From owner-freebsd-scsi Sat Mar 30 19:22:54 2002 Delivered-To: freebsd-scsi@freebsd.org Received: from mass.dis.org (dhcp45-24.dis.org [216.240.45.24]) by hub.freebsd.org (Postfix) with ESMTP id 9E6EB37B405 for ; Sat, 30 Mar 2002 19:22:50 -0800 (PST) Received: from mass.dis.org (localhost [127.0.0.1]) by mass.dis.org (8.11.6/8.11.6) with ESMTP id g2TMGWN01304; Fri, 29 Mar 2002 14:16:36 -0800 (PST) (envelope-from msmith@mass.dis.org) Message-Id: <200203292216.g2TMGWN01304@mass.dis.org> X-Mailer: exmh version 2.5 07/13/2001 with nmh-1.0.4 To: "Kenneth D. Merry" Cc: Lukas Ertl , freebsd-scsi@freebsd.org Subject: Re: ciss driver and tagged queuing In-reply-to: Your message of "Fri, 29 Mar 2002 08:11:13 MST." <20020329081113.A28622@panzer.kdm.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Fri, 29 Mar 2002 14:16:32 -0800 From: Michael Smith Sender: owner-freebsd-scsi@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org > > da1 at ciss1 bus 0 target 0 lun 0 > > da1: Fixed Direct Access SCSI-0 device > > da1: 135.168MB/s transfers > > da1: 416780MB (853565580 512 byte sectors: 255H 32S/T 39067C) > > da0 at ciss0 bus 0 target 0 lun 0 > > da0: Fixed Direct Access SCSI-0 device > > da0: 135.168MB/s transfers > > da0: 17359MB (35553120 512 byte sectors: 255H 32S/T 4357C) > > The problem is that the inquiry data doesn't indicate that the arrays > support tagged queueing, so you only get one tag at a time. The arrays don't support tagged queueing, but they do support multiple outstanding commands. I don't want to have to handle tags; I just want CAM to keep giving me commands until I ask it to stop. 8) One other complication is that the limit on outstanding commands is per-adapter not per-array, so the automatic tag-backoff that CAM does won't work correctly under load. Any suggestions on improved behaviour here would be welcome. -- To announce that there must be no criticism of the president, or that we are to stand by the president, right or wrong, is not only unpatriotic and servile, but is morally treasonable to the American public. - Theodore Roosevelt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message