DefaultVelocityManager's getVelocityEngine() method seems to be taking too long to execute

According to Ludovic on mailing list (see http://markmail.org/thread/na33ve23kvgjjlul):

Velocity is clearly quite expensive. Now I see particularly:

8.5% - com.xpn.xwiki.render.DefaultVelocityManager.getVelocityEngine

Would this mean we are spending 8,5% of the time getting the velocity
engine to use ?
This sounds a lot.

One reason I could see is that this method is synchronized and thus when there are lots of threads, they'll wait to get the lock on the object.