From owner-freebsd-scsi@FreeBSD.ORG Mon Jan 21 14:46:10 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 2C273D54; Mon, 21 Jan 2013 14:46:10 +0000 (UTC) (envelope-from Kashyap.Desai@lsi.com) Received: from na3sys009aog138.obsmtp.com (na3sys009aog138.obsmtp.com [74.125.149.19]) by mx1.freebsd.org (Postfix) with ESMTP id 7B0706FF; Mon, 21 Jan 2013 14:46:09 +0000 (UTC) Received: from paledge01.lsi.com ([192.19.193.42]) (using TLSv1) by na3sys009aob138.postini.com ([74.125.148.12]) with SMTP ID DSNKUP1UoF9foAMAHcbawBf6sEDcCfHXb1xI@postini.com; Mon, 21 Jan 2013 06:46:09 PST Received: from PALCAS01.lsi.com (128.94.213.117) by PALEDGE01.lsi.com (192.19.193.42) with Microsoft SMTP Server (TLS) id 8.3.264.0; Mon, 21 Jan 2013 09:45:49 -0500 Received: from inbexch01.lsi.com (135.36.98.37) by PALCAS01.lsi.com (128.94.213.117) with Microsoft SMTP Server (TLS) id 8.3.264.0; Mon, 21 Jan 2013 09:45:52 -0500 Received: from inbmail01.lsi.com ([135.36.98.64]) by inbexch01.lsi.com ([135.36.98.37]) with mapi; Mon, 21 Jan 2013 20:15:48 +0530 From: "Desai, Kashyap" To: "freebsd-scsi@freebsd.org" Date: Mon, 21 Jan 2013 20:15:47 +0530 Subject: Max Queue depth of HBA limited to 256 ? Thread-Topic: Max Queue depth of HBA limited to 256 ? Thread-Index: Ac335f/Ukr+NszdkQQqQECSOu+WvGg== Message-ID: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Cc: "Kenneth D. Merry" , "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 14:46:10 -0000 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 maxtag= s 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 outs= tanding commands to the HBA. I used "rawio -p 256 /dev/da1" and more /dev/dax in loop. I have sysctl par= ameter in Driver to display outstanding "FW commands". Max value for FW out= standing 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 ? ~ Kashyap