From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757624Ab0CaAZ4 (ORCPT ); Tue, 30 Mar 2010 20:25:56 -0400 Received: from out3.smtp.messagingengine.com ([66.111.4.27]:57689 "EHLO out3.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757641Ab0CaAZw (ORCPT ); Tue, 30 Mar 2010 20:25:52 -0400 X-Sasl-enc: Ju5KNaOoy6AVADSpkHfhoqRsTJHILpLgLfyXPf1D6LbM 1269995151 Date: Tue, 30 Mar 2010 21:25:49 -0300 From: Henrique de Moraes Holschuh To: Thomas Pilarski Cc: linux-kernel@vger.kernel.org, Andrew Morton , Ingo Molnar , Peter Zijlstra , Jens Axboe Subject: Re: [Bug 12309] Large I/O operations result in slow performance and high iowait times Message-ID: <20100331002549.GB9925@khazad-dum.debian.net> References: <201003162357.o2GNvkNF024562@demeter.kernel.org> <1269935094.2481.23.camel@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1269935094.2481.23.camel@localhost> X-GPG-Fingerprint: 1024D/1CDB0FE3 5422 5C61 F6B7 06FB 7E04 3738 EE25 DE3F 1CDB 0FE3 User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 30 Mar 2010, Thomas Pilarski wrote: > This problem is enormous increased, while the ultra bay disc is acceded > with udma2 instead of udma6 (caused by another bug), There is a thinkpad BIOS bug that could cause that: it will not signal a 80-wire cable when you hot-add an HD on a PATA ultrabay. Exists at least on all T4x, including the T43. The fix is to whitelist these thinkpads for high-speed UDMA even on 40-wire cables. The workaround is to add a kernel command line parameter (I forget which). Does that match your udma2 instead of udma6 problem? -- "One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh