From owner-freebsd-current@FreeBSD.ORG Mon Jan 7 23:54:25 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 201401F4 for ; Mon, 7 Jan 2013 23:54:25 +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 03785DCC for ; Mon, 7 Jan 2013 23:54:24 +0000 (UTC) Received: from epsilon.delphij.net (drawbridge.ixsystems.com [206.40.55.65]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by anubis.delphij.net (Postfix) with ESMTPSA id F34551FB3E; Mon, 7 Jan 2013 15:54:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=delphij.net; s=anubis; t=1357602864; bh=MskYA/hUdiiMtBBUatfafKOCNrdvgS8BwqaNn65TIyI=; h=Date:From:Reply-To:To:Subject; b=nfyZ8CHtRyxrZAAJMCSbFONMVAcePEZqrHnx4B7LYTcwb7kG8eypPVb5OJkXs1/8A 6qu2lq4Q50ld7it4FzuFkkTYOO8Bo927+CiZxmVcg/veppVrzAe8D/2OVf54OBXmD3 2SJdSjW5Pdk5cejztUUcAauV2xItsmGaHPpOescM= Message-ID: <50EB602F.9050300@delphij.net> Date: Mon, 07 Jan 2013 15:54:23 -0800 From: Xin Li Organization: The FreeBSD Project MIME-Version: 1.0 To: freebsd-current@freebsd.org Subject: sysctl -a causes kernel trap 12 X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit 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: Mon, 07 Jan 2013 23:54:25 -0000 -----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... Cheers, - -- Xin LI https://www.delphij.net/ FreeBSD - The Power to Serve! Live free or die -----BEGIN PGP SIGNATURE----- iQEcBAEBCAAGBQJQ62AvAAoJEG80Jeu8UPuzW0IH/0D0PxoTIr6qdHFhzG1It1r2 HRnkCaVKzllc6a0obdHzthBLe7dd3bMARuVLR/NiD611mhrFGY2P4W9x+bp9KwMH gTp18fWsHamkj5jEO8zpLjVWF62WwaFKuCEvg1zKLS+Fo3K7vSr5i5O6SeUhueeR iUNldC5m5E6Nwkbn9OW8jHzadhHmmIbUAfoWs8K7FCFQpLYXg5e8Q8gW5RsJvPmT v92vwAC2L3MOBiSGKfRkKngBihHlDnkX0xRhWuI+PIh5yr8kijgA4DDroOhJv3RF ga0NKanjZFk9k1+gFVua3gmMmCopvkIs7XHsjJbKBcMcvEtTXQxkrJwVmgX+q80= =Wubv -----END PGP SIGNATURE-----