Re: [PATCH v3 2/4] perf counts: Reset prev_raw_counts counts

[Jin, Yao]

Hi Jiri,

On 5/7/2020 11:19 PM, Jiri Olsa wrote:
> On Thu, May 07, 2020 at 02:58:20PM +0800, Jin Yao wrote:
> > The evsel->prev_raw_counts is updated in perf_evsel__compute_deltas:
> >
> > perf_evsel__compute_deltas()
> > {
> > 	tmp = *perf_counts(evsel->prev_raw_counts, cpu, thread);
> > 	*perf_counts(evsel->prev_raw_counts, cpu, thread) = *count;
> > }
> >
> > When we want to reset the evsel->prev_raw_counts in
> > perf_evsel__reset_prev_raw_counts, zeroing the aggr is not enough,
> > we need to reset the counts too.
> >
> > Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
> > ---
> >   tools/perf/util/counts.c | 5 +++++
> >   tools/perf/util/counts.h | 2 ++
> >   tools/perf/util/stat.c   | 1 +
> >   3 files changed, 8 insertions(+)
> >
> > diff --git a/tools/perf/util/counts.c b/tools/perf/util/counts.c
> > index f94e1a23dad6..af3bf36f7c63 100644
> > --- a/tools/perf/util/counts.c
> > +++ b/tools/perf/util/counts.c
> > @@ -64,3 +64,8 @@ void perf_evsel__free_counts(struct evsel *evsel)
> >   	perf_counts__delete(evsel->counts);
> >   	evsel->counts = NULL;
> >   }
> > +
> > +void perf_evsel__reset_raw_counts(struct evsel *evsel)
> > +{
> > +	perf_counts__reset(evsel->prev_raw_counts);
> > +}
> > diff --git a/tools/perf/util/counts.h b/tools/perf/util/counts.h
> > index 92196df4945f..15bb9acb7cb0 100644
> > --- a/tools/perf/util/counts.h
> > +++ b/tools/perf/util/counts.h
> > @@ -42,4 +42,6 @@ void perf_evsel__reset_counts(struct evsel *evsel);
> >   int perf_evsel__alloc_counts(struct evsel *evsel, int ncpus, int nthreads);
> >   void perf_evsel__free_counts(struct evsel *evsel);
> >   
> > +void perf_evsel__reset_raw_counts(struct evsel *evsel);
> > +
> >   #endif /* __PERF_COUNTS_H */
> > diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
> > index 774468341851..89e541564ed5 100644
> > --- a/tools/perf/util/stat.c
> > +++ b/tools/perf/util/stat.c
> > @@ -168,6 +168,7 @@ static void perf_evsel__reset_prev_raw_counts(struct evsel *evsel)
> >   		evsel->prev_raw_counts->aggr.val = 0;
> >   		evsel->prev_raw_counts->aggr.ena = 0;
> >   		evsel->prev_raw_counts->aggr.run = 0;
> > +		perf_evsel__reset_raw_counts(evsel);
>
> that seems needed, but we have it scathered all over the place,
> could you centralize the reset? the way I see it the perf_counts__reset
> should zero all the members of struct perf_counts.. so also
> the aggr values
>
> it could also check for counts != NULL and we could call it
> instead of:
>    perf_evsel__reset_prev_raw_counts
>      perf_evsel__reset_raw_counts
>        perf_counts__reset
>
> jirka

While sometime, we may want to only reset evsel->counts and sometime we just 
want to reset the evsel->prev_raw_counts. So maybe we improve 
perf_evsel__reset_counts to:

void perf_evsel__reset_counts(struct evsel *evsel, bool counts, bool 
prev_raw_counts)
{
	if (counts)
		perf_counts__reset(evsel->counts);

	if (prev_raw_counts && evsel->prev_raw_counts);
		perf_counts__reset(evsel->prev_raw_counts);
}

static void perf_counts__reset(struct perf_counts *counts)
{
	counts->aggr.val = 0;
	counts->aggr.ena = 0;
	counts->aggr.run = 0;
	xyarray__reset(counts->loaded);
	xyarray__reset(counts->values);
}

So we will only keep perf_evsel__reset_counts and remove 
perf_evsel__reset_prev_raw_counts.

Thanks
Jin Yao