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-rw-r--r--tools/perf/builtin-stat.c31
1 files changed, 23 insertions, 8 deletions
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 0c16d20d7e32..3c7452b39f57 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -331,7 +331,7 @@ static int read_counter(struct perf_evsel *counter)
return 0;
}
-static void read_counters(bool close_counters)
+static void read_counters(void)
{
struct perf_evsel *counter;
@@ -341,11 +341,6 @@ static void read_counters(bool close_counters)
if (perf_stat_process_counter(&stat_config, counter))
pr_warning("failed to process counter %s\n", counter->name);
-
- if (close_counters) {
- perf_evsel__close_fd(counter, perf_evsel__nr_cpus(counter),
- thread_map__nr(evsel_list->threads));
- }
}
}
@@ -353,7 +348,7 @@ static void process_interval(void)
{
struct timespec ts, rs;
- read_counters(false);
+ read_counters();
clock_gettime(CLOCK_MONOTONIC, &ts);
diff_timespec(&rs, &ts, &ref_time);
@@ -380,6 +375,17 @@ static void enable_counters(void)
perf_evlist__enable(evsel_list);
}
+static void disable_counters(void)
+{
+ /*
+ * If we don't have tracee (attaching to task or cpu), counters may
+ * still be running. To get accurate group ratios, we must stop groups
+ * from counting before reading their constituent counters.
+ */
+ if (!target__none(&target))
+ perf_evlist__disable(evsel_list);
+}
+
static volatile int workload_exec_errno;
/*
@@ -657,11 +663,20 @@ try_again:
}
}
+ disable_counters();
+
t1 = rdclock();
update_stats(&walltime_nsecs_stats, t1 - t0);
- read_counters(true);
+ /*
+ * Closing a group leader splits the group, and as we only disable
+ * group leaders, results in remaining events becoming enabled. To
+ * avoid arbitrary skew, we must read all counters before closing any
+ * group leaders.
+ */
+ read_counters();
+ perf_evlist__close(evsel_list);
return WEXITSTATUS(status);
}