use larger pacer headroom

Author: lherman-cs

Makefile

@@ -46,21 +46,22 @@ flamegraph: profile
 perf-server:
 	$(eval PIDS := $(shell pgrep -x $(TARGET) | paste -sd "," -))
 	@if [ -z "$(PIDS)" ]; then echo "Error: pulsebeam not running"; exit 1; fi
+	sudo sysctl -w kernel.perf_event_max_stack=64
 	sudo sysctl -w kernel.kptr_restrict=0
 	sudo sysctl -w kernel.perf_event_paranoid=-1
 	@echo "Recording pulsebeam PIDs=$(PIDS) for 15s at 999Hz..."
 	perf config annotate.objdump=llvm-objdump
 	  # -p $(PIDS) 
 	perf record \
-		-F 99 \
 		-a \
-		-e cycles \
 		-g \
+		-e cycles \
 		--call-graph fp \
-		-m 128M \
+		-F 15000 \
+		-m 256M \
 		-o perf.data \
 		-- sleep 15
-	perf script -F +pid > perf-firefox.data
+	#perf script -F +pid > perf-firefox.data
 	@echo "Launching UI..."
 	hotspot perf.data
 

pulsebeam-agent/src/actor.rs

@@ -246,7 +246,7 @@ impl BitrateController {
             self.config.min_bitrate.as_f64(),
             self.config.max_bitrate.as_f64(),
         );
-        Bitrate::from(current_bitrate)
+        Bitrate::from(current_bitrate) * 1.50
     }
 }
 
@@ -926,6 +926,8 @@ impl AgentDriver {
             return Some(ev);
         }
 
+        let mut last_desired = Bitrate::bps(0);
+
         loop {
             // Drain all str0m output — this may queue pending_events.
             let Some(deadline) = self.poll_rtc() else {
@@ -1020,7 +1022,11 @@ impl AgentDriver {
                     let desired_bps = self.layer_ctrl.tick(self.now);
                     let desired_bitrate = Bitrate::from(desired_bps.max(0.0) as u64);
                     let filtered_bitrate = self.desired_ctrl.update(desired_bitrate);
-                    self.rtc.bwe().set_desired_bitrate(filtered_bitrate);
+                    if filtered_bitrate != last_desired {
+                        last_desired = filtered_bitrate;
+                        self.rtc.bwe().set_desired_bitrate(filtered_bitrate);
+                    }
+                    tracing::debug!("desired={}", filtered_bitrate);
                 }
                 _ = self.sleep.as_mut() => {
                     if self.rtc.handle_input(Input::Timeout(Instant::now().into())).is_err() {
@@ -1031,12 +1037,6 @@ impl AgentDriver {
                     self.perform_reconnect().await;
                 }
             }
-
-            // Return any events produced by this select iteration.
-            if let Some(ev) = self.pending_events.pop_front() {
-                return Some(ev);
-            }
-            // No event yet — loop back to drain str0m output.
         }
     }
 

pulsebeam-cli/src/main.rs

@@ -109,6 +109,7 @@ fn main() -> Result<()> {
     let cli = Cli::parse();
     let mut builder = Builder::new_multi_thread();
     builder.enable_all().enable_alt_timer();
+    tracing_subscriber::fmt::init();
 
     let runtime = builder.build()?;
     runtime.block_on(async move {
@@ -292,6 +293,7 @@ async fn spawn_agent(
                         }
                     }
                     AgentEvent::MediaReceived { frame, receive_time, .. } => {
+                        tracing::info!("received: {}", frame.data.len());
                         if let Some(abs_capture_time) = frame.abs_capture_time {
                             let wallclock = wallclock_at(receive_time);
                             if let Ok(latency) = wallclock.duration_since(abs_capture_time) {

pulsebeam/src/bitrate.rs

@@ -81,7 +81,7 @@ impl BitrateController {
             self.config.min_bitrate.as_f64(),
             self.config.max_bitrate.as_f64(),
         );
-        Bitrate::from(current_bitrate)
+        Bitrate::from(current_bitrate) * 1.50
     }
 }