Does MAT support analysis of heap dumps corresponding to hotspot JVM with CompressedOop enabled?
We see significant difference when comparing a heap in yourkit with MAT. yourkit supports reading CompressedOop heap's, need to find out if MAT does and if not, maybe this is the reason for the delta in reported memory consumption.
The Hprof parser doesn't currently take account of -XX:+UseCompresssedOops
I'm busy doing other things, so this isn't a priority for me at the moment. However, Memory Analyzer is an open source project, so you do have access to the source to make changes. I've put some comments in bug 346317 for how it could be solved. We'd welcome a contribution under the Eclipse Public License for this.