From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrea Arcangeli Subject: Re: [PATCH] speed up SATA Date: Mon, 29 Mar 2004 15:05:54 +0200 Sender: linux-kernel-owner@vger.kernel.org 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 Return-path: Content-Disposition: inline In-Reply-To: <20040329042912.GI18054@ca-server1.us.oracle.com> 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 List-Id: linux-ide@vger.kernel.org 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?