From owner-freebsd-current@FreeBSD.ORG Sat Jun 25 14:37:27 2011 Return-Path: Delivered-To: freebsd-current@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 575EB106566C for ; Sat, 25 Jun 2011 14:37:27 +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 A99828FC17 for ; Sat, 25 Jun 2011 14:37:26 +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 RAA00389; Sat, 25 Jun 2011 17:37:24 +0300 (EEST) (envelope-from avg@FreeBSD.org) Message-ID: <4E05F2A4.6060908@FreeBSD.org> Date: Sat, 25 Jun 2011 17:37:24 +0300 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US; rv:1.9.2.18) Gecko/20110622 Lightning/1.0b2 Thunderbird/3.1.11 MIME-Version: 1.0 To: freebsd-current@FreeBSD.org X-Enigmail-Version: 1.1.2 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: Subject: Fwd: stop scheduler in panic context X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 25 Jun 2011 14:37:27 -0000 I would like to ask for testing of the following patch. Since the patch affects panic(9) context, then obviously its testing requires getting some sort of panic, and preferably some sort of "post-panic" activity too: doing something in kdb, dumping a core (via debugger command or in unattended mode), resetting a machine finally. At minimum I hope that no regressions are introduced. At maximum I hope that some things are improved like, e.g., crash dump succeeding where it failed before (PR amd64/139614). The patch is for recent head/CURRENT. It mostly affects SMP systems, but also has a smaller impact on UP systems. I can try to adapt it to stable/8, if sufficient interest arises. Please see the following message for the patch and some more details. -------- Original Message -------- I would like to present the following diff for review and discussion: http://people.freebsd.org/~avg/stop_scheduler_on_panic.diff The idea is to stop scheduler in a panic context and to provide a special environment for the only running thread, the one that called panic(9). I tried to make this diff as minimal as possible, it doesn't include changes that I consider to be useful improvements and [even] bug fixes, but which generated controversy in non-public discussions. If there is no negative feedback within next few days, then I plan to post the patch to current@ to solicit some testing. I will definitely wait for positive feedback before committing this change. I hope that I will be able to sneak it into the 9 release (unless there are objections to this). Thank you! -- Andriy Gapon