update readme.

@@ -572,6 +572,7 @@ Remark:
 (b) The CLI architecture is similar to this, instead, cli process
 (b) The CLI architecture is similar to this, instead, cli process
     will collect informations from all stream process, master process
     will collect informations from all stream process, master process
     only send signals to child processes.
     only send signals to child processes.
+(c) Maybe multiple thread is ok? By winlin.
 </pre>
 </pre>
 
 
 ### Bandwidth Test Workflow
 ### Bandwidth Test Workflow