Re: [PATCH 07/12] add ftrace_event_call void * 'data' field

[Frederic Weisbecker <fweisbec@gmail.com>]

On Mon, Aug 17, 2009 at 06:19:33PM -0400, Steven Rostedt wrote:
> 
> On Tue, 11 Aug 2009, Frederic Weisbecker wrote:
> 
> > On Mon, Aug 10, 2009 at 04:52:44PM -0400, Jason Baron wrote:
> > > add an optional * void pointer to 'ftrace_event_call' that is
> > > passed in for regfunc and unregfunc.
> > > 
> > > Signed-off-by: Jason Baron <jbaron@redhat.com>
> > > 
> > > ---
> > >  include/linux/ftrace_event.h |    5 +++--
> > >  include/trace/ftrace.h       |    4 ++--
> > >  kernel/trace/trace_events.c  |    4 ++--
> > >  3 files changed, 7 insertions(+), 6 deletions(-)
> > > 
> > > diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
> > > index ac8c6f8..8544f12 100644
> > > --- a/include/linux/ftrace_event.h
> > > +++ b/include/linux/ftrace_event.h
> > > @@ -112,8 +112,8 @@ struct ftrace_event_call {
> > >  	struct dentry		*dir;
> > >  	struct trace_event	*event;
> > >  	int			enabled;
> > > -	int			(*regfunc)(void);
> > > -	void			(*unregfunc)(void);
> > > +	int			(*regfunc)(void *);
> > > +	void			(*unregfunc)(void *);
> > >  	int			id;
> > >  	int			(*raw_init)(void);
> > >  	int			(*show_format)(struct trace_seq *s);
> > > @@ -122,6 +122,7 @@ struct ftrace_event_call {
> > >  	int			filter_active;
> > >  	struct event_filter	*filter;
> > >  	void			*mod;
> > > +	void			*data;
> > >  
> > >  	atomic_t		profile_count;
> > >  	int			(*profile_enable)(struct ftrace_event_call *);
> > > diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
> > > index 80e5f6c..a0de384 100644
> > > --- a/include/trace/ftrace.h
> > > +++ b/include/trace/ftrace.h
> > > @@ -568,7 +568,7 @@ static void ftrace_raw_event_##call(proto)				\
> > >  		trace_nowake_buffer_unlock_commit(event, irq_flags, pc); \
> > >  }									\
> > >  									\
> > > -static int ftrace_raw_reg_event_##call(void)				\
> > > +static int ftrace_raw_reg_event_##call(void *ptr)			\
> > 
> > 
> > Shouldn't it have a __used attribute here, or something?
> 
> Do function parameters need that? There's lots of places where the 
> parameter of a function is not used by a function itself.
> 
> -- Steve


No actually, I thought gcc would warn, but it didn't :-)