TODO:

== current problems / short term
   - symux queues rrd values for a particular time. Cheers to Jean-Grard
     Pailloncy for the suggestion.

- rewrite sm_proc.c, don't count shared pages twice

- check for availability of rrd before compilation
- release probe memory at config reload
- same for pagetob and friends

== longer term
- change rrd to accommodate batch updates
