From owner-freebsd-current@freebsd.org Tue Nov 17 20:43:50 2015 Return-Path: Delivered-To: freebsd-current@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 566ECA3139D for ; Tue, 17 Nov 2015 20:43:50 +0000 (UTC) (envelope-from pete@nomadlogic.org) Received: from mailman.ysv.freebsd.org (mailman.ysv.freebsd.org [IPv6:2001:1900:2254:206a::50:5]) by mx1.freebsd.org (Postfix) with ESMTP id 3D73511F1 for ; Tue, 17 Nov 2015 20:43:50 +0000 (UTC) (envelope-from pete@nomadlogic.org) Received: by mailman.ysv.freebsd.org (Postfix) id 3C88EA3139C; Tue, 17 Nov 2015 20:43:50 +0000 (UTC) Delivered-To: current@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 3C231A3139B for ; Tue, 17 Nov 2015 20:43:50 +0000 (UTC) (envelope-from pete@nomadlogic.org) Received: from mail.nomadlogic.org (mail.nomadlogic.org [IPv6:2607:f2f8:a098::4]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 283AF11F0 for ; Tue, 17 Nov 2015 20:43:50 +0000 (UTC) (envelope-from pete@nomadlogic.org) Received: from mail.nomadlogic.org (localhost [127.0.0.1]) (using TLSv1 with cipher ADH-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by mail.nomadlogic.org (Postfix) with ESMTPS id 93406125EE1 for ; Tue, 17 Nov 2015 12:43:43 -0800 (PST) Received: from pop.rubicorp.com (unknown [72.34.113.100]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by mail.nomadlogic.org (Postfix) with ESMTPSA id 7BF5F125EBA for ; Tue, 17 Nov 2015 12:43:43 -0800 (PST) Subject: Re: LOR in mpr(4) To: current@freebsd.org References: <5644D014.4080601@nomadlogic.org> From: Pete Wright Message-ID: <564B917E.4000205@nomadlogic.org> Date: Tue, 17 Nov 2015 12:43:42 -0800 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <5644D014.4080601@nomadlogic.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 Nov 2015 20:43:50 -0000 On 11/12/15 09:44, Pete Wright wrote: > Hi All, > Just wanted a sanity check before filing a PR. I am running r290688 and > am seeing a LOR being triggered in the mpr(4) device: > > $ uname -ar > FreeBSD srd0013 11.0-CURRENT FreeBSD 11.0-CURRENT #1 r290688: Wed Nov 11 > 21:28:26 PST 2015 root@srd0013:/usr/obj/usr/src/sys/GENERIC amd64 > > > lock order reversal: > 1st 0xfffff8000d26bc60 CAM device lock (CAM device lock) @ > /usr/src/sys/cam/cam_xpt.c:784 > 2nd 0xfffffe00012811c0 MPR lock (MPR lock) @ > /usr/src/sys/cam/cam_xpt.c:2620 > KDB: stack backtrace: > db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame > 0xfffffe04608ee890 > witness_checkorder() at witness_checkorder+0xe79/frame 0xfffffe04608ee910 > __mtx_lock_flags() at __mtx_lock_flags+0xa4/frame 0xfffffe04608ee960 > xpt_action_default() at xpt_action_default+0xb6c/frame 0xfffffe04608ee9b0 > scsi_scan_bus() at scsi_scan_bus+0x1d5/frame 0xfffffe04608eea20 > xpt_scanner_thread() at xpt_scanner_thread+0x15c/frame 0xfffffe04608eea70 > fork_exit() at fork_exit+0x84/frame 0xfffffe04608eeab0 > fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe04608eeab0 > --- trap 0, rip = 0, rsp = 0, rbp = 0 --- > FWIW I filed the following PR as I can still reproduce this on boot: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=204614 cheers, -pete -- Pete Wright pete@nomadlogic.org twitter => @nomadlogicLA