1998 22:03:45 +0100 Received: from kairos.algonet.se (194.213.74.18) by hromeo.algonet.se with SMTP; 10 Dec 1998 22:03:45 +0100 Received: (mal@localhost) by kairos.algonet.se (8.8.8+Sun/8.6.12) id WAA24473; Thu, 10 Dec 1998 22:03:44 +0100 (MET) Date: Thu, 10 Dec 1998 22:03:44 +0100 (MET) Message-Id: <199812102103.WAA24473@kairos.algonet.se> X-Authentication-Warning: kairos.algonet.se: mal set sender to mal@kairos.algonet.se using -f From: Mats Lofkvist To: tlambert@primenet.com CC: alk@pobox.com, tlambert@primenet.com, peter@netplex.com.au, gpalmer@FreeBSD.ORG, marcelk@stack.nl, smp@FreeBSD.ORG In-reply-to: <199812082132.OAA25044@usr09.primenet.com> (message from Terry Lambert on Tue, 8 Dec 1998 21:32:43 +0000 (GMT)) Subject: Re: Pthreads and SMP References: <199812082132.OAA25044@usr09.primenet.com> Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Terry Lambert 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 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message