From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264463AbTL3FJp (ORCPT ); Tue, 30 Dec 2003 00:09:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264464AbTL3FJp (ORCPT ); Tue, 30 Dec 2003 00:09:45 -0500 Received: from holomorphy.com ([199.26.172.102]:10689 "EHLO holomorphy.com") by vger.kernel.org with ESMTP id S264463AbTL3FJo (ORCPT ); Tue, 30 Dec 2003 00:09:44 -0500 Date: Mon, 29 Dec 2003 21:09:34 -0800 From: William Lee Irwin III To: Martin Schlemmer Cc: Thomas Molina , Linus Torvalds , Kernel Mailing List Subject: Re: 2.6.0 performance problems Message-ID: <20031230050934.GM27687@holomorphy.com> Mail-Followup-To: William Lee Irwin III , Martin Schlemmer , Thomas Molina , Linus Torvalds , Kernel Mailing List References: <1072739685.25741.65.camel@nosferatu.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1072739685.25741.65.camel@nosferatu.lan> Organization: The Domain of Holomorphy User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2003-12-30 at 00:58, Thomas Molina wrote: >> It certainly looks like DMA is enabled. Under 2.4 I get: >> [root@lap root]# hdparm /dev/hda [...] >> readahead = 8 (on) [...] >> Under 2.6 I get: >> [root@lap root]# hdparm /dev/hda [...] >> readahead = 256 (on) On Tue, Dec 30, 2003 at 01:14:45AM +0200, Martin Schlemmer wrote: > Increase your readahead: > # hdparm -a 8192 /dev/hda > BTW: As we really do get this question a _lot_ of times, why > don't the ide layer automatically set a higher readahead > if there is enough cache on the drive or something? Could you try lowering 2.6's readahead to 2.4's levels in order to rule out readahead-induced thrashing? -- wli