Issue

• After moving to Java 7, our JVM frequently crashes in CMS operations:

Stack: [0x00000000,0x00000000],  sp=0xfb77f4c0,  free space=4120061k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V  [libjvm.so+0x95f214]  void ParRootScanWithBarrierTwoGensClosure::do_oop(oopDesc**)+0xc0
V  [libjvm.so+0x92e554]  int objArrayKlass::oop_oop_iterate_nv_m(oopDesc*,FilteringClosure*,MemRegion)+0xb8
V  [libjvm.so+0x4f3dd4]  void FreeListSpace_DCTOC::walk_mem_region_with_cl_par(MemRegion,HeapWord*,HeapWord*,FilteringClosure*)+0x384
V  [libjvm.so+0x4f3a48]  void FreeListSpace_DCTOC::walk_mem_region_with_cl(MemRegion,HeapWord*,HeapWord*,FilteringClosure*)+0x74
V  [libjvm.so+0x9e9e34]  void Filtering_DCTOC::walk_mem_region(MemRegion,HeapWord*,HeapWord*)+0x64
V  [libjvm.so+0x9e9c14]  void DirtyCardToOopClosure::do_MemRegion(MemRegion)+0xfc
V  [libjvm.so+0x4785f4]  void ClearNoncleanCardWrapper::do_MemRegion(MemRegion)+0x194
V  [libjvm.so+0x95aa30]  void CardTableModRefBS::non_clean_card_iterate_parallel_work(Space*,MemRegion,OopsInGenClosure*,CardTableRS*,int)+0x390
V  [libjvm.so+0x4774fc]  void CardTableModRefBS::non_clean_card_iterate_possibly_parallel(Space*,MemRegion,OopsInGenClosure*,CardTableRS*)+0x50
V  [libjvm.so+0x4786b8]  void CardTableRS::younger_refs_in_space_iterate(Space*,OopsInGenClosure*)+0x38
V  [libjvm.so+0x529da0]  void ConcurrentMarkSweepGeneration::younger_refs_iterate(OopsInGenClosure*)+0x40
V  [libjvm.so+0x5f5f3c]  void GenCollectedHeap::gen_process_strong_roots(int,bool,bool,bool,SharedHeap::ScanningOption,OopsInGenClosure*,bool,OopsInGenClosure*)+0x194
V  [libjvm.so+0x95fe00]  void ParNewGenTask::work(unsigned)+0x13c
V  [libjvm.so+0xac9c38]  void GangWorker::loop()+0xa4
V  [libjvm.so+0x9438c0]  java_start+0x338