Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262949AbUC2NIl (ORCPT ); Mon, 29 Mar 2004 08:08:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262951AbUC2NII (ORCPT ); Mon, 29 Mar 2004 08:08:08 -0500 Received: from ppp-217-133-42-200.cust-adsl.tiscali.it ([217.133.42.200]:24477 "EHLO dualathlon.random") by vger.kernel.org with ESMTP id S262949AbUC2NF5 (ORCPT ); Mon, 29 Mar 2004 08:05:57 -0500 Date: Mon, 29 Mar 2004 15:05:54 +0200 From: Andrea Arcangeli To: Wim Coekaerts Cc: Jeff Garzik , Bartlomiej Zolnierkiewicz , Jens Axboe , William Lee Irwin III , Nick Piggin , linux-ide@vger.kernel.org, Linux Kernel , Andrew Morton Subject: Re: [PATCH] speed up SATA Message-ID: <20040329130554.GI3039@dualathlon.random> 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> User-Agent: Mutt/1.4.1i X-GPG-Key: 1024D/68B9CB43 13D9 8355 295F 4823 7C49 C012 DFA1 686E 68B9 CB43 X-PGP-Key: 1024R/CB4660B9 CC A0 71 81 F4 A0 63 AC C0 4B 81 1D 8C 15 C8 E5 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1042 Lines: 22 On Sun, Mar 28, 2004 at 08:29:12PM -0800, 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. > > 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. 1M certainly it's reasonable, though for 8M I've my doubt you can measure a throughput improvement, can you? - 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/