From owner-freebsd-arch Thu Dec 9 21:30:59 1999 Delivered-To: freebsd-arch@freebsd.org Received: from ns1.yes.no (ns1.yes.no [195.204.136.10]) by hub.freebsd.org (Postfix) with ESMTP id 5A4E7153B1 for ; Thu, 9 Dec 1999 21:30:53 -0800 (PST) (envelope-from eivind@bitbox.follo.net) Received: from bitbox.follo.net (bitbox.follo.net [195.204.143.218]) by ns1.yes.no (8.9.3/8.9.3) with ESMTP id GAA14555 for ; Fri, 10 Dec 1999 06:30:50 +0100 (CET) Received: (from eivind@localhost) by bitbox.follo.net (8.8.8/8.8.6) id GAA33704 for freebsd-arch@freebsd.org; Fri, 10 Dec 1999 06:30:49 +0100 (MET) Received: from picnic.mat.net (picnic.mat.net [206.246.122.133]) by hub.freebsd.org (Postfix) with ESMTP id 40E9E1537E for ; Thu, 9 Dec 1999 21:30:25 -0800 (PST) (envelope-from chuckr@picnic.mat.net) Received: from localhost (chuckr@localhost [127.0.0.1]) by picnic.mat.net (8.9.3/8.9.3) with ESMTP id AAA08943; Fri, 10 Dec 1999 00:28:17 -0500 (EST) (envelope-from chuckr@picnic.mat.net) Date: Fri, 10 Dec 1999 00:28:17 -0500 (EST) From: Chuck Robey To: Peter Jeremy Cc: freebsd-arch@freebsd.org Subject: Re: Thread scheduling In-Reply-To: <99Dec10.155600est.40337@border.alcanet.com.au> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Fri, 10 Dec 1999, Peter Jeremy wrote: > On 1999-Dec-10 15:40:40 +1100, Chuck Robey wrote: > >That is, is it important at all that all processors be doing the same > >multithreading task (if it's multithreaded, and wants it) at exactly the > >same time? > > I don't think this is guaranteed anywhere. In any case, IMHO it would > be virtually impossible for a system to provide such a guarantee - > consider a system which provided such a guarantee and currently has > two threads executing on two CPUs. An interrupt then occurs on one > CPU - what happens to the thread on the other CPU (which hasn't seen > the interrupt)? What happens if (as a result of the interrupt) a > higher priority process becomes runnable? I can think of several ways for it to be done, so lets concentrate on whether it's needed or desireable. I think all the caching is done per processor, so that wouldn't be an issue, right? Hiw about memory usage? ---------------------------------------------------------------------------- Chuck Robey | Interests include C programming, Electronics, 213 Lakeside Dr. Apt. T-1 | communications, and signal processing. Greenbelt, MD 20770 | I run picnic.mat.net: FreeBSD-current(i386) and (301) 220-2114 | jaunt.mat.net : FreeBSD-current(Alpha) ---------------------------------------------------------------------------- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message