[mat-dev] GarbageCleaner phase code

[Jason Koch <jkoch@xxxxxxxxxxx>]

Hi all,

Looking for some input on suitability to raise a bug and submit this change. If you can advise any additional specific tests to run I will be happy to build them out and execute them..

Results on a 73GB file over 5 runs on a 48GB 8+8cores machine are here, in brief it is 2-4x faster for large heaps:

https://gist.github.com/jasonk000/9f31e2446a84b56f11d494c146969e7b

I understand that my last round of commits required an additional pass of discussion on memory footprint. I believe the memory footprint here would be reduced as it merges the maps during generation (C maps, scaling to C cores) vs previous approach (N maps, when the processing was split into N chunks and scaled to object heap). All existing functional tests work ok.

There are a sequence of five commits presented here:

https://github.com/jasonk000/eclipse-mat/compare/gc-opt

Thanks

Jason