From owner-freebsd-scsi@FreeBSD.ORG Mon Jan 21 17:05:35 2013 Return-Path: Delivered-To: freebsd-scsi@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id EC607374; Mon, 21 Jan 2013 17:05:35 +0000 (UTC) (envelope-from ken@kdm.org) Received: from nargothrond.kdm.org (nargothrond.kdm.org [70.56.43.81]) by mx1.freebsd.org (Postfix) with ESMTP id 98781F48; Mon, 21 Jan 2013 17:05:35 +0000 (UTC) Received: from nargothrond.kdm.org (localhost [127.0.0.1]) by nargothrond.kdm.org (8.14.2/8.14.2) with ESMTP id r0LH5TlA064744; Mon, 21 Jan 2013 10:05:29 -0700 (MST) (envelope-from ken@nargothrond.kdm.org) Received: (from ken@localhost) by nargothrond.kdm.org (8.14.2/8.14.2/Submit) id r0LH5TVN064743; Mon, 21 Jan 2013 10:05:29 -0700 (MST) (envelope-from ken) Date: Mon, 21 Jan 2013 10:05:29 -0700 From: "Kenneth D. Merry" To: "Desai, Kashyap" Subject: Re: Max Queue depth of HBA limited to 256 ? Message-ID: <20130121170529.GA64188@nargothrond.kdm.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2i Cc: "freebsd-scsi@freebsd.org" , "jhb@freebsd.org" , "McConnell, Stephen" X-BeenThere: freebsd-scsi@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: SCSI subsystem List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 21 Jan 2013 17:05:36 -0000 On Mon, Jan 21, 2013 at 20:15:47 +0530, Desai, Kashyap wrote: > Hi, > > I was trying to check few things on LSI controller, where we have more than 256 queue depth support. > I added default maxtags in scsi/scsi_xpt.c as below. (Because I don't want mattags to restrict any outstanding commands the LSI HBA. > > { > /* Default tagged queuing parameters for all devices */ > { > T_ANY, SIP_MEDIA_REMOVABLE|SIP_MEDIA_FIXED, > /*vendor*/"*", /*product*/"*", /*revision*/"*" > }, > /*quirks*/0, /*mintags*/2, /*maxtags*/1024 <--- Default maxtags were 256. I increase it to 10234 > }, > > > LSI's SAS-HBA and MR-HBA can support more than 256 outstanding commands in Firmware. But due to some reason, I am not able to pump more than 256 outstanding commands to the HBA. > > I used "rawio -p 256 /dev/da1" and more /dev/dax in loop. I have sysctl parameter in Driver to display outstanding "FW commands". Max value for FW outstanding only goes up to 256. > > Also from some other mail thread Subject "mfi driver performance", I found that folks talk about tuning queue depth _but_ nobody discussed to increase it beyond 256. Is there any limitation in FreeBSD ? > As Jim pointed out, one thing to check is the values passed into cam_sim_alloc(). In the case of the mps(4) driver, the calculation is in mps_attach(): sc->num_reqs = MIN(MPS_REQ_FRAMES, sc->facts->RequestCredit); What is reported for the RequestCredit on this particular adapter? The other question is, what does 'camcontrol tags daX -v' show when you are running the test? Ken -- Kenneth Merry ken@FreeBSD.ORG