From owner-freebsd-hackers Sun Mar 31 13:27:31 2002 Delivered-To: freebsd-hackers@freebsd.org Received: from falcon.prod.itd.earthlink.net (falcon.mail.pas.earthlink.net [207.217.120.74]) by hub.freebsd.org (Postfix) with ESMTP id A1CC737B400 for ; Sun, 31 Mar 2002 13:27:27 -0800 (PST) Received: from pool0321.cvx21-bradley.dialup.earthlink.net ([209.179.193.66] helo=mindspring.com) by falcon.prod.itd.earthlink.net with esmtp (Exim 3.33 #1) id 16rmqc-0003cG-00; Sun, 31 Mar 2002 13:26:46 -0800 Message-ID: <3CA77EFE.2C00A81F@mindspring.com> Date: Sun, 31 Mar 2002 13:26:22 -0800 From: Terry Lambert X-Mailer: Mozilla 4.7 [en]C-CCK-MCD {Sony} (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Josh Paetzel Cc: Alfred Perlstein , Andrew , Dan Nelson , Volker Stolz , Ian , hackers@FreeBSD.ORG Subject: Re: idprio References: <3CA0D3FE.8113515C@mindspring.com> <20020327092520.V24232-100000@starbug.ugh.net.au> <20020326223103.GC93885@elvis.mu.org> <3CA156F5.79580CE3@mindspring.com> <20020331134608.A286@twincat.vladsempire.net> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Josh Paetzel wrote: > On Tue, Mar 26, 2002 at 09:21:57PM -0800, Terry Lambert wrote: > > Alfred Perlstein wrote: > > > > But if system calls aren't preempted under what circumstances can a > > > > process hold a vnode lock and then be usurped for processor? > > > > > > While sleeping for IO. > > > > Ideal systems release and reacquire locks when they are going > > to suspend for a long time (Djikstra's "Banker's Algorithm"). > > Of course, the downside of this is that a low priority process that > needs a lot of resources may never be able get all of the resources > that it needs. :) That's a feature, not a bug. -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message