Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262775AbUC2IQn (ORCPT ); Mon, 29 Mar 2004 03:16:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262770AbUC2IOM (ORCPT ); Mon, 29 Mar 2004 03:14:12 -0500 Received: from ns.virtualhost.dk ([195.184.98.160]:59278 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S262756AbUC2INs (ORCPT ); Mon, 29 Mar 2004 03:13:48 -0500 Date: Mon, 29 Mar 2004 10:13:21 +0200 From: Jens Axboe To: Wim Coekaerts Cc: Andrea Arcangeli , Jeff Garzik , Bartlomiej Zolnierkiewicz , William Lee Irwin III , Nick Piggin , linux-ide@vger.kernel.org, Linux Kernel , Andrew Morton Subject: Re: [PATCH] speed up SATA Message-ID: <20040329081320.GS24370@suse.de> References: <4066021A.20308@pobox.com> <200403282030.11743.bzolnier@elka.pw.edu.pl> <20040328183010.GQ24370@suse.de> <200403282045.07246.bzolnier@elka.pw.edu.pl> <406720A7.1050501@pobox.com> <20040329005502.GG3039@dualathlon.random> <20040329042912.GI18054@ca-server1.us.oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040329042912.GI18054@ca-server1.us.oracle.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1119 Lines: 29 On Sun, Mar 28 2004, Wim Coekaerts wrote: > > In 2.4 reaching 512k DMA units that helped a lot, but going past 512k > > didn't help in my measurements. 1M maybe these days is needed (as Jens > > suggested) but >1M still sounds overkill and I completely agree with > > Jens about that. > > at least 1Mb... more than 1mb (I doubt 32mb is really necessarily > useful) is nice for flushing contiguous journal data to disk. between > 1-8mb in one io. 'is nice' means what, in real numbers? :) > at least 1mb is good when you have to process massive amounts of data, > just read huge chunks of files, we tend to do 1mb. anyway, > as you said, at some point it's a bit overkill . I thinkg 1-8mb makes > sense. Yeah, that _range_ makes sense. 1MB is a lot more supportable than 8MB though, so the benefit needs to be something more than a feel good sensation. -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/