Nightly testing for 2014-01-07 triggered the follwoing assert:

# Internal Error (/opt/jprt/T/P1/155441.amurillo/s/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp:2069), pid=6893, tid=4152105840
# assert(_hrs.max_length() == _expansion_regions) failed: max length: 14784 expansion regions: 2496

This is in G1CollectedHeap::initialize() while we are setting up the heap.

 _hrs.max_length() contains the number of regions that we have set up.
_expansion_regions represents the number of regions based on MaxHeapSize.

The assert says that these values should be the same, which of course makes sense. In this case we have _hrs.max_length() > _expansion_regions, which looks like we for some reason set up more regions than was required to cover the MaxHeapSize.


Impact=M, the crash happens at startup. No loss of data.
Likelihood=L, we have not seen this before so it is likely that this has to do with some condition on the specific machine. Low memory?
Workaround=H, Unknown at the moment.

ILW=MLH -> P4