--- old/src/share/vm/gc_implementation/g1/concurrentMark.cpp 2014-04-29 14:52:35.371186125 +0200 +++ new/src/share/vm/gc_implementation/g1/concurrentMark.cpp 2014-04-29 14:52:35.231012337 +0200 @@ -819,7 +819,7 @@ // false before we start remark. At this point we should also be // in a STW phase. assert(!concurrent_marking_in_progress(), "invariant"); - assert(_finger == _heap_end, + assert(out_of_regions(), err_msg("only way to get here: _finger: "PTR_FORMAT", _heap_end: "PTR_FORMAT, _finger, _heap_end)); update_g1_committed(true); --- old/src/share/vm/gc_implementation/g1/concurrentMark.hpp 2014-04-29 14:52:36.172025105 +0200 +++ new/src/share/vm/gc_implementation/g1/concurrentMark.hpp 2014-04-29 14:52:36.041961873 +0200 @@ -542,8 +542,12 @@ // frequently. HeapRegion* claim_region(uint worker_id); - // It determines whether we've run out of regions to scan - bool out_of_regions() { return _finger == _heap_end; } + // It determines whether we've run out of regions to scan. Note that + // the finger can point past the heap end in case the heap was expanded + // to satisfy an allocation without doing a GC. This is fine, because all + // objects in those regions will be considered live anyway because of + // SATB guarantees (i.e. their TAMS will be equal to bottom). + bool out_of_regions() { return _finger >= _heap_end; } // Returns the task with the given id CMTask* task(int id) {