From owner-freebsd-current@FreeBSD.ORG Tue Jan 8 02:40:18 2013 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.FreeBSD.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 8A534979 for ; Tue, 8 Jan 2013 02:40:18 +0000 (UTC) (envelope-from delphij@delphij.net) Received: from anubis.delphij.net (anubis.delphij.net [64.62.153.212]) by mx1.freebsd.org (Postfix) with ESMTP id 6BE3C3FA for ; Tue, 8 Jan 2013 02:40:18 +0000 (UTC) Received: from Xins-MacBook-Pro-2.local (unknown [IPv6:2001:470:83bf:0:fde3:6b6f:53d:dc1a]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by anubis.delphij.net (Postfix) with ESMTPSA id 6BCE91F5D9; Mon, 7 Jan 2013 18:40:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=delphij.net; s=anubis; t=1357612817; bh=GdBFJtCevdxzSVxo92EWXExrQdY7nJCVhh15cx9+9cA=; h=Date:From:Reply-To:To:CC:Subject:References:In-Reply-To; b=AUa021DjAaxXvoteaWFGtYN1wZMZi8yE7YgQ/dX0FbBjVGomrr/3olwfTh+/3udk2 k5Qkygze6CiRrMB9qGOdlfGvUYW3hQoqr0lBZKP3zIv0cmOuySMlED1ouxdK9sYoTJ tYO67tBM1RquYJ/TZIagoV3pmD8IuhIYy8nG4rbg= Message-ID: <50EB870D.3020306@delphij.net> Date: Mon, 07 Jan 2013 18:40:13 -0800 From: Xin Li Organization: The FreeBSD Project MIME-Version: 1.0 To: Brandon Gooch Subject: Re: sysctl -a causes kernel trap 12 References: <50EB602F.9050300@delphij.net> <20130108000233.GZ82219@kib.kiev.ua> <50EB63A9.50903@delphij.net> In-Reply-To: X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Konstantin Belousov , freebsd-current@freebsd.org, d@delphij.net X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list Reply-To: d@delphij.net List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 08 Jan 2013 02:40:18 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 On 1/7/13 5:33 PM, Brandon Gooch wrote: > On Mon, Jan 7, 2013 at 6:09 PM, Xin Li > wrote: > > -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 > > On 01/07/13 16:02, Konstantin Belousov wrote: >> On Mon, Jan 07, 2013 at 03:54:23PM -0800, Xin Li wrote: >>> -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 >>> >>> Hi, >>> >>> I've recently (by mid-December I think) noticed that sysctl -a >>> can sometimes cause kernel trap 12. Tried enabling INVARIANTS >>> and the problem mysteriously disappeared. After some >>> experiments on this, it seems that this can be triggered by >>> sysctl -a but the system have an 1 in 10 chance to survive. >>> When INVARIANTS is enabled however, I can not trigger the >>> panic. "sysctl hw" triggers the panic sometimes, but not >>> always. >>> >>> Do anybody have clue on this? The system hangs hard when it >>> panics so kernel debugger won't work. When it panics, the >>> fault instruction pointer is always 0x20:0xffffffff808d61c9, >>> which is sys/kern/subr_turnstile.c:297: >>> >>>> /* Resort td on the list if needed. */ if >>>> (!turnstile_adjust_thread(ts, td)) { >>>> mtx_unlock_spin(&ts->ts_lock); // 297 // return; } >>> >>> This sounds like a race condition but I haven't yet able to >>> track it down... >> >> Could you try to isolate the sub-leaf under hw which causes the >> panic ? Just shot in the dark, do you have Intel GPU gemified >> driver loaded ? > > It seems that it was not hw itself that causes the problem (I > thought about isolating to sub-leaf and at one point believed it > was hw.acpi.battery but doing so repeatedly doesn't panic the > system, with or without INVARIANTS; doing 'sysctl hw' sometimes > causes panic but not always). > > The laptop is running nVidia but it's using i7-3610QM which does > have Intel GPU, but I have not loaded drm2.ko and the panic is > reproducible in single user mode. > > Cheers, - -- Xin LI > https://www.delphij.net/ FreeBSD - > The Power to Serve! Live free or die > > > Xin, did you compile the NVIDIA driver port with clang? I was > having this issue until I set an exception for the NVIDIA driver > port to be built with GCC. > > Actually, I just remembered (and checked), and what I'm actually > doing is setting CFLAGS for the NVIDIA driver port to -O0, and > building with clang. Clang optimizes out important bits, I didn't > investigate deeply enough to determine what was actually going > awry... Yes my nVidia driver is compiled with clang. I'll try gcc tomorrow, thanks for the pointer. (Note that the panic was a NULL pointer deference and it's a race condition so I doubt if it's compiler related but will try). Cheers, -----BEGIN PGP SIGNATURE----- iQEcBAEBCAAGBQJQ64cNAAoJEG80Jeu8UPuzkLwIAKgjgbcBaow64mWzrJ0XtczM 6Xi4mC0Oq5kdomx0y+Vgks/qTvq28Ff/JqyxN8osD959Vwaq0vbQumFiDtbWCr0h /MD0w5m7Asdbf8KzJE80il90Vv1/nJrOVdwj3qoNIqtKIomi12CHDKL5zFs2Ja2i rscN22SBh8+3vV1rBSE6NGzJ7jPSs/B0o73YuIdwj6bUYMiBqHWWGGTfFStNhc4U 1JX6WWsDdiWxNvGPH5lE3HelSgya+WCltD+B6/8mYaByBQbXD+JBOA9AvX97h2kk muQROSMOz6OVdGmtM6U/19Bsiv/8kUtItJF2k19Y/eTQEohH/2xBhq+37EG8cqg= =b9UF -----END PGP SIGNATURE-----