[Haskell-cafe] Current heap size and other runtime statistics -- API for accessing in GHC?

Hi cafe, The rtsopts (-s etc) can provide some nice debugging information regarding memory management. And System.Mem.performGC can initiate garbage collection. But are there APIs for querying the current state of the heap? I've googled and come up dry. In this case I'm running benchmarks and for the sake of fair comparison I want to make sure that everything from a previous run is cleaned up before the next run. Thanks, -Ryan