1 files changed, 51 insertions, 0 deletions
diff --git a/tools/perf/util/events_stats.h b/tools/perf/util/events_stats.h
new file mode 100644
index 000000000000..859cb34fcff2
--- /dev/null
+++ b/tools/perf/util/events_stats.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PERF_EVENTS_STATS_
+#define __PERF_EVENTS_STATS_
+
+#include <stdio.h>
+#include <perf/event.h>
+#include <linux/types.h>
+#include "auxtrace.h"
+
+/*
+ * The kernel collects the number of events it couldn't send in a stretch and
+ * when possible sends this number in a PERF_RECORD_LOST event. The number of
+ * such "chunks" of lost events is stored in .nr_events[PERF_EVENT_LOST] while
+ * total_lost tells exactly how many events the kernel in fact lost, i.e. it is
+ * the sum of all struct perf_record_lost.lost fields reported.
+ *
+ * The kernel discards mixed up samples and sends the number in a
+ * PERF_RECORD_LOST_SAMPLES event. The number of lost-samples events is stored
+ * in .nr_events[PERF_RECORD_LOST_SAMPLES] while total_lost_samples tells
+ * exactly how many samples the kernel in fact dropped, i.e. it is the sum of
+ * all struct perf_record_lost_samples.lost fields reported.
+ *
+ * The total_period is needed because by default auto-freq is used, so
+ * multipling nr_events[PERF_EVENT_SAMPLE] by a frequency isn't possible to get
+ * the total number of low level events, it is necessary to to sum all struct
+ * perf_record_sample.period and stash the result in total_period.
+ */
+struct events_stats {
+	u64 total_period;
+	u64 total_non_filtered_period;
+	u64 total_lost;
+	u64 total_lost_samples;
+	u64 total_aux_lost;
+	u64 total_aux_partial;
+	u64 total_invalid_chains;
+	u32 nr_events[PERF_RECORD_HEADER_MAX];
+	u32 nr_non_filtered_samples;
+	u32 nr_lost_warned;
+	u32 nr_unknown_events;
+	u32 nr_invalid_chains;
+	u32 nr_unknown_id;
+	u32 nr_unprocessable_samples;
+	u32 nr_auxtrace_errors[PERF_AUXTRACE_ERROR_MAX];
+	u32 nr_proc_map_timeout;
+};
+
+void events_stats__inc(struct events_stats *stats, u32 type);
+
+size_t events_stats__fprintf(struct events_stats *stats, FILE *fp);
+
+#endif /* __PERF_EVENTS_STATS_ */