I really like the profiling options in GHC, but I wonder if there's any good way of improving heap profiling speed? I've tried using -i to reduce the number of measurements, but it didn't seem to help a lot.
I see an order of magnitude speed degradation with heap profiling, which is slightly annoying, since it is with large runs heap consumption starts to become troublesome :-)
Any tricks I ought to know about?
Have you tried one of the recent snapshots? Heap profiling was overhauled significantly since the 5.02 branch, and one of the things I did was to make the -i option work better. Previously profiling was forced to use the 2-space collector, but now it can use generational collection and just force a major GC before it does a heap census. If you're stuck with 5.02.x, you can try increasing the size of the allocation area with (say) -A4m to increase the time between garbage collections. Cheers, Simon