From owner-svn-src-head@FreeBSD.ORG Fri Aug 23 20:12:08 2013 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id E0746D2C for ; Fri, 23 Aug 2013 20:12:07 +0000 (UTC) (envelope-from scott4long@yahoo.com) Received: from nm5-vm0.bullet.mail.bf1.yahoo.com (nm5-vm0.bullet.mail.bf1.yahoo.com [98.139.213.150]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 67BC72144 for ; Fri, 23 Aug 2013 20:12:07 +0000 (UTC) Received: from [98.139.212.152] by nm5.bullet.mail.bf1.yahoo.com with NNFMP; 23 Aug 2013 20:12:04 -0000 Received: from [98.139.213.11] by tm9.bullet.mail.bf1.yahoo.com with NNFMP; 23 Aug 2013 20:12:04 -0000 Received: from [127.0.0.1] by smtp111.mail.bf1.yahoo.com with NNFMP; 23 Aug 2013 20:12:04 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.com; s=s1024; t=1377288724; bh=bFkuJy0ApGy9taqJTauzjLKWKQgT7MP20OvHIBhv33w=; h=X-Yahoo-Newman-Id:X-Yahoo-Newman-Property:X-YMail-OSG:X-Yahoo-SMTP:X-Rocket-Received:Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc:Content-Transfer-Encoding:Message-Id:References:To:X-Mailer; b=iGuzL34vO7hno0SNUjtbeXOZlX/Qztql+qNCV+Wqzy51knlouYC3qysV2vEP9HKPahfiZggIZJSuLJmZTpSsTAS99Y8dQ4dnyVlspb8G5aLq3Mph+sAvJY0ynYMsXseXytpTh7QZrYni1SmRKKG2HjQVAbA+JGiiBMs2nm+NvJY= X-Yahoo-Newman-Id: 735067.71430.bm@smtp111.mail.bf1.yahoo.com X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: cftSODcVM1kGWBHWA6BwLWUru5EkPenx_aH6owiGJ3WUOXk 9TZ2S9d1QsvPHIyuFQIWFZR4woR4aVDhEHEHBOjRR2DhdEv7jYJTKsIE9lRw Vnm2XyqADyQFg8bzbOeCIzyKAxe0_grFyEOnpZYO0bvKxiIQ3iKNkSOtOr62 UtmHs.Vrxuq5uPHA2trCRf3XowMjlJGHOgrcw0OmRSlSiRCv8uWK5Dy64aHP dtUDPQWrKR3QAxpNzTVRHPNt293ZkOH2zK.HsKugI7FPsBY5lzj7StOoeOCb s3bMXq0.5t1vH6EQeBo3hpQEnQQPnNaG.EuyOGmt2qDVsfaao2WSTfk1SzX1 UbQyxvXconWA8GM.io673OE457v4kmMZ7kios4gOq93lvq5hDw_u80VKsPj1 hxUxuZ5rdbk139SHXyRnvJYKjo7.k6MGyN28M1SLwv77fHcPv1Zp.8_h7E28 Rvz2kdlP_uYicLUBHFlcEYMD5j2f5P43Muw0yTRO83iHk9knLYqHa1adM2P3 prhb.NYLjsWjmLK.uJpC5IDAInkNKP62xYJkfZ4.5qGmdm8rCoFDMhYT2 X-Yahoo-SMTP: clhABp.swBB7fs.LwIJpv3jkWgo2NU8- X-Rocket-Received: from phobos.samsco.home (scott4long@168.103.85.57 with ) by smtp111.mail.bf1.yahoo.com with SMTP; 23 Aug 2013 13:12:04 -0700 PDT Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 6.5 \(1508\)) Subject: Re: svn commit: r254615 - head/sys/dev/mps From: Scott Long In-Reply-To: Date: Fri, 23 Aug 2013 10:00:59 -0700 Content-Transfer-Encoding: quoted-printable Message-Id: <74108713-986A-4CBD-A441-395C7B54456A@yahoo.com> References: <201308212130.r7LLUvO5008991@svn.freebsd.org> <20130822142107.GA49996@nargothrond.kdm.org> To: Dmitry Morozovsky X-Mailer: Apple Mail (2.1508) Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, "Kenneth D. Merry" X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 23 Aug 2013 20:12:08 -0000 On Aug 22, 2013, at 7:58 AM, Dmitry Morozovsky wrote: > On Thu, 22 Aug 2013, Kenneth D. Merry wrote: >=20 >>>> Fix mps(4) driver breakage that came in in change 253550 that >>>> manifested itself in out of chain frame conditions. >>>>=20 >>>> When the driver ran out of chain frames, the request in question >>>> would get completed early, and go through = mpssas_scsiio_complete(). >=20 >>> what is real impact of the bug? >>=20 >> Your system will essentially hang, certainly as far as anything = connected >> to the controller in question. >=20 > [snip] >=20 >> 5. Look for an out of chain frames message on the console. To see = how far >> you are towards using the chain frames, run 'sysctl dev.mps'. You = can see >> how many chain frames you have free, and how many requests have = failed. >>=20 >> This change just needs to be merged along with the other changes to = avoid >> having the regression in stable. >=20 > Thank you very much for the explanation. We use a couple of servers = with mps=20 > (and many spindles there), all on stable/9 from this summer, and you = commit=20 > turns on an alarm light in my head ;) I'll confirm with my netflix hat on that this isn't a problem in 9. Scott