Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261404AbVE2TIG (ORCPT ); Sun, 29 May 2005 15:08:06 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261410AbVE2THx (ORCPT ); Sun, 29 May 2005 15:07:53 -0400 Received: from ns.virtualhost.dk ([195.184.98.160]:653 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S261404AbVE2TFz (ORCPT ); Sun, 29 May 2005 15:05:55 -0400 Date: Sun, 29 May 2005 21:06:08 +0200 From: Jens Axboe To: Michael Thonke Cc: Jeff Garzik , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: Playing with SATA NCQ Message-ID: <20050529190608.GC29770@suse.de> References: <20050526140058.GR1419@suse.de> <429793C8.8090007@gmail.com> <42979C4F.8020007@pobox.com> <42979FA3.1010106@gmail.com> <20050528121258.GA17869@suse.de> <429A05AC.9020805@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <429A05AC.9020805@gmail.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1457 Lines: 44 On Sun, May 29 2005, Michael Thonke wrote: > Jens Axboe schrieb: > > >There's really nothing to be tuned. If NCQ is enabled for your drive, it > >will be printed in dmesg after the lba48 flag, such as: > > > >ata1: dev 0 ATA, max UDMA/133, 488281250 sectors lba48 ncq > > > >If you don't see NCQ there, your drive/controller doesn't support it. > >Likewise you will have a queueing depth of > 1 if NCQ is enabled, check > >/sys/block/sdX/device/queue_depth to see what the configured queueing > >depth is for that device. > > > > > > > Hello again, > > the queue_depth of 30 is okay? On boot the CFQ scheduler tells: By default, the maximum depth is used. For desktop use, a depth of 2-4 is probably more appropriate until the io schedulers become a little more intelligent wrt queueing. > cfq: depth 4 reached, tagging now on > > This only appears with AHCI enabled what does that mean? It only appears if AHCI is enabled, because tagged command queueing is only working/enabled on AHCI. The message is informational only, CFQ tells you that it has detected queueing hardware (driver maintains a depth of >= 4). > Also a question which options can be set in queue_type? Nothing. -- Jens Axboe - 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/