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....@linux.intel.com>
---
  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