Add [Startup] JobEngineEnabled setting that allows the job engine to be disabled for testing purposes if necessary.

OpenSim/Region/Application/OpenSimBase.cs

@@ -337,7 +337,9 @@ namespace OpenSim
         {
             // Called from base.StartUp()
 
-            Watchdog.JobEngine.Start();
+            IConfig startupConfig = Config.Configs["Startup"];
+            if (startupConfig != null && startupConfig.GetBoolean("JobEngineEnabled", true))
+                Watchdog.JobEngine.Start();
 
             m_httpServerPort = m_networkServersInfo.HttpListenerPort;
             SceneManager.OnRestartSim += HandleRestartRegion;

bin/OpenSimDefaults.ini

@@ -57,6 +57,10 @@
     ; when running with the SmartThreadPool option above
     MaxPoolThreads = 300
 
+    ; Allow certain jobs to be run consecutively in a job engine rather than always concurrently.
+    ; This improves performance in regions with large numbers of connections (in the hundreds).
+    JobEngineEnabled = true
+
     ; Plugin Registry Location
     ; Set path to directory for plugin registry. Information about the 
     ; registered repositories and installed plugins will be stored here.