From owner-freebsd-arch Wed Jul 17 3:54:48 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 A885B37B400 for ; Wed, 17 Jul 2002 03:54:46 -0700 (PDT) Received: from hardtime.linuxman.net (hardtime.linuxman.net [66.147.26.65]) by mx1.FreeBSD.org (Postfix) with ESMTP id 774FD43E42 for ; Wed, 17 Jul 2002 03:54:45 -0700 (PDT) (envelope-from fullermd@over-yonder.net) Received: from mortis.over-yonder.net (localhost [127.0.0.1]) by hardtime.linuxman.net (8.11.6/8.11.6) with ESMTP id g6HAB3J05589; Wed, 17 Jul 2002 05:11:08 -0500 Received: by mortis.over-yonder.net (Postfix, from userid 100) id 39C131F06; Wed, 17 Jul 2002 05:54:34 -0500 (CDT) Date: Wed, 17 Jul 2002 05:54:34 -0500 From: "Matthew D. Fuller" To: Luigi Rizzo Cc: arch@freebsd.org Subject: Re: proposed changes to kern_switch.c and kern_synch.c Message-ID: <20020717105433.GB29269@over-yonder.net> References: <20020716235216.B6785@iguana.icir.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20020716235216.B6785@iguana.icir.org> User-Agent: Mutt/1.4i-fullermd.1 X-Editor: vi X-OS: FreeBSD 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 Tue, Jul 16, 2002 at 11:52:16PM -0700 I heard the voice of Luigi Rizzo, and lo! it spake thus: > > --- Re. the multi-scheduler architecture --- > > The general idea is to make the process/thread/kse scheduler > a replaceable piece of the kernel, requiring no modifications > to the "struct proc", and with the ability of switching from > one scheduler to another one at runtime (this both for testing > purposes and for whatever need may arise). Random related thoughts: 1) From the work you've done on this already, how difficult would you expect it to be to do this in such a way that you could have multiple (>2) schedulers around, loading and unloading at will (when disabled, of course) through KLD's? 2) How much unavoidable overhead is there in switching between the schedulers? Could it get low enough that it might be meaningful to, instead of writing One True Scheduler, instead write 3 or 4 different optimized ones, and have some intelligence to switch between them automagically as load demands? -- Matthew Fuller (MF4839) | fullermd@over-yonder.net Systems/Network Administrator | http://www.over-yonder.net/~fullermd/ "The only reason I'm burning my candle at both ends, is because I haven't figured out how to light the middle yet" To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message