From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267077AbUBMQJ5 (ORCPT ); Fri, 13 Feb 2004 11:09:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267079AbUBMQJ5 (ORCPT ); Fri, 13 Feb 2004 11:09:57 -0500 Received: from mion.elka.pw.edu.pl ([194.29.160.35]:56961 "EHLO mion.elka.pw.edu.pl") by vger.kernel.org with ESMTP id S267077AbUBMQJw (ORCPT ); Fri, 13 Feb 2004 11:09:52 -0500 From: Bartlomiej Zolnierkiewicz To: "Daniel Blueman" Subject: Re: File system performance, hardware performance, ext3, 3ware RAID1, etc. Date: Fri, 13 Feb 2004 17:15:33 +0100 User-Agent: KMail/1.5.3 References: <20040213142719.GA28100@mail.shareable.org> <17899.1076683453@www11.gmx.net> In-Reply-To: <17899.1076683453@www11.gmx.net> Cc: linux-kernel@vger.kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-2" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200402131715.33710.bzolnier@elka.pw.edu.pl> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Friday 13 of February 2004 15:44, Daniel Blueman wrote: > It is a small loss that the TCQ-support implementation hasn't been stable > on linux so far. I guess mostly due to the great I/O scheduling Linux has > (ie anticipatory scheduler). > > Yes, a growing number of IDE disk manufacturers are using native S-ATA > controllers in their disks, and TCQ is one of the core features (ie unique > selling point), as well as being implemented on the more lavish P-ATA > controllers. Ugh, you are messing PATA drive TCQ, PATA host TCQ and SATA TCQ. > It's just a shame that there are still issues saturating a bunch of IDE > disks with software RAID in the 2.6 series, but I guess that'll be ironed > out in time... > > > Daniel Blueman wrote: > > > many modern IDE disks and > > > controllers also have tagged command queuing, so it is even more of a > > > > corner case. > > > > Linux doesn't use tagged command queueing, though - the code has been > > disabled for some time. I thought the TCQ stuff was disabled because > > only very few disks supported it and the code wasn't reliable. You can re-enable it quite simply 8). --- Kconfig.orig 2004-02-10 16:29:19.000000000 +0100 +++ Kconfig 2004-02-13 17:06:57.628617096 +0100 @@ -441,7 +441,7 @@ # TCQ is disabled for now config BLK_DEV_IDE_TCQ bool "ATA tagged command queueing (EXPERIMENTAL)" - depends on EXPERIMENTAL && n + depends on EXPERIMENTAL help Support for tagged command queueing on ATA disk drives. This enables the IDE layer to have multiple in-flight requests on hardware that > > Yet you say many modern disks support it? No, only IBM/Hitachi and some WD disks support IDE TCQ.