1 files changed, 14 insertions, 1 deletions

diff --git a/tools/perf/util/events_stats.h b/tools/perf/util/events_stats.h
index f43e5b1a366a..eabd7913c309 100644
--- a/tools/perf/util/events_stats.h
+++ b/tools/perf/util/events_stats.h
@@ -18,7 +18,18 @@
  * 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.
+ * all struct perf_record_lost_samples.lost fields reported without setting the
+ * misc field in the header.
+ *
+ * The BPF program can discard samples according to the filter expressions given
+ * by the user.  This number is kept in a BPF map and dumped at the end of perf
+ * record in a PERF_RECORD_LOST_SAMPLES event.  To differentiate it from other
+ * lost samples, perf tools sets PERF_RECORD_MISC_LOST_SAMPLES_BPF flag in the
+ * header.misc field.  The number of dropped-samples events is stored in
+ * .nr_events[PERF_RECORD_LOST_SAMPLES] while total_dropped_samples tells
+ * exactly how many samples the BPF program in fact dropped, i.e. it is the sum
+ * of all struct perf_record_lost_samples.lost fields reported with the misc
+ * field set in the header.
  *
  * The total_period is needed because by default auto-freq is used, so
  * multiplying nr_events[PERF_EVENT_SAMPLE] by a frequency isn't possible to get
@@ -28,6 +39,7 @@
 struct events_stats {
 	u64 total_lost;
 	u64 total_lost_samples;
+	u64 total_dropped_samples;
 	u64 total_aux_lost;
 	u64 total_aux_partial;
 	u64 total_aux_collision;
@@ -48,6 +60,7 @@ struct hists_stats {
 	u32 nr_samples;
 	u32 nr_non_filtered_samples;
 	u32 nr_lost_samples;
+	u32 nr_dropped_samples;
 };
 
 void events_stats__inc(struct events_stats *stats, u32 type);