[PATCH V4] kernel, add bug_on_warn

[Prarit Bhargava]

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.