[PATCH v6 07/11] perf stat: Allocate shadow stats buffer for threads

From: Jin Yao
Date: Tue Dec 05 2017 - 01:08:35 EST


After perf_evlist__create_maps() being executed, we can get all
threads from /proc. And via thread_map__nr(), we can also get
the number of threads.

With the number of threads, the patch allocates a buffer which
will record the shadow stats for these threads.

The buffer pointer is saved in stat_config.

Signed-off-by: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
---
tools/perf/builtin-stat.c | 46 +++++++++++++++++++++++++++++++++++++++++++++-
tools/perf/util/stat.h | 2 ++
2 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 1edc082..8ff3348 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -214,8 +214,13 @@ static inline void diff_timespec(struct timespec *r, struct timespec *a,

static void perf_stat__reset_stats(void)
{
+ int i;
+
perf_evlist__reset_stats(evsel_list);
perf_stat__reset_shadow_stats();
+
+ for (i = 0; i < stat_config.stats_num; i++)
+ perf_stat__reset_shadow_per_stat(&stat_config.stats[i]);
}

static int create_perf_stat_counter(struct perf_evsel *evsel)
@@ -2496,6 +2501,35 @@ int process_cpu_map_event(struct perf_tool *tool,
return set_maps(st);
}

+static int runtime_stat_new(struct perf_stat_config *config, int nthreads)
+{
+ int i;
+
+ config->stats = calloc(nthreads, sizeof(struct runtime_stat));
+ if (!config->stats)
+ return -1;
+
+ config->stats_num = nthreads;
+
+ for (i = 0; i < nthreads; i++)
+ runtime_stat__init(&config->stats[i]);
+
+ return 0;
+}
+
+static void runtime_stat_delete(struct perf_stat_config *config)
+{
+ int i;
+
+ if (!config->stats)
+ return;
+
+ for (i = 0; i < config->stats_num; i++)
+ runtime_stat__exit(&config->stats[i]);
+
+ free(config->stats);
+}
+
static const char * const stat_report_usage[] = {
"perf stat report [<options>]",
NULL,
@@ -2751,8 +2785,15 @@ int cmd_stat(int argc, const char **argv)
* Initialize thread_map with comm names,
* so we could print it out on output.
*/
- if (stat_config.aggr_mode == AGGR_THREAD)
+ if (stat_config.aggr_mode == AGGR_THREAD) {
thread_map__read_comms(evsel_list->threads);
+ if (target.system_wide) {
+ if (runtime_stat_new(&stat_config,
+ thread_map__nr(evsel_list->threads))) {
+ goto out;
+ }
+ }
+ }

if (interval && interval < 100) {
if (interval < 10) {
@@ -2842,5 +2883,8 @@ int cmd_stat(int argc, const char **argv)
sysfs__write_int(FREEZE_ON_SMI_PATH, 0);

perf_evlist__delete(evsel_list);
+
+ runtime_stat_delete(&stat_config);
+
return status;
}
diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
index 27d7a18..06475c4 100644
--- a/tools/perf/util/stat.h
+++ b/tools/perf/util/stat.h
@@ -90,6 +90,8 @@ struct perf_stat_config {
bool scale;
FILE *output;
unsigned int interval;
+ struct runtime_stat *stats;
+ int stats_num;
};

void update_stats(struct stats *stats, u64 val);
--
2.7.4