From owner-freebsd-smp Thu Aug 28 08:14:31 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id IAA03484 for smp-outgoing; Thu, 28 Aug 1997 08:14:31 -0700 (PDT) Received: from phaeton.artisoft.com (phaeton.Artisoft.COM [198.17.250.50]) by hub.freebsd.org (8.8.7/8.8.7) with SMTP id IAA03479 for ; Thu, 28 Aug 1997 08:14:26 -0700 (PDT) Received: (from terry@localhost) by phaeton.artisoft.com (8.6.11/8.6.9) id IAA00933; Thu, 28 Aug 1997 08:10:55 -0700 From: Terry Lambert Message-Id: <199708281510.IAA00933@phaeton.artisoft.com> Subject: Re: A how does it work question. To: Shimon@i-connect.net (Simon Shapiro) Date: Thu, 28 Aug 1997 08:10:55 -0700 (MST) Cc: peter@spinner.dialix.com.au, petrilli@amber.org, smp@FreeBSD.ORG, peters@gil.com.au, mestery@winternet.com In-Reply-To: from "Simon Shapiro" at Aug 27, 97 11:18:37 pm X-Mailer: ELM [version 2.4 PL24] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-smp@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > Of course you are right. I will not mention my contribution to the concept > of ``giant lock''. But trust that I understand it, although I may not be > able to say so in a streight sentence :-) > > Now, ffs is a different story :-) FFS *can* be trivial. You just have to divorce blocking and non-blocking operations. The technology to do this is called "soft updates". 8-). For a general soloution instead, which will work with all FS's, even under stacking, a graphical soloution is required. You precompute Warshal's over the graph for everything but the next event to be added. This lets you (1) recompute it in linear time (O(n)), and (2) run dependencies between stacked layers. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.