Changed the INT then KILL delay to 2 s to be a little more friendly.

IPython/kernel/client.py

@@ -64,7 +64,8 b' get_task_client = _client_tub.get_task_client'
 MultiEngineClient = get_multiengine_client
 TaskClient = get_task_client
 
-twisted_log = StringIO()
+# This isn't great.  I should probably set this up in the ReactorInThread
+# class below.  But, it does work for now.
 log.startLogging(sys.stdout, setStdout=0)
 
 # Now we start the reactor in a thread

IPython/kernel/launcher.py

@@ -245,7 +245,7 b' class LocalProcessLauncher(BaseLauncher):'
             self.process_transport.signalProcess(sig)
 
     @inlineCallbacks
-    def interrupt_then_kill(self, delay=1.0):
+    def interrupt_then_kill(self, delay=2.0):
         yield self.signal('INT')
         yield sleep_deferred(delay)
         yield self.signal('KILL')