From owner-freebsd-hackers@FreeBSD.ORG Thu Dec 6 15:19:08 2012 Return-Path: Delivered-To: freebsd-hackers@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 96D60A73 for ; Thu, 6 Dec 2012 15:19:08 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id C88B28FC08 for ; Thu, 6 Dec 2012 15:19:07 +0000 (UTC) Received: from odyssey.starpoint.kiev.ua (alpha-e.starpoint.kiev.ua [212.40.38.101]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id RAA29608 for ; Thu, 06 Dec 2012 17:19:00 +0200 (EET) (envelope-from avg@FreeBSD.org) Message-ID: <50C0B763.8000004@FreeBSD.org> Date: Thu, 06 Dec 2012 17:18:59 +0200 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: FreeBSD Hackers Subject: huge ktr buffer X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 06 Dec 2012 15:19:08 -0000 So I configured a kernel with the following option: options KTR_ENTRIES="(1024UL*1024)" then booted the kernel and did $ sysctl debug.ktr.clear=1 and got an insta-reboot. No panic, nothing, just a reset. I suspect that the huge static buffer resulting from the above option could be a cause. But I would like to understand the details, if possible. Also, perhaps ktr could be a little bit more sophisticated with its buffer than just using a static array. -- Andriy Gapon