From: Jiri Olsa <jolsa@redhat.com>
To: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
lkml <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Arnaldo Carvalho de Melo <acme@kernel.org>
Subject: Re: [PATCH 1/5] ftrace perf: Check sample types only for sampling events
Date: Thu, 10 Mar 2016 08:25:02 +0100 [thread overview]
Message-ID: <20160310072502.GA11206@krava.redhat.com> (raw)
In-Reply-To: <20160310003637.GA21119@sejong>
On Thu, Mar 10, 2016 at 09:36:37AM +0900, Namhyung Kim wrote:
> 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 <jolsa@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.
right, will check
thanks,
jirka
next prev parent reply other threads:[~2016-03-10 7:25 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-09 20:46 [RFC 0/5] ftrace perf: Fixes and speedup Jiri Olsa
2016-03-09 20:46 ` [PATCH 1/5] ftrace perf: Check sample types only for sampling events Jiri Olsa
2016-03-10 0:36 ` Namhyung Kim
2016-03-10 7:25 ` Jiri Olsa [this message]
2016-03-11 8:36 ` Jiri Olsa
2016-03-11 13:48 ` Namhyung Kim
2016-03-11 18:14 ` Jiri Olsa
2016-03-15 20:06 ` Steven Rostedt
2016-03-15 21:51 ` Jiri Olsa
2016-03-09 20:46 ` [PATCH 2/5] ftrace perf: Move exclude_kernel tracepoint check to init event Jiri Olsa
2016-03-10 0:39 ` Namhyung Kim
2016-03-11 8:39 ` Jiri Olsa
2016-03-09 20:46 ` [PATCH 3/5] ftrace perf: Use ftrace_ops::private to store event pointer Jiri Olsa
2016-03-10 1:29 ` Namhyung Kim
2016-03-09 20:46 ` [PATCH 4/5] ftrace: Make ftrace_hash_rec_enable return update bool Jiri Olsa
2016-03-11 14:28 ` Namhyung Kim
2016-03-11 18:15 ` Jiri Olsa
2016-03-12 8:35 ` Namhyung Kim
2016-03-15 19:43 ` Steven Rostedt
2016-03-09 20:46 ` [PATCH 5/5] ftrace: Update dynamic ftrace calls only if necessary Jiri Olsa
2016-03-16 14:34 [PATCHv2 0/5] ftrace perf: Fixes and speedup Jiri Olsa
2016-03-16 14:34 ` [PATCH 1/5] ftrace perf: Check sample types only for sampling events Jiri Olsa
2016-03-18 14:27 ` Steven Rostedt
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