experiments: add support for disabling sync in switch

experiments/pyexps/dist_netperf.py

@@ -41,6 +41,7 @@ for host_type in host_types:
             # host
             if host_type == 'qemu':
                 host_class = sim.QemuHost
+                net.sync = False
             elif host_type == 'qt':
                 def qemu_timing():
                     h = sim.QemuHost()

experiments/simbricks/simulators.py

@@ -255,9 +255,15 @@ class WireNet(NetSim):
         return cmd
 
 class SwitchNet(NetSim):
+    sync = True
+
     def run_cmd(self, env):
         cmd = env.repodir + '/sims/net/switch/net_switch'
         cmd += f' -m {self.sync_mode} -S {self.sync_period} -E {self.eth_latency}'
+
+        if not self.sync:
+            cmd += ' -u'
+
         if len(env.pcap_file) > 0:
             cmd += ' -p ' + env.pcap_file
         for n in self.nics: