Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757643AbYACIpk (ORCPT ); Thu, 3 Jan 2008 03:45:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752945AbYACIpb (ORCPT ); Thu, 3 Jan 2008 03:45:31 -0500 Received: from aun.it.uu.se ([130.238.12.36]:62050 "EHLO aun.it.uu.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752652AbYACIpa (ORCPT ); Thu, 3 Jan 2008 03:45:30 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <18300.40661.199761.488061@harpo.it.uu.se> Date: Thu, 3 Jan 2008 09:37:41 +0100 From: Mikael Pettersson To: Linda Walsh Cc: Robert Hancock , Alan Cox , LKML , linux-ide@vger.kernel.org Subject: Re: SATA kernel-buffered read VERY slow (not raid, Promise TX300 card); 2.6.23.1(vanilla) In-Reply-To: <477C63AA.8080006@tlinx.org> References: <4777E08C.4000603@shaw.ca> <4779870E.5070507@tlinx.org> <20080101015812.59e9ebf0@the-village.bc.nu> <477BEF8D.8090307@tlinx.org> <477C2B71.7040504@shaw.ca> <477C63AA.8080006@tlinx.org> X-Mailer: VM 7.17 under Emacs 20.7.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2273 Lines: 51 Linda Walsh writes: > Robert Hancock wrote: > > Linda Walsh wrote: > >> Alan Cox wrote: > >>>> rate began falling; at 128k block-reads-at-a-time or larger, it > >>>> drops below > >>>> 20MB/s (only on buffered SATA). > >>> Try disabling NCQ - see if you've got a drive with the 'NCQ = no > >>> readahead' flaw. > > http://linux-ata.org/faq.html#ncq > --- > When drive initializes, dmesg says it has NCQ (depth 0/32) > Reading the queue_depth under /sys, shows a queuedepth of "1". > > But more importantly -- I notice a chronic error message associate > with this drive that may be causing some or all of the problem: > --- > Jan 2 20:06:10 Ishtar kernel: ata1.00: exception Emask 0x0 SAct 0x0 > SErr 0x0 action 0x2 > Jan 2 20:06:10 Ishtar kernel: ata1.00: port_status 0x20080000 > Jan 2 20:06:10 Ishtar kernel: ata1.00: cmd > c8/00:10:30:06:03/00:00:00:00:00/e0 tag 0 cdb 0x0 data 8192 in > Jan 2 20:06:10 Ishtar kernel: res > 50/00:00:3f:06:03/00:00:00:00:00/e0 Emask 0x2 (HSM violation) > Jan 2 20:06:13 Ishtar kernel: ata1: limiting SATA link speed to 1.5 Gbps > Jan 2 20:06:13 Ishtar kernel: ata1.00: exception Emask 0x0 SAct 0x0 > SErr 0x0 action 0x6 > Jan 2 20:06:13 Ishtar kernel: ata1.00: port_status 0x20080000 > Jan 2 20:06:13 Ishtar kernel: ata1.00: cmd > c8/00:10:00:8b:04/00:00:00:00:00/e0 tag 0 cdb 0x0 data 8192 in > Jan 2 20:06:13 Ishtar kernel: res > 50/00:00:0f:8b:04/00:00:00:00:00/e0 Emask 0x2 (HSM violation) > Jan 2 20:06:14 Ishtar kernel: ata1: exception Emask 0x10 SAct 0x0 SErr > 0x0 action 0x3 > Jan 2 20:06:14 Ishtar kernel: ata1: hotplug_status 0x80 > Jan 2 20:06:15 Ishtar kernel: ata1: exception Emask 0x10 SAct 0x0 SErr > 0x0 action 0x3 > Jan 2 20:06:15 Ishtar kernel: ata1: hotplug_status 0x80 > --- > What da heck? Looks like the Promise ASIC SG bug. Apply and let us know if things improve. /Mikael -- 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/