From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264974AbUEYRCH (ORCPT ); Tue, 25 May 2004 13:02:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264986AbUEYRCG (ORCPT ); Tue, 25 May 2004 13:02:06 -0400 Received: from 80-169-17-66.mesanetworks.net ([66.17.169.80]:56459 "EHLO mail.bounceswoosh.org") by vger.kernel.org with ESMTP id S264974AbUEYRAY (ORCPT ); Tue, 25 May 2004 13:00:24 -0400 Date: Tue, 25 May 2004 11:02:14 -0600 From: "Eric D. Mudama" To: Giuliano Pochini Cc: "Eric D. Mudama" , Tom Vier , linux-kernel@vger.kernel.org Subject: Re: Linux Kernel 2.6.6 IDE shutdown problems. Message-ID: <20040525170214.GA26785@bounceswoosh.org> Mail-Followup-To: Giuliano Pochini , "Eric D. Mudama" , Tom Vier , linux-kernel@vger.kernel.org References: <200405151506.20765.bzolnier@elka.pw.edu.pl> <20040524024136.GB2502@zero> <20040524171656.GA19026@bounceswoosh.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.5.1+cvs20040105i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 25 at 11:05, Giuliano Pochini wrote: > > >On Mon, 24 May 2004, Eric D. Mudama wrote: > >> Picture a nice fast drive doing 100 writes/second to the media... if >> you give it over 200 writes at a time, it'll occupy your 2 seconds. >> Newer drives with 8MB or larger buffers are certainly capable of >> caching a lot more than 200 writes... > >Quite unlikely. Usually disks have a big cache but it can hold a very >limited number of blocks. 8MB of cache is probably divided in 8 blocks >of 1MB each. Sorry, but that isn't true, unless some company is just plain stupid. Everyone has different metrics for cache granularity based on their cache architecture, but I can assure you that 8x 1MB segments is off by 1-2 orders of magnitude, and has been for years. In practice, depending on the workload, there may appear to only be 8 active segments as drives today can merge cache segments or other similar things (architectually dependant), but the worst-case (best case?) is significantly more. --eric -- Eric D. Mudama edmudama@mail.bounceswoosh.org