src/share/vm/gc_implementation/g1/g1CollectorPolicy.hpp

rev 3486 : 7185699: G1: Prediction model discrepancies
Summary: Correct the result value of G1CollectedHeap::pending_card_num(). Change the code that calculates the GC efficiency of a non-young heap region to use historical data from mixed GCs and the actual number of live bytes when predicting how long it would take to collect the region.
Reviewed-by:

*** 493,508 ****
    double accum_yg_surv_rate_pred(int age) {
      return _short_lived_surv_rate_group->accum_surv_rate_pred(age);
    }
  
  private:
-   size_t _bytes_in_collection_set_before_gc;
-   size_t _bytes_copied_during_gc;
- 
-   // Used to count used bytes in CS.
-   friend class CountCSClosure;
- 
    // Statistics kept per GC stoppage, pause or full.
    TruncatedSeq* _recent_prev_end_times_for_all_gcs_sec;
  
    // Add a new GC of the given duration and end time to the record.
    void update_recent_gc_times(double end_time_sec, double elapsed_ms);
--- 493,502 ----
*** 512,524 ****
    // set at the start of the pause.
    HeapRegion* _collection_set;
  
    // The number of bytes in the collection set before the pause. Set from
    // the incrementally built collection set at the start of an evacuation
!   // pause.
    size_t _collection_set_bytes_used_before;
  
    // The associated information that is maintained while the incremental
    // collection set is being built with young regions. Used to populate
    // the recorded info for the evacuation pause.
  
    enum CSetBuildType {
--- 506,522 ----
    // set at the start of the pause.
    HeapRegion* _collection_set;
  
    // The number of bytes in the collection set before the pause. Set from
    // the incrementally built collection set at the start of an evacuation
!   // pause, and incremented in finalize_cset() when adding old regions
!   // (if any) to the collection set.
    size_t _collection_set_bytes_used_before;
  
+   // The number of bytes copied during the GC.
+   size_t _bytes_copied_during_gc;
+ 
    // The associated information that is maintained while the incremental
    // collection set is being built with young regions. Used to populate
    // the recorded info for the evacuation pause.
  
    enum CSetBuildType {
*** 644,656 ****
    // given free space (expressed by base_free_regions).  It is used by
    // calculate_young_list_target_length().
    bool predict_will_fit(uint young_length, double base_time_ms,
                          uint base_free_regions, double target_pause_time_ms);
  
-   // Count the number of bytes used in the CS.
-   void count_CS_bytes_used();
- 
  public:
  
    G1CollectorPolicy();
  
    virtual G1CollectorPolicy* as_g1_policy() { return this; }
--- 642,651 ----
*** 664,677 ****
    // Check the current value of the young list RSet lengths and
    // compare it against the last prediction. If the current value is
    // higher, recalculate the young list target length prediction.
    void revise_young_list_target_length_if_necessary();
  
-   size_t bytes_in_collection_set() {
-     return _bytes_in_collection_set_before_gc;
-   }
- 
    // This should be called after the heap is resized.
    void record_new_heap_size(uint new_number_of_regions);
  
    void init();
  
--- 659,668 ----