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From: Prarit Bhargava <prarit-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
To: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	Andi Kleen <ak-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>,
	Jonathan Corbet <corbet-T1hC0tSOHrs@public.gmane.org>,
	kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
	Rusty Russell <rusty-8n+1lVoiYb80n/F98K4Iww@public.gmane.org>,
	linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	jbaron-JqFfY2XvxFXQT0dZR+AlfA@public.gmane.org,
	Fabian Frederick <fabf-AgBVmzD5pcezQB+pC5nmwQ@public.gmane.org>,
	isimatu.yasuaki-+CUm20s59erQFUHtdCDX3A@public.gmane.org,
	"H. Peter Anvin" <hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>,
	Masami Hiramatsu
	<masami.hiramatsu.pt-FCd8Q96Dh0JBDgjK7y7TUQ@public.gmane.org>,
	Andrew Morton
	<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
	linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
	vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org
Subject: Re: [PATCH] kernel, add panic_on_warn
Date: Mon, 03 Nov 2014 08:32:42 -0500	[thread overview]
Message-ID: <545783FA.4050508@redhat.com> (raw)
In-Reply-To: <20141031015843.GW9743-2aXy8kx9jd5qWu+OMeiFJmRHvnxUvMa2@public.gmane.org>



On 10/30/2014 09:58 PM, Hedi Berriche wrote:
> On Thu, Oct 30, 2014 at 17:06 Prarit Bhargava wrote:
> | There have been several times where I have had to rebuild a kernel to
> | cause a panic when hitting a WARN() in the code in order to get a crash
> | dump from a system.  Sometimes this is easy to do, other times (such as
> | in the case of a remote admin) it is not trivial to send new images to the
> | user.
> | 
> | A much easier method would be a switch to change the WARN() over to a
> | panic.  This makes debugging easier in that I can now test the actual
> | image the WARN() was seen on and I do not have to engage in remote
> | debugging.
> 
> Do we want to leave it to usersspace[1] to ensure panic_on_warn is out
> of the way in when the kdump kernel boots? or would a self-contained
> approach be more preferable i.e. test whether we're a kdump kernel
> before bothering with panic_on_warn?

Hmm ... this is a good point.  Vivek, do you have a preference?  I'm willing to
code it either way.  I should be able to put in a is_kdump_kernel() check
without any problems but I'm not sure if that is the right thing to do here.

P.

> 
> Cheers,
> Hedi.
> 
> [1] kexec-tools in the case of the boot param by filtering it out of the
>     kdump kernel cmdline. In the case of sysctl.conf, it would depend on
>     whether there are distros out there that  include it in the kdump
>     initrd.
> 

  parent reply	other threads:[~2014-11-03 13:32 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-30 17:03 [PATCH] kernel, add panic_on_warn Prarit Bhargava
     [not found] ` <1414688627-5298-1-git-send-email-prarit-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-10-30 17:24   ` H. Peter Anvin
2014-10-31  1:58   ` Hedi Berriche
     [not found]     ` <20141031015843.GW9743-2aXy8kx9jd5qWu+OMeiFJmRHvnxUvMa2@public.gmane.org>
2014-11-03 13:32       ` Prarit Bhargava [this message]
     [not found]         ` <545783FA.4050508-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-11-03 15:18           ` Vivek Goyal
  -- strict thread matches above, loose matches on Subject: below --
2014-11-04 15:41 Prarit Bhargava
2014-11-05  4:27 ` WANG Chao
2014-11-05  4:55 ` Yasuaki Ishimatsu

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