when a link becomes idle and packet are buffered that the link could send, send at least 65535 bytes worth instead of 1 packet, this reduces syscall overhead when small packets are sent through the network

src/yggdrasil/debug.go

@@ -556,9 +556,11 @@ func DEBUG_simLinkPeers(p, q *peer) {
 	goWorkers := func(source, dest *peer) {
 		source.linkOut = make(chan []byte, 1)
 		send := make(chan []byte, 1)
-		source.out = func(bs []byte) {
+		source.out = func(bss [][]byte) {
+			for _, bs := range bss {
 				send <- bs
 			}
+		}
 		go source.linkLoop()
 		go func() {
 			var packets [][]byte

src/yggdrasil/switch.go

@@ -784,10 +784,13 @@ func (t *switchTable) handleIdle(port switchPort) bool {
 	if to == nil {
 		return true
 	}
-	var best string
+	var packets [][]byte
-	var bestPriority float64
+	var psize int
 	t.queues.cleanup(t)
 	now := time.Now()
+	for psize < 65535 {
+		var best string
+		var bestPriority float64
 		for streamID, buf := range t.queues.bufs {
 			// Filter over the streams that this node is closer to
 			// Keep the one with the smallest queue
@@ -812,11 +815,18 @@ func (t *switchTable) handleIdle(port switchPort) bool {
 				// Need to update the map, since buf was retrieved by value
 				t.queues.bufs[best] = buf
 			}
-		to.sendPackets([][]byte{packet.bytes})
+			packets = append(packets, packet.bytes)
-		return true
+			psize += len(packet.bytes)
 		} else {
-		return false
+			// Finished finding packets
+			break
 		}
+	}
+	if len(packets) > 0 {
+		to.sendPackets(packets)
+		return true
+	}
+	return false
 }
 
 // The switch worker does routing lookups and sends packets to where they need to be