src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp

rev 7558 : 8048179: Early reclaim of large objects that are referenced by a few objects
Summary:
Reviewed-by:
rev 7559 : imported patch bengt-review
rev 7560 : [mq]: bengt-review2

*** 2067,2077 ****
      G1StringDedup::stop();
    }
  }
  
  void G1CollectedHeap::clear_humongous_is_live_table() {
!   guarantee(G1ReclaimDeadHumongousObjectsAtYoungGC, "Should only be called if true");
    _humongous_is_live.clear();
  }
  
  size_t G1CollectedHeap::conservative_max_heap_alignment() {
    return HeapRegion::max_region_size();
--- 2067,2077 ----
      G1StringDedup::stop();
    }
  }
  
  void G1CollectedHeap::clear_humongous_is_live_table() {
!   guarantee(G1EagerReclaimHumongousObjects, "Should only be called if true");
    _humongous_is_live.clear();
  }
  
  size_t G1CollectedHeap::conservative_max_heap_alignment() {
    return HeapRegion::max_region_size();
*** 3493,3503 ****
  
    bool humongous_region_is_candidate(uint index) {
      HeapRegion* region = G1CollectedHeap::heap()->region_at(index);
      assert(region->is_starts_humongous(), "Must start a humongous object");
      HeapRegionRemSet* const rset = region->rem_set();
!     bool const allow_stale_refs = G1ReclaimDeadHumongousObjectsWithStaleRefsAtYoungGC;
      return !oop(region->bottom())->is_objArray() &&
             ((allow_stale_refs && rset->occupancy_less_or_equal_than(G1RSetSparseRegionEntries)) ||
              (!allow_stale_refs && rset->is_empty()));
    }
  
--- 3493,3503 ----
  
    bool humongous_region_is_candidate(uint index) {
      HeapRegion* region = G1CollectedHeap::heap()->region_at(index);
      assert(region->is_starts_humongous(), "Must start a humongous object");
      HeapRegionRemSet* const rset = region->rem_set();
!     bool const allow_stale_refs = G1EagerReclaimHumongousObjectsWithStaleRefs;
      return !oop(region->bottom())->is_objArray() &&
             ((allow_stale_refs && rset->occupancy_less_or_equal_than(G1RSetSparseRegionEntries)) ||
              (!allow_stale_refs && rset->is_empty()));
    }
  
*** 3551,3561 ****
  
    void flush_rem_set_entries() { _dcq.flush(); }
  };
  
  void G1CollectedHeap::register_humongous_regions_with_in_cset_fast_test() {
!   if (!G1ReclaimDeadHumongousObjectsAtYoungGC) {
      g1_policy()->phase_times()->record_fast_reclaim_humongous_stats(0.0, 0, 0);
      return;
    }
    double time = os::elapsed_counter();
  
--- 3551,3561 ----
  
    void flush_rem_set_entries() { _dcq.flush(); }
  };
  
  void G1CollectedHeap::register_humongous_regions_with_in_cset_fast_test() {
!   if (!G1EagerReclaimHumongousObjects) {
      g1_policy()->phase_times()->record_fast_reclaim_humongous_stats(0.0, 0, 0);
      return;
    }
    double time = os::elapsed_counter();
  
*** 3566,3576 ****
    g1_policy()->phase_times()->record_fast_reclaim_humongous_stats(time,
                                                                    cl.total_humongous(),
                                                                    cl.candidate_humongous());
    _has_humongous_reclaim_candidates = cl.candidate_humongous() > 0;
  
!   if (_has_humongous_reclaim_candidates || G1TraceReclaimDeadHumongousObjectsAtYoungGC) {
      clear_humongous_is_live_table();
    }
  
    // Finally flush all remembered set entries to re-check into the global DCQS.
    cl.flush_rem_set_entries();
--- 3566,3576 ----
    g1_policy()->phase_times()->record_fast_reclaim_humongous_stats(time,
                                                                    cl.total_humongous(),
                                                                    cl.candidate_humongous());
    _has_humongous_reclaim_candidates = cl.candidate_humongous() > 0;
  
!   if (_has_humongous_reclaim_candidates || G1TraceEagerReclaimHumongousObjects) {
      clear_humongous_is_live_table();
    }
  
    // Finally flush all remembered set entries to re-check into the global DCQS.
    cl.flush_rem_set_entries();
*** 6182,6192 ****
      // are currently allocated into.
      uint region_idx = r->hrm_index();
      if (g1h->humongous_is_live(region_idx) ||
          g1h->humongous_region_is_always_live(region_idx)) {
  
!       if (G1TraceReclaimDeadHumongousObjectsAtYoungGC) {
          gclog_or_tty->print_cr("Live humongous region %u size "SIZE_FORMAT" start "PTR_FORMAT" length "UINT32_FORMAT" with remset "SIZE_FORMAT" code roots "SIZE_FORMAT" is marked %d live-other %d obj array %d",
                                 region_idx,
                                 obj->size()*HeapWordSize,
                                 r->bottom(),
                                 r->region_num(),
--- 6182,6192 ----
      // are currently allocated into.
      uint region_idx = r->hrm_index();
      if (g1h->humongous_is_live(region_idx) ||
          g1h->humongous_region_is_always_live(region_idx)) {
  
!       if (G1TraceEagerReclaimHumongousObjects) {
          gclog_or_tty->print_cr("Live humongous region %u size "SIZE_FORMAT" start "PTR_FORMAT" length "UINT32_FORMAT" with remset "SIZE_FORMAT" code roots "SIZE_FORMAT" is marked %d live-other %d obj array %d",
                                 region_idx,
                                 obj->size()*HeapWordSize,
                                 r->bottom(),
                                 r->region_num(),
*** 6203,6213 ****
  
      guarantee(!obj->is_objArray(),
                err_msg("Eagerly reclaiming object arrays is not supported, but the object "PTR_FORMAT" is.",
                        r->bottom()));
  
!     if (G1TraceReclaimDeadHumongousObjectsAtYoungGC) {
        gclog_or_tty->print_cr("Dead humongous region %u size "SIZE_FORMAT" start "PTR_FORMAT" length "UINT32_FORMAT" with remset "SIZE_FORMAT" code roots "SIZE_FORMAT" is marked %d live-other %d obj array %d",
                               region_idx,
                               obj->size()*HeapWordSize,
                               r->bottom(),
                               r->region_num(),
--- 6203,6213 ----
  
      guarantee(!obj->is_objArray(),
                err_msg("Eagerly reclaiming object arrays is not supported, but the object "PTR_FORMAT" is.",
                        r->bottom()));
  
!     if (G1TraceEagerReclaimHumongousObjects) {
        gclog_or_tty->print_cr("Dead humongous region %u size "SIZE_FORMAT" start "PTR_FORMAT" length "UINT32_FORMAT" with remset "SIZE_FORMAT" code roots "SIZE_FORMAT" is marked %d live-other %d obj array %d",
                               region_idx,
                               obj->size()*HeapWordSize,
                               r->bottom(),
                               r->region_num(),
*** 6244,6255 ****
  };
  
  void G1CollectedHeap::eagerly_reclaim_humongous_regions() {
    assert_at_safepoint(true);
  
!   if (!G1ReclaimDeadHumongousObjectsAtYoungGC ||
!       (!_has_humongous_reclaim_candidates && !G1TraceReclaimDeadHumongousObjectsAtYoungGC)) {
      g1_policy()->phase_times()->record_fast_reclaim_humongous_time_ms(0.0, 0);
      return;
    }
  
    double start_time = os::elapsedTime();
--- 6244,6255 ----
  };
  
  void G1CollectedHeap::eagerly_reclaim_humongous_regions() {
    assert_at_safepoint(true);
  
!   if (!G1EagerReclaimHumongousObjects ||
!       (!_has_humongous_reclaim_candidates && !G1TraceEagerReclaimHumongousObjects)) {
      g1_policy()->phase_times()->record_fast_reclaim_humongous_time_ms(0.0, 0);
      return;
    }
  
    double start_time = os::elapsedTime();