From owner-freebsd-current Sat Mar 7 16:02:55 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id QAA00782 for freebsd-current-outgoing; Sat, 7 Mar 1998 16:02:55 -0800 (PST) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from ns.mt.sri.com (sri-gw.MT.net [206.127.105.141]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id QAA00777 for ; Sat, 7 Mar 1998 16:02:53 -0800 (PST) (envelope-from nate@mt.sri.com) Received: from mt.sri.com (rocky.mt.sri.com [206.127.76.100]) by ns.mt.sri.com (8.8.8/8.8.8) with SMTP id RAA15064; Sat, 7 Mar 1998 17:02:50 -0700 (MST) (envelope-from nate@rocky.mt.sri.com) Received: by mt.sri.com (SMI-8.6/SMI-SVR4) id RAA05223; Sat, 7 Mar 1998 17:02:48 -0700 Date: Sat, 7 Mar 1998 17:02:48 -0700 Message-Id: <199803080002.RAA05223@mt.sri.com> From: Nate Williams MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: Dmitrij Tejblum Cc: Terry Lambert , current@FreeBSD.ORG Subject: Re: vnode_pager: *** WARNING *** stale FS code in system In-Reply-To: <199803072354.CAA02807@tejblum.dnttm.rssi.ru> References: <199803070154.SAA27728@usr09.primenet.com> <199803072354.CAA02807@tejblum.dnttm.rssi.ru> X-Mailer: VM 6.29 under 19.15 XEmacs Lucid Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG As a complete newbie to this, let me see if I can inject my thoughts into this. Terry wants FS implementors (therefore all FS's) to explicitly write code for vnode_pagers, rather than having the (potentially buggy) code used by FS writers. Dima wants people to not have write potentially trivial code into their FS, but give them a default that will work in most cases. Terry claims that if they rely on the trivial code, it could cause bugs. Dima claims that for most existing FS's, the trivial stuff is good enough for their purposes, and that any FS developer that isn't writing a trivial FS already is smart enough to write a non-default vnode_pager implementation. Terry claims that this vnode_pager stuff should go away, and it'll be easier to remove it by making sure that all FS's have this code, but then he loses me from that point on. Is everything I said up to this point true for the most part? If so, I've gotta agree with Dima here. Anyone silly enough to write FS's should know what they're doing, and forcing them to write more boilerplate code that could be done by default is simply silliness. If you're smart enough to write FS, you should also be smart enough to figure out when the defaults won't cut it. This is the intent of stacking FS's as I understand. The VFS stuff is intended to make FS design more OOP, so that you can pick what things you need to implement, and not have to implement others, just like object inheritence. Tell me what I'm missing, if anything? Nate To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message