From owner-freebsd-hackers Wed Apr 26 11:51:40 2000 Delivered-To: freebsd-hackers@freebsd.org Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by hub.freebsd.org (Postfix) with ESMTP id F3EC337B970 for ; Wed, 26 Apr 2000 11:51:35 -0700 (PDT) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.9.3/8.9.3) id NAA21930; Wed, 26 Apr 2000 13:51:11 -0500 (CDT) (envelope-from dan) Date: Wed, 26 Apr 2000 13:51:11 -0500 From: Dan Nelson To: Kent Stewart Cc: Matthew Dillon , Narvi , Michael Bacarella , Alfred Perlstein , Kevin Day , hackers@FreeBSD.ORG Subject: Re: Double buffered cp(1) Message-ID: <20000426135111.A21368@dan.emsphone.com> References: <3907177C.5CFEC69A@3-cities.com> <200004261751.KAA96154@apollo.backplane.com> <39073655.56A70C00@3-cities.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.1.9i In-Reply-To: <39073655.56A70C00@3-cities.com>; from "Kent Stewart" on Wed Apr 26 11:32:53 GMT 2000 X-OS: FreeBSD 5.0-CURRENT Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In the last episode (Apr 26), Kent Stewart said: > I just noticed that mine isn't showing "Tagged Queueing Enabled" is > that something I can set? The adapter is an Adaptec 2940uw. > > da0 at ahc0 bus 0 target 4 lun 0 > da0: Fixed Direct Access SCSI-2 device > da0: 40.000MB/s transfers (20.000MHz, offset 8, 16bit) > da0: 4134MB (8467200 512 byte sectors: 255H 63S/T 527C) The CAM code has a quirk entry for IBM DCAS drives that turns it off; check out /sys/cam/cam_xpt.c, line 320. I suggest benchmarking with and without the quirk entry, and if it's faster with tagged queueing, update PR kern/10398. -- Dan Nelson dnelson@emsphone.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message