From owner-freebsd-current@FreeBSD.ORG Sat Nov 6 12:06:08 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id AD65C16A4CF for ; Sat, 6 Nov 2004 12:06:08 +0000 (GMT) Received: from mailout06.sul.t-online.com (mailout06.sul.t-online.com [194.25.134.19]) by mx1.FreeBSD.org (Postfix) with ESMTP id 298B843D53 for ; Sat, 6 Nov 2004 12:06:08 +0000 (GMT) (envelope-from Alexander@Leidinger.net) Received: from fwd02.aul.t-online.de by mailout06.sul.t-online.com with smtp id 1CQPKW-0001mO-03; Sat, 06 Nov 2004 13:06:04 +0100 Received: from Andro-Beta.Leidinger.net (JlV+OaZvwewZ5AQbawMMN58HW5sbxlnrLPMJrUBRDUw0OeQSGHIxo0@[217.229.210.11]) by fmrl02.sul.t-online.com with esmtp id 1CQPKS-0xLGNc0; Sat, 6 Nov 2004 13:06:00 +0100 Received: from Magellan.Leidinger.net (Magellan.Leidinger.net [192.168.1.1]) iA6C65km067479; Sat, 6 Nov 2004 13:06:05 +0100 (CET) (envelope-from Alexander@Leidinger.net) Date: Sat, 6 Nov 2004 13:06:06 +0100 From: Alexander Leidinger To: Julian Elischer Message-ID: <20041106130606.60f3dea3@Magellan.Leidinger.net> In-Reply-To: <418BD796.3040706@elischer.org> References: <40541.1099561211@critter.freebsd.dk> <1099650992.418b57b01c33b@netchild.homeip.net> <418BD796.3040706@elischer.org> X-Mailer: Sylpheed-Claws 0.9.12b (GTK+ 1.2.10; i386-portbld-freebsd6.0) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-ID: JlV+OaZvwewZ5AQbawMMN58HW5sbxlnrLPMJrUBRDUw0OeQSGHIxo0@t-dialin.net X-TOI-MSGID: cbaf9567-1585-45fd-9794-751fca443d41 cc: Poul-Henning Kamp cc: current@freebsd.org Subject: Re: cvs commit: src/sys/sys buf.h X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 06 Nov 2004 12:06:08 -0000 On Fri, 05 Nov 2004 11:42:14 -0800 Julian Elischer wrote: [buf-junta work] > >Do you have an outline where this heads to and why? > > > > when systems were smaller the number of cached bufs was small, and bufs > represented 'buffers' likely to used soon fo rIO and IO requests were > simple, > it made sence to combine the IO request and the storage descriptor (buf). > > Since then, storage is done via the vm system, IO requests have gotten > bigger, > and the number of IO requests needed at any time has remained small. it > makes less > sense to have an IO request with every buf storage descriptor. You haven't said it explicitly, but I assume there are cases where an IO request doesn't need a buf storage descriptor. Is this correct? I was asking for something like an annotated roadmap. Something like "After X will be done, we need to look at Y, X is an infrastructure change for Y and we want Y because it allows us to do Z." This would allow those who are reading cvs-all to see where we are standing and where we are heading (and to applaud when we reach milestones). Bye, Alexander. -- The best things in life are free, but the expensive ones are still worth a look. http://www.Leidinger.net Alexander @ Leidinger.net GPG fingerprint = C518 BC70 E67F 143F BE91 3365 79E2 9C60 B006 3FE7