+/*
+ * When perf record finishes a pass on every buffers, it records this pseudo
+ * event.
+ * We record the max timestamp t found in the pass n.
+ * Assuming these timestamps are monotonic across cpus, we know that if
+ * a buffer still has events with timestamps below t, they will be all
+ * available and then read in the pass n + 1.
+ * Hence when we start to read the pass n + 2, we can safely flush every
+ * events with timestamps below t.
+ *
+ * ============ PASS n =================
+ * CPU 0 | CPU 1
+ * |
+ * cnt1 timestamps | cnt2 timestamps
+ * 1 | 2
+ * 2 | 3
+ * - | 4 <--- max recorded
+ *
+ * ============ PASS n + 1 ==============
+ * CPU 0 | CPU 1
+ * |
+ * cnt1 timestamps | cnt2 timestamps
+ * 3 | 5
+ * 4 | 6
+ * 5 | 7 <---- max recorded
+ *
+ * Flush every events below timestamp 4
+ *
+ * ============ PASS n + 2 ==============
+ * CPU 0 | CPU 1
+ * |
+ * cnt1 timestamps | cnt2 timestamps
+ * 6 | 8
+ * 7 | 9
+ * - | 10
+ *
+ * Flush every events below timestamp 7
+ * etc...
+ */
+static int process_finished_round(event_t *event __used,
+ struct perf_session *session,
+ struct perf_event_ops *ops)
+{
+ flush_sample_queue(session, ops);
+ session->ordered_samples.next_flush = session->ordered_samples.max_timestamp;
+
+ return 0;
+}
+