From owner-freebsd-smp@FreeBSD.ORG Fri Jun 3 00:35:34 2005 Return-Path: X-Original-To: freebsd-smp@freebsd.org Delivered-To: freebsd-smp@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id BCB6C16A42A for ; Fri, 3 Jun 2005 00:35:34 +0000 (GMT) (envelope-from ketralnis@ketralnis.dyndns.org) Received: from ylpvm12.prodigy.net (ylpvm12-ext.prodigy.net [207.115.57.43]) by mx1.FreeBSD.org (Postfix) with ESMTP id 2FA8E43D48 for ; Fri, 3 Jun 2005 00:35:33 +0000 (GMT) (envelope-from ketralnis@ketralnis.dyndns.org) Received: from pimout6-ext.prodigy.net (pimout6-int.prodigy.net [207.115.4.22]) by ylpvm12.prodigy.net (8.12.10 outbound/8.12.10) with ESMTP id j530ZV28025647 for ; Thu, 2 Jun 2005 20:35:31 -0400 X-ORBL: [64.173.11.131] Received: from ketralnis.dyndns.org (adsl-64-173-11-131.dsl.sntc01.pacbell.net [64.173.11.131]) by pimout6-ext.prodigy.net (8.12.10 milter /8.12.10) with ESMTP id j530ZWug422994 for ; Thu, 2 Jun 2005 20:35:32 -0400 Received: from [10.0.2.239] ([10.0.2.239]) by ketralnis.dyndns.org (8.13.1/8.13.1) with ESMTP id j530ZEre000515 for ; Thu, 2 Jun 2005 17:35:14 -0700 (PDT) (envelope-from ketralnis@ketralnis.dyndns.org) Mime-Version: 1.0 (Apple Message framework v622) In-Reply-To: <429F759F.1000403@landgren.net> References: <429E67CB.6090901@pacific.net.sg> <6845d25a0506020616293991e3@mail.gmail.com> <429F759F.1000403@landgren.net> Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: <845448d08ea438ecc1d735af8eaf5f6f@ketralnis.dyndns.org> Content-Transfer-Encoding: 7bit From: David King Date: Thu, 2 Jun 2005 17:35:34 -0700 To: freebsd-smp@freebsd.org X-Mailer: Apple Mail (2.622) Subject: Re: Assignmet of CPUs X-BeenThere: freebsd-smp@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: FreeBSD SMP implementation group List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 03 Jun 2005 00:35:34 -0000 > Well, round-robin startup would at least be better than always using > one process to start all processes. That would go some of the way > towards improving asymmetric heating. (Says me, whose knowledge of > kernel scheduling could be written on the face of a chip and still > leave room for footnotes...) In the spirit of small amounts of scheduling knowledge, are load averages kept on individual processors? Or can they be determined fast enough to not increase the process creation time significantly (or at least to be offset by the speed gained), in order to put a process or thread on the least encumbered processor? top(1) lists the assigned CPU, so it seems like it would be simple enough to determine on-the-fly, but if it's not kept somewhere, I wouldn't want to iterate every process to get its assigned CPU every time I create a new one. Is there a "scheduling-for-dummies" feasibly (even if not easily) read by non-kernel hackers? :) > David > >> On 6/1/05, Erich Dollansky wrote: > [...] > >>> The last, but hardly used parameter, is the CPU temperature. I >>> noticed >>> that FreeBSD tends to use always the same CPU to start a task. This >>> makes one CPU real hot while the other stays cool. Taking the CPU >>> temperature into account for starting at least new threads would also >>> have an advantage of systems with an less then ideal cooling system. >>> >>> Spreading tasks all over the system with the coolest CPU being the >>> one >>> to be started next will make systems a bit cooler. > > _______________________________________________ > freebsd-smp@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-smp > To unsubscribe, send any mail to "freebsd-smp-unsubscribe@freebsd.org"