From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264268AbTDPIdC (for ); Wed, 16 Apr 2003 04:33:02 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264275AbTDPIdC (for ); Wed, 16 Apr 2003 04:33:02 -0400 Received: from c-97a870d5.037-69-73746f23.cust.bredbandsbolaget.se ([213.112.168.151]:19841 "EHLO zaphod.guide") by vger.kernel.org with ESMTP id S264268AbTDPIdB (for ); Wed, 16 Apr 2003 04:33:01 -0400 To: Ivan Kokshaysky Cc: Alan Cox , Linux Kernel Mailing List Subject: Re: DMA transfers in 2.5.67 References: <1050438684.28586.8.camel@dhcp22.swansea.linux.org.uk> <1050439715.28586.17.camel@dhcp22.swansea.linux.org.uk> <20030416123654.A2629@jurassic.park.msu.ru> From: mru@users.sourceforge.net (=?iso-8859-1?q?M=E5ns_Rullg=E5rd?=) Date: 16 Apr 2003 10:43:47 +0200 In-Reply-To: <20030416123654.A2629@jurassic.park.msu.ru> Message-ID: User-Agent: Gnus/5.0808 (Gnus v5.8.8) XEmacs/21.4 (Portable Code) MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Ivan Kokshaysky writes: > On Wed, Apr 16, 2003 at 12:09:00AM +0200, Måns Rullgård wrote: > > Btw, I just noticed that hard disk throughput is much lower with 2.5 > > than 2.4. With 2.4.21-pre5 I get ~40 MB/s, but with 2.5.67 the speed > > drops to 25-30 MB/s. Everything according to hdparm. Is it possible > > that DMA is generally slow for some reason? > > Possible reason is that in 2.4 we've forced reasonable latency timer > value for all PCI devices, while in 2.5 we haven't as yet. Do you mean whatever causes this message (for a 3com NIC)? PCI: Setting latency timer of device 00:05.0 to 64 Would that also explain why my hard disks are slow under 2.5? There is no corresponding message for the ide controller (htp374). -- Måns Rullgård mru@users.sf.net