7143511: G1: Another instance of high GC Worker Other time (50ms)
Summary: Tiered compilation has increased the number of nmethods in the code cache. This has, in turn, significantly increased the number of marked nmethods processed during the StrongRootsScope destructor. Create a specialized version of CodeBlobToOopClosure for G1 which places only those nmethods that contain pointers into the collection set on to the marked nmethods list.
Reviewed-by: iveresov, tonyp
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#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTG1REFINETHREAD_HPP
#define SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTG1REFINETHREAD_HPP
#include "gc_implementation/shared/concurrentGCThread.hpp"
// Forward Decl.
class ConcurrentG1Refine;
// The G1 Concurrent Refinement Thread (could be several in the future).
class ConcurrentG1RefineThread: public ConcurrentGCThread {
friend class VMStructs;
friend class G1CollectedHeap;
double _vtime_start; // Initial virtual time.
double _vtime_accum; // Initial virtual time.
int _worker_id;
int _worker_id_offset;
// The refinement threads collection is linked list. A predecessor can activate a successor
// when the number of the rset update buffer crosses a certain threshold. A successor
// would self-deactivate when the number of the buffers falls below the threshold.
bool _active;
ConcurrentG1RefineThread* _next;
Monitor* _monitor;
ConcurrentG1Refine* _cg1r;
int _thread_threshold_step;
// This thread activation threshold
int _threshold;
// This thread deactivation threshold
int _deactivation_threshold;
void sample_young_list_rs_lengths();
void run_young_rs_sampling();
void wait_for_completed_buffers();
void set_active(bool x) { _active = x; }
bool is_active();
void activate();
void deactivate();
// For use by G1CollectedHeap, which is a friend.
static SuspendibleThreadSet* sts() { return &_sts; }
public:
virtual void run();
// Constructor
ConcurrentG1RefineThread(ConcurrentG1Refine* cg1r, ConcurrentG1RefineThread* next,
int worker_id_offset, int worker_id);
void initialize();
// Printing
void print() const;
void print_on(outputStream* st) const;
// Total virtual time so far.
double vtime_accum() { return _vtime_accum; }
ConcurrentG1Refine* cg1r() { return _cg1r; }
// Yield for GC
void yield();
// shutdown
void stop();
};
#endif // SHARE_VM_GC_IMPLEMENTATION_G1_CONCURRENTG1REFINETHREAD_HPP