From owner-freebsd-arch Fri Sep 20 12:56:10 2002 Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 29E6D37B401 for ; Fri, 20 Sep 2002 12:56:09 -0700 (PDT) Received: from 2-225.ctame701-1.telepar.net.br (2-225.ctame701-1.telepar.net.br [200.193.160.225]) by mx1.FreeBSD.org (Postfix) with ESMTP id B61E843E65 for ; Fri, 20 Sep 2002 12:56:04 -0700 (PDT) (envelope-from riel@conectiva.com.br) Received: from localhost ([IPv6:::ffff:127.0.0.1]:33994 "EHLO localhost") by imladris.surriel.com with ESMTP id ; Fri, 20 Sep 2002 16:55:53 -0300 Date: Fri, 20 Sep 2002 16:55:52 -0300 (BRT) From: Rik van Riel X-X-Sender: riel@imladris.surriel.com To: Julian Elischer Cc: Bill Huey , Subject: Re: New Linux threading model In-Reply-To: Message-ID: X-spambait: aardvark@kernelnewbies.org X-spammeplease: aardvark@nl.linux.org MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Fri, 20 Sep 2002, Julian Elischer wrote: > On Fri, 20 Sep 2002, Rik van Riel wrote: > > There don't seem to be any O(n) loops left in or near this scheduler, > > meaning that 1:1 threading with lots of threads becomes possible. > > The FreeBSD scheduler is moving towards a big rewrite but we want to > change "one thing at a time" :-) in that area.. This is doable in a smallish number of steps, which don't even need to be done in this order: 1) per-cpu runqueues instead of a global one, which wants ... 2) ... load balancer between these per-cpu queues 3) two runqueue arrays (current and expired) instead of just one, which enables ... 4) ... event-driver priority recalculation, instead of recalculating the priority of each task separately These changes are probably small enough that they can be done without the risk of destabilising anything. Rik -- Bravely reimplemented by the knights who say "NIH". http://www.surriel.com/ http://distro.conectiva.com/ Spamtraps of the month: september@surriel.com trac@trac.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message