Re: [RFC PATCH] hw-breakpoints, kgdb, x86: add a flagtopassDIE_DEBUG notification

[Jason Wessel <jason.wessel@windriver.com>]

On 07/28/2010 12:08 PM, Frederic Weisbecker wrote:
> On Mon, Jul 26, 2010 at 07:13:23PM +0800, DDD wrote:
>   
>> Frederic Weisbecker wrote:
>>     
>>> Why? It seems to me a kernel debugger should have the highest priority
>>> over anything.
>>>       
>> In my option, the reason of kgdb set the lowest-prio for
>> notifier is:
>>
>> For letting kgdb to keep simple, there is no codes to check the
>> breakpoint event was generated by kgdb or not, thus it have to set kgdb
>> as lowest priority to notifier.
>>
>> If the breakpoint event is not generated by kgdb, the source of the
>> breakpoint event will consume that event before passing to kgdb's
>> routine, so that the breakpoint event of kgdb getting must be generated  
>> by kgdb itself.
>>     
>
>
>
> Ok, but that makes it hard to differentiate from a spurious breakpoint
> event.
>
>
>
>   

The original thinking was that if you are using a low level debugger
that you would want to stop on such a event or breakpoint because there
is nothing else handling it and your system is about to print an oops
message.


Jason.