From owner-freebsd-stable@FreeBSD.ORG Mon Jul 22 12:58:57 2013 Return-Path: Delivered-To: freebsd-stable@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 7F579351 for ; Mon, 22 Jul 2013 12:58:57 +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 446E12C96 for ; Mon, 22 Jul 2013 12:58:57 +0000 (UTC) Received: from mobileKamikaze.norad (MN-VPN2.HS-Karlsruhe.DE [193.196.117.63]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by mail.server1.bsdforen.de (Postfix) with ESMTPSA id 4878686219; Mon, 22 Jul 2013 14:58:55 +0200 (CEST) Message-ID: <51ED2C8F.7040009@bsdforen.de> Date: Mon, 22 Jul 2013 14:58:55 +0200 From: Dominic Fandrey MIME-Version: 1.0 To: Ronald Klop Subject: Re: stopping amd causes a freeze References: <51ED0060.2050502@bsdforen.de> <20130722100720.GI5991@kib.kiev.ua> <51ED2360.2060104@bsdforen.de> In-Reply-To: Content-Type: text/plain; charset=ascii Content-Transfer-Encoding: 7bit Cc: Konstantin Belousov , 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: Mon, 22 Jul 2013 12:58:57 -0000 On 22/07/2013 14:35, Ronald Klop wrote: > On Mon, 22 Jul 2013 14:19:44 +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: >>>> Occasionally stopping amd freezes my system. It's a rare occurrence, >>>> and I haven't found a reliable way to reproduce it. >>>> >>>> It's also a real freeze, so there's no way to get into the debugger >>>> or grab a core dump. I only can perform the 4 seconds hard shutdown to >>>> revive the system. >>>> >>>> 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 may cause the freeze. >>>> >>>> Nothing was mounted (by amd) during the last freeze. >>>> >>>> I don't see any angle to tackle this, but I'm throwing it out here >>>> any way, in the hopes that someone actually has an idea how to approach >>>> the issue. >>> >>> Are you sure that the machine did not paniced ? Do you have serial console ? >> >> No, I don't have one. All that I can tell is that everything freezes >> (i.e. Xorg screen and mouse). ACPI events like shutdown don't cause a >> reaction. And the system doesn't respond to ICMP queries. >> >>> 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. >> >> From head? That may be worth a try. It would be better for testing if I >> managed to reproduce the problem reliably, before I test patches. >> >> I see it's scheduled for MFC, soon. >> > > Did you try a run with the INVARIANTS, etc. options in the kernel? That enables more sanity checking for locks which is too slow for production. No I didn't, but I managed to reproduce it in combination with heavy tmpfs load. So now I've got a working test case and will be able to determine whether the suggested fix works. I suppose INVARIANTS would be the next step. -- 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?