[Devel] Re: [PATCH 3/7] perf: add ability to change event according to sample (v2)

[Arnaldo Carvalho de Melo]

Em Tue, Dec 06, 2011 at 12:19:42PM -0200, Arnaldo Carvalho de Melo escreveu:
> Em Mon, Nov 28, 2011 at 12:03:31PM +0300, Andrew Vagin escreveu:
> > It's opposition of perf_session__parse_sample.
> > 
> > v2: fixed mistakes which David Arhen found
> 
> Ok, I'm taking this one, David, can I added an 'Acked-by: you"? Or even
> "reviewed-by:" ?
> 
> I'm just changing 'data' to 'sample', data is way to vague, I kept it
> for a while in the past just to reduce patch size, but this is something
> completely new, so better use 'sample'.

Also I'm changing it from perf_event__change_sample() to
perf_event__synthesize_sample() as that is what is happening, you're not
taking some perf_sample and changing it just a bit, but synthesizing it
completely.

Since synthesize is used elsewhere when we synthesize PERF_RECORD_MMAP,
etc for existing threads, I'll use it here too.
 
> - Arnaldo
>  
> > Signed-off-by: Andrew Vagin <avagin at openvz.org>
> > ---
> >  tools/perf/util/event.h   |    2 +
> >  tools/perf/util/evsel.c   |   74 +++++++++++++++++++++++++++++++++++++++++++++
> >  tools/perf/util/session.h |    9 +++++
> >  3 files changed, 85 insertions(+), 0 deletions(-)
> > 
> > diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
> > index 357a85b..0493101 100644
> > --- a/tools/perf/util/event.h
> > +++ b/tools/perf/util/event.h
> > @@ -187,5 +187,7 @@ const char *perf_event__name(unsigned int id);
> >  int perf_event__parse_sample(const union perf_event *event, u64 type,
> >  			     int sample_size, bool sample_id_all,
> >  			     struct perf_sample *sample, bool swapped);
> > +int perf_event__change_sample(union perf_event *event, u64 type,
> > +			     const struct perf_sample *data, bool swapped);
> >  
> >  #endif /* __PERF_RECORD_H */
> > diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> > index e426264..d697568 100644
> > --- a/tools/perf/util/evsel.c
> > +++ b/tools/perf/util/evsel.c
> > @@ -494,3 +494,77 @@ int perf_event__parse_sample(const union perf_event *event, u64 type,
> >  
> >  	return 0;
> >  }
> > +
> > +int perf_event__change_sample(union perf_event *event, u64 type,
> > +			     const struct perf_sample *data, bool swapped)
> > +{
> > +	u64 *array;
> > +
> > +	/*
> > +	 * used for cross-endian analysis. See git commit 65014ab3
> > +	 * for why this goofiness is needed.
> > +	 */
> > +	union {
> > +		u64 val64;
> > +		u32 val32[2];
> > +	} u;
> > +
> > +	array = event->sample.array;
> > +
> > +	if (type & PERF_SAMPLE_IP) {
> > +		event->ip.ip = data->ip;
> > +		array++;
> > +	}
> > +
> > +	if (type & PERF_SAMPLE_TID) {
> > +		u.val32[0] = data->pid;
> > +		u.val32[1] = data->tid;
> > +		if (swapped) {
> > +			/* undo swap of u64, then swap on individual u32s */
> > +			u.val32[0] = bswap_32(u.val32[0]);
> > +			u.val32[1] = bswap_32(u.val32[1]);
> > +			u.val64 = bswap_64(u.val64);
> > +		}
> > +
> > +		*array = u.val64;
> > +		array++;
> > +	}
> > +
> > +	if (type & PERF_SAMPLE_TIME) {
> > +		*array = data->time;
> > +		array++;
> > +	}
> > +
> > +	if (type & PERF_SAMPLE_ADDR) {
> > +		*array = data->addr;
> > +		array++;
> > +	}
> > +
> > +	if (type & PERF_SAMPLE_ID) {
> > +		*array = data->id;
> > +		array++;
> > +	}
> > +
> > +	if (type & PERF_SAMPLE_STREAM_ID) {
> > +		*array = data->stream_id;
> > +		array++;
> > +	}
> > +
> > +	if (type & PERF_SAMPLE_CPU) {
> > +		u.val32[0] = data->cpu;
> > +		if (swapped) {
> > +			/* undo swap of u64, then swap on individual u32s */
> > +			u.val32[0] = bswap_32(u.val32[0]);
> > +			u.val64 = bswap_64(u.val64);
> > +		}
> > +		*array = u.val64;
> > +		array++;
> > +	}
> > +
> > +	if (type & PERF_SAMPLE_PERIOD) {
> > +		*array = data->period;
> > +		array++;
> > +	}
> > +
> > +	return 0;
> > +}
> > diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
> > index 6e393c9..444f121 100644
> > --- a/tools/perf/util/session.h
> > +++ b/tools/perf/util/session.h
> > @@ -167,6 +167,15 @@ static inline int perf_session__parse_sample(struct perf_session *session,
> >  					session->header.needs_swap);
> >  }
> >  
> > +static inline int perf_session__change_sample(struct perf_session *session,
> > +					     union perf_event *event,
> > +					     const struct perf_sample *sample)
> > +{
> > +	return perf_event__change_sample(event, session->sample_type,
> > +					sample,
> > +					session->header.needs_swap);
> > +}
> > +
> >  struct perf_evsel *perf_session__find_first_evtype(struct perf_session *session,
> >  					    unsigned int type);
> >  
> > -- 
> > 1.7.1