Re: [PATCH 1/3] perf: record TRACE_INFO only if using tracepointsand SAMPLE_RAW

From: Arnaldo Carvalho de Melo
Date: Tue May 04 2010 - 17:19:35 EST


Em Tue, May 04, 2010 at 07:06:45PM +0200, Frederic Weisbecker escreveu:
> On Tue, May 04, 2010 at 11:00:05AM -0300, Arnaldo Carvalho de Melo wrote:
> > From: Tom Zanussi <tzanussi@xxxxxxxxx>
> >
> > The current perf code implicitly assumes SAMPLE_RAW means tracepoints
> > are being used, but doesn't check for that. It happily records the
> > TRACE_INFO even if SAMPLE_RAW is used without tracepoints, but when the
> > perf data is read it won't go any further when it finds TRACE_INFO but
> > no tracepoints, and displays misleading errors.
> >
> > This adds a check for both in perf-record, and won't record TRACE_INFO
> > unless both are true. This at least allows perf report -D to dump raw
> > events, and avoids triggering a misleading error condition in perf
> > trace. It doesn't actually enable the non-tracepoint raw events to be
> > displayed in perf trace, since perf trace currently only deals with
> > tracepoint events.
> >
> > Cc: Frédéric Weisbecker <fweisbec@xxxxxxxxx>
> > Cc: Mike Galbraith <efault@xxxxxx>
> > Cc: Paul Mackerras <paulus@xxxxxxxxx>
> > Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> > LKML-Reference: <1272865861.7932.16.camel@tropicana>
> > Signed-off-by: Tom Zanussi <tzanussi@xxxxxxxxx>
> > Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> > ---
> > tools/perf/builtin-record.c | 35 +++++++++++++++++++++--------------
> > tools/perf/util/header.c | 1 -
> > tools/perf/util/parse-events.h | 1 +
> > tools/perf/util/trace-event-info.c | 5 +++++
> > 4 files changed, 27 insertions(+), 15 deletions(-)
> >
> > diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> > index ac989e9..0ff67d1 100644
> > --- a/tools/perf/builtin-record.c
> > +++ b/tools/perf/builtin-record.c
> > @@ -560,11 +560,12 @@ static int __cmd_record(int argc, const char **argv)
> > return err;
> > }
> >
> > - if (raw_samples) {
> > + if (raw_samples && have_tracepoints(attrs, nr_counters)) {
> > perf_header__set_feat(&session->header, HEADER_TRACE_INFO);
> > } else {
>
>
>
> Using get_tracepoints_path() is a bit costly just to check if we use
> tracepoints as it allocates and fill the paths.

Can you please send a fix?

- Arnaldo
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