From owner-cvs-src@FreeBSD.ORG Tue Apr 8 10:30:47 2003 Return-Path: Delivered-To: cvs-src@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 535D237B404; Tue, 8 Apr 2003 10:30:47 -0700 (PDT) Received: from mailout07.sul.t-online.com (mailout07.sul.t-online.com [194.25.134.83]) by mx1.FreeBSD.org (Postfix) with ESMTP id 63A2143F75; Tue, 8 Apr 2003 10:30:46 -0700 (PDT) (envelope-from Alexander@Leidinger.net) Received: from fwd10.sul.t-online.de by mailout07.sul.t-online.com with smtp id 192wvf-00037a-00; Tue, 08 Apr 2003 19:30:39 +0200 Received: from Andro-Beta.Leidinger.net (520065502893-0001@[80.131.125.201]) by fmrl10.sul.t-online.com with esmtp id 192wvQ-07HnM0C; Tue, 8 Apr 2003 19:30:24 +0200 Received: from Magelan.Leidinger.net (Magelan [192.168.1.1]) h38HUMBR002683; Tue, 8 Apr 2003 19:30:22 +0200 (CEST) (envelope-from Alexander@Leidinger.net) Received: from Magelan.Leidinger.net (netchild@localhost [127.0.0.1]) by Magelan.Leidinger.net (8.12.9/8.12.9) with SMTP id h38HULpr006071; Tue, 8 Apr 2003 19:30:21 +0200 (CEST) (envelope-from Alexander@Leidinger.net) Date: Tue, 8 Apr 2003 19:30:21 +0200 From: Alexander Leidinger To: Dag-Erling Smorgrav Message-Id: <20030408193021.77aa8706.Alexander@Leidinger.net> In-Reply-To: References: X-Mailer: Sylpheed version 0.8.9claws (GTK+ 1.2.10; i386-portbld-freebsd5.0) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Sender: 520065502893-0001@t-dialin.net cc: src-committers@freebsd.org cc: nate@root.org cc: cvs-src@freebsd.org cc: sos@spider.deepcore.dk cc: cvs-all@freebsd.org cc: sos@freebsd.org Subject: Re: cvs commit: src/sys/dev/ata ata-all.c ata-all.h ata-chipset.cata-dma.c ata-pci.c ata-pci.h X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 08 Apr 2003 17:30:47 -0000 On Tue, 08 Apr 2003 19:15:04 +0200 Dag-Erling Smorgrav wrote: > Nate Lawson writes: > > Tagged queuing is orthogonal to caching. TQ allows multiple transactions > > to be passed to the drive, allowing it to order and aggregate the requests > > as it thinks best. TQ can be done with no cache because all the drive is > > tracking is handles to transactions (typically 16 bit ids). Think of it > > as more like a pipeline than a cache. > > It can't be done without cache, because you can't queue and reorder > transactions without some sort of cache. I like to think about it as a buffer, not a cache. A write-cache acknowledges the write as soon as it hits the cache (and not the physical storage) and talking about TQ as a cache makes me feel bad... Bye, Alexander. -- To boldly go where I surely don't belong. http://www.Leidinger.net Alexander @ Leidinger.net GPG fingerprint = C518 BC70 E67F 143F BE91 3365 79E2 9C60 B006 3FE7