From owner-freebsd-stable@FreeBSD.ORG Thu Jul 11 21:43:49 2013 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) by hub.freebsd.org (Postfix) with ESMTP id 494E81CD; Thu, 11 Jul 2013 21:43:49 +0000 (UTC) (envelope-from asmrookie@gmail.com) Received: from mail-ie0-x229.google.com (mail-ie0-x229.google.com [IPv6:2607:f8b0:4001:c03::229]) by mx1.freebsd.org (Postfix) with ESMTP id 0ADB7177F; Thu, 11 Jul 2013 21:43:49 +0000 (UTC) Received: by mail-ie0-f169.google.com with SMTP id 10so19553194ied.28 for ; Thu, 11 Jul 2013 14:43:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:reply-to:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; bh=AWfOZkZ1iXnb5BiUnGYgW1lQxbjrzHmiALTYgXKqVpg=; b=xdL6EBpPf4gk1iuLu+rhi0QAGn23Os5gPQoJwUuM/bdVgFy2D+uf2eXy7/j0A3ongK w1KWXA/mWWityS+vZTzrAUZTbp0zTPAECs/f5+CiFv5H9Ts0uWTRFpH+Dnh3hrSWI5hH Ozhgq9WEsG4MaSS64A4qNR5iKrl/yjr2S9Yj34X5Rdm3Ngp55u7x1SGqN5nmf0AnjO+A UN2PgN+TrjoWMkPhceMicfbGu+fz867taff5yZI6+DxnuNATaCn/fm5S/sttBhYaCGZf z3JyQdFp5s7oTeBYdc6Y22gCoupM5QXMK8Ox9WndLhI9fZmT2KuD2KhbbV4ZVtiOcV8o sSGQ== MIME-Version: 1.0 X-Received: by 10.43.73.7 with SMTP id yq7mr11635793icb.76.1373579028670; Thu, 11 Jul 2013 14:43:48 -0700 (PDT) Sender: asmrookie@gmail.com Received: by 10.42.253.129 with HTTP; Thu, 11 Jul 2013 14:43:48 -0700 (PDT) In-Reply-To: <201307111621.41665.jhb@freebsd.org> References: <77F3F7FC35D843ADA82D54EF37249ED0@multiplay.co.uk> <201307111621.41665.jhb@freebsd.org> Date: Thu, 11 Jul 2013 14:43:48 -0700 X-Google-Sender-Auth: 3xjuGprOCrdW23tYTIv6U4djmG0 Message-ID: Subject: Re: locks under printf(9) and WITNESS = panic? From: Attilio Rao To: John Baldwin Content-Type: text/plain; charset=UTF-8 Cc: Steven Hartland , stable@freebsd.org, freebsd-stable X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list Reply-To: attilio@FreeBSD.org List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 11 Jul 2013 21:43:49 -0000 On Thu, Jul 11, 2013 at 1:21 PM, John Baldwin wrote: > On Saturday, June 29, 2013 9:19:24 pm Steven Hartland wrote: >> when booting stable/9 under a debug kernel with WITNESS >> enabled and verbose I get the following panic.. >> >> It seems very much like the discussion from a year back on >> current: http://lists.freebsd.org/pipermail/freebsd-current/2012- > January/031375.html >> >> Any ideas? > > Yeah, that lock needs to be MTX_RECURSE (the cnputs_mtx). However, it > only recurses under witness. *sigh* I have a patch to make mtx_lock_flags() to accept MTX_RECURSE. I will commit it as long as all the consumers code will be reviewed which should be any day. Attilio -- Peace can only be achieved by understanding - A. Einstein