Hello developers,

When using apr_pollset_poll, I missed the Edge Trigered behavior. In the epoll manual it's the recommended way of use.  Epoll is most efficient when used with Edge Trigered interface... It's Linux specific it's not portable but including extra APR_ flags won't hurt. The Platforms that do not support it will simply take no effect. The patch is included, your commens && questions are welcome. Note*  The patch is against apr 1.2.8, but it will cleanly apply against SVN, tested.

Comments && questions welcome.