Hi Jiri, On Wed, Mar 09, 2016 at 09:46:41PM +0100, Jiri Olsa wrote: > Currently we check sample type for ftrace:function event > even if it's not created as sampling event. That prevents > creating ftrace_function event in counting mode. > > Making sure we check sample types only for sampling events. > > Before: > $ sudo perf stat -e ftrace:function ls > ... > > Performance counter stats for 'ls': > > <not supported> ftrace:function > > 0.001983662 seconds time elapsed > > After: > $ sudo perf stat -e ftrace:function ls > ... > > Performance counter stats for 'ls': > > 44,498 ftrace:function > > 0.037534722 seconds time elapsed > > Signed-off-by: Jiri Olsa <jo...@kernel.org> > --- > kernel/trace/trace_event_perf.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c > index 00df25fd86ef..a7171ec2c1ca 100644 > --- a/kernel/trace/trace_event_perf.c > +++ b/kernel/trace/trace_event_perf.c > @@ -52,14 +52,14 @@ static int perf_trace_event_perm(struct trace_event_call > *tp_event, > * event, due to issues with page faults while tracing page > * fault handler and its overall trickiness nature. > */ > - if (!p_event->attr.exclude_callchain_user) > + if (is_sampling_event(p_event) && > !p_event->attr.exclude_callchain_user) > return -EINVAL; > > /* > * Same reason to disable user stack dump as for user space > * callchains above. > */ > - if (p_event->attr.sample_type & PERF_SAMPLE_STACK_USER) > + if (is_sampling_event(p_event) && p_event->attr.sample_type & > PERF_SAMPLE_STACK_USER) > return -EINVAL; > } >
What about checking is_sampling_event() first and goto the last paranoid_tracepoint_raw check instead? This way we can remove the same check in the function trace case. Thanks, Namhyung
