[PATCH 3/4] perf tools: Add perf_evsel__read_counter function

From: Jiri Olsa
Date: Fri Jul 21 2017 - 08:12:29 EST


Adding perf_evsel__read_counter function to read single or
group counter. After calling this function the counter's
evsel::counts struct is filled with values for the counter
and member of its group if there are any.

Link: http://lkml.kernel.org/n/tip-itsuxdyt7rp4mvij1t6k7bcl@xxxxxxxxxxxxxx
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
---
tools/perf/util/evsel.c | 100 ++++++++++++++++++++++++++++++++++++++++++++++++
tools/perf/util/evsel.h | 2 +
tools/perf/util/stat.c | 3 ++
tools/perf/util/stat.h | 5 ++-
4 files changed, 108 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 4dd0fcc06db9..89aecf3a35c7 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1302,6 +1302,106 @@ int perf_evsel__read(struct perf_evsel *evsel, int cpu, int thread,
return 0;
}

+static int
+perf_evsel__read_one(struct perf_evsel *evsel, int cpu, int thread)
+{
+ struct perf_counts_values *count = perf_counts(evsel->counts, cpu, thread);
+
+ return perf_evsel__read(evsel, cpu, thread, count);
+}
+
+static void
+perf_evsel__set_count(struct perf_evsel *counter, int cpu, int thread,
+ u64 val, u64 ena, u64 run)
+{
+ struct perf_counts_values *count;
+
+ count = perf_counts(counter->counts, cpu, thread);
+
+ count->val = val;
+ count->ena = ena;
+ count->run = run;
+}
+
+static int
+perf_evsel__process_group_data(struct perf_evsel *leader,
+ int cpu, int thread, u64 *data)
+{
+ u64 read_format = leader->attr.read_format;
+ struct sample_read_value *v;
+ u64 nr, ena = 0, run = 0, i;
+
+ nr = *data++;
+
+ if (nr != (u64) leader->nr_members)
+ return -EINVAL;
+
+ if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
+ ena = *data++;
+
+ if (read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
+ run = *data++;
+
+ v = (struct sample_read_value *) data;
+
+ perf_evsel__set_count(leader, cpu, thread,
+ v[0].value, ena, run);
+
+ for (i = 1; i < nr; i++) {
+ struct perf_evsel *counter;
+
+ counter = perf_evlist__id2evsel(leader->evlist, v[i].id);
+ if (!counter)
+ return -EINVAL;
+
+ perf_evsel__set_count(counter, cpu, thread,
+ v[i].value, ena, run);
+ }
+
+ return 0;
+}
+
+static int
+perf_evsel__read_group(struct perf_evsel *leader, int cpu, int thread)
+{
+ struct perf_stat_evsel *ps = leader->priv;
+ u64 read_format = leader->attr.read_format;
+ int size = perf_evsel__read_size(leader);
+ u64 *data = ps->group_data;
+
+ if (!(read_format & PERF_FORMAT_ID))
+ return -EINVAL;
+
+ if (!perf_evsel__is_group_leader(leader))
+ return -EINVAL;
+
+ if (!data) {
+ data = zalloc(size);
+ if (!data)
+ return -ENOMEM;
+
+ ps->group_data = data;
+ }
+
+ if (FD(leader, cpu, thread) < 0)
+ return -EINVAL;
+
+ if (readn(FD(leader, cpu, thread), data, size) <= 0)
+ return -errno;
+
+ return perf_evsel__process_group_data(leader, cpu, thread, data);
+}
+
+int perf_evsel__read_counter(struct perf_evsel *evsel, int cpu, int thread)
+{
+ u64 read_format = evsel->attr.read_format;
+
+ if (read_format & PERF_FORMAT_GROUP)
+ return perf_evsel__read_group(evsel, cpu, thread);
+ else
+ return perf_evsel__read_one(evsel, cpu, thread);
+}
+
int __perf_evsel__read_on_cpu(struct perf_evsel *evsel,
int cpu, int thread, bool scale)
{
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index fb40ca3c6519..de03c18daaf0 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -299,6 +299,8 @@ static inline bool perf_evsel__match2(struct perf_evsel *e1,
int perf_evsel__read(struct perf_evsel *evsel, int cpu, int thread,
struct perf_counts_values *count);

+int perf_evsel__read_counter(struct perf_evsel *evsel, int cpu, int thread);
+
int __perf_evsel__read_on_cpu(struct perf_evsel *evsel,
int cpu, int thread, bool scale);

diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
index 53b9a994a3dc..2c258554f94d 100644
--- a/tools/perf/util/stat.c
+++ b/tools/perf/util/stat.c
@@ -128,6 +128,9 @@ static int perf_evsel__alloc_stat_priv(struct perf_evsel *evsel)

static void perf_evsel__free_stat_priv(struct perf_evsel *evsel)
{
+ struct perf_stat_evsel *ps = evsel->priv;
+
+ free(ps->group_data);
zfree(&evsel->priv);
}

diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
index 7522bf10b03e..eacaf958e19d 100644
--- a/tools/perf/util/stat.h
+++ b/tools/perf/util/stat.h
@@ -28,8 +28,9 @@ enum perf_stat_evsel_id {
};

struct perf_stat_evsel {
- struct stats res_stats[3];
- enum perf_stat_evsel_id id;
+ struct stats res_stats[3];
+ enum perf_stat_evsel_id id;
+ u64 *group_data;
};

enum aggr_mode {
--
2.9.4