Re: [tip:perfcounters/urgent] ftrace: Fix perf-tracepoint OOPS

[Ingo Molnar <mingo@elte.hu>]

* Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:

> 
> > [ v2: fix build error in the !CONFIG_EVENT_PROFILE case ]
> > Signed-off-by: Ingo Molnar <mingo@elte.hu>
> > 
> > 
> > ---
> >  include/linux/ftrace_event.h       |    8 +++-----
> >  kernel/trace/trace_event_profile.c |    2 +-
> >  kernel/trace/trace_events.c        |    2 +-
> >  3 files changed, 5 insertions(+), 7 deletions(-)
> > 
> > diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
> > index 5c093ff..d7cd193 100644
> > --- a/include/linux/ftrace_event.h
> > +++ b/include/linux/ftrace_event.h
> > @@ -119,11 +119,9 @@ struct ftrace_event_call {
> >  	void			*filter;
> >  	void			*mod;
> >  
> > -#ifdef CONFIG_EVENT_PROFILE
> > -	atomic_t	profile_count;
> > -	int		(*profile_enable)(struct ftrace_event_call *);
> > -	void		(*profile_disable)(struct ftrace_event_call *);
> > -#endif
> > +	atomic_t		profile_count;
> > +	int			(*profile_enable)(struct ftrace_event_call *);
> > +	void			(*profile_disable)(struct ftrace_event_call *);
> >  };
> 
> Ah, I would have added ifdefs around the below bit.
> 
> > diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
> > index 23d2972..e75276a 100644
> > --- a/kernel/trace/trace_events.c
> > +++ b/kernel/trace/trace_events.c
> > @@ -940,7 +940,7 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
> >  		entry = trace_create_file("enable", 0644, call->dir, call,
> >  					  enable);
> >  
> > -	if (call->id)
> #ifdef CONFIG_EVENT_PROFILE
> > +	if (call->id && call->profile_enable)
> >  		entry = trace_create_file("id", 0444, call->dir, call,
> >  					  id);
> #endif
> 
> Like that, but I guess this works too ;-)

i think CONFIG_EVENT_PROFILE should go away - it's clearly a core 
functionality of ftrace. Whenever we hit a Kconfig induced build 
breakage we should first consider reducing the Kconfig complexity a 
bit.

	Ingo