This problem is specially visible in a larger heap dumps >600M., where opening heap dump is significantly slower for second half (opening progress is bigger than 50%). The computation of the references is also significantly slower (compared to other Operating systems).
Fixed in profiler-main
user: Tomas Hurka <firstname.lastname@example.org>
date: Wed Feb 01 13:46:49 2012 +0100
summary: bugfix #207728, use FileChannel.MapMode.PRIVATE on Linux
the fix was tested with ~ 1G heap dump and the loading heap dump is now down to 37 seconds from 10 minutes and computation of references is down to 80 sec. from 11 minutes.