Re: [PATCH 1/4] tracing: add DEFINE_TRACE_FMT to tracepoint.h

[Ingo Molnar <mingo@elte.hu>]

* Steven Rostedt <rostedt@goodmis.org> wrote:

> On Wed, 25 Feb 2009, Mathieu Desnoyers wrote:
> 
> > * Steven Rostedt (rostedt@goodmis.org) wrote:
> > > From: Steven Rostedt <srostedt@redhat.com>
> > > 
> > > This patch creates a DEFINE_TRACE_FMT to map to DECLARE_TRACE.
> > > This allows for the developers to place format strings and
> > > args in with their tracepoint declaration. A tracer may now
> > > override the DEFINE_TRACE_FMT macro and use it to record
> > > a default format.
> > > 
> > 
> > Hi Steven,
> > 
> > How comes does a DEFINE_* maps to a DECLARE_* ?
> > 
> > Usually, DEFINE_* are meant to be put in .c files. DECLARE_* are in
> > headers. I don't see how the mapping you propose here can be
> > semantically correct ?
> 
> Because it can be either a define or a declare ;-)
> 
> Gag, I can't win! First Andrew points out that I use 
> DECLARE_TRACE_FMT when it should be a DEFINE. Now I go change 
> it and you state that it should be a DECLARE not a DEFINE!
> 
> Well, any tracer that remaps it, it should be a DEFINE. Just 
> in the "default" case of trace points, is it used as a 
> DECLARE. Because, it ignores the fmt parameter that would be 
> used in the define.

Add either both or none of them. I'd suggest the latter ;-)

TRACE_FORMAT() would be perfect.

	Ingo