From mboxrd@z Thu Jan 1 00:00:00 1970 From: Prarit Bhargava Subject: Re: [PATCH V4] kernel, add bug_on_warn Date: Tue, 28 Oct 2014 08:48:49 -0400 Message-ID: <544F90B1.1070102@redhat.com> References: <1414155207-29839-1-git-send-email-prarit@redhat.com> <20141028121636.GC3274@tassilo.jf.intel.com> <544F8A78.9070008@redhat.com> <20141028122900.GA10632@redhat.com> <20141028124425.GD3274@tassilo.jf.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20141028124425.GD3274-KWJ+5VKanrL29G5dvP0v1laTQe2KTcn/@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "kexec" Errors-To: kexec-bounces+glkk-kexec=m.gmane.org-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org To: Andi Kleen Cc: Jonathan Corbet , kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, jason.wessel-CWA4WttNNZF54TAoqtyWWQ@public.gmane.org, Rusty Russell , linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Fabian Frederick , isimatu.yasuaki-+CUm20s59erQFUHtdCDX3A@public.gmane.org, "H. Peter Anvin" , Masami Hiramatsu , Andrew Morton , linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Vivek Goyal List-Id: linux-api@vger.kernel.org On 10/28/2014 08:44 AM, Andi Kleen wrote: >>> I suppose ... but that would mean I would have to explain to an end user the >>> elaborate process of enabling kdb, inserting a break point, etc. The whole >>> purpose of this is to let an end user panic on WARN() easily. >>> >>> Asking an end user to enable kdb is magnitudes worse than asking them to >>> recompile a kernel. >> >> Agreed. Asking a customer to setup and run kdb and put breakpoints is much >> more pain than simply asking to reboot kernel with a command line option. > > If you have a command line option to execute kdb commands you still > would only have a command line option, just a slightly longer one. > > kdb="on, bp warn_slowpath_common sr c, go" KDB is not on all kernels. This would require me to go to great lengths to explain to a user how to set it up, etc., rather than saying "Hi, please add panic_on_warn as a kernel parameter/echo 1 into /proc/sys/kernel/panic_on_warn and on the next time you see that WARN() the system will panic and kdump. Send me that kdump." > > But it would be a generic facility instead of a special purpose hack. Generic to KDB be configured on and it is in no way trivial to use. P.