From owner-freebsd-stable@FreeBSD.ORG Fri Jul 26 17:10:54 2013 Return-Path: Delivered-To: freebsd-stable@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 09997B22 for ; Fri, 26 Jul 2013 17:10:54 +0000 (UTC) (envelope-from kamikaze@bsdforen.de) Received: from mail.server1.bsdforen.de (bsdforen.de [82.193.243.81]) by mx1.freebsd.org (Postfix) with ESMTP id BEC28271A for ; Fri, 26 Jul 2013 17:10:53 +0000 (UTC) Received: from mobileKamikaze.norad (HSI-KBW-134-3-231-194.hsi14.kabel-badenwuerttemberg.de [134.3.231.194]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by mail.server1.bsdforen.de (Postfix) with ESMTPSA id DFCFA8628A; Fri, 26 Jul 2013 19:10:36 +0200 (CEST) Message-ID: <51F2AD8C.1000003@bsdforen.de> Date: Fri, 26 Jul 2013 19:10:36 +0200 From: Dominic Fandrey MIME-Version: 1.0 To: Konstantin Belousov Subject: Re: stopping amd causes a freeze References: <51ED0060.2050502@bsdforen.de> <20130722100720.GI5991@kib.kiev.ua> <51F0DA4B.3000809@bsdforen.de> <20130725100037.GM5991@kib.kiev.ua> In-Reply-To: <20130725100037.GM5991@kib.kiev.ua> Content-Type: text/plain; charset=ascii Content-Transfer-Encoding: 7bit Cc: freebsd-stable@freebsd.org X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 26 Jul 2013 17:10:54 -0000 On 25/07/2013 12:00, Konstantin Belousov wrote: > On Thu, Jul 25, 2013 at 09:56:59AM +0200, Dominic Fandrey wrote: >> On 22/07/2013 12:07, Konstantin Belousov wrote: >>> On Mon, Jul 22, 2013 at 11:50:24AM +0200, Dominic Fandrey wrote: >>>> ... >>>> >>>> I run amd through sysutils/automounter, which is a scripting solution >>>> that generates an amd.map file based on encountered devices and devd >>>> events. The SIGHUP it sends to amd to tell it the map file was updated >>>> does not cause problems, only a -SIGKILL- SIGTERM may cause the freeze. >>>> >>>> Nothing was mounted (by amd) during the last freeze. >>>> >>>> ... >>> >>> Are you sure that the machine did not paniced ? Do you have serial console ? >>> >>> The amd(8) locks itself into memory, most likely due to the fear of >>> deadlock. There are some known issues with user wirings in stable/9. >>> If the problem you see is indeed due to wiring, you might try to apply >>> r253187-r253191. >> >> I tried that. Applying the diff was straightforward enough. But the >> resulting kernel paniced as soon as it tried to mount the root fs. > You did provided a useful info to diagnose the issue. > > Patch should keep KBI compatible, but, just in case, if you have any > third-party module, rebuild it. > >> >> So I'll wait for the MFC from someone who knows what he/she is doing. > > Patch below booted for me, and I run some sanity check tests for the > mlockall(2), which also did not resulted in misbehaviour. > Your patch applied cleanly and the system booted with the resulting kernel. Amd exhibits several very strange behaviours. a) During the first start it writes the wrong PID into the pidfile, it however still reacts to SIGTERM. b) After starting it again, it no longer reacts to SIGTERM. c) It appear to be no longer reacting to SIGHUP, which is required to tell it that the amd.map was updated. d) It doesn't work at all, I only get: # cd /media/ufs/FreeBSD_Install /media/ufs/FreeBSD_Install: Too many levels of symbolic links. e) A SIGKILL without load will terminate the process. A SIGKILL while there is heavy file system load panics the system. I'll try a clean buildworld buildkernel and repeat. -- A: Because it fouls the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing on usenet and in e-mail?