debug script to track droppped frames (#1749)

selfdrive/debug/internal/measure_modeld_packet_drop.py

@@ -0,0 +1,30 @@
+#!/usr/bin/env python3
+import cereal.messaging as messaging
+
+if __name__ == "__main__":
+  modeld_sock = messaging.sub_sock("model")
+
+  last_frame_id = None
+  start_t = None
+  frame_cnt = 0
+  dropped = 0
+
+  while True:
+    m = messaging.recv_one(modeld_sock)
+    frame_id = m.model.frameId
+    t = m.logMonoTime / 1e9
+    frame_cnt += 1
+
+    if start_t is None:
+      start_t = t
+      last_frame_id = frame_id
+      continue
+
+    d_frame = frame_id - last_frame_id
+    dropped += d_frame - 1
+
+    expected_num_frames = int((t - start_t) * 20)
+    frame_drop = 100 * (1 - (expected_num_frames / frame_cnt))
+    print(f"Num dropped {dropped}, Drop compared to 20Hz: {frame_drop:.2f}%")
+
+    last_frame_id = frame_id