Re: [PATCH v2 1/2] tracing: Move tracepoint callbacks into DEFINE

[Josh Stone <jistone@redhat.com>]

On 08/21/2009 07:47 AM, Ingo Molnar wrote:
> 
> * Josh Stone <jistone@redhat.com> wrote:
> 
>> It's not strictly correct for the tracepoint reg/unreg callbacks 
>> to occur when a client is hooking up, because the actual 
>> tracepoint may no be present yet.  This happens to be fine for 
>> syscall, since that's in the core kernel, but it would cause 
>> problems for tracepoints defined in a module that hasn't been 
>> loaded yet.  It also means the reg/unreg has to be EXPORTed for 
>> any modules to use the tracepoint (as in SystemTap).
>>
>> This patch removes DECLARE_TRACE_WITH_CALLBACK, and instead 
>> introduces DEFINE_TRACE_WITH_CALLBACK which stores the callbacks 
>> in struct tracepoint.  The callbacks are used now when the active 
>> state of the tracepoint changes in set_tracepoint & 
>> disable_tracepoint.
>>
>> This also introduces TRACE_EVENT_WITH_CALLBACK, so those events 
>> can also provide callbacks if needed.
> 
> i think something shorter would be nicer, such as:
> 
>  DECLARE_TRACE_FN
>  TRACE_EVENT_FN

Well I took out the DECLARE_TRACE_ part, but sure, DEFINE_TRACE_FN and
TRACE_EVENT_FN sound fine to me.

Josh