remove User Switch from linearBandwidth due to poor performance

examples/linearbandwidth.py

@@ -24,7 +24,7 @@ of switches, this example demonstrates:
 """
 
 from mininet.net import Mininet
-from mininet.node import UserSwitch, OVSKernelSwitch, Controller
+from mininet.node import OVSKernelSwitch, Controller
 from mininet.topo import Topo
 from mininet.log import lg
 from mininet.util import irange
@@ -67,8 +67,7 @@ def linearBandwidthTest( lengths ):
     switchCount = max( lengths )
     hostCount = switchCount + 1
 
-    switches = { 'reference user': UserSwitch,
-                 'Open vSwitch kernel': OVSKernelSwitch }
+    switches = { 'Open vSwitch kernel': OVSKernelSwitch }
 
     topo = LinearTestTopo( hostCount )
 

examples/test/test_linearbandwidth.py

@@ -21,7 +21,6 @@ class testLinearBandwidth( unittest.TestCase ):
         while True:
             index = p.expect( opts, timeout=600 )
             if index == 0:
-                previous_bw = 10 ** 10 # 10 Gbits
                 count += 1
             elif index == 1:
                 n = int( p.match.group( 1 ) )
@@ -32,12 +31,15 @@ class testLinearBandwidth( unittest.TestCase ):
                 elif unit[ 0 ] == 'M':
                     bw *= 10 ** 6
                 elif unit[ 0 ] == 'G':
-                    bw *= 10 ** 9
-                self.assertTrue( bw < previous_bw )
+                    bw *= 10 ** 9a
+                # check that we have a previous result to compare to
+                if n != 1:
+                    self.assertTrue( bw < previous_bw )
                 previous_bw = bw
             else:
                 break
 
+        # verify that we received results from at least one switch
         self.assertTrue( count > 0 )
 
 if __name__ == '__main__':