how to know which user is using most MySQL

I see my top process is 'mysqld' which seems to be pushing the server load over 1.0 and sometimes over 2.0, I would like to moce the heavy mysql users to another server, but how can I track down which user has the most mysql usage? (with the PID or 'user' I just see the root process for 'mysqld')

 

 

 

 

Top