From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751722Ab3KSHJN (ORCPT ); Tue, 19 Nov 2013 02:09:13 -0500 Received: from mail-ee0-f53.google.com ([74.125.83.53]:59796 "EHLO mail-ee0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750840Ab3KSHJJ (ORCPT ); Tue, 19 Nov 2013 02:09:09 -0500 Date: Tue, 19 Nov 2013 08:09:05 +0100 From: Ingo Molnar To: Jason Baron Cc: Andrew Morton , "benh@kernel.crashing.org" , "paulus@samba.org" , "ralf@linux-mips.org" , "linux-kernel@vger.kernel.org" , Felipe Contreras Subject: Re: [PATCH v2] panic: Make panic_timeout configurable Message-ID: <20131119070905.GF32367@gmail.com> References: <20131118210436.233B5202A@prod-mail-relay06.akamai.com> <20131118143059.afe17d2faced16171a05eb10@linux-foundation.org> <528A9F24.1000206@akamai.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <528A9F24.1000206@akamai.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Jason Baron wrote: > On 11/18/2013 05:30 PM, Andrew Morton wrote: > > On Mon, 18 Nov 2013 21:04:36 +0000 (GMT) Jason Baron wrote: > > > >> The panic_timeout value can be set via the command line option 'panic=x', or via > >> /proc/sys/kernel/panic, however that is not sufficient when the panic occurs > >> before we are able to set up these values. Thus, add a CONFIG_PANIC_TIMEOUT > >> so that we can set the desired value from the .config. > >> > >> The default panic_timeout value continues to be 0 - wait forever, > >> except for powerpc and mips, which have been defaulted to 180 and > >> 5 respectively. This is in keeping with the fact that these > >> arches already set panic_timeout in their arch init code. > >> However, I found three exceptions- two in mips and one in powerpc > >> where the settings didn't match these default values. In those > >> cases, I left the arch code so it continues to override, in case > >> the user has not changed from the default. It would nice if these > >> arches had one default value, or if we could determine the > >> correct setting at compile-time. > > > > Felipe is proposing a simpler patch ("panic: setup panic_timeout > > early") which switches to early_param(). Is that sufficient for > > the (undescribed!) failure which you are presumably observing? > > > > No - that patch doesn't change the 'panic_timeout' value until the > call to 'parse_early_param()' is made. If there is a panic before > that point, the param doesn't do anything. The idea of this patch is > to allow it to be configured at build-time. > > I've tested the patch by simply inserting a panic() call at the > beginning of 'start_kernel()'. So, no I do not have a specific panic > in mind for this. Would you be interested in picking up Felipe's patch/fix on top of yours? I was unable to communicate with him efficiently, but I'd take the patch if it's signed off by you. Thanks, Ingo