Merge

hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/cmsCollectorPolicy.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2007-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -32,11 +32,10 @@ class ConcurrentMarkSweepPolicy : public TwoGenerationCollectorPolicy {
   ConcurrentMarkSweepPolicy* as_concurrent_mark_sweep_policy() { return this; }
 
   void initialize_gc_policy_counters();
-#if 1
+
   virtual void initialize_size_policy(size_t init_eden_size,
                                       size_t init_promo_size,
                                       size_t init_survivor_size);
-#endif
 
   // Returns true if the incremental mode is enabled.
   virtual bool has_soft_ended_eden();

hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -1815,8 +1815,19 @@ NOT_PRODUCT(
     do_compaction_work(clear_all_soft_refs);
 
     // Has the GC time limit been exceeded?
-    check_gc_time_limit();
+    DefNewGeneration* young_gen = _young_gen->as_DefNewGeneration();
-
+    size_t max_eden_size = young_gen->max_capacity() -
+                           young_gen->to()->capacity() -
+                           young_gen->from()->capacity();
+    GenCollectedHeap* gch = GenCollectedHeap::heap();
+    GCCause::Cause gc_cause = gch->gc_cause();
+    size_policy()->check_gc_overhead_limit(_young_gen->used(),
+                                           young_gen->eden()->used(),
+                                           _cmsGen->max_capacity(),
+                                           max_eden_size,
+                                           full,
+                                           gc_cause,
+                                           gch->collector_policy());
   } else {
     do_mark_sweep_work(clear_all_soft_refs, first_state,
       should_start_over);
@@ -1828,55 +1839,6 @@ NOT_PRODUCT(
   return;
 }
 
-void CMSCollector::check_gc_time_limit() {
-
-  // Ignore explicit GC's.  Exiting here does not set the flag and
-  // does not reset the count.  Updating of the averages for system
-  // GC's is still controlled by UseAdaptiveSizePolicyWithSystemGC.
-  GCCause::Cause gc_cause = GenCollectedHeap::heap()->gc_cause();
-  if (GCCause::is_user_requested_gc(gc_cause) ||
-      GCCause::is_serviceability_requested_gc(gc_cause)) {
-    return;
-  }
-
-  // Calculate the fraction of the CMS generation was freed during
-  // the last collection.
-  // Only consider the STW compacting cost for now.
-  //
-  // Note that the gc time limit test only works for the collections
-  // of the young gen + tenured gen and not for collections of the
-  // permanent gen.  That is because the calculation of the space
-  // freed by the collection is the free space in the young gen +
-  // tenured gen.
-
-  double fraction_free =
-    ((double)_cmsGen->free())/((double)_cmsGen->max_capacity());
-  if ((100.0 * size_policy()->compacting_gc_cost()) >
-         ((double) GCTimeLimit) &&
-        ((fraction_free * 100) < GCHeapFreeLimit)) {
-    size_policy()->inc_gc_time_limit_count();
-    if (UseGCOverheadLimit &&
-        (size_policy()->gc_time_limit_count() >
-         AdaptiveSizePolicyGCTimeLimitThreshold)) {
-      size_policy()->set_gc_time_limit_exceeded(true);
-      // Avoid consecutive OOM due to the gc time limit by resetting
-      // the counter.
-      size_policy()->reset_gc_time_limit_count();
-      if (PrintGCDetails) {
-        gclog_or_tty->print_cr("      GC is exceeding overhead limit "
-          "of %d%%", GCTimeLimit);
-      }
-    } else {
-      if (PrintGCDetails) {
-        gclog_or_tty->print_cr("      GC would exceed overhead limit "
-          "of %d%%", GCTimeLimit);
-      }
-    }
-  } else {
-    size_policy()->reset_gc_time_limit_count();
-  }
-}
-
 // Resize the perm generation and the tenured generation
 // after obtaining the free list locks for the
 // two generations.
@@ -6182,6 +6144,11 @@ void CMSCollector::reset(bool asynch) {
       }
       curAddr = chunk.end();
     }
+    // A successful mostly concurrent collection has been done.
+    // Because only the full (i.e., concurrent mode failure) collections
+    // are being measured for gc overhead limits, clean the "near" flag
+    // and count.
+    sp->reset_gc_overhead_limit_count();
     _collectorState = Idling;
   } else {
     // already have the lock

hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -570,10 +570,6 @@ class CMSCollector: public CHeapObj {
   ConcurrentMarkSweepPolicy* _collector_policy;
   ConcurrentMarkSweepPolicy* collector_policy() { return _collector_policy; }
 
-  // Check whether the gc time limit has been
-  // exceeded and set the size policy flag
-  // appropriately.
-  void check_gc_time_limit();
   // XXX Move these to CMSStats ??? FIX ME !!!
   elapsedTimer _inter_sweep_timer;   // time between sweeps
   elapsedTimer _intra_sweep_timer;   // time _in_ sweeps

hotspot/src/share/vm/gc_implementation/g1/concurrentG1RefineThread.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -69,9 +69,9 @@ void ConcurrentG1RefineThread::sample_young_list_rs_lengths() {
   G1CollectorPolicy* g1p = g1h->g1_policy();
   if (g1p->adaptive_young_list_length()) {
     int regions_visited = 0;
-    g1h->young_list_rs_length_sampling_init();
+    g1h->young_list()->rs_length_sampling_init();
-    while (g1h->young_list_rs_length_sampling_more()) {
+    while (g1h->young_list()->rs_length_sampling_more()) {
-      g1h->young_list_rs_length_sampling_next();
+      g1h->young_list()->rs_length_sampling_next();
       ++regions_visited;
 
       // we try to yield every time we visit 10 regions
@@ -162,6 +162,7 @@ void ConcurrentG1RefineThread::run() {
   if (_worker_id >= cg1r()->worker_thread_num()) {
     run_young_rs_sampling();
     terminate();
+    return;
   }
 
   _vtime_start = os::elapsedVTime();

hotspot/src/share/vm/gc_implementation/g1/concurrentMark.cpp

@@ -767,7 +767,8 @@ void ConcurrentMark::checkpointRootsInitialPre() {
   _has_aborted = false;
 
   if (G1PrintReachableAtInitialMark) {
-    print_reachable(true, "before");
+    print_reachable("at-cycle-start",
+                    true /* use_prev_marking */, true /* all */);
   }
 
   // Initialise marking structures. This has to be done in a STW phase.
@@ -1979,19 +1980,21 @@ void ConcurrentMark::checkpointRootsFinalWork() {
 
 #ifndef PRODUCT
 
-class ReachablePrinterOopClosure: public OopClosure {
+class PrintReachableOopClosure: public OopClosure {
 private:
   G1CollectedHeap* _g1h;
   CMBitMapRO*      _bitmap;
   outputStream*    _out;
   bool             _use_prev_marking;
+  bool             _all;
 
 public:
-  ReachablePrinterOopClosure(CMBitMapRO*   bitmap,
+  PrintReachableOopClosure(CMBitMapRO*   bitmap,
-                             outputStream* out,
+                           outputStream* out,
-                             bool          use_prev_marking) :
+                           bool          use_prev_marking,
+                           bool          all) :
     _g1h(G1CollectedHeap::heap()),
-    _bitmap(bitmap), _out(out), _use_prev_marking(use_prev_marking) { }
+    _bitmap(bitmap), _out(out), _use_prev_marking(use_prev_marking), _all(all) { }
 
   void do_oop(narrowOop* p) { do_oop_work(p); }
   void do_oop(      oop* p) { do_oop_work(p); }
@@ -2001,9 +2004,11 @@ public:
     const char* str = NULL;
     const char* str2 = "";
 
-    if (!_g1h->is_in_g1_reserved(obj))
+    if (obj == NULL) {
-      str = "outside G1 reserved";
+      str = "";
-    else {
+    } else if (!_g1h->is_in_g1_reserved(obj)) {
+      str = " O";
+    } else {
       HeapRegion* hr  = _g1h->heap_region_containing(obj);
       guarantee(hr != NULL, "invariant");
       bool over_tams = false;
@@ -2012,74 +2017,67 @@ public:
       } else {
         over_tams = hr->obj_allocated_since_next_marking(obj);
       }
+      bool marked = _bitmap->isMarked((HeapWord*) obj);
 
       if (over_tams) {
-        str = "over TAMS";
+        str = " >";
-        if (_bitmap->isMarked((HeapWord*) obj)) {
+        if (marked) {
           str2 = " AND MARKED";
         }
-      } else if (_bitmap->isMarked((HeapWord*) obj)) {
+      } else if (marked) {
-        str = "marked";
+        str = " M";
       } else {
-        str = "#### NOT MARKED ####";
+        str = " NOT";
       }
     }
 
-    _out->print_cr("    "PTR_FORMAT" contains "PTR_FORMAT" %s%s",
+    _out->print_cr("  "PTR_FORMAT": "PTR_FORMAT"%s%s",
                    p, (void*) obj, str, str2);
   }
 };
 
-class ReachablePrinterClosure: public BitMapClosure {
+class PrintReachableObjectClosure : public ObjectClosure {
 private:
   CMBitMapRO*   _bitmap;
   outputStream* _out;
   bool          _use_prev_marking;
+  bool          _all;
+  HeapRegion*   _hr;
 
 public:
-  ReachablePrinterClosure(CMBitMapRO*   bitmap,
+  PrintReachableObjectClosure(CMBitMapRO*   bitmap,
-                          outputStream* out,
+                              outputStream* out,
-                          bool          use_prev_marking) :
+                              bool          use_prev_marking,
-    _bitmap(bitmap), _out(out), _use_prev_marking(use_prev_marking) { }
+                              bool          all,
-
+                              HeapRegion*   hr) :
-  bool do_bit(size_t offset) {
+    _bitmap(bitmap), _out(out),
-    HeapWord* addr = _bitmap->offsetToHeapWord(offset);
+    _use_prev_marking(use_prev_marking), _all(all), _hr(hr) { }
-    ReachablePrinterOopClosure oopCl(_bitmap, _out, _use_prev_marking);
-
-    _out->print_cr("  obj "PTR_FORMAT", offset %10d (marked)", addr, offset);
-    oop(addr)->oop_iterate(&oopCl);
-    _out->print_cr("");
-
-    return true;
-  }
-};
-
-class ObjInRegionReachablePrinterClosure : public ObjectClosure {
-private:
-  CMBitMapRO*   _bitmap;
-  outputStream* _out;
-  bool          _use_prev_marking;
-
-public:
-  ObjInRegionReachablePrinterClosure(CMBitMapRO*   bitmap,
-                                     outputStream* out,
-                                     bool          use_prev_marking) :
-    _bitmap(bitmap), _out(out), _use_prev_marking(use_prev_marking) { }
 
   void do_object(oop o) {
-    ReachablePrinterOopClosure oopCl(_bitmap, _out, _use_prev_marking);
+    bool over_tams;
+    if (_use_prev_marking) {
+      over_tams = _hr->obj_allocated_since_prev_marking(o);
+    } else {
+      over_tams = _hr->obj_allocated_since_next_marking(o);
+    }
+    bool marked = _bitmap->isMarked((HeapWord*) o);
+    bool print_it = _all || over_tams || marked;
 
-    _out->print_cr("  obj "PTR_FORMAT" (over TAMS)", (void*) o);
+    if (print_it) {
-    o->oop_iterate(&oopCl);
+      _out->print_cr(" "PTR_FORMAT"%s",
-    _out->print_cr("");
+                     o, (over_tams) ? " >" : (marked) ? " M" : "");
+      PrintReachableOopClosure oopCl(_bitmap, _out, _use_prev_marking, _all);
+      o->oop_iterate(&oopCl);
+    }
   }
 };
 
-class RegionReachablePrinterClosure : public HeapRegionClosure {
+class PrintReachableRegionClosure : public HeapRegionClosure {
 private:
   CMBitMapRO*   _bitmap;
   outputStream* _out;
   bool          _use_prev_marking;
+  bool          _all;
 
 public:
   bool doHeapRegion(HeapRegion* hr) {
@@ -2094,22 +2092,35 @@ public:
     }
     _out->print_cr("** ["PTR_FORMAT", "PTR_FORMAT"] top: "PTR_FORMAT" "
                    "TAMS: "PTR_FORMAT, b, e, t, p);
-    _out->print_cr("");
+    _out->cr();
 
-    ObjInRegionReachablePrinterClosure ocl(_bitmap, _out, _use_prev_marking);
+    HeapWord* from = b;
-    hr->object_iterate_mem_careful(MemRegion(p, t), &ocl);
+    HeapWord* to   = t;
+
+    if (to > from) {
+      _out->print_cr("Objects in ["PTR_FORMAT", "PTR_FORMAT"]", from, to);
+      _out->cr();
+      PrintReachableObjectClosure ocl(_bitmap, _out,
+                                      _use_prev_marking, _all, hr);
+      hr->object_iterate_mem_careful(MemRegion(from, to), &ocl);
+      _out->cr();
+    }
 
     return false;
   }
 
-  RegionReachablePrinterClosure(CMBitMapRO*   bitmap,
+  PrintReachableRegionClosure(CMBitMapRO*   bitmap,
-                                outputStream* out,
+                              outputStream* out,
-                                bool          use_prev_marking) :
+                              bool          use_prev_marking,
-    _bitmap(bitmap), _out(out), _use_prev_marking(use_prev_marking) { }
+                              bool          all) :
+    _bitmap(bitmap), _out(out), _use_prev_marking(use_prev_marking), _all(all) { }
 };
 
-void ConcurrentMark::print_reachable(bool use_prev_marking, const char* str) {
+void ConcurrentMark::print_reachable(const char* str,
-  gclog_or_tty->print_cr("== Doing reachable object dump... ");
+                                     bool use_prev_marking,
+                                     bool all) {
+  gclog_or_tty->cr();
+  gclog_or_tty->print_cr("== Doing heap dump... ");
 
   if (G1PrintReachableBaseFile == NULL) {
     gclog_or_tty->print_cr("  #### error: no base file defined");
@@ -2144,19 +2155,14 @@ void ConcurrentMark::print_reachable(bool use_prev_marking, const char* str) {
   out->print_cr("-- USING %s", (use_prev_marking) ? "PTAMS" : "NTAMS");
   out->cr();
 
-  RegionReachablePrinterClosure rcl(bitmap, out, use_prev_marking);
+  out->print_cr("--- ITERATING OVER REGIONS");
-  out->print_cr("--- ITERATING OVER REGIONS WITH TAMS < TOP");
   out->cr();
+  PrintReachableRegionClosure rcl(bitmap, out, use_prev_marking, all);
   _g1h->heap_region_iterate(&rcl);
   out->cr();
 
-  ReachablePrinterClosure cl(bitmap, out, use_prev_marking);
-  out->print_cr("--- ITERATING OVER MARKED OBJECTS ON THE BITMAP");
-  out->cr();
-  bitmap->iterate(&cl);
-  out->cr();
-
   gclog_or_tty->print_cr("  done");
+  gclog_or_tty->flush();
 }
 
 #endif // PRODUCT

hotspot/src/share/vm/gc_implementation/g1/concurrentMark.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -652,11 +652,24 @@ public:
   // we do nothing.
   void markAndGrayObjectIfNecessary(oop p);
 
-  // This iterates over the marking bitmap (either prev or next) and
+  // It iterates over the heap and for each object it comes across it
-  // prints out all objects that are marked on the bitmap and indicates
+  // will dump the contents of its reference fields, as well as
-  // whether what they point to is also marked or not. It also iterates
+  // liveness information for the object and its referents. The dump
-  // the objects over TAMS (either prev or next).
+  // will be written to a file with the following name:
-  void print_reachable(bool use_prev_marking, const char* str);
+  // G1PrintReachableBaseFile + "." + str. use_prev_marking decides
+  // whether the prev (use_prev_marking == true) or next
+  // (use_prev_marking == false) marking information will be used to
+  // determine the liveness of each object / referent. If all is true,
+  // all objects in the heap will be dumped, otherwise only the live
+  // ones. In the dump the following symbols / abbreviations are used:
+  //   M : an explicitly live object (its bitmap bit is set)
+  //   > : an implicitly live object (over tams)
+  //   O : an object outside the G1 heap (typically: in the perm gen)
+  //   NOT : a reference field whose referent is not live
+  //   AND MARKED : indicates that an object is both explicitly and
+  //   implicitly live (it should be one or the other, not both)
+  void print_reachable(const char* str,
+                       bool use_prev_marking, bool all) PRODUCT_RETURN;
 
   // Clear the next marking bitmap (will be called concurrently).
   void clearNextBitmap();
@@ -720,6 +733,19 @@ public:
   // to determine whether any heap regions are located above the finger.
   void registerCSetRegion(HeapRegion* hr);
 
+  // Registers the maximum region-end associated with a set of
+  // regions with CM. Again this is used to determine whether any
+  // heap regions are located above the finger.
+  void register_collection_set_finger(HeapWord* max_finger) {
+    // max_finger is the highest heap region end of the regions currently
+    // contained in the collection set. If this value is larger than
+    // _min_finger then we need to gray objects.
+    // This routine is like registerCSetRegion but for an entire
+    // collection of regions.
+    if (max_finger > _min_finger)
+      _should_gray_objects = true;
+  }
+
   // Returns "true" if at least one mark has been completed.
   bool at_least_one_mark_complete() { return _at_least_one_mark_complete; }
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -30,7 +30,7 @@ size_t G1CollectedHeap::_humongous_object_threshold_in_words = 0;
 // turn it on so that the contents of the young list (scan-only /
 // to-be-collected) are printed at "strategic" points before / during
 // / after the collection --- this is useful for debugging
-#define SCAN_ONLY_VERBOSE 0
+#define YOUNG_LIST_VERBOSE 0
 // CURRENT STATUS
 // This file is under construction.  Search for "FIXME".
 
@@ -133,8 +133,7 @@ public:
 
 YoungList::YoungList(G1CollectedHeap* g1h)
   : _g1h(g1h), _head(NULL),
-    _scan_only_head(NULL), _scan_only_tail(NULL), _curr_scan_only(NULL),
+    _length(0),
-    _length(0), _scan_only_length(0),
     _last_sampled_rs_lengths(0),
     _survivor_head(NULL), _survivor_tail(NULL), _survivor_length(0)
 {
@@ -166,48 +165,6 @@ void YoungList::add_survivor_region(HeapRegion* hr) {
   ++_survivor_length;
 }
 
-HeapRegion* YoungList::pop_region() {
-  while (_head != NULL) {
-    assert( length() > 0, "list should not be empty" );
-    HeapRegion* ret = _head;
-    _head = ret->get_next_young_region();
-    ret->set_next_young_region(NULL);
-    --_length;
-    assert(ret->is_young(), "region should be very young");
-
-    // Replace 'Survivor' region type with 'Young'. So the region will
-    // be treated as a young region and will not be 'confused' with
-    // newly created survivor regions.
-    if (ret->is_survivor()) {
-      ret->set_young();
-    }
-
-    if (!ret->is_scan_only()) {
-      return ret;
-    }
-
-    // scan-only, we'll add it to the scan-only list
-    if (_scan_only_tail == NULL) {
-      guarantee( _scan_only_head == NULL, "invariant" );
-
-      _scan_only_head = ret;
-      _curr_scan_only = ret;
-    } else {
-      guarantee( _scan_only_head != NULL, "invariant" );
-      _scan_only_tail->set_next_young_region(ret);
-    }
-    guarantee( ret->get_next_young_region() == NULL, "invariant" );
-    _scan_only_tail = ret;
-
-    // no need to be tagged as scan-only any more
-    ret->set_young();
-
-    ++_scan_only_length;
-  }
-  assert( length() == 0, "list should be empty" );
-  return NULL;
-}
-
 void YoungList::empty_list(HeapRegion* list) {
   while (list != NULL) {
     HeapRegion* next = list->get_next_young_region();
@@ -225,12 +182,6 @@ void YoungList::empty_list() {
   _head = NULL;
   _length = 0;
 
-  empty_list(_scan_only_head);
-  _scan_only_head = NULL;
-  _scan_only_tail = NULL;
-  _scan_only_length = 0;
-  _curr_scan_only = NULL;
-
   empty_list(_survivor_head);
   _survivor_head = NULL;
   _survivor_tail = NULL;
@@ -248,11 +199,11 @@ bool YoungList::check_list_well_formed() {
   HeapRegion* curr = _head;
   HeapRegion* last = NULL;
   while (curr != NULL) {
-    if (!curr->is_young() || curr->is_scan_only()) {
+    if (!curr->is_young()) {
       gclog_or_tty->print_cr("### YOUNG REGION "PTR_FORMAT"-"PTR_FORMAT" "
-                             "incorrectly tagged (%d, %d)",
+                             "incorrectly tagged (y: %d, surv: %d)",
                              curr->bottom(), curr->end(),
-                             curr->is_young(), curr->is_scan_only());
+                             curr->is_young(), curr->is_survivor());
       ret = false;
     }
     ++length;
@@ -267,47 +218,10 @@ bool YoungList::check_list_well_formed() {
                            length, _length);
   }
 
-  bool scan_only_ret = true;
+  return ret;
-  length = 0;
-  curr = _scan_only_head;
-  last = NULL;
-  while (curr != NULL) {
-    if (!curr->is_young() || curr->is_scan_only()) {
-      gclog_or_tty->print_cr("### SCAN-ONLY REGION "PTR_FORMAT"-"PTR_FORMAT" "
-                             "incorrectly tagged (%d, %d)",
-                             curr->bottom(), curr->end(),
-                             curr->is_young(), curr->is_scan_only());
-      scan_only_ret = false;
-    }
-    ++length;
-    last = curr;
-    curr = curr->get_next_young_region();
-  }
-  scan_only_ret = scan_only_ret && (length == _scan_only_length);
-
-  if ( (last != _scan_only_tail) ||
-       (_scan_only_head == NULL && _scan_only_tail != NULL) ||
-       (_scan_only_head != NULL && _scan_only_tail == NULL) ) {
-     gclog_or_tty->print_cr("## _scan_only_tail is set incorrectly");
-     scan_only_ret = false;
-  }
-
-  if (_curr_scan_only != NULL && _curr_scan_only != _scan_only_head) {
-    gclog_or_tty->print_cr("### _curr_scan_only is set incorrectly");
-    scan_only_ret = false;
-   }
-
-  if (!scan_only_ret) {
-    gclog_or_tty->print_cr("### SCAN-ONLY LIST seems not well formed!");
-    gclog_or_tty->print_cr("###   list has %d entries, _scan_only_length is %d",
-                  length, _scan_only_length);
-  }
-
-  return ret && scan_only_ret;
 }
 
-bool YoungList::check_list_empty(bool ignore_scan_only_list,
+bool YoungList::check_list_empty(bool check_sample) {
-                                 bool check_sample) {
   bool ret = true;
 
   if (_length != 0) {
@@ -327,28 +241,7 @@ bool YoungList::check_list_empty(bool ignore_scan_only_list,
     gclog_or_tty->print_cr("### YOUNG LIST does not seem empty");
   }
 
-  if (ignore_scan_only_list)
+  return ret;
-    return ret;
-
-  bool scan_only_ret = true;
-  if (_scan_only_length != 0) {
-    gclog_or_tty->print_cr("### SCAN-ONLY LIST should have 0 length, not %d",
-                  _scan_only_length);
-    scan_only_ret = false;
-  }
-  if (_scan_only_head != NULL) {
-    gclog_or_tty->print_cr("### SCAN-ONLY LIST does not have a NULL head");
-     scan_only_ret = false;
-  }
-  if (_scan_only_tail != NULL) {
-    gclog_or_tty->print_cr("### SCAN-ONLY LIST does not have a NULL tail");
-    scan_only_ret = false;
-  }
-  if (!scan_only_ret) {
-    gclog_or_tty->print_cr("### SCAN-ONLY LIST does not seem empty");
-  }
-
-  return ret && scan_only_ret;
 }
 
 void
@@ -365,7 +258,18 @@ YoungList::rs_length_sampling_more() {
 void
 YoungList::rs_length_sampling_next() {
   assert( _curr != NULL, "invariant" );
-  _sampled_rs_lengths += _curr->rem_set()->occupied();
+  size_t rs_length = _curr->rem_set()->occupied();
+
+  _sampled_rs_lengths += rs_length;
+
+  // The current region may not yet have been added to the
+  // incremental collection set (it gets added when it is
+  // retired as the current allocation region).
+  if (_curr->in_collection_set()) {
+    // Update the collection set policy information for this region
+    _g1h->g1_policy()->update_incremental_cset_info(_curr, rs_length);
+  }
+
   _curr = _curr->get_next_young_region();
   if (_curr == NULL) {
     _last_sampled_rs_lengths = _sampled_rs_lengths;
@@ -375,54 +279,46 @@ YoungList::rs_length_sampling_next() {
 
 void
 YoungList::reset_auxilary_lists() {
-  // We could have just "moved" the scan-only list to the young list.
-  // However, the scan-only list is ordered according to the region
-  // age in descending order, so, by moving one entry at a time, we
-  // ensure that it is recreated in ascending order.
-
   guarantee( is_empty(), "young list should be empty" );
   assert(check_list_well_formed(), "young list should be well formed");
 
   // Add survivor regions to SurvRateGroup.
   _g1h->g1_policy()->note_start_adding_survivor_regions();
   _g1h->g1_policy()->finished_recalculating_age_indexes(true /* is_survivors */);
+
   for (HeapRegion* curr = _survivor_head;
        curr != NULL;
        curr = curr->get_next_young_region()) {
     _g1h->g1_policy()->set_region_survivors(curr);
+
+    // The region is a non-empty survivor so let's add it to
+    // the incremental collection set for the next evacuation
+    // pause.
+    _g1h->g1_policy()->add_region_to_incremental_cset_rhs(curr);
   }
   _g1h->g1_policy()->note_stop_adding_survivor_regions();
 
+  _head   = _survivor_head;
+  _length = _survivor_length;
   if (_survivor_head != NULL) {
-    _head           = _survivor_head;
+    assert(_survivor_tail != NULL, "cause it shouldn't be");
-    _length         = _survivor_length + _scan_only_length;
+    assert(_survivor_length > 0, "invariant");
-    _survivor_tail->set_next_young_region(_scan_only_head);
+    _survivor_tail->set_next_young_region(NULL);
-  } else {
-    _head           = _scan_only_head;
-    _length         = _scan_only_length;
   }
 
-  for (HeapRegion* curr = _scan_only_head;
+  // Don't clear the survivor list handles until the start of
-       curr != NULL;
+  // the next evacuation pause - we need it in order to re-tag
-       curr = curr->get_next_young_region()) {
+  // the survivor regions from this evacuation pause as 'young'
-    curr->recalculate_age_in_surv_rate_group();
+  // at the start of the next.
-  }
-  _scan_only_head   = NULL;
-  _scan_only_tail   = NULL;
-  _scan_only_length = 0;
-  _curr_scan_only   = NULL;
 
-  _survivor_head    = NULL;
-  _survivor_tail   = NULL;
-  _survivor_length  = 0;
   _g1h->g1_policy()->finished_recalculating_age_indexes(false /* is_survivors */);
 
   assert(check_list_well_formed(), "young list should be well formed");
 }
 
 void YoungList::print() {
-  HeapRegion* lists[] = {_head,   _scan_only_head, _survivor_head};
+  HeapRegion* lists[] = {_head,   _survivor_head};
-  const char* names[] = {"YOUNG", "SCAN-ONLY",     "SURVIVOR"};
+  const char* names[] = {"YOUNG", "SURVIVOR"};
 
   for (unsigned int list = 0; list < ARRAY_SIZE(lists); ++list) {
     gclog_or_tty->print_cr("%s LIST CONTENTS", names[list]);
@@ -431,7 +327,7 @@ void YoungList::print() {
       gclog_or_tty->print_cr("  empty");
     while (curr != NULL) {
       gclog_or_tty->print_cr("  [%08x-%08x], t: %08x, P: %08x, N: %08x, C: %08x, "
-                             "age: %4d, y: %d, s-o: %d, surv: %d",
+                             "age: %4d, y: %d, surv: %d",
                              curr->bottom(), curr->end(),
                              curr->top(),
                              curr->prev_top_at_mark_start(),
@@ -439,7 +335,6 @@ void YoungList::print() {
                              curr->top_at_conc_mark_count(),
                              curr->age_in_surv_rate_group_cond(),
                              curr->is_young(),
-                             curr->is_scan_only(),
                              curr->is_survivor());
       curr = curr->get_next_young_region();
     }
@@ -707,6 +602,12 @@ G1CollectedHeap::attempt_allocation_slow(size_t word_size,
     // region below.
     if (_cur_alloc_region != NULL) {
       // We're finished with the _cur_alloc_region.
+      // As we're builing (at least the young portion) of the collection
+      // set incrementally we'll add the current allocation region to
+      // the collection set here.
+      if (_cur_alloc_region->is_young()) {
+        g1_policy()->add_region_to_incremental_cset_lhs(_cur_alloc_region);
+      }
       _summary_bytes_used += _cur_alloc_region->used();
       _cur_alloc_region = NULL;
     }
@@ -820,6 +721,12 @@ void G1CollectedHeap::abandon_cur_alloc_region() {
       _free_regions++;
       free_region(_cur_alloc_region);
     } else {
+      // As we're builing (at least the young portion) of the collection
+      // set incrementally we'll add the current allocation region to
+      // the collection set here.
+      if (_cur_alloc_region->is_young()) {
+        g1_policy()->add_region_to_incremental_cset_lhs(_cur_alloc_region);
+      }
       _summary_bytes_used += _cur_alloc_region->used();
     }
     _cur_alloc_region = NULL;
@@ -913,20 +820,25 @@ void G1CollectedHeap::do_collection(bool full, bool clear_all_soft_refs,
   }
 
   if (full && DisableExplicitGC) {
-    gclog_or_tty->print("\n\n\nDisabling Explicit GC\n\n\n");
     return;
   }
 
   assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
   assert(Thread::current() == VMThread::vm_thread(), "should be in vm thread");
 
+  const bool do_clear_all_soft_refs = clear_all_soft_refs ||
+                           collector_policy()->should_clear_all_soft_refs();
+
+  ClearedAllSoftRefs casr(do_clear_all_soft_refs, collector_policy());
+
   {
     IsGCActiveMark x;
 
     // Timing
     gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
     TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
-    TraceTime t(full ? "Full GC (System.gc())" : "Full GC", PrintGC, true, gclog_or_tty);
+    TraceTime t(full ? "Full GC (System.gc())" : "Full GC",
+                PrintGC, true, gclog_or_tty);
 
     TraceMemoryManagerStats tms(true /* fullGC */);
 
@@ -970,6 +882,15 @@ void G1CollectedHeap::do_collection(bool full, bool clear_all_soft_refs,
     g1_rem_set()->as_HRInto_G1RemSet()->cleanupHRRS();
     tear_down_region_lists();
     set_used_regions_to_need_zero_fill();
+
+    // We may have added regions to the current incremental collection
+    // set between the last GC or pause and now. We need to clear the
+    // incremental collection set and then start rebuilding it afresh
+    // after this full GC.
+    abandon_collection_set(g1_policy()->inc_cset_head());
+    g1_policy()->clear_incremental_cset();
+    g1_policy()->stop_incremental_cset_building();
+
     if (g1_policy()->in_young_gc_mode()) {
       empty_young_list();
       g1_policy()->set_full_young_gcs(true);
@@ -985,12 +906,12 @@ void G1CollectedHeap::do_collection(bool full, bool clear_all_soft_refs,
     ReferenceProcessorIsAliveMutator rp_is_alive_null(ref_processor(), NULL);
 
     ref_processor()->enable_discovery();
-    ref_processor()->setup_policy(clear_all_soft_refs);
+    ref_processor()->setup_policy(do_clear_all_soft_refs);
 
     // Do collection work
     {
       HandleMark hm;  // Discard invalid handles created during gc
-      G1MarkSweep::invoke_at_safepoint(ref_processor(), clear_all_soft_refs);
+      G1MarkSweep::invoke_at_safepoint(ref_processor(), do_clear_all_soft_refs);
     }
     // Because freeing humongous regions may have added some unclean
     // regions, it is necessary to tear down again before rebuilding.
@@ -1053,6 +974,15 @@ void G1CollectedHeap::do_collection(bool full, bool clear_all_soft_refs,
       perm()->compute_new_size();
     }
 
+    // Start a new incremental collection set for the next pause
+    assert(g1_policy()->collection_set() == NULL, "must be");
+    g1_policy()->start_incremental_cset_building();
+
+    // Clear the _cset_fast_test bitmap in anticipation of adding
+    // regions to the incremental collection set for the next
+    // evacuation pause.
+    clear_cset_fast_test();
+
     double end = os::elapsedTime();
     g1_policy()->record_full_collection_end();
 
@@ -1071,7 +1001,9 @@ void G1CollectedHeap::do_collection(bool full, bool clear_all_soft_refs,
 
   if (g1_policy()->in_young_gc_mode()) {
     _young_list->reset_sampled_info();
-    assert( check_young_list_empty(false, false),
+    // At this point there should be no regions in the
+    // entire heap tagged as young.
+    assert( check_young_list_empty(true /* check_heap */),
             "young list should be empty at this point");
   }
 
@@ -1208,6 +1140,9 @@ G1CollectedHeap::satisfy_failed_allocation(size_t word_size) {
     return result;
   }
 
+  assert(!collector_policy()->should_clear_all_soft_refs(),
+    "Flag should have been handled and cleared prior to this point");
+
   // What else?  We might try synchronous finalization later.  If the total
   // space available is large enough for the allocation, then a more
   // complete compaction phase than we've tried so far might be
@@ -1565,6 +1500,20 @@ jint G1CollectedHeap::initialize() {
 
   _g1h = this;
 
+   _in_cset_fast_test_length = max_regions();
+   _in_cset_fast_test_base = NEW_C_HEAP_ARRAY(bool, _in_cset_fast_test_length);
+
+   // We're biasing _in_cset_fast_test to avoid subtracting the
+   // beginning of the heap every time we want to index; basically
+   // it's the same with what we do with the card table.
+   _in_cset_fast_test = _in_cset_fast_test_base -
+                ((size_t) _g1_reserved.start() >> HeapRegion::LogOfHRGrainBytes);
+
+   // Clear the _cset_fast_test bitmap in anticipation of adding
+   // regions to the incremental collection set for the first
+   // evacuation pause.
+   clear_cset_fast_test();
+
   // Create the ConcurrentMark data structure and thread.
   // (Must do this late, so that "max_regions" is defined.)
   _cm       = new ConcurrentMark(heap_rs, (int) max_regions());
@@ -2185,8 +2134,10 @@ public:
     assert(o != NULL, "Huh?");
     if (!_g1h->is_obj_dead_cond(o, _use_prev_marking)) {
       o->oop_iterate(&isLive);
-      if (!_hr->obj_allocated_since_prev_marking(o))
+      if (!_hr->obj_allocated_since_prev_marking(o)) {
-        _live_bytes += (o->size() * HeapWordSize);
+        size_t obj_size = o->size();    // Make sure we don't overflow
+        _live_bytes += (obj_size * HeapWordSize);
+      }
     }
   }
   size_t live_bytes() { return _live_bytes; }
@@ -2388,8 +2339,8 @@ void G1CollectedHeap::verify(bool allow_dirty,
       print_on(gclog_or_tty, true /* extended */);
       gclog_or_tty->print_cr("");
       if (VerifyDuringGC && G1VerifyDuringGCPrintReachable) {
-        concurrent_mark()->print_reachable(use_prev_marking,
+        concurrent_mark()->print_reachable("at-verification-failure",
-                                           "failed-verification");
+                                           use_prev_marking, false /* all */);
       }
       gclog_or_tty->flush();
     }
@@ -2741,25 +2692,19 @@ G1CollectedHeap::do_collection_pause_at_safepoint() {
       double start_time_sec = os::elapsedTime();
       size_t start_used_bytes = used();
 
+#if YOUNG_LIST_VERBOSE
+      gclog_or_tty->print_cr("\nBefore recording pause start.\nYoung_list:");
+      _young_list->print();
+      g1_policy()->print_collection_set(g1_policy()->inc_cset_head(), gclog_or_tty);
+#endif // YOUNG_LIST_VERBOSE
+
       g1_policy()->record_collection_pause_start(start_time_sec,
                                                  start_used_bytes);
 
-      guarantee(_in_cset_fast_test == NULL, "invariant");
+#if YOUNG_LIST_VERBOSE
-      guarantee(_in_cset_fast_test_base == NULL, "invariant");
+      gclog_or_tty->print_cr("\nAfter recording pause start.\nYoung_list:");
-      _in_cset_fast_test_length = max_regions();
-      _in_cset_fast_test_base =
-                             NEW_C_HEAP_ARRAY(bool, _in_cset_fast_test_length);
-      memset(_in_cset_fast_test_base, false,
-                                     _in_cset_fast_test_length * sizeof(bool));
-      // We're biasing _in_cset_fast_test to avoid subtracting the
-      // beginning of the heap every time we want to index; basically
-      // it's the same with what we do with the card table.
-      _in_cset_fast_test = _in_cset_fast_test_base -
-              ((size_t) _g1_reserved.start() >> HeapRegion::LogOfHRGrainBytes);
-
-#if SCAN_ONLY_VERBOSE
       _young_list->print();
-#endif // SCAN_ONLY_VERBOSE
+#endif // YOUNG_LIST_VERBOSE
 
       if (g1_policy()->during_initial_mark_pause()) {
         concurrent_mark()->checkpointRootsInitialPre();
@@ -2786,12 +2731,15 @@ G1CollectedHeap::do_collection_pause_at_safepoint() {
       if (mark_in_progress())
         concurrent_mark()->newCSet();
 
-      // Now choose the CS.
+#if YOUNG_LIST_VERBOSE
-      g1_policy()->choose_collection_set();
+      gclog_or_tty->print_cr("\nBefore choosing collection set.\nYoung_list:");
+      _young_list->print();
+      g1_policy()->print_collection_set(g1_policy()->inc_cset_head(), gclog_or_tty);
+#endif // YOUNG_LIST_VERBOSE
 
-      // We may abandon a pause if we find no region that will fit in the MMU
+      // Now choose the CS. We may abandon a pause if we find no
-      // pause.
+      // region that will fit in the MMU pause.
-      bool abandoned = (g1_policy()->collection_set() == NULL);
+      bool abandoned = g1_policy()->choose_collection_set();
 
       // Nothing to do if we were unable to choose a collection set.
       if (!abandoned) {
@@ -2809,40 +2757,64 @@ G1CollectedHeap::do_collection_pause_at_safepoint() {
 
         // Actually do the work...
         evacuate_collection_set();
+
         free_collection_set(g1_policy()->collection_set());
         g1_policy()->clear_collection_set();
 
-        FREE_C_HEAP_ARRAY(bool, _in_cset_fast_test_base);
-        // this is more for peace of mind; we're nulling them here and
-        // we're expecting them to be null at the beginning of the next GC
-        _in_cset_fast_test = NULL;
-        _in_cset_fast_test_base = NULL;
-
         cleanup_surviving_young_words();
 
+        // Start a new incremental collection set for the next pause.
+        g1_policy()->start_incremental_cset_building();
+
+        // Clear the _cset_fast_test bitmap in anticipation of adding
+        // regions to the incremental collection set for the next
+        // evacuation pause.
+        clear_cset_fast_test();
+
         if (g1_policy()->in_young_gc_mode()) {
           _young_list->reset_sampled_info();
-          assert(check_young_list_empty(true),
-                 "young list should be empty");
 
-#if SCAN_ONLY_VERBOSE
+          // Don't check the whole heap at this point as the
+          // GC alloc regions from this pause have been tagged
+          // as survivors and moved on to the survivor list.
+          // Survivor regions will fail the !is_young() check.
+          assert(check_young_list_empty(false /* check_heap */),
+              "young list should be empty");
+
+#if YOUNG_LIST_VERBOSE
+          gclog_or_tty->print_cr("Before recording survivors.\nYoung List:");
           _young_list->print();
-#endif // SCAN_ONLY_VERBOSE
+#endif // YOUNG_LIST_VERBOSE
 
           g1_policy()->record_survivor_regions(_young_list->survivor_length(),
                                           _young_list->first_survivor_region(),
                                           _young_list->last_survivor_region());
+
           _young_list->reset_auxilary_lists();
         }
       } else {
-        if (_in_cset_fast_test != NULL) {
+        // We have abandoned the current collection. This can only happen
-          assert(_in_cset_fast_test_base != NULL, "Since _in_cset_fast_test isn't");
+        // if we're not doing young or partially young collections, and
-          FREE_C_HEAP_ARRAY(bool, _in_cset_fast_test_base);
+        // we didn't find an old region that we're able to collect within
-          //  this is more for peace of mind; we're nulling them here and
+        // the allowed time.
-          // we're expecting them to be null at the beginning of the next GC
+
-          _in_cset_fast_test = NULL;
+        assert(g1_policy()->collection_set() == NULL, "should be");
-          _in_cset_fast_test_base = NULL;
+        assert(_young_list->length() == 0, "because it should be");
-        }
+
+        // This should be a no-op.
+        abandon_collection_set(g1_policy()->inc_cset_head());
+
+        g1_policy()->clear_incremental_cset();
+        g1_policy()->stop_incremental_cset_building();
+
+        // Start a new incremental collection set for the next pause.
+        g1_policy()->start_incremental_cset_building();
+
+        // Clear the _cset_fast_test bitmap in anticipation of adding
+        // regions to the incremental collection set for the next
+        // evacuation pause.
+        clear_cset_fast_test();
+
         // This looks confusing, because the DPT should really be empty
         // at this point -- since we have not done any collection work,
         // there should not be any derived pointers in the table to update;
@@ -2876,9 +2848,11 @@ G1CollectedHeap::do_collection_pause_at_safepoint() {
         doConcurrentMark();
       }
 
-#if SCAN_ONLY_VERBOSE
+#if YOUNG_LIST_VERBOSE
+      gclog_or_tty->print_cr("\nEnd of the pause.\nYoung_list:");
       _young_list->print();
-#endif // SCAN_ONLY_VERBOSE
+      g1_policy()->print_collection_set(g1_policy()->inc_cset_head(), gclog_or_tty);
+#endif // YOUNG_LIST_VERBOSE
 
       double end_time_sec = os::elapsedTime();
       double pause_time_ms = (end_time_sec - start_time_sec) * MILLIUNITS;
@@ -2936,6 +2910,25 @@ G1CollectedHeap::do_collection_pause_at_safepoint() {
   }
 }
 
+size_t G1CollectedHeap::desired_plab_sz(GCAllocPurpose purpose)
+{
+  size_t gclab_word_size;
+  switch (purpose) {
+    case GCAllocForSurvived:
+      gclab_word_size = YoungPLABSize;
+      break;
+    case GCAllocForTenured:
+      gclab_word_size = OldPLABSize;
+      break;
+    default:
+      assert(false, "unknown GCAllocPurpose");
+      gclab_word_size = OldPLABSize;
+      break;
+  }
+  return gclab_word_size;
+}
+
+
 void G1CollectedHeap::set_gc_alloc_region(int purpose, HeapRegion* r) {
   assert(purpose >= 0 && purpose < GCAllocPurposeCount, "invalid purpose");
   // make sure we don't call set_gc_alloc_region() multiple times on
@@ -3109,6 +3102,11 @@ void G1CollectedHeap::get_gc_alloc_regions() {
     } else {
       // the region was retained from the last collection
       ++_gc_alloc_region_counts[ap];
+      if (G1PrintHeapRegions) {
+        gclog_or_tty->print_cr("new alloc region %d:["PTR_FORMAT", "PTR_FORMAT"], "
+                               "top "PTR_FORMAT,
+                               alloc_region->hrs_index(), alloc_region->bottom(), alloc_region->end(), alloc_region->top());
+      }
     }
 
     if (alloc_region != NULL) {
@@ -3665,6 +3663,8 @@ G1ParScanThreadState::G1ParScanThreadState(G1CollectedHeap* g1h, int queue_num)
     _g1_rem(g1h->g1_rem_set()),
     _hash_seed(17), _queue_num(queue_num),
     _term_attempts(0),
+    _surviving_alloc_buffer(g1h->desired_plab_sz(GCAllocForSurvived)),
+    _tenured_alloc_buffer(g1h->desired_plab_sz(GCAllocForTenured)),
     _age_table(false),
 #if G1_DETAILED_STATS
     _pushes(0), _pops(0), _steals(0),
@@ -3691,6 +3691,9 @@ G1ParScanThreadState::G1ParScanThreadState(G1CollectedHeap* g1h, int queue_num)
 
   _overflowed_refs = new OverflowQueue(10);
 
+  _alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer;
+  _alloc_buffers[GCAllocForTenured]  = &_tenured_alloc_buffer;
+
   _start = os::elapsedTime();
 }
 
@@ -3988,16 +3991,13 @@ public:
 
     OopsInHeapRegionClosure        *scan_root_cl;
     OopsInHeapRegionClosure        *scan_perm_cl;
-    OopsInHeapRegionClosure        *scan_so_cl;
 
     if (_g1h->g1_policy()->during_initial_mark_pause()) {
       scan_root_cl = &scan_mark_root_cl;
       scan_perm_cl = &scan_mark_perm_cl;
-      scan_so_cl   = &scan_mark_heap_rs_cl;
     } else {
       scan_root_cl = &only_scan_root_cl;
       scan_perm_cl = &only_scan_perm_cl;
-      scan_so_cl   = &only_scan_heap_rs_cl;
     }
 
     pss.start_strong_roots();
@@ -4005,7 +4005,6 @@ public:
                                   SharedHeap::SO_AllClasses,
                                   scan_root_cl,
                                   &push_heap_rs_cl,
-                                  scan_so_cl,
                                   scan_perm_cl,
                                   i);
     pss.end_strong_roots();
@@ -4067,7 +4066,6 @@ g1_process_strong_roots(bool collecting_perm_gen,
                         SharedHeap::ScanningOption so,
                         OopClosure* scan_non_heap_roots,
                         OopsInHeapRegionClosure* scan_rs,
-                        OopsInHeapRegionClosure* scan_so,
                         OopsInGenClosure* scan_perm,
                         int worker_i) {
   // First scan the strong roots, including the perm gen.
@@ -4087,6 +4085,7 @@ g1_process_strong_roots(bool collecting_perm_gen,
                        &buf_scan_non_heap_roots,
                        &eager_scan_code_roots,
                        &buf_scan_perm);
+
   // Finish up any enqueued closure apps.
   buf_scan_non_heap_roots.done();
   buf_scan_perm.done();
@@ -4109,9 +4108,6 @@ g1_process_strong_roots(bool collecting_perm_gen,
 
   // XXX What should this be doing in the parallel case?
   g1_policy()->record_collection_pause_end_CH_strong_roots();
-  if (scan_so != NULL) {
-    scan_scan_only_set(scan_so, worker_i);
-  }
   // Now scan the complement of the collection set.
   if (scan_rs != NULL) {
     g1_rem_set()->oops_into_collection_set_do(scan_rs, worker_i);
@@ -4124,54 +4120,6 @@ g1_process_strong_roots(bool collecting_perm_gen,
   _process_strong_tasks->all_tasks_completed();
 }
 
-void
-G1CollectedHeap::scan_scan_only_region(HeapRegion* r,
-                                       OopsInHeapRegionClosure* oc,
-                                       int worker_i) {
-  HeapWord* startAddr = r->bottom();
-  HeapWord* endAddr = r->used_region().end();
-
-  oc->set_region(r);
-
-  HeapWord* p = r->bottom();
-  HeapWord* t = r->top();
-  guarantee( p == r->next_top_at_mark_start(), "invariant" );
-  while (p < t) {
-    oop obj = oop(p);
-    p += obj->oop_iterate(oc);
-  }
-}
-
-void
-G1CollectedHeap::scan_scan_only_set(OopsInHeapRegionClosure* oc,
-                                    int worker_i) {
-  double start = os::elapsedTime();
-
-  BufferingOopsInHeapRegionClosure boc(oc);
-
-  FilterInHeapRegionAndIntoCSClosure scan_only(this, &boc);
-  FilterAndMarkInHeapRegionAndIntoCSClosure scan_and_mark(this, &boc, concurrent_mark());
-
-  OopsInHeapRegionClosure *foc;
-  if (g1_policy()->during_initial_mark_pause())
-    foc = &scan_and_mark;
-  else
-    foc = &scan_only;
-
-  HeapRegion* hr;
-  int n = 0;
-  while ((hr = _young_list->par_get_next_scan_only_region()) != NULL) {
-    scan_scan_only_region(hr, foc, worker_i);
-    ++n;
-  }
-  boc.done();
-
-  double closure_app_s = boc.closure_app_seconds();
-  g1_policy()->record_obj_copy_time(worker_i, closure_app_s * 1000.0);
-  double ms = (os::elapsedTime() - start - closure_app_s)*1000.0;
-  g1_policy()->record_scan_only_time(worker_i, ms, n);
-}
-
 void
 G1CollectedHeap::g1_process_weak_roots(OopClosure* root_closure,
                                        OopClosure* non_root_closure) {
@@ -4370,17 +4318,14 @@ void G1CollectedHeap::dirtyCardsForYoungRegions(CardTableModRefBS* ct_bs, HeapRe
 class G1ParCleanupCTTask : public AbstractGangTask {
   CardTableModRefBS* _ct_bs;
   G1CollectedHeap* _g1h;
-  HeapRegion* volatile _so_head;
   HeapRegion* volatile _su_head;
 public:
   G1ParCleanupCTTask(CardTableModRefBS* ct_bs,
                      G1CollectedHeap* g1h,
-                     HeapRegion* scan_only_list,
                      HeapRegion* survivor_list) :
     AbstractGangTask("G1 Par Cleanup CT Task"),
     _ct_bs(ct_bs),
     _g1h(g1h),
-    _so_head(scan_only_list),
     _su_head(survivor_list)
   { }
 
@@ -4389,14 +4334,13 @@ public:
     while (r = _g1h->pop_dirty_cards_region()) {
       clear_cards(r);
     }
-    // Redirty the cards of the scan-only and survivor regions.
+    // Redirty the cards of the survivor regions.
-    dirty_list(&this->_so_head);
     dirty_list(&this->_su_head);
   }
 
   void clear_cards(HeapRegion* r) {
-    // Cards for Survivor and Scan-Only regions will be dirtied later.
+    // Cards for Survivor regions will be dirtied later.
-    if (!r->is_scan_only() && !r->is_survivor()) {
+    if (!r->is_survivor()) {
       _ct_bs->clear(MemRegion(r->bottom(), r->end()));
     }
   }
@@ -4429,7 +4373,7 @@ public:
   virtual bool doHeapRegion(HeapRegion* r)
   {
     MemRegion mr(r->bottom(), r->end());
-    if (r->is_scan_only() || r->is_survivor()) {
+    if (r->is_survivor()) {
       _ct_bs->verify_dirty_region(mr);
     } else {
       _ct_bs->verify_clean_region(mr);
@@ -4445,8 +4389,8 @@ void G1CollectedHeap::cleanUpCardTable() {
 
   // Iterate over the dirty cards region list.
   G1ParCleanupCTTask cleanup_task(ct_bs, this,
-                                  _young_list->first_scan_only_region(),
                                   _young_list->first_survivor_region());
+
   if (ParallelGCThreads > 0) {
     set_par_threads(workers()->total_workers());
     workers()->run_task(&cleanup_task);
@@ -4462,12 +4406,12 @@ void G1CollectedHeap::cleanUpCardTable() {
       }
       r->set_next_dirty_cards_region(NULL);
     }
-    // now, redirty the cards of the scan-only and survivor regions
+    // now, redirty the cards of the survivor regions
     // (it seemed faster to do it this way, instead of iterating over
     // all regions and then clearing / dirtying as appropriate)
-    dirtyCardsForYoungRegions(ct_bs, _young_list->first_scan_only_region());
     dirtyCardsForYoungRegions(ct_bs, _young_list->first_survivor_region());
   }
+
   double elapsed = os::elapsedTime() - start;
   g1_policy()->record_clear_ct_time( elapsed * 1000.0);
 #ifndef PRODUCT
@@ -4488,6 +4432,11 @@ void G1CollectedHeap::free_collection_set(HeapRegion* cs_head) {
   double young_time_ms     = 0.0;
   double non_young_time_ms = 0.0;
 
+  // Since the collection set is a superset of the the young list,
+  // all we need to do to clear the young list is clear its
+  // head and length, and unlink any young regions in the code below
+  _young_list->clear();
+
   G1CollectorPolicy* policy = g1_policy();
 
   double start_sec = os::elapsedTime();
@@ -4531,6 +4480,12 @@ void G1CollectedHeap::free_collection_set(HeapRegion* cs_head) {
       guarantee( (size_t)index < policy->young_cset_length(), "invariant" );
       size_t words_survived = _surviving_young_words[index];
       cur->record_surv_words_in_group(words_survived);
+
+      // At this point the we have 'popped' cur from the collection set
+      // (linked via next_in_collection_set()) but it is still in the
+      // young list (linked via next_young_region()). Clear the
+      // _next_young_region field.
+      cur->set_next_young_region(NULL);
     } else {
       int index = cur->young_index_in_cset();
       guarantee( index == -1, "invariant" );
@@ -4546,7 +4501,6 @@ void G1CollectedHeap::free_collection_set(HeapRegion* cs_head) {
              "Should not have empty regions in a CS.");
       free_region(cur);
     } else {
-      guarantee( !cur->is_scan_only(), "should not be scan only" );
       cur->uninstall_surv_rate_group();
       if (cur->is_young())
         cur->set_young_index_in_cset(-1);
@@ -4570,6 +4524,27 @@ void G1CollectedHeap::free_collection_set(HeapRegion* cs_head) {
   policy->record_non_young_free_cset_time_ms(non_young_time_ms);
 }
 
+// This routine is similar to the above but does not record
+// any policy statistics or update free lists; we are abandoning
+// the current incremental collection set in preparation of a
+// full collection. After the full GC we will start to build up
+// the incremental collection set again.
+// This is only called when we're doing a full collection
+// and is immediately followed by the tearing down of the young list.
+
+void G1CollectedHeap::abandon_collection_set(HeapRegion* cs_head) {
+  HeapRegion* cur = cs_head;
+
+  while (cur != NULL) {
+    HeapRegion* next = cur->next_in_collection_set();
+    assert(cur->in_collection_set(), "bad CS");
+    cur->set_next_in_collection_set(NULL);
+    cur->set_in_collection_set(false);
+    cur->set_young_index_in_cset(-1);
+    cur = next;
+  }
+}
+
 HeapRegion*
 G1CollectedHeap::alloc_region_from_unclean_list_locked(bool zero_filled) {
   assert(ZF_mon->owned_by_self(), "Precondition");
@@ -4936,12 +4911,10 @@ public:
   bool success() { return _success; }
 };
 
-bool G1CollectedHeap::check_young_list_empty(bool ignore_scan_only_list,
+bool G1CollectedHeap::check_young_list_empty(bool check_heap, bool check_sample) {
-                                             bool check_sample) {
+  bool ret = _young_list->check_list_empty(check_sample);
-  bool ret = true;
 
-  ret = _young_list->check_list_empty(ignore_scan_only_list, check_sample);
+  if (check_heap) {
-  if (!ignore_scan_only_list) {
     NoYoungRegionsClosure closure;
     heap_region_iterate(&closure);
     ret = ret && closure.success();

hotspot/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -81,33 +81,29 @@ private:
 
   HeapRegion* _head;
 
-  HeapRegion* _scan_only_head;
+  HeapRegion* _survivor_head;
-  HeapRegion* _scan_only_tail;
+  HeapRegion* _survivor_tail;
+
+  HeapRegion* _curr;
+
   size_t      _length;
-  size_t      _scan_only_length;
+  size_t      _survivor_length;
 
   size_t      _last_sampled_rs_lengths;
   size_t      _sampled_rs_lengths;
-  HeapRegion* _curr;
-  HeapRegion* _curr_scan_only;
 
-  HeapRegion* _survivor_head;
+  void         empty_list(HeapRegion* list);
-  HeapRegion* _survivor_tail;
-  size_t      _survivor_length;
-
-  void          empty_list(HeapRegion* list);
 
 public:
   YoungList(G1CollectedHeap* g1h);
 
-  void          push_region(HeapRegion* hr);
+  void         push_region(HeapRegion* hr);
-  void          add_survivor_region(HeapRegion* hr);
+  void         add_survivor_region(HeapRegion* hr);
-  HeapRegion*   pop_region();
+
-  void          empty_list();
+  void         empty_list();
-  bool          is_empty() { return _length == 0; }
+  bool         is_empty() { return _length == 0; }
-  size_t        length() { return _length; }
+  size_t       length() { return _length; }
-  size_t        scan_only_length() { return _scan_only_length; }
+  size_t       survivor_length() { return _survivor_length; }
-  size_t        survivor_length() { return _survivor_length; }
 
   void rs_length_sampling_init();
   bool rs_length_sampling_more();
@@ -120,22 +116,21 @@ public:
 
   // for development purposes
   void reset_auxilary_lists();
+  void clear() { _head = NULL; _length = 0; }
+
+  void clear_survivors() {
+    _survivor_head    = NULL;
+    _survivor_tail    = NULL;
+    _survivor_length  = 0;
+  }
+
   HeapRegion* first_region() { return _head; }
-  HeapRegion* first_scan_only_region() { return _scan_only_head; }
   HeapRegion* first_survivor_region() { return _survivor_head; }
   HeapRegion* last_survivor_region() { return _survivor_tail; }
-  HeapRegion* par_get_next_scan_only_region() {
-    MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag);
-    HeapRegion* ret = _curr_scan_only;
-    if (ret != NULL)
-      _curr_scan_only = ret->get_next_young_region();
-    return ret;
-  }
 
   // debugging
   bool          check_list_well_formed();
-  bool          check_list_empty(bool ignore_scan_only_list,
+  bool          check_list_empty(bool check_sample = true);
-                                 bool check_sample = true);
   void          print();
 };
 
@@ -232,6 +227,9 @@ private:
   // current collection.
   HeapRegion* _gc_alloc_region_list;
 
+  // Determines PLAB size for a particular allocation purpose.
+  static size_t desired_plab_sz(GCAllocPurpose purpose);
+
   // When called by par thread, require par_alloc_during_gc_lock() to be held.
   void push_gc_alloc_region(HeapRegion* hr);
 
@@ -402,8 +400,7 @@ public:
     assert(_in_cset_fast_test_base != NULL, "sanity");
     assert(r->in_collection_set(), "invariant");
     int index = r->hrs_index();
-    assert(0 <= (size_t) index && (size_t) index < _in_cset_fast_test_length,
+    assert(0 <= index && (size_t) index < _in_cset_fast_test_length, "invariant");
-           "invariant");
     assert(!_in_cset_fast_test_base[index], "invariant");
     _in_cset_fast_test_base[index] = true;
   }
@@ -428,6 +425,12 @@ public:
     }
   }
 
+  void clear_cset_fast_test() {
+    assert(_in_cset_fast_test_base != NULL, "sanity");
+    memset(_in_cset_fast_test_base, false,
+        _in_cset_fast_test_length * sizeof(bool));
+  }
+
 protected:
 
   // Shrink the garbage-first heap by at most the given size (in bytes!).
@@ -473,6 +476,10 @@ protected:
   // regions.
   void free_collection_set(HeapRegion* cs_head);
 
+  // Abandon the current collection set without recording policy
+  // statistics or updating free lists.
+  void abandon_collection_set(HeapRegion* cs_head);
+
   // Applies "scan_non_heap_roots" to roots outside the heap,
   // "scan_rs" to roots inside the heap (having done "set_region" to
   // indicate the region in which the root resides), and does "scan_perm"
@@ -485,16 +492,9 @@ protected:
                                SharedHeap::ScanningOption so,
                                OopClosure* scan_non_heap_roots,
                                OopsInHeapRegionClosure* scan_rs,
-                               OopsInHeapRegionClosure* scan_so,
                                OopsInGenClosure* scan_perm,
                                int worker_i);
 
-  void scan_scan_only_set(OopsInHeapRegionClosure* oc,
-                          int worker_i);
-  void scan_scan_only_region(HeapRegion* hr,
-                             OopsInHeapRegionClosure* oc,
-                             int worker_i);
-
   // Apply "blk" to all the weak roots of the system.  These include
   // JNI weak roots, the code cache, system dictionary, symbol table,
   // string table, and referents of reachable weak refs.
@@ -1133,36 +1133,14 @@ public:
   void set_region_short_lived_locked(HeapRegion* hr);
   // add appropriate methods for any other surv rate groups
 
-  void young_list_rs_length_sampling_init() {
+  YoungList* young_list() { return _young_list; }
-    _young_list->rs_length_sampling_init();
-  }
-  bool young_list_rs_length_sampling_more() {
-    return _young_list->rs_length_sampling_more();
-  }
-  void young_list_rs_length_sampling_next() {
-    _young_list->rs_length_sampling_next();
-  }
-  size_t young_list_sampled_rs_lengths() {
-    return _young_list->sampled_rs_lengths();
-  }
-
-  size_t young_list_length()   { return _young_list->length(); }
-  size_t young_list_scan_only_length() {
-                                      return _young_list->scan_only_length(); }
-
-  HeapRegion* pop_region_from_young_list() {
-    return _young_list->pop_region();
-  }
-
-  HeapRegion* young_list_first_region() {
-    return _young_list->first_region();
-  }
 
   // debugging
   bool check_young_list_well_formed() {
     return _young_list->check_list_well_formed();
   }
-  bool check_young_list_empty(bool ignore_scan_only_list,
+
+  bool check_young_list_empty(bool check_heap,
                               bool check_sample = true);
 
   // *** Stuff related to concurrent marking.  It's not clear to me that so
@@ -1367,12 +1345,18 @@ private:
     return BitsPerWord << shifter();
   }
 
-  static size_t gclab_word_size() {
+  size_t gclab_word_size() const {
-    return G1ParallelGCAllocBufferSize / HeapWordSize;
+    return _gclab_word_size;
   }
 
-  static size_t bitmap_size_in_bits() {
+  // Calculates actual GCLab size in words
-    size_t bits_in_bitmap = gclab_word_size() >> shifter();
+  size_t gclab_real_word_size() const {
+    return bitmap_size_in_bits(pointer_delta(_real_end_word, _start_word))
+           / BitsPerWord;
+  }
+
+  static size_t bitmap_size_in_bits(size_t gclab_word_size) {
+    size_t bits_in_bitmap = gclab_word_size >> shifter();
     // We are going to ensure that the beginning of a word in this
     // bitmap also corresponds to the beginning of a word in the
     // global marking bitmap. To handle the case where a GCLab
@@ -1382,13 +1366,13 @@ private:
     return bits_in_bitmap + BitsPerWord - 1;
   }
 public:
-  GCLabBitMap(HeapWord* heap_start)
+  GCLabBitMap(HeapWord* heap_start, size_t gclab_word_size)
-    : BitMap(bitmap_size_in_bits()),
+    : BitMap(bitmap_size_in_bits(gclab_word_size)),
       _cm(G1CollectedHeap::heap()->concurrent_mark()),
       _shifter(shifter()),
       _bitmap_word_covers_words(bitmap_word_covers_words()),
       _heap_start(heap_start),
-      _gclab_word_size(gclab_word_size()),
+      _gclab_word_size(gclab_word_size),
       _real_start_word(NULL),
       _real_end_word(NULL),
       _start_word(NULL)
@@ -1483,7 +1467,7 @@ public:
       mark_bitmap->mostly_disjoint_range_union(this,
                                 0, // always start from the start of the bitmap
                                 _start_word,
-                                size_in_words());
+                                gclab_real_word_size());
       _cm->grayRegionIfNecessary(MemRegion(_real_start_word, _real_end_word));
 
 #ifndef PRODUCT
@@ -1495,9 +1479,10 @@ public:
     }
   }
 
-  static size_t bitmap_size_in_words() {
+  size_t bitmap_size_in_words() const {
-    return (bitmap_size_in_bits() + BitsPerWord - 1) / BitsPerWord;
+    return (bitmap_size_in_bits(gclab_word_size()) + BitsPerWord - 1) / BitsPerWord;
   }
+
 };
 
 class G1ParGCAllocBuffer: public ParGCAllocBuffer {
@@ -1507,10 +1492,10 @@ private:
   GCLabBitMap _bitmap;
 
 public:
-  G1ParGCAllocBuffer() :
+  G1ParGCAllocBuffer(size_t gclab_word_size) :
-    ParGCAllocBuffer(G1ParallelGCAllocBufferSize / HeapWordSize),
+    ParGCAllocBuffer(gclab_word_size),
     _during_marking(G1CollectedHeap::heap()->mark_in_progress()),
-    _bitmap(G1CollectedHeap::heap()->reserved_region().start()),
+    _bitmap(G1CollectedHeap::heap()->reserved_region().start(), gclab_word_size),
     _retired(false)
   { }
 
@@ -1549,8 +1534,10 @@ protected:
   typedef GrowableArray<StarTask> OverflowQueue;
   OverflowQueue* _overflowed_refs;
 
-  G1ParGCAllocBuffer _alloc_buffers[GCAllocPurposeCount];
+  G1ParGCAllocBuffer  _surviving_alloc_buffer;
-  ageTable           _age_table;
+  G1ParGCAllocBuffer  _tenured_alloc_buffer;
+  G1ParGCAllocBuffer* _alloc_buffers[GCAllocPurposeCount];
+  ageTable            _age_table;
 
   size_t           _alloc_buffer_waste;
   size_t           _undo_waste;
@@ -1619,7 +1606,7 @@ public:
   ageTable*         age_table()       { return &_age_table;       }
 
   G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose) {
-    return &_alloc_buffers[purpose];
+    return _alloc_buffers[purpose];
   }
 
   size_t alloc_buffer_waste()                    { return _alloc_buffer_waste; }
@@ -1684,15 +1671,15 @@ public:
   HeapWord* allocate_slow(GCAllocPurpose purpose, size_t word_sz) {
 
     HeapWord* obj = NULL;
-    if (word_sz * 100 <
+    size_t gclab_word_size = _g1h->desired_plab_sz(purpose);
-        (size_t)(G1ParallelGCAllocBufferSize / HeapWordSize) *
+    if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) {
-                                                  ParallelGCBufferWastePct) {
       G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose);
+      assert(gclab_word_size == alloc_buf->word_sz(),
+             "dynamic resizing is not supported");
       add_to_alloc_buffer_waste(alloc_buf->words_remaining());
       alloc_buf->retire(false, false);
 
-      HeapWord* buf =
+      HeapWord* buf = _g1h->par_allocate_during_gc(purpose, gclab_word_size);
-        _g1h->par_allocate_during_gc(purpose, G1ParallelGCAllocBufferSize / HeapWordSize);
       if (buf == NULL) return NULL; // Let caller handle allocation failure.
       // Otherwise.
       alloc_buf->set_buf(buf);
@@ -1786,9 +1773,9 @@ public:
 
   void retire_alloc_buffers() {
     for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
-      size_t waste = _alloc_buffers[ap].words_remaining();
+      size_t waste = _alloc_buffers[ap]->words_remaining();
       add_to_alloc_buffer_waste(waste);
-      _alloc_buffers[ap].retire(true, false);
+      _alloc_buffers[ap]->retire(true, false);
     }
   }
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -61,7 +61,6 @@ class MainBodySummary: public CHeapObj {
   define_num_seq(parallel) // parallel only
     define_num_seq(ext_root_scan)
     define_num_seq(mark_stack_scan)
-    define_num_seq(scan_only)
     define_num_seq(update_rs)
     define_num_seq(scan_rs)
     define_num_seq(scan_new_refs) // Only for temp use; added to
@@ -174,8 +173,6 @@ protected:
 
   double* _par_last_ext_root_scan_times_ms;
   double* _par_last_mark_stack_scan_times_ms;
-  double* _par_last_scan_only_times_ms;
-  double* _par_last_scan_only_regions_scanned;
   double* _par_last_update_rs_start_times_ms;
   double* _par_last_update_rs_times_ms;
   double* _par_last_update_rs_processed_buffers;
@@ -196,7 +193,6 @@ protected:
   bool _adaptive_young_list_length;
   size_t _young_list_min_length;
   size_t _young_list_target_length;
-  size_t _young_list_so_prefix_length;
   size_t _young_list_fixed_length;
 
   size_t _young_cset_length;
@@ -234,7 +230,6 @@ private:
   TruncatedSeq* _pending_card_diff_seq;
   TruncatedSeq* _rs_length_diff_seq;
   TruncatedSeq* _cost_per_card_ms_seq;
-  TruncatedSeq* _cost_per_scan_only_region_ms_seq;
   TruncatedSeq* _fully_young_cards_per_entry_ratio_seq;
   TruncatedSeq* _partially_young_cards_per_entry_ratio_seq;
   TruncatedSeq* _cost_per_entry_ms_seq;
@@ -249,19 +244,16 @@ private:
   TruncatedSeq* _rs_lengths_seq;
 
   TruncatedSeq* _cost_per_byte_ms_during_cm_seq;
-  TruncatedSeq* _cost_per_scan_only_region_ms_during_cm_seq;
 
   TruncatedSeq* _young_gc_eff_seq;
 
   TruncatedSeq* _max_conc_overhead_seq;
 
   size_t _recorded_young_regions;
-  size_t _recorded_scan_only_regions;
   size_t _recorded_non_young_regions;
   size_t _recorded_region_num;
 
   size_t _free_regions_at_end_of_collection;
-  size_t _scan_only_regions_at_end_of_collection;
 
   size_t _recorded_rs_lengths;
   size_t _max_rs_lengths;
@@ -277,7 +269,6 @@ private:
   double _predicted_survival_ratio;
   double _predicted_rs_update_time_ms;
   double _predicted_rs_scan_time_ms;
-  double _predicted_scan_only_scan_time_ms;
   double _predicted_object_copy_time_ms;
   double _predicted_constant_other_time_ms;
   double _predicted_young_other_time_ms;
@@ -344,8 +335,6 @@ public:
   bool verify_young_ages();
 #endif // PRODUCT
 
-  void tag_scan_only(size_t short_lived_scan_only_length);
-
   double get_new_prediction(TruncatedSeq* seq) {
     return MAX2(seq->davg() + sigma() * seq->dsd(),
                 seq->davg() * confidence_factor(seq->num()));
@@ -431,23 +420,6 @@ public:
         get_new_prediction(_partially_young_cost_per_entry_ms_seq);
   }
 
-  double predict_scan_only_time_ms_during_cm(size_t scan_only_region_num) {
-    if (_cost_per_scan_only_region_ms_during_cm_seq->num() < 3)
-      return 1.5 * (double) scan_only_region_num *
-        get_new_prediction(_cost_per_scan_only_region_ms_seq);
-    else
-      return (double) scan_only_region_num *
-        get_new_prediction(_cost_per_scan_only_region_ms_during_cm_seq);
-  }
-
-  double predict_scan_only_time_ms(size_t scan_only_region_num) {
-    if (_in_marking_window_im)
-      return predict_scan_only_time_ms_during_cm(scan_only_region_num);
-    else
-      return (double) scan_only_region_num *
-        get_new_prediction(_cost_per_scan_only_region_ms_seq);
-  }
-
   double predict_object_copy_time_ms_during_cm(size_t bytes_to_copy) {
     if (_cost_per_byte_ms_during_cm_seq->num() < 3)
       return 1.1 * (double) bytes_to_copy *
@@ -490,24 +462,21 @@ public:
   size_t predict_bytes_to_copy(HeapRegion* hr);
   double predict_region_elapsed_time_ms(HeapRegion* hr, bool young);
 
-  // for use by: calculate_optimal_so_length(length)
+    // for use by: calculate_young_list_target_length(rs_length)
-  void predict_gc_eff(size_t young_region_num,
+  bool predict_will_fit(size_t young_region_num,
-                      size_t so_length,
+                        double base_time_ms,
-                      double base_time_ms,
+                        size_t init_free_regions,
-                      double *gc_eff,
+                        double target_pause_time_ms);
-                      double *pause_time_ms);
-
-  // for use by: calculate_young_list_target_config(rs_length)
-  bool predict_gc_eff(size_t young_region_num,
-                      size_t so_length,
-                      double base_time_with_so_ms,
-                      size_t init_free_regions,
-                      double target_pause_time_ms,
-                      double* gc_eff);
 
   void start_recording_regions();
-  void record_cset_region(HeapRegion* hr, bool young);
+  void record_cset_region_info(HeapRegion* hr, bool young);
-  void record_scan_only_regions(size_t scan_only_length);
+  void record_non_young_cset_region(HeapRegion* hr);
+
+  void set_recorded_young_regions(size_t n_regions);
+  void set_recorded_young_bytes(size_t bytes);
+  void set_recorded_rs_lengths(size_t rs_lengths);
+  void set_predicted_bytes_to_copy(size_t bytes);
+
   void end_recording_regions();
 
   void record_vtime_diff_ms(double vtime_diff_ms) {
@@ -638,11 +607,74 @@ protected:
   void update_recent_gc_times(double end_time_sec, double elapsed_ms);
 
   // The head of the list (via "next_in_collection_set()") representing the
-  // current collection set.
+  // current collection set. Set from the incrementally built collection
+  // set at the start of the pause.
   HeapRegion* _collection_set;
+
+  // The number of regions in the collection set. Set from the incrementally
+  // built collection set at the start of an evacuation pause.
   size_t _collection_set_size;
+
+  // 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 {
+    Active,             // We are actively building the collection set
+    Inactive            // We are not actively building the collection set
+  };
+
+  CSetBuildType _inc_cset_build_state;
+
+  // The head of the incrementally built collection set.
+  HeapRegion* _inc_cset_head;
+
+  // The tail of the incrementally built collection set.
+  HeapRegion* _inc_cset_tail;
+
+  // The number of regions in the incrementally built collection set.
+  // Used to set _collection_set_size at the start of an evacuation
+  // pause.
+  size_t _inc_cset_size;
+
+  // Used as the index in the surving young words structure
+  // which tracks the amount of space, for each young region,
+  // that survives the pause.
+  size_t _inc_cset_young_index;
+
+  // The number of bytes in the incrementally built collection set.
+  // Used to set _collection_set_bytes_used_before at the start of
+  // an evacuation pause.
+  size_t _inc_cset_bytes_used_before;
+
+  // Used to record the highest end of heap region in collection set
+  HeapWord* _inc_cset_max_finger;
+
+  // The number of recorded used bytes in the young regions
+  // of the collection set. This is the sum of the used() bytes
+  // of retired young regions in the collection set.
+  size_t _inc_cset_recorded_young_bytes;
+
+  // The RSet lengths recorded for regions in the collection set
+  // (updated by the periodic sampling of the regions in the
+  // young list/collection set).
+  size_t _inc_cset_recorded_rs_lengths;
+
+  // The predicted elapsed time it will take to collect the regions
+  // in the collection set (updated by the periodic sampling of the
+  // regions in the young list/collection set).
+  double _inc_cset_predicted_elapsed_time_ms;
+
+  // The predicted bytes to copy for the regions in the collection
+  // set (updated by the periodic sampling of the regions in the
+  // young list/collection set).
+  size_t _inc_cset_predicted_bytes_to_copy;
+
   // Info about marking.
   int _n_marks; // Sticky at 2, so we know when we've done at least 2.
 
@@ -761,9 +793,8 @@ protected:
   double _mark_closure_time_ms;
 
   void   calculate_young_list_min_length();
-  void   calculate_young_list_target_config();
+  void   calculate_young_list_target_length();
-  void   calculate_young_list_target_config(size_t rs_lengths);
+  void   calculate_young_list_target_length(size_t rs_lengths);
-  size_t calculate_optimal_so_length(size_t young_list_length);
 
 public:
 
@@ -868,11 +899,6 @@ public:
     _par_last_mark_stack_scan_times_ms[worker_i] = ms;
   }
 
-  void record_scan_only_time(int worker_i, double ms, int n) {
-    _par_last_scan_only_times_ms[worker_i] = ms;
-    _par_last_scan_only_regions_scanned[worker_i] = (double) n;
-  }
-
   void record_satb_drain_time(double ms) {
     _cur_satb_drain_time_ms = ms;
     _satb_drain_time_set    = true;
@@ -987,20 +1013,67 @@ public:
   // Choose a new collection set.  Marks the chosen regions as being
   // "in_collection_set", and links them together.  The head and number of
   // the collection set are available via access methods.
-  virtual void choose_collection_set() = 0;
+  virtual bool choose_collection_set() = 0;
-
-  void clear_collection_set() { _collection_set = NULL; }
 
   // The head of the list (via "next_in_collection_set()") representing the
   // current collection set.
   HeapRegion* collection_set() { return _collection_set; }
 
+  void clear_collection_set() { _collection_set = NULL; }
+
   // The number of elements in the current collection set.
   size_t collection_set_size() { return _collection_set_size; }
 
   // Add "hr" to the CS.
   void add_to_collection_set(HeapRegion* hr);
 
+  // Incremental CSet Support
+
+  // The head of the incrementally built collection set.
+  HeapRegion* inc_cset_head() { return _inc_cset_head; }
+
+  // The tail of the incrementally built collection set.
+  HeapRegion* inc_set_tail() { return _inc_cset_tail; }
+
+  // The number of elements in the incrementally built collection set.
+  size_t inc_cset_size() { return _inc_cset_size; }
+
+  // Initialize incremental collection set info.
+  void start_incremental_cset_building();
+
+  void clear_incremental_cset() {
+    _inc_cset_head = NULL;
+    _inc_cset_tail = NULL;
+  }
+
+  // Stop adding regions to the incremental collection set
+  void stop_incremental_cset_building() { _inc_cset_build_state = Inactive; }
+
+  // Add/remove information about hr to the aggregated information
+  // for the incrementally built collection set.
+  void add_to_incremental_cset_info(HeapRegion* hr, size_t rs_length);
+  void remove_from_incremental_cset_info(HeapRegion* hr);
+
+  // Update information about hr in the aggregated information for
+  // the incrementally built collection set.
+  void update_incremental_cset_info(HeapRegion* hr, size_t new_rs_length);
+
+private:
+  // Update the incremental cset information when adding a region
+  // (should not be called directly).
+  void add_region_to_incremental_cset_common(HeapRegion* hr);
+
+public:
+  // Add hr to the LHS of the incremental collection set.
+  void add_region_to_incremental_cset_lhs(HeapRegion* hr);
+
+  // Add hr to the RHS of the incremental collection set.
+  void add_region_to_incremental_cset_rhs(HeapRegion* hr);
+
+#ifndef PRODUCT
+  void print_collection_set(HeapRegion* list_head, outputStream* st);
+#endif // !PRODUCT
+
   bool initiate_conc_mark_if_possible()       { return _initiate_conc_mark_if_possible;  }
   void set_initiate_conc_mark_if_possible()   { _initiate_conc_mark_if_possible = true;  }
   void clear_initiate_conc_mark_if_possible() { _initiate_conc_mark_if_possible = false; }
@@ -1191,7 +1264,7 @@ class G1CollectorPolicy_BestRegionsFirst: public G1CollectorPolicy {
   // If the estimated is less then desirable, resize if possible.
   void expand_if_possible(size_t numRegions);
 
-  virtual void choose_collection_set();
+  virtual bool choose_collection_set();
   virtual void record_collection_pause_start(double start_time_sec,
                                              size_t start_used);
   virtual void record_concurrent_mark_cleanup_end(size_t freed_bytes,

hotspot/src/share/vm/gc_implementation/g1/g1MarkSweep.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -31,6 +31,12 @@ void G1MarkSweep::invoke_at_safepoint(ReferenceProcessor* rp,
                                       bool clear_all_softrefs) {
   assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
 
+  SharedHeap* sh = SharedHeap::heap();
+#ifdef ASSERT
+  if (sh->collector_policy()->should_clear_all_soft_refs()) {
+    assert(clear_all_softrefs, "Policy should have been checked earler");
+  }
+#endif
   // hook up weak ref data so it can be used during Mark-Sweep
   assert(GenMarkSweep::ref_processor() == NULL, "no stomping");
   assert(rp != NULL, "should be non-NULL");
@@ -44,7 +50,6 @@ void G1MarkSweep::invoke_at_safepoint(ReferenceProcessor* rp,
 
   // Increment the invocation count for the permanent generation, since it is
   // implicitly collected whenever we do a full mark sweep collection.
-  SharedHeap* sh = SharedHeap::heap();
   sh->perm_gen()->stat_record()->invocations++;
 
   bool marked_for_unloading = false;

hotspot/src/share/vm/gc_implementation/g1/g1_globals.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -28,9 +28,6 @@
 
 #define G1_FLAGS(develop, develop_pd, product, product_pd, diagnostic, experimental, notproduct, manageable, product_rw) \
                                                                             \
-  product(intx, G1ParallelGCAllocBufferSize, 8*K,                           \
-          "Size of parallel G1 allocation buffers in to-space.")            \
-                                                                            \
   product(intx, G1ConfidencePercent, 50,                                    \
           "Confidence level for MMU/pause predictions")                     \
                                                                             \
@@ -229,10 +226,6 @@
           "the number of regions for which we'll print a surv rate "        \
           "summary.")                                                       \
                                                                             \
-  develop(bool, G1UseScanOnlyPrefix, false,                                 \
-          "It determines whether the system will calculate an optimum "     \
-          "scan-only set.")                                                 \
-                                                                            \
   product(intx, G1ReservePercent, 10,                                       \
           "It determines the minimum reserve we should have in the heap "   \
           "to minimize the probability of promotion failure.")              \

hotspot/src/share/vm/gc_implementation/g1/heapRegion.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -75,6 +75,16 @@ public:
   virtual void do_oop(narrowOop* p) { do_oop_work(p); }
   virtual void do_oop(      oop* p) { do_oop_work(p); }
 
+  void print_object(outputStream* out, oop obj) {
+#ifdef PRODUCT
+    klassOop k = obj->klass();
+    const char* class_name = instanceKlass::cast(k)->external_name();
+    out->print_cr("class name %s", class_name);
+#else // PRODUCT
+    obj->print_on(out);
+#endif // PRODUCT
+  }
+
   template <class T> void do_oop_work(T* p) {
     assert(_containing_obj != NULL, "Precondition");
     assert(!_g1h->is_obj_dead_cond(_containing_obj, _use_prev_marking),
@@ -90,21 +100,29 @@ public:
           gclog_or_tty->print_cr("----------");
         }
         if (!_g1h->is_in_closed_subset(obj)) {
+          HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
           gclog_or_tty->print_cr("Field "PTR_FORMAT
-                        " of live obj "PTR_FORMAT
+                                 " of live obj "PTR_FORMAT" in region "
-                        " points to obj "PTR_FORMAT
+                                 "["PTR_FORMAT", "PTR_FORMAT")",
-                        " not in the heap.",
+                                 p, (void*) _containing_obj,
-                        p, (void*) _containing_obj, (void*) obj);
+                                 from->bottom(), from->end());
+          print_object(gclog_or_tty, _containing_obj);
+          gclog_or_tty->print_cr("points to obj "PTR_FORMAT" not in the heap",
+                                 (void*) obj);
         } else {
+          HeapRegion* from = _g1h->heap_region_containing((HeapWord*)p);
+          HeapRegion* to   = _g1h->heap_region_containing((HeapWord*)obj);
           gclog_or_tty->print_cr("Field "PTR_FORMAT
-                        " of live obj "PTR_FORMAT
+                                 " of live obj "PTR_FORMAT" in region "
-                        " points to dead obj "PTR_FORMAT".",
+                                 "["PTR_FORMAT", "PTR_FORMAT")",
-                        p, (void*) _containing_obj, (void*) obj);
+                                 p, (void*) _containing_obj,
+                                 from->bottom(), from->end());
+          print_object(gclog_or_tty, _containing_obj);
+          gclog_or_tty->print_cr("points to dead obj "PTR_FORMAT" in region "
+                                 "["PTR_FORMAT", "PTR_FORMAT")",
+                                 (void*) obj, to->bottom(), to->end());
+          print_object(gclog_or_tty, obj);
         }
-        gclog_or_tty->print_cr("Live obj:");
-        _containing_obj->print_on(gclog_or_tty);
-        gclog_or_tty->print_cr("Bad referent:");
-        obj->print_on(gclog_or_tty);
         gclog_or_tty->print_cr("----------");
         _failures = true;
         failed = true;
@@ -432,7 +450,9 @@ HeapRegion(G1BlockOffsetSharedArray* sharedOffsetArray,
     _young_type(NotYoung), _next_young_region(NULL),
     _next_dirty_cards_region(NULL),
     _young_index_in_cset(-1), _surv_rate_group(NULL), _age_index(-1),
-    _rem_set(NULL), _zfs(NotZeroFilled)
+    _rem_set(NULL), _zfs(NotZeroFilled),
+    _recorded_rs_length(0), _predicted_elapsed_time_ms(0),
+    _predicted_bytes_to_copy(0)
 {
   _orig_end = mr.end();
   // Note that initialize() will set the start of the unmarked area of the
@@ -715,7 +735,7 @@ void HeapRegion::print_on(outputStream* st) const {
   else
     st->print("   ");
   if (is_young())
-    st->print(is_scan_only() ? " SO" : (is_survivor() ? " SU" : " Y "));
+    st->print(is_survivor() ? " SU" : " Y ");
   else
     st->print("   ");
   if (is_empty())
@@ -723,6 +743,8 @@ void HeapRegion::print_on(outputStream* st) const {
   else
     st->print("  ");
   st->print(" %5d", _gc_time_stamp);
+  st->print(" PTAMS "PTR_FORMAT" NTAMS "PTR_FORMAT,
+            prev_top_at_mark_start(), next_top_at_mark_start());
   G1OffsetTableContigSpace::print_on(st);
 }
 

hotspot/src/share/vm/gc_implementation/g1/heapRegion.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -247,7 +247,6 @@ class HeapRegion: public G1OffsetTableContigSpace {
 
   enum YoungType {
     NotYoung,                   // a region is not young
-    ScanOnly,                   // a region is young and scan-only
     Young,                      // a region is young
     Survivor                    // a region is young and it contains
                                 // survivor
@@ -292,6 +291,20 @@ class HeapRegion: public G1OffsetTableContigSpace {
     _young_type = new_type;
   }
 
+  // Cached attributes used in the collection set policy information
+
+  // The RSet length that was added to the total value
+  // for the collection set.
+  size_t _recorded_rs_length;
+
+  // The predicted elapsed time that was added to total value
+  // for the collection set.
+  double _predicted_elapsed_time_ms;
+
+  // The predicted number of bytes to copy that was added to
+  // the total value for the collection set.
+  size_t _predicted_bytes_to_copy;
+
  public:
   // If "is_zeroed" is "true", the region "mr" can be assumed to contain zeros.
   HeapRegion(G1BlockOffsetSharedArray* sharedOffsetArray,
@@ -614,7 +627,6 @@ class HeapRegion: public G1OffsetTableContigSpace {
   // </PREDICTION>
 
   bool is_young() const     { return _young_type != NotYoung; }
-  bool is_scan_only() const { return _young_type == ScanOnly; }
   bool is_survivor() const  { return _young_type == Survivor; }
 
   int  young_index_in_cset() const { return _young_index_in_cset; }
@@ -629,12 +641,6 @@ class HeapRegion: public G1OffsetTableContigSpace {
     return _surv_rate_group->age_in_group(_age_index);
   }
 
-  void recalculate_age_in_surv_rate_group() {
-    assert( _surv_rate_group != NULL, "pre-condition" );
-    assert( _age_index > -1, "pre-condition" );
-    _age_index = _surv_rate_group->recalculate_age_index(_age_index);
-  }
-
   void record_surv_words_in_group(size_t words_survived) {
     assert( _surv_rate_group != NULL, "pre-condition" );
     assert( _age_index > -1, "pre-condition" );
@@ -676,8 +682,6 @@ class HeapRegion: public G1OffsetTableContigSpace {
 
   void set_young() { set_young_type(Young); }
 
-  void set_scan_only() { set_young_type(ScanOnly); }
-
   void set_survivor() { set_young_type(Survivor); }
 
   void set_not_young() { set_young_type(NotYoung); }
@@ -775,6 +779,22 @@ class HeapRegion: public G1OffsetTableContigSpace {
     _zero_filler = NULL;
   }
 
+  size_t recorded_rs_length() const        { return _recorded_rs_length; }
+  double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; }
+  size_t predicted_bytes_to_copy() const   { return _predicted_bytes_to_copy; }
+
+  void set_recorded_rs_length(size_t rs_length) {
+    _recorded_rs_length = rs_length;
+  }
+
+  void set_predicted_elapsed_time_ms(double ms) {
+    _predicted_elapsed_time_ms = ms;
+  }
+
+  void set_predicted_bytes_to_copy(size_t bytes) {
+    _predicted_bytes_to_copy = bytes;
+  }
+
 #define HeapRegion_OOP_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix)  \
   virtual void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl);
   SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES(HeapRegion_OOP_SINCE_SAVE_MARKS_DECL)

hotspot/src/share/vm/gc_implementation/g1/heapRegionRemSet.cpp

@@ -662,8 +662,6 @@ void OtherRegionsTable::add_reference(OopOrNarrowOopStar from, int tid) {
         prt = PosParPRT::alloc(from_hr);
       }
       prt->init(from_hr);
-      // Record the outgoing pointer in the from_region's outgoing bitmap.
-      from_hr->rem_set()->add_outgoing_reference(hr());
 
       PosParPRT* first_prt = _fine_grain_regions[ind];
       prt->set_next(first_prt);  // XXX Maybe move to init?
@@ -1073,11 +1071,7 @@ int HeapRegionRemSet::num_par_rem_sets() {
 
 HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetSharedArray* bosa,
                                    HeapRegion* hr)
-    : _bosa(bosa), _other_regions(hr),
+  : _bosa(bosa), _other_regions(hr), _iter_state(Unclaimed) { }
-      _outgoing_region_map(G1CollectedHeap::heap()->max_regions(),
-                           false /* in-resource-area */),
-      _iter_state(Unclaimed)
-{}
 
 
 void HeapRegionRemSet::setup_remset_size() {
@@ -1148,30 +1142,11 @@ void HeapRegionRemSet::par_cleanup() {
   PosParPRT::par_contract_all();
 }
 
-void HeapRegionRemSet::add_outgoing_reference(HeapRegion* to_hr) {
-  _outgoing_region_map.par_at_put(to_hr->hrs_index(), 1);
-}
-
 void HeapRegionRemSet::clear() {
-  clear_outgoing_entries();
-  _outgoing_region_map.clear();
   _other_regions.clear();
   assert(occupied() == 0, "Should be clear.");
 }
 
-void HeapRegionRemSet::clear_outgoing_entries() {
-  G1CollectedHeap* g1h = G1CollectedHeap::heap();
-  size_t i = _outgoing_region_map.get_next_one_offset(0);
-  while (i < _outgoing_region_map.size()) {
-    HeapRegion* to_region = g1h->region_at(i);
-    if (!to_region->in_collection_set()) {
-      to_region->rem_set()->clear_incoming_entry(hr());
-    }
-    i = _outgoing_region_map.get_next_one_offset(i+1);
-  }
-}
-
-
 void HeapRegionRemSet::scrub(CardTableModRefBS* ctbs,
                              BitMap* region_bm, BitMap* card_bm) {
   _other_regions.scrub(ctbs, region_bm, card_bm);

hotspot/src/share/vm/gc_implementation/g1/heapRegionRemSet.hpp

@@ -179,13 +179,6 @@ private:
 
   OtherRegionsTable _other_regions;
 
-  // One set bit for every region that has an entry for this one.
-  BitMap _outgoing_region_map;
-
-  // Clear entries for the current region in any rem sets named in
-  // the _outgoing_region_map.
-  void clear_outgoing_entries();
-
   enum ParIterState { Unclaimed, Claimed, Complete };
   volatile ParIterState _iter_state;
   volatile jlong _iter_claimed;
@@ -243,10 +236,6 @@ public:
     _other_regions.add_reference(from, tid);
   }
 
-  // Records the fact that the current region contains an outgoing
-  // reference into "to_hr".
-  void add_outgoing_reference(HeapRegion* to_hr);
-
   // Removes any entries shown by the given bitmaps to contain only dead
   // objects.
   void scrub(CardTableModRefBS* ctbs, BitMap* region_bm, BitMap* card_bm);

hotspot/src/share/vm/gc_implementation/g1/survRateGroup.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -55,7 +55,6 @@ SurvRateGroup::SurvRateGroup(G1CollectorPolicy* g1p,
 void SurvRateGroup::reset()
 {
   _all_regions_allocated = 0;
-  _scan_only_prefix      = 0;
   _setup_seq_num         = 0;
   _stats_arrays_length   = 0;
   _accum_surv_rate       = 0.0;
@@ -74,7 +73,7 @@ void SurvRateGroup::reset()
 void
 SurvRateGroup::start_adding_regions() {
   _setup_seq_num   = _stats_arrays_length;
-  _region_num      = _scan_only_prefix;
+  _region_num      = 0;
   _accum_surv_rate = 0.0;
 
 #if 0
@@ -163,12 +162,6 @@ SurvRateGroup::next_age_index() {
   return (int) ++_all_regions_allocated;
 }
 
-void
-SurvRateGroup::record_scan_only_prefix(size_t scan_only_prefix) {
-  guarantee( scan_only_prefix <= _region_num, "pre-condition" );
-  _scan_only_prefix = scan_only_prefix;
-}
-
 void
 SurvRateGroup::record_surviving_words(int age_in_group, size_t surv_words) {
   guarantee( 0 <= age_in_group && (size_t) age_in_group < _region_num,
@@ -218,13 +211,12 @@ SurvRateGroup::all_surviving_words_recorded(bool propagate) {
 #ifndef PRODUCT
 void
 SurvRateGroup::print() {
-  gclog_or_tty->print_cr("Surv Rate Group: %s (%d entries, %d scan-only)",
+  gclog_or_tty->print_cr("Surv Rate Group: %s (%d entries)",
-                _name, _region_num, _scan_only_prefix);
+                _name, _region_num);
   for (size_t i = 0; i < _region_num; ++i) {
-    gclog_or_tty->print_cr("    age %4d   surv rate %6.2lf %%   pred %6.2lf %%%s",
+    gclog_or_tty->print_cr("    age %4d   surv rate %6.2lf %%   pred %6.2lf %%",
                   i, _surv_rate[i] * 100.0,
-                  _g1p->get_new_prediction(_surv_rate_pred[i]) * 100.0,
+                  _g1p->get_new_prediction(_surv_rate_pred[i]) * 100.0);
-                  (i < _scan_only_prefix) ? " S-O" : "    ");
   }
 }
 

hotspot/src/share/vm/gc_implementation/g1/survRateGroup.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -41,7 +41,6 @@ private:
 
   int _all_regions_allocated;
   size_t _region_num;
-  size_t _scan_only_prefix;
   size_t _setup_seq_num;
 
 public:
@@ -51,13 +50,11 @@ public:
   void reset();
   void start_adding_regions();
   void stop_adding_regions();
-  void record_scan_only_prefix(size_t scan_only_prefix);
   void record_surviving_words(int age_in_group, size_t surv_words);
   void all_surviving_words_recorded(bool propagate);
   const char* name() { return _name; }
 
   size_t region_num() { return _region_num; }
-  size_t scan_only_length() { return _scan_only_prefix; }
   double accum_surv_rate_pred(int age) {
     assert(age >= 0, "must be");
     if ((size_t)age < _stats_arrays_length)
@@ -82,17 +79,12 @@ public:
 
   int next_age_index();
   int age_in_group(int age_index) {
-    int ret = (int) (_all_regions_allocated -  age_index);
+    int ret = (int) (_all_regions_allocated - age_index);
     assert( ret >= 0, "invariant" );
     return ret;
   }
-  int recalculate_age_index(int age_index) {
-    int new_age_index = (int) _scan_only_prefix - age_in_group(age_index);
-    guarantee( new_age_index >= 0, "invariant" );
-    return new_age_index;
-  }
   void finished_recalculating_age_indexes() {
-    _all_regions_allocated = (int) _scan_only_prefix;
+    _all_regions_allocated = 0;
   }
 
 #ifndef PRODUCT

hotspot/src/share/vm/gc_implementation/includeDB_gc_parallelScavenge

@@ -1,5 +1,5 @@
 //
-// Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+// Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
 // DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 //
 // This code is free software; you can redistribute it and/or modify it
@@ -161,8 +161,10 @@ parMarkBitMap.cpp                       psParallelCompact.hpp
 parMarkBitMap.hpp			bitMap.inline.hpp
 parMarkBitMap.hpp			psVirtualspace.hpp
 
+psAdaptiveSizePolicy.cpp                collectorPolicy.hpp
 psAdaptiveSizePolicy.cpp                gcPolicyCounters.hpp
 psAdaptiveSizePolicy.cpp		gcCause.hpp
+psAdaptiveSizePolicy.cpp                generationSizer.hpp
 psAdaptiveSizePolicy.cpp                psAdaptiveSizePolicy.hpp
 psAdaptiveSizePolicy.cpp                psGCAdaptivePolicyCounters.hpp
 psAdaptiveSizePolicy.cpp                psScavenge.hpp
@@ -215,6 +217,7 @@ psMarkSweep.cpp                         events.hpp
 psMarkSweep.cpp                         fprofiler.hpp
 psMarkSweep.cpp                         gcCause.hpp
 psMarkSweep.cpp                         gcLocker.inline.hpp
+psMarkSweep.cpp                         generationSizer.hpp
 psMarkSweep.cpp                         isGCActiveMark.hpp
 psMarkSweep.cpp                         oop.inline.hpp
 psMarkSweep.cpp                         memoryService.hpp
@@ -256,6 +259,7 @@ psParallelCompact.cpp			fprofiler.hpp
 psParallelCompact.cpp			gcCause.hpp
 psParallelCompact.cpp			gcLocker.inline.hpp
 psParallelCompact.cpp                   gcTaskManager.hpp
+psParallelCompact.cpp                   generationSizer.hpp
 psParallelCompact.cpp			isGCActiveMark.hpp
 psParallelCompact.cpp			management.hpp
 psParallelCompact.cpp			memoryService.hpp
@@ -344,10 +348,12 @@ psPromotionLAB.hpp                      objectStartArray.hpp
 psScavenge.cpp                          psAdaptiveSizePolicy.hpp
 psScavenge.cpp                          biasedLocking.hpp
 psScavenge.cpp                          cardTableExtension.hpp
+psScavenge.cpp                          collectorPolicy.hpp
 psScavenge.cpp                          fprofiler.hpp
 psScavenge.cpp                          gcCause.hpp
 psScavenge.cpp                          gcLocker.inline.hpp
 psScavenge.cpp                          gcTaskManager.hpp
+psScavenge.cpp                          generationSizer.hpp
 psScavenge.cpp                          handles.inline.hpp
 psScavenge.cpp                          isGCActiveMark.hpp
 psScavenge.cpp                          oop.inline.hpp

hotspot/src/share/vm/gc_implementation/includeDB_gc_serial

@@ -1,5 +1,5 @@
 //
-// Copyright (c) 2007 Sun Microsystems, Inc.  All Rights Reserved.
+// Copyright 2007-2010 Sun Microsystems, Inc.  All Rights Reserved.
 // DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 //   
 // This code is free software; you can redistribute it and/or modify it
@@ -29,6 +29,7 @@ adaptiveSizePolicy.hpp			allocation.hpp
 adaptiveSizePolicy.hpp			universe.hpp
 
 adaptiveSizePolicy.cpp			adaptiveSizePolicy.hpp
+adaptiveSizePolicy.cpp			collectorPolicy.hpp
 adaptiveSizePolicy.cpp			gcCause.hpp
 adaptiveSizePolicy.cpp			ostream.hpp
 adaptiveSizePolicy.cpp			timer.hpp

hotspot/src/share/vm/gc_implementation/parNew/parNewGeneration.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -892,6 +892,10 @@ void ParNewGeneration::collect(bool   full,
     }
     swap_spaces();
 
+    // A successful scavenge should restart the GC time limit count which is
+    // for full GC's.
+    size_policy->reset_gc_overhead_limit_count();
+
     assert(to()->is_empty(), "to space should be empty now");
   } else {
     assert(HandlePromotionFailure,

hotspot/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -54,15 +54,16 @@ jint ParallelScavengeHeap::initialize() {
   CollectedHeap::pre_initialize();
 
   // Cannot be initialized until after the flags are parsed
-  GenerationSizer flag_parser;
+  // GenerationSizer flag_parser;
+  _collector_policy = new GenerationSizer();
 
-  size_t yg_min_size = flag_parser.min_young_gen_size();
+  size_t yg_min_size = _collector_policy->min_young_gen_size();
-  size_t yg_max_size = flag_parser.max_young_gen_size();
+  size_t yg_max_size = _collector_policy->max_young_gen_size();
-  size_t og_min_size = flag_parser.min_old_gen_size();
+  size_t og_min_size = _collector_policy->min_old_gen_size();
-  size_t og_max_size = flag_parser.max_old_gen_size();
+  size_t og_max_size = _collector_policy->max_old_gen_size();
   // Why isn't there a min_perm_gen_size()?
-  size_t pg_min_size = flag_parser.perm_gen_size();
+  size_t pg_min_size = _collector_policy->perm_gen_size();
-  size_t pg_max_size = flag_parser.max_perm_gen_size();
+  size_t pg_max_size = _collector_policy->max_perm_gen_size();
 
   trace_gen_sizes("ps heap raw",
                   pg_min_size, pg_max_size,
@@ -89,12 +90,14 @@ jint ParallelScavengeHeap::initialize() {
   // move to the common code.
   yg_min_size = align_size_up(yg_min_size, yg_align);
   yg_max_size = align_size_up(yg_max_size, yg_align);
-  size_t yg_cur_size = align_size_up(flag_parser.young_gen_size(), yg_align);
+  size_t yg_cur_size =
+    align_size_up(_collector_policy->young_gen_size(), yg_align);
   yg_cur_size = MAX2(yg_cur_size, yg_min_size);
 
   og_min_size = align_size_up(og_min_size, og_align);
   og_max_size = align_size_up(og_max_size, og_align);
-  size_t og_cur_size = align_size_up(flag_parser.old_gen_size(), og_align);
+  size_t og_cur_size =
+    align_size_up(_collector_policy->old_gen_size(), og_align);
   og_cur_size = MAX2(og_cur_size, og_min_size);
 
   pg_min_size = align_size_up(pg_min_size, pg_align);
@@ -355,6 +358,11 @@ HeapWord* ParallelScavengeHeap::mem_allocate(
   assert(Thread::current() != (Thread*)VMThread::vm_thread(), "should not be in vm thread");
   assert(!Heap_lock->owned_by_self(), "this thread should not own the Heap_lock");
 
+  // In general gc_overhead_limit_was_exceeded should be false so
+  // set it so here and reset it to true only if the gc time
+  // limit is being exceeded as checked below.
+  *gc_overhead_limit_was_exceeded = false;
+
   HeapWord* result = young_gen()->allocate(size, is_tlab);
 
   uint loop_count = 0;
@@ -428,24 +436,6 @@ HeapWord* ParallelScavengeHeap::mem_allocate(
 
     if (result == NULL) {
 
-      // Exit the loop if if the gc time limit has been exceeded.
-      // The allocation must have failed above (result must be NULL),
-      // and the most recent collection must have exceeded the
-      // gc time limit.  Exit the loop so that an out-of-memory
-      // will be thrown (returning a NULL will do that), but
-      // clear gc_time_limit_exceeded so that the next collection
-      // will succeeded if the applications decides to handle the
-      // out-of-memory and tries to go on.
-      *gc_overhead_limit_was_exceeded = size_policy()->gc_time_limit_exceeded();
-      if (size_policy()->gc_time_limit_exceeded()) {
-        size_policy()->set_gc_time_limit_exceeded(false);
-        if (PrintGCDetails && Verbose) {
-        gclog_or_tty->print_cr("ParallelScavengeHeap::mem_allocate: "
-          "return NULL because gc_time_limit_exceeded is set");
-        }
-        return NULL;
-      }
-
       // Generate a VM operation
       VM_ParallelGCFailedAllocation op(size, is_tlab, gc_count);
       VMThread::execute(&op);
@@ -463,16 +453,34 @@ HeapWord* ParallelScavengeHeap::mem_allocate(
           assert(op.result() == NULL, "must be NULL if gc_locked() is true");
           continue;  // retry and/or stall as necessary
         }
-        // If a NULL result is being returned, an out-of-memory
+
-        // will be thrown now.  Clear the gc_time_limit_exceeded
+        // Exit the loop if the gc time limit has been exceeded.
-        // flag to avoid the following situation.
+        // The allocation must have failed above ("result" guarding
-        //      gc_time_limit_exceeded is set during a collection
+        // this path is NULL) and the most recent collection has exceeded the
-        //      the collection fails to return enough space and an OOM is thrown
+        // gc overhead limit (although enough may have been collected to
-        //      the next GC is skipped because the gc_time_limit_exceeded
+        // satisfy the allocation).  Exit the loop so that an out-of-memory
-        //        flag is set and another OOM is thrown
+        // will be thrown (return a NULL ignoring the contents of
-        if (op.result() == NULL) {
+        // op.result()),
-          size_policy()->set_gc_time_limit_exceeded(false);
+        // but clear gc_overhead_limit_exceeded so that the next collection
+        // starts with a clean slate (i.e., forgets about previous overhead
+        // excesses).  Fill op.result() with a filler object so that the
+        // heap remains parsable.
+        const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
+        const bool softrefs_clear = collector_policy()->all_soft_refs_clear();
+        assert(!limit_exceeded || softrefs_clear, "Should have been cleared");
+        if (limit_exceeded && softrefs_clear) {
+          *gc_overhead_limit_was_exceeded = true;
+          size_policy()->set_gc_overhead_limit_exceeded(false);
+          if (PrintGCDetails && Verbose) {
+            gclog_or_tty->print_cr("ParallelScavengeHeap::mem_allocate: "
+              "return NULL because gc_overhead_limit_exceeded is set");
+          }
+          if (op.result() != NULL) {
+            CollectedHeap::fill_with_object(op.result(), size);
+          }
+          return NULL;
         }
+
         return op.result();
       }
     }
@@ -613,14 +621,15 @@ HeapWord* ParallelScavengeHeap::permanent_mem_allocate(size_t size) {
       // and the most recent collection must have exceeded the
       // gc time limit.  Exit the loop so that an out-of-memory
       // will be thrown (returning a NULL will do that), but
-      // clear gc_time_limit_exceeded so that the next collection
+      // clear gc_overhead_limit_exceeded so that the next collection
       // will succeeded if the applications decides to handle the
       // out-of-memory and tries to go on.
-      if (size_policy()->gc_time_limit_exceeded()) {
+      const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
-        size_policy()->set_gc_time_limit_exceeded(false);
+      if (limit_exceeded) {
+        size_policy()->set_gc_overhead_limit_exceeded(false);
         if (PrintGCDetails && Verbose) {
-        gclog_or_tty->print_cr("ParallelScavengeHeap::permanent_mem_allocate: "
+          gclog_or_tty->print_cr("ParallelScavengeHeap::permanent_mem_allocate:"
-          "return NULL because gc_time_limit_exceeded is set");
+            " return NULL because gc_overhead_limit_exceeded is set");
         }
         assert(result == NULL, "Allocation did not fail");
         return NULL;
@@ -643,14 +652,15 @@ HeapWord* ParallelScavengeHeap::permanent_mem_allocate(size_t size) {
           continue;  // retry and/or stall as necessary
         }
         // If a NULL results is being returned, an out-of-memory
-        // will be thrown now.  Clear the gc_time_limit_exceeded
+        // will be thrown now.  Clear the gc_overhead_limit_exceeded
         // flag to avoid the following situation.
-        //      gc_time_limit_exceeded is set during a collection
+        //      gc_overhead_limit_exceeded is set during a collection
         //      the collection fails to return enough space and an OOM is thrown
-        //      the next GC is skipped because the gc_time_limit_exceeded
+        //      a subsequent GC prematurely throws an out-of-memory because
-        //        flag is set and another OOM is thrown
+        //        the gc_overhead_limit_exceeded counts did not start
+        //        again from 0.
         if (op.result() == NULL) {
-          size_policy()->set_gc_time_limit_exceeded(false);
+          size_policy()->reset_gc_overhead_limit_count();
         }
         return op.result();
       }

hotspot/src/share/vm/gc_implementation/parallelScavenge/parallelScavengeHeap.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,6 +25,8 @@
 class AdjoiningGenerations;
 class GCTaskManager;
 class PSAdaptiveSizePolicy;
+class GenerationSizer;
+class CollectorPolicy;
 
 class ParallelScavengeHeap : public CollectedHeap {
   friend class VMStructs;
@@ -43,6 +45,8 @@ class ParallelScavengeHeap : public CollectedHeap {
   size_t _young_gen_alignment;
   size_t _old_gen_alignment;
 
+  GenerationSizer* _collector_policy;
+
   inline size_t set_alignment(size_t& var, size_t val);
 
   // Collection of generations that are adjacent in the
@@ -72,6 +76,9 @@ class ParallelScavengeHeap : public CollectedHeap {
     return CollectedHeap::ParallelScavengeHeap;
   }
 
+CollectorPolicy* collector_policy() const { return (CollectorPolicy*) _collector_policy; }
+  // GenerationSizer* collector_policy() const { return _collector_policy; }
+
   static PSYoungGen* young_gen()     { return _young_gen; }
   static PSOldGen* old_gen()         { return _old_gen; }
   static PSPermGen* perm_gen()       { return _perm_gen; }

hotspot/src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2002-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -184,18 +184,19 @@ void PSAdaptiveSizePolicy::clear_generation_free_space_flags() {
   set_change_young_gen_for_maj_pauses(0);
 }
 
-
 // If this is not a full GC, only test and modify the young generation.
 
-void PSAdaptiveSizePolicy::compute_generation_free_space(size_t young_live,
+void PSAdaptiveSizePolicy::compute_generation_free_space(
-                                               size_t eden_live,
+                                           size_t young_live,
-                                               size_t old_live,
+                                           size_t eden_live,
-                                               size_t perm_live,
+                                           size_t old_live,
-                                               size_t cur_eden,
+                                           size_t perm_live,
-                                               size_t max_old_gen_size,
+                                           size_t cur_eden,
-                                               size_t max_eden_size,
+                                           size_t max_old_gen_size,
-                                               bool   is_full_gc,
+                                           size_t max_eden_size,
-                                               GCCause::Cause gc_cause) {
+                                           bool   is_full_gc,
+                                           GCCause::Cause gc_cause,
+                                           CollectorPolicy* collector_policy) {
 
   // Update statistics
   // Time statistics are updated as we go, update footprint stats here
@@ -380,91 +381,16 @@ void PSAdaptiveSizePolicy::compute_generation_free_space(size_t young_live,
   // Is too much time being spent in GC?
   //   Is the heap trying to grow beyond it's limits?
 
-  const size_t free_in_old_gen = (size_t)(max_old_gen_size - avg_old_live()->average());
+  const size_t free_in_old_gen =
+    (size_t)(max_old_gen_size - avg_old_live()->average());
   if (desired_promo_size > free_in_old_gen && desired_eden_size > eden_limit) {
-
+    check_gc_overhead_limit(young_live,
-    // eden_limit is the upper limit on the size of eden based on
+                            eden_live,
-    // the maximum size of the young generation and the sizes
+                            max_old_gen_size,
-    // of the survivor space.
+                            max_eden_size,
-    // The question being asked is whether the gc costs are high
+                            is_full_gc,
-    // and the space being recovered by a collection is low.
+                            gc_cause,
-    // free_in_young_gen is the free space in the young generation
+                            collector_policy);
-    // after a collection and promo_live is the free space in the old
-    // generation after a collection.
-    //
-    // Use the minimum of the current value of the live in the
-    // young gen or the average of the live in the young gen.
-    // If the current value drops quickly, that should be taken
-    // into account (i.e., don't trigger if the amount of free
-    // space has suddenly jumped up).  If the current is much
-    // higher than the average, use the average since it represents
-    // the longer term behavor.
-    const size_t live_in_eden = MIN2(eden_live, (size_t) avg_eden_live()->average());
-    const size_t free_in_eden = eden_limit > live_in_eden ?
-      eden_limit - live_in_eden : 0;
-    const size_t total_free_limit = free_in_old_gen + free_in_eden;
-    const size_t total_mem = max_old_gen_size + max_eden_size;
-    const double mem_free_limit = total_mem * (GCHeapFreeLimit/100.0);
-    if (PrintAdaptiveSizePolicy && (Verbose ||
-        (total_free_limit < (size_t) mem_free_limit))) {
-      gclog_or_tty->print_cr(
-            "PSAdaptiveSizePolicy::compute_generation_free_space limits:"
-            " promo_limit: " SIZE_FORMAT
-            " eden_limit: " SIZE_FORMAT
-            " total_free_limit: " SIZE_FORMAT
-            " max_old_gen_size: " SIZE_FORMAT
-            " max_eden_size: " SIZE_FORMAT
-            " mem_free_limit: " SIZE_FORMAT,
-            promo_limit, eden_limit, total_free_limit,
-            max_old_gen_size, max_eden_size,
-            (size_t) mem_free_limit);
-    }
-
-    if (is_full_gc) {
-      if (gc_cost() > gc_cost_limit &&
-        total_free_limit < (size_t) mem_free_limit) {
-        // Collections, on average, are taking too much time, and
-        //      gc_cost() > gc_cost_limit
-        // we have too little space available after a full gc.
-        //      total_free_limit < mem_free_limit
-        // where
-        //   total_free_limit is the free space available in
-        //     both generations
-        //   total_mem is the total space available for allocation
-        //     in both generations (survivor spaces are not included
-        //     just as they are not included in eden_limit).
-        //   mem_free_limit is a fraction of total_mem judged to be an
-        //     acceptable amount that is still unused.
-        // The heap can ask for the value of this variable when deciding
-        // whether to thrown an OutOfMemory error.
-        // Note that the gc time limit test only works for the collections
-        // of the young gen + tenured gen and not for collections of the
-        // permanent gen.  That is because the calculation of the space
-        // freed by the collection is the free space in the young gen +
-        // tenured gen.
-        // Ignore explicit GC's. Ignoring explicit GC's at this level
-        // is the equivalent of the GC did not happen as far as the
-        // overhead calculation is concerted (i.e., the flag is not set
-        // and the count is not affected).  Also the average will not
-        // have been updated unless UseAdaptiveSizePolicyWithSystemGC is on.
-        if (!GCCause::is_user_requested_gc(gc_cause) &&
-            !GCCause::is_serviceability_requested_gc(gc_cause)) {
-          inc_gc_time_limit_count();
-          if (UseGCOverheadLimit &&
-              (gc_time_limit_count() > AdaptiveSizePolicyGCTimeLimitThreshold)){
-            // All conditions have been met for throwing an out-of-memory
-            _gc_time_limit_exceeded = true;
-            // Avoid consecutive OOM due to the gc time limit by resetting
-            // the counter.
-            reset_gc_time_limit_count();
-          }
-          _print_gc_time_limit_would_be_exceeded = true;
-        }
-      } else {
-        // Did not exceed overhead limits
-        reset_gc_time_limit_count();
-      }
-    }
   }
 
 

hotspot/src/share/vm/gc_implementation/parallelScavenge/psAdaptiveSizePolicy.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2002-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -45,6 +45,7 @@
 
 // Forward decls
 class elapsedTimer;
+class GenerationSizer;
 
 class PSAdaptiveSizePolicy : public AdaptiveSizePolicy {
  friend class PSGCAdaptivePolicyCounters;
@@ -340,7 +341,8 @@ class PSAdaptiveSizePolicy : public AdaptiveSizePolicy {
                                      size_t max_old_gen_size,
                                      size_t max_eden_size,
                                      bool   is_full_gc,
-                                     GCCause::Cause gc_cause);
+                                     GCCause::Cause gc_cause,
+                                     CollectorPolicy* collector_policy);
 
   // Calculates new survivor space size;  returns a new tenuring threshold
   // value. Stores new survivor size in _survivor_size.

hotspot/src/share/vm/gc_implementation/parallelScavenge/psGCAdaptivePolicyCounters.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2003-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -117,11 +117,13 @@ PSGCAdaptivePolicyCounters::PSGCAdaptivePolicyCounters(const char* name_arg,
       PerfData::U_Bytes, (jlong) ps_size_policy()->avg_base_footprint()->average(), CHECK);
 
     cname = PerfDataManager::counter_name(name_space(), "gcTimeLimitExceeded");
-    _gc_time_limit_exceeded = PerfDataManager::create_variable(SUN_GC, cname,
+    _gc_overhead_limit_exceeded_counter =
-      PerfData::U_Events, ps_size_policy()->gc_time_limit_exceeded(), CHECK);
+      PerfDataManager::create_variable(SUN_GC, cname,
+      PerfData::U_Events, ps_size_policy()->gc_overhead_limit_exceeded(), CHECK);
 
     cname = PerfDataManager::counter_name(name_space(), "liveAtLastFullGc");
-    _live_at_last_full_gc = PerfDataManager::create_variable(SUN_GC, cname,
+    _live_at_last_full_gc_counter =
+      PerfDataManager::create_variable(SUN_GC, cname,
       PerfData::U_Bytes, ps_size_policy()->live_at_last_full_gc(), CHECK);
 
     cname = PerfDataManager::counter_name(name_space(), "majorPauseOldSlope");
@@ -189,6 +191,8 @@ void PSGCAdaptivePolicyCounters::update_counters_from_policy() {
     update_minor_pause_old_slope();
     update_major_pause_young_slope();
     update_minor_collection_slope_counter();
+    update_gc_overhead_limit_exceeded_counter();
+    update_live_at_last_full_gc_counter();
   }
 }
 

hotspot/src/share/vm/gc_implementation/parallelScavenge/psGCAdaptivePolicyCounters.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2003-2005 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2003-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -44,8 +44,8 @@ class PSGCAdaptivePolicyCounters : public GCAdaptivePolicyCounters {
   PerfVariable* _live_space;
   PerfVariable* _free_space;
   PerfVariable* _avg_base_footprint;
-  PerfVariable* _gc_time_limit_exceeded;
+  PerfVariable* _gc_overhead_limit_exceeded_counter;
-  PerfVariable* _live_at_last_full_gc;
+  PerfVariable* _live_at_last_full_gc_counter;
   PerfVariable* _old_capacity;
   PerfVariable* _boundary_moved;
 
@@ -169,6 +169,14 @@ class PSGCAdaptivePolicyCounters : public GCAdaptivePolicyCounters {
       (jlong)(ps_size_policy()->major_pause_young_slope() * 1000)
     );
   }
+  inline void update_gc_overhead_limit_exceeded_counter() {
+    _gc_overhead_limit_exceeded_counter->set_value(
+      (jlong) ps_size_policy()->gc_overhead_limit_exceeded());
+  }
+  inline void update_live_at_last_full_gc_counter() {
+    _live_at_last_full_gc_counter->set_value(
+      (jlong)(ps_size_policy()->live_at_last_full_gc()));
+  }
 
   inline void update_scavenge_skipped(int cause) {
     _scavenge_skipped->set_value(cause);

hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -46,6 +46,12 @@ void PSMarkSweep::initialize() {
 //
 // Note that this method should only be called from the vm_thread while
 // at a safepoint!
+//
+// Note that the all_soft_refs_clear flag in the collector policy
+// may be true because this method can be called without intervening
+// activity.  For example when the heap space is tight and full measure
+// are being taken to free space.
+
 void PSMarkSweep::invoke(bool maximum_heap_compaction) {
   assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
   assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
@@ -54,24 +60,18 @@ void PSMarkSweep::invoke(bool maximum_heap_compaction) {
   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
   GCCause::Cause gc_cause = heap->gc_cause();
   PSAdaptiveSizePolicy* policy = heap->size_policy();
+  IsGCActiveMark mark;
 
-  // Before each allocation/collection attempt, find out from the
+  if (ScavengeBeforeFullGC) {
-  // policy object if GCs are, on the whole, taking too long. If so,
+    PSScavenge::invoke_no_policy();
-  // bail out without attempting a collection.  The exceptions are
-  // for explicitly requested GC's.
-  if (!policy->gc_time_limit_exceeded() ||
-      GCCause::is_user_requested_gc(gc_cause) ||
-      GCCause::is_serviceability_requested_gc(gc_cause)) {
-    IsGCActiveMark mark;
-
-    if (ScavengeBeforeFullGC) {
-      PSScavenge::invoke_no_policy();
-    }
-
-    int count = (maximum_heap_compaction)?1:MarkSweepAlwaysCompactCount;
-    IntFlagSetting flag_setting(MarkSweepAlwaysCompactCount, count);
-    PSMarkSweep::invoke_no_policy(maximum_heap_compaction);
   }
+
+  const bool clear_all_soft_refs =
+    heap->collector_policy()->should_clear_all_soft_refs();
+
+  int count = (maximum_heap_compaction)?1:MarkSweepAlwaysCompactCount;
+  IntFlagSetting flag_setting(MarkSweepAlwaysCompactCount, count);
+  PSMarkSweep::invoke_no_policy(clear_all_soft_refs || maximum_heap_compaction);
 }
 
 // This method contains no policy. You should probably
@@ -89,6 +89,10 @@ void PSMarkSweep::invoke_no_policy(bool clear_all_softrefs) {
   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
   PSAdaptiveSizePolicy* size_policy = heap->size_policy();
 
+  // The scope of casr should end after code that can change
+  // CollectorPolicy::_should_clear_all_soft_refs.
+  ClearedAllSoftRefs casr(clear_all_softrefs, heap->collector_policy());
+
   PSYoungGen* young_gen = heap->young_gen();
   PSOldGen* old_gen = heap->old_gen();
   PSPermGen* perm_gen = heap->perm_gen();
@@ -275,7 +279,8 @@ void PSMarkSweep::invoke_no_policy(bool clear_all_softrefs) {
                                  old_gen->max_gen_size(),
                                  max_eden_size,
                                  true /* full gc*/,
-                                 gc_cause);
+                                 gc_cause,
+                                 heap->collector_policy());
 
         heap->resize_old_gen(size_policy->calculated_old_free_size_in_bytes());
 
@@ -326,19 +331,6 @@ void PSMarkSweep::invoke_no_policy(bool clear_all_softrefs) {
     // Track memory usage and detect low memory
     MemoryService::track_memory_usage();
     heap->update_counters();
-
-    if (PrintGCDetails) {
-      if (size_policy->print_gc_time_limit_would_be_exceeded()) {
-        if (size_policy->gc_time_limit_exceeded()) {
-          gclog_or_tty->print_cr("      GC time is exceeding GCTimeLimit "
-            "of %d%%", GCTimeLimit);
-        } else {
-          gclog_or_tty->print_cr("      GC time would exceed GCTimeLimit "
-            "of %d%%", GCTimeLimit);
-        }
-      }
-      size_policy->set_print_gc_time_limit_would_be_exceeded(false);
-    }
   }
 
   if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) {

hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2005-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2005-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -1923,31 +1923,32 @@ void PSParallelCompact::summary_phase(ParCompactionManager* cm,
 //
 // Note that this method should only be called from the vm_thread while at a
 // safepoint.
+//
+// Note that the all_soft_refs_clear flag in the collector policy
+// may be true because this method can be called without intervening
+// activity.  For example when the heap space is tight and full measure
+// are being taken to free space.
 void PSParallelCompact::invoke(bool maximum_heap_compaction) {
   assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
   assert(Thread::current() == (Thread*)VMThread::vm_thread(),
          "should be in vm thread");
+
   ParallelScavengeHeap* heap = gc_heap();
   GCCause::Cause gc_cause = heap->gc_cause();
   assert(!heap->is_gc_active(), "not reentrant");
 
   PSAdaptiveSizePolicy* policy = heap->size_policy();
+  IsGCActiveMark mark;
 
-  // Before each allocation/collection attempt, find out from the
+  if (ScavengeBeforeFullGC) {
-  // policy object if GCs are, on the whole, taking too long. If so,
+    PSScavenge::invoke_no_policy();
-  // bail out without attempting a collection.  The exceptions are
-  // for explicitly requested GC's.
-  if (!policy->gc_time_limit_exceeded() ||
-      GCCause::is_user_requested_gc(gc_cause) ||
-      GCCause::is_serviceability_requested_gc(gc_cause)) {
-    IsGCActiveMark mark;
-
-    if (ScavengeBeforeFullGC) {
-      PSScavenge::invoke_no_policy();
-    }
-
-    PSParallelCompact::invoke_no_policy(maximum_heap_compaction);
   }
+
+  const bool clear_all_soft_refs =
+    heap->collector_policy()->should_clear_all_soft_refs();
+
+  PSParallelCompact::invoke_no_policy(clear_all_soft_refs ||
+                                      maximum_heap_compaction);
 }
 
 bool ParallelCompactData::region_contains(size_t region_index, HeapWord* addr) {
@@ -1976,6 +1977,11 @@ void PSParallelCompact::invoke_no_policy(bool maximum_heap_compaction) {
   PSPermGen* perm_gen = heap->perm_gen();
   PSAdaptiveSizePolicy* size_policy = heap->size_policy();
 
+  // The scope of casr should end after code that can change
+  // CollectorPolicy::_should_clear_all_soft_refs.
+  ClearedAllSoftRefs casr(maximum_heap_compaction,
+                          heap->collector_policy());
+
   if (ZapUnusedHeapArea) {
     // Save information needed to minimize mangling
     heap->record_gen_tops_before_GC();
@@ -2109,7 +2115,8 @@ void PSParallelCompact::invoke_no_policy(bool maximum_heap_compaction) {
                               old_gen->max_gen_size(),
                               max_eden_size,
                               true /* full gc*/,
-                              gc_cause);
+                              gc_cause,
+                              heap->collector_policy());
 
         heap->resize_old_gen(
           size_policy->calculated_old_free_size_in_bytes());
@@ -2157,19 +2164,6 @@ void PSParallelCompact::invoke_no_policy(bool maximum_heap_compaction) {
     // Track memory usage and detect low memory
     MemoryService::track_memory_usage();
     heap->update_counters();
-
-    if (PrintGCDetails) {
-      if (size_policy->print_gc_time_limit_would_be_exceeded()) {
-        if (size_policy->gc_time_limit_exceeded()) {
-          gclog_or_tty->print_cr("      GC time is exceeding GCTimeLimit "
-            "of %d%%", GCTimeLimit);
-        } else {
-          gclog_or_tty->print_cr("      GC time would exceed GCTimeLimit "
-            "of %d%%", GCTimeLimit);
-        }
-      }
-      size_policy->set_print_gc_time_limit_would_be_exceeded(false);
-    }
   }
 
   if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) {

hotspot/src/share/vm/gc_implementation/parallelScavenge/psScavenge.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2002-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -187,8 +187,7 @@ void PSRefProcTaskExecutor::execute(EnqueueTask& task)
 //
 // Note that this method should only be called from the vm_thread while
 // at a safepoint!
-void PSScavenge::invoke()
+void PSScavenge::invoke() {
-{
   assert(SafepointSynchronize::is_at_safepoint(), "should be at safepoint");
   assert(Thread::current() == (Thread*)VMThread::vm_thread(), "should be in vm thread");
   assert(!Universe::heap()->is_gc_active(), "not reentrant");
@@ -197,29 +196,25 @@ void PSScavenge::invoke()
   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
 
   PSAdaptiveSizePolicy* policy = heap->size_policy();
+  IsGCActiveMark mark;
 
-  // Before each allocation/collection attempt, find out from the
+  bool scavenge_was_done = PSScavenge::invoke_no_policy();
-  // policy object if GCs are, on the whole, taking too long. If so,
-  // bail out without attempting a collection.
-  if (!policy->gc_time_limit_exceeded()) {
-    IsGCActiveMark mark;
 
-    bool scavenge_was_done = PSScavenge::invoke_no_policy();
+  PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters();
-
+  if (UsePerfData)
-    PSGCAdaptivePolicyCounters* counters = heap->gc_policy_counters();
+    counters->update_full_follows_scavenge(0);
+  if (!scavenge_was_done ||
+      policy->should_full_GC(heap->old_gen()->free_in_bytes())) {
     if (UsePerfData)
-      counters->update_full_follows_scavenge(0);
+      counters->update_full_follows_scavenge(full_follows_scavenge);
-    if (!scavenge_was_done ||
+    GCCauseSetter gccs(heap, GCCause::_adaptive_size_policy);
-        policy->should_full_GC(heap->old_gen()->free_in_bytes())) {
+    CollectorPolicy* cp = heap->collector_policy();
-      if (UsePerfData)
+    const bool clear_all_softrefs = cp->should_clear_all_soft_refs();
-        counters->update_full_follows_scavenge(full_follows_scavenge);
 
-      GCCauseSetter gccs(heap, GCCause::_adaptive_size_policy);
+    if (UseParallelOldGC) {
-      if (UseParallelOldGC) {
+      PSParallelCompact::invoke_no_policy(clear_all_softrefs);
-        PSParallelCompact::invoke_no_policy(false);
+    } else {
-      } else {
+      PSMarkSweep::invoke_no_policy(clear_all_softrefs);
-        PSMarkSweep::invoke_no_policy(false);
-      }
     }
   }
 }
@@ -447,6 +442,9 @@ bool PSScavenge::invoke_no_policy() {
       size_t promoted = old_gen->used_in_bytes() - old_gen_used_before;
       size_policy->update_averages(_survivor_overflow, survived, promoted);
 
+      // A successful scavenge should restart the GC time limit count which is
+      // for full GC's.
+      size_policy->reset_gc_overhead_limit_count();
       if (UseAdaptiveSizePolicy) {
         // Calculate the new survivor size and tenuring threshold
 
@@ -523,7 +521,8 @@ bool PSScavenge::invoke_no_policy() {
                                    old_gen->max_gen_size(),
                                    max_eden_size,
                                    false  /* full gc*/,
-                                   gc_cause);
+                                   gc_cause,
+                                   heap->collector_policy());
 
         }
         // Resize the young generation at every collection

hotspot/src/share/vm/gc_implementation/shared/adaptiveSizePolicy.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2004-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2004-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -44,13 +44,15 @@ AdaptiveSizePolicy::AdaptiveSizePolicy(size_t init_eden_size,
     _survivor_size(init_survivor_size),
     _gc_pause_goal_sec(gc_pause_goal_sec),
     _throughput_goal(1.0 - double(1.0 / (1.0 + (double) gc_cost_ratio))),
-    _gc_time_limit_exceeded(false),
+    _gc_overhead_limit_exceeded(false),
-    _print_gc_time_limit_would_be_exceeded(false),
+    _print_gc_overhead_limit_would_be_exceeded(false),
-    _gc_time_limit_count(0),
+    _gc_overhead_limit_count(0),
     _latest_minor_mutator_interval_seconds(0),
     _threshold_tolerance_percent(1.0 + ThresholdTolerance/100.0),
     _young_gen_change_for_minor_throughput(0),
     _old_gen_change_for_major_throughput(0) {
+  assert(AdaptiveSizePolicyGCTimeLimitThreshold > 0,
+    "No opportunity to clear SoftReferences before GC overhead limit");
   _avg_minor_pause    =
     new AdaptivePaddedAverage(AdaptiveTimeWeight, PausePadding);
   _avg_minor_interval = new AdaptiveWeightedAverage(AdaptiveTimeWeight);
@@ -278,6 +280,147 @@ void AdaptiveSizePolicy::clear_generation_free_space_flags() {
   set_decide_at_full_gc(0);
 }
 
+void AdaptiveSizePolicy::check_gc_overhead_limit(
+                                          size_t young_live,
+                                          size_t eden_live,
+                                          size_t max_old_gen_size,
+                                          size_t max_eden_size,
+                                          bool   is_full_gc,
+                                          GCCause::Cause gc_cause,
+                                          CollectorPolicy* collector_policy) {
+
+  // Ignore explicit GC's.  Exiting here does not set the flag and
+  // does not reset the count.  Updating of the averages for system
+  // GC's is still controlled by UseAdaptiveSizePolicyWithSystemGC.
+  if (GCCause::is_user_requested_gc(gc_cause) ||
+      GCCause::is_serviceability_requested_gc(gc_cause)) {
+    return;
+  }
+  // eden_limit is the upper limit on the size of eden based on
+  // the maximum size of the young generation and the sizes
+  // of the survivor space.
+  // The question being asked is whether the gc costs are high
+  // and the space being recovered by a collection is low.
+  // free_in_young_gen is the free space in the young generation
+  // after a collection and promo_live is the free space in the old
+  // generation after a collection.
+  //
+  // Use the minimum of the current value of the live in the
+  // young gen or the average of the live in the young gen.
+  // If the current value drops quickly, that should be taken
+  // into account (i.e., don't trigger if the amount of free
+  // space has suddenly jumped up).  If the current is much
+  // higher than the average, use the average since it represents
+  // the longer term behavor.
+  const size_t live_in_eden =
+    MIN2(eden_live, (size_t) avg_eden_live()->average());
+  const size_t free_in_eden = max_eden_size > live_in_eden ?
+    max_eden_size - live_in_eden : 0;
+  const size_t free_in_old_gen = (size_t)(max_old_gen_size - avg_old_live()->average());
+  const size_t total_free_limit = free_in_old_gen + free_in_eden;
+  const size_t total_mem = max_old_gen_size + max_eden_size;
+  const double mem_free_limit = total_mem * (GCHeapFreeLimit/100.0);
+  const double mem_free_old_limit = max_old_gen_size * (GCHeapFreeLimit/100.0);
+  const double mem_free_eden_limit = max_eden_size * (GCHeapFreeLimit/100.0);
+  const double gc_cost_limit = GCTimeLimit/100.0;
+  size_t promo_limit = (size_t)(max_old_gen_size - avg_old_live()->average());
+  // But don't force a promo size below the current promo size. Otherwise,
+  // the promo size will shrink for no good reason.
+  promo_limit = MAX2(promo_limit, _promo_size);
+
+
+  if (PrintAdaptiveSizePolicy && (Verbose ||
+      (free_in_old_gen < (size_t) mem_free_old_limit &&
+       free_in_eden < (size_t) mem_free_eden_limit))) {
+    gclog_or_tty->print_cr(
+          "PSAdaptiveSizePolicy::compute_generation_free_space limits:"
+          " promo_limit: " SIZE_FORMAT
+          " max_eden_size: " SIZE_FORMAT
+          " total_free_limit: " SIZE_FORMAT
+          " max_old_gen_size: " SIZE_FORMAT
+          " max_eden_size: " SIZE_FORMAT
+          " mem_free_limit: " SIZE_FORMAT,
+          promo_limit, max_eden_size, total_free_limit,
+          max_old_gen_size, max_eden_size,
+          (size_t) mem_free_limit);
+  }
+
+  bool print_gc_overhead_limit_would_be_exceeded = false;
+  if (is_full_gc) {
+    if (gc_cost() > gc_cost_limit &&
+      free_in_old_gen < (size_t) mem_free_old_limit &&
+      free_in_eden < (size_t) mem_free_eden_limit) {
+      // Collections, on average, are taking too much time, and
+      //      gc_cost() > gc_cost_limit
+      // we have too little space available after a full gc.
+      //      total_free_limit < mem_free_limit
+      // where
+      //   total_free_limit is the free space available in
+      //     both generations
+      //   total_mem is the total space available for allocation
+      //     in both generations (survivor spaces are not included
+      //     just as they are not included in eden_limit).
+      //   mem_free_limit is a fraction of total_mem judged to be an
+      //     acceptable amount that is still unused.
+      // The heap can ask for the value of this variable when deciding
+      // whether to thrown an OutOfMemory error.
+      // Note that the gc time limit test only works for the collections
+      // of the young gen + tenured gen and not for collections of the
+      // permanent gen.  That is because the calculation of the space
+      // freed by the collection is the free space in the young gen +
+      // tenured gen.
+      // At this point the GC overhead limit is being exceeded.
+      inc_gc_overhead_limit_count();
+      if (UseGCOverheadLimit) {
+        if (gc_overhead_limit_count() >=
+            AdaptiveSizePolicyGCTimeLimitThreshold){
+          // All conditions have been met for throwing an out-of-memory
+          set_gc_overhead_limit_exceeded(true);
+          // Avoid consecutive OOM due to the gc time limit by resetting
+          // the counter.
+          reset_gc_overhead_limit_count();
+        } else {
+          // The required consecutive collections which exceed the
+          // GC time limit may or may not have been reached. We
+          // are approaching that condition and so as not to
+          // throw an out-of-memory before all SoftRef's have been
+          // cleared, set _should_clear_all_soft_refs in CollectorPolicy.
+          // The clearing will be done on the next GC.
+          bool near_limit = gc_overhead_limit_near();
+          if (near_limit) {
+            collector_policy->set_should_clear_all_soft_refs(true);
+            if (PrintGCDetails && Verbose) {
+              gclog_or_tty->print_cr("  Nearing GC overhead limit, "
+                "will be clearing all SoftReference");
+            }
+          }
+        }
+      }
+      // Set this even when the overhead limit will not
+      // cause an out-of-memory.  Diagnostic message indicating
+      // that the overhead limit is being exceeded is sometimes
+      // printed.
+      print_gc_overhead_limit_would_be_exceeded = true;
+
+    } else {
+      // Did not exceed overhead limits
+      reset_gc_overhead_limit_count();
+    }
+  }
+
+  if (UseGCOverheadLimit && PrintGCDetails && Verbose) {
+    if (gc_overhead_limit_exceeded()) {
+      gclog_or_tty->print_cr("      GC is exceeding overhead limit "
+        "of %d%%", GCTimeLimit);
+      reset_gc_overhead_limit_count();
+    } else if (print_gc_overhead_limit_would_be_exceeded) {
+      assert(gc_overhead_limit_count() > 0, "Should not be printing");
+      gclog_or_tty->print_cr("      GC would exceed overhead limit "
+        "of %d%% %d consecutive time(s)",
+        GCTimeLimit, gc_overhead_limit_count());
+    }
+  }
+}
 // Printing
 
 bool AdaptiveSizePolicy::print_adaptive_size_policy_on(outputStream* st) const {

hotspot/src/share/vm/gc_implementation/shared/adaptiveSizePolicy.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2004-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2004-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -27,6 +27,7 @@
 
 // Forward decls
 class elapsedTimer;
+class CollectorPolicy;
 
 class AdaptiveSizePolicy : public CHeapObj {
  friend class GCAdaptivePolicyCounters;
@@ -75,13 +76,16 @@ class AdaptiveSizePolicy : public CHeapObj {
 
   // This is a hint for the heap:  we've detected that gc times
   // are taking longer than GCTimeLimit allows.
-  bool _gc_time_limit_exceeded;
+  bool _gc_overhead_limit_exceeded;
-  // Use for diagnostics only.  If UseGCTimeLimit is false,
+  // Use for diagnostics only.  If UseGCOverheadLimit is false,
   // this variable is still set.
-  bool _print_gc_time_limit_would_be_exceeded;
+  bool _print_gc_overhead_limit_would_be_exceeded;
   // Count of consecutive GC that have exceeded the
   // GC time limit criterion.
-  uint _gc_time_limit_count;
+  uint _gc_overhead_limit_count;
+  // This flag signals that GCTimeLimit is being exceeded
+  // but may not have done so for the required number of consequetive
+  // collections.
 
   // Minor collection timers used to determine both
   // pause and interval times for collections.
@@ -406,22 +410,21 @@ class AdaptiveSizePolicy : public CHeapObj {
   // Most heaps will choose to throw an OutOfMemoryError when
   // this occurs but it is up to the heap to request this information
   // of the policy
-  bool gc_time_limit_exceeded() {
+  bool gc_overhead_limit_exceeded() {
-    return _gc_time_limit_exceeded;
+    return _gc_overhead_limit_exceeded;
   }
-  void set_gc_time_limit_exceeded(bool v) {
+  void set_gc_overhead_limit_exceeded(bool v) {
-    _gc_time_limit_exceeded = v;
+    _gc_overhead_limit_exceeded = v;
-  }
-  bool print_gc_time_limit_would_be_exceeded() {
-    return _print_gc_time_limit_would_be_exceeded;
-  }
-  void set_print_gc_time_limit_would_be_exceeded(bool v) {
-    _print_gc_time_limit_would_be_exceeded = v;
   }
 
-  uint gc_time_limit_count() { return _gc_time_limit_count; }
+  // Tests conditions indicate the GC overhead limit is being approached.
-  void reset_gc_time_limit_count() { _gc_time_limit_count = 0; }
+  bool gc_overhead_limit_near() {
-  void inc_gc_time_limit_count() { _gc_time_limit_count++; }
+    return gc_overhead_limit_count() >=
+        (AdaptiveSizePolicyGCTimeLimitThreshold - 1);
+  }
+  uint gc_overhead_limit_count() { return _gc_overhead_limit_count; }
+  void reset_gc_overhead_limit_count() { _gc_overhead_limit_count = 0; }
+  void inc_gc_overhead_limit_count() { _gc_overhead_limit_count++; }
   // accessors for flags recording the decisions to resize the
   // generations to meet the pause goal.
 
@@ -436,6 +439,16 @@ class AdaptiveSizePolicy : public CHeapObj {
   int decide_at_full_gc() { return _decide_at_full_gc; }
   void set_decide_at_full_gc(int v) { _decide_at_full_gc = v; }
 
+  // Check the conditions for an out-of-memory due to excessive GC time.
+  // Set _gc_overhead_limit_exceeded if all the conditions have been met.
+  void check_gc_overhead_limit(size_t young_live,
+                               size_t eden_live,
+                               size_t max_old_gen_size,
+                               size_t max_eden_size,
+                               bool   is_full_gc,
+                               GCCause::Cause gc_cause,
+                               CollectorPolicy* collector_policy);
+
   // Printing support
   virtual bool print_adaptive_size_policy_on(outputStream* st) const;
   bool print_adaptive_size_policy_on(outputStream* st, int

hotspot/src/share/vm/gc_implementation/shared/vmGCOperations.cpp

@@ -115,11 +115,25 @@ bool VM_GC_HeapInspection::skip_operation() const {
 void VM_GC_HeapInspection::doit() {
   HandleMark hm;
   CollectedHeap* ch = Universe::heap();
+  ch->ensure_parsability(false); // must happen, even if collection does
+                                 // not happen (e.g. due to GC_locker)
   if (_full_gc) {
-    ch->collect_as_vm_thread(GCCause::_heap_inspection);
+    // The collection attempt below would be skipped anyway if
-  } else {
+    // the gc locker is held. The following dump may then be a tad
-    // make the heap parsable (no need to retire TLABs)
+    // misleading to someone expecting only live objects to show
-    ch->ensure_parsability(false);
+    // up in the dump (see CR 6944195). Just issue a suitable warning
+    // in that case and do not attempt to do a collection.
+    // The latter is a subtle point, because even a failed attempt
+    // to GC will, in fact, induce one in the future, which we
+    // probably want to avoid in this case because the GC that we may
+    // be about to attempt holds value for us only
+    // if it happens now and not if it happens in the eventual
+    // future.
+    if (GC_locker::is_active()) {
+      warning("GC locker is held; pre-dump GC was skipped");
+    } else {
+      ch->collect_as_vm_thread(GCCause::_heap_inspection);
+    }
   }
   HeapInspection::heap_inspection(_out, _need_prologue /* need_prologue */);
 }

hotspot/src/share/vm/gc_implementation/shared/vmGCOperations.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2005-2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2005-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -89,8 +89,19 @@ class VM_GC_Operation: public VM_Operation {
     if (full) {
       _full_gc_count_before = full_gc_count_before;
     }
+    // In ParallelScavengeHeap::mem_allocate() collections can be
+    // executed within a loop and _all_soft_refs_clear can be set
+    // true after they have been cleared by a collection and another
+    // collection started so that _all_soft_refs_clear can be true
+    // when this collection is started.  Don't assert that
+    // _all_soft_refs_clear have to be false here even though
+    // mutators have run.  Soft refs will be cleared again in this
+    // collection.
+  }
+  ~VM_GC_Operation() {
+    CollectedHeap* ch = Universe::heap();
+    ch->collector_policy()->set_all_soft_refs_clear(false);
   }
-  ~VM_GC_Operation() {}
 
   // Acquire the reference synchronization lock
   virtual bool doit_prologue();

hotspot/src/share/vm/gc_interface/collectedHeap.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -31,6 +31,7 @@ class BarrierSet;
 class ThreadClosure;
 class AdaptiveSizePolicy;
 class Thread;
+class CollectorPolicy;
 
 //
 // CollectedHeap
@@ -506,6 +507,9 @@ class CollectedHeap : public CHeapObj {
   // Return the AdaptiveSizePolicy for the heap.
   virtual AdaptiveSizePolicy* size_policy() = 0;
 
+  // Return the CollectorPolicy for the heap
+  virtual CollectorPolicy* collector_policy() const = 0;
+
   // Iterate over all the ref-containing fields of all objects, calling
   // "cl.do_oop" on each. This includes objects in permanent memory.
   virtual void oop_iterate(OopClosure* cl) = 0;

hotspot/src/share/vm/memory/collectorPolicy.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -112,6 +112,11 @@ void CollectorPolicy::initialize_perm_generation(PermGen::Name pgnm) {
   }
 }
 
+bool CollectorPolicy::use_should_clear_all_soft_refs(bool v) {
+  bool result = _should_clear_all_soft_refs;
+  set_should_clear_all_soft_refs(false);
+  return result;
+}
 
 GenRemSet* CollectorPolicy::create_rem_set(MemRegion whole_heap,
                                            int max_covered_regions) {
@@ -126,6 +131,17 @@ GenRemSet* CollectorPolicy::create_rem_set(MemRegion whole_heap,
   }
 }
 
+void CollectorPolicy::cleared_all_soft_refs() {
+  // If near gc overhear limit, continue to clear SoftRefs.  SoftRefs may
+  // have been cleared in the last collection but if the gc overhear
+  // limit continues to be near, SoftRefs should still be cleared.
+  if (size_policy() != NULL) {
+    _should_clear_all_soft_refs = size_policy()->gc_overhead_limit_near();
+  }
+  _all_soft_refs_clear = true;
+}
+
+
 // GenCollectorPolicy methods.
 
 size_t GenCollectorPolicy::scale_by_NewRatio_aligned(size_t base_size) {
@@ -489,6 +505,12 @@ HeapWord* GenCollectorPolicy::mem_allocate_work(size_t size,
 
   debug_only(gch->check_for_valid_allocation_state());
   assert(gch->no_gc_in_progress(), "Allocation during gc not allowed");
+
+  // In general gc_overhead_limit_was_exceeded should be false so
+  // set it so here and reset it to true only if the gc time
+  // limit is being exceeded as checked below.
+  *gc_overhead_limit_was_exceeded = false;
+
   HeapWord* result = NULL;
 
   // Loop until the allocation is satisified,
@@ -524,12 +546,6 @@ HeapWord* GenCollectorPolicy::mem_allocate_work(size_t size,
         return result;
       }
 
-      // There are NULL's returned for different circumstances below.
-      // In general gc_overhead_limit_was_exceeded should be false so
-      // set it so here and reset it to true only if the gc time
-      // limit is being exceeded as checked below.
-      *gc_overhead_limit_was_exceeded = false;
-
       if (GC_locker::is_active_and_needs_gc()) {
         if (is_tlab) {
           return NULL;  // Caller will retry allocating individual object
@@ -568,18 +584,6 @@ HeapWord* GenCollectorPolicy::mem_allocate_work(size_t size,
       gc_count_before = Universe::heap()->total_collections();
     }
 
-    // Allocation has failed and a collection is about
-    // to be done.  If the gc time limit was exceeded the
-    // last time a collection was done, return NULL so
-    // that an out-of-memory will be thrown.  Clear
-    // gc_time_limit_exceeded so that subsequent attempts
-    // at a collection will be made.
-    if (size_policy()->gc_time_limit_exceeded()) {
-      *gc_overhead_limit_was_exceeded = true;
-      size_policy()->set_gc_time_limit_exceeded(false);
-      return NULL;
-    }
-
     VM_GenCollectForAllocation op(size,
                                   is_tlab,
                                   gc_count_before);
@@ -590,6 +594,24 @@ HeapWord* GenCollectorPolicy::mem_allocate_work(size_t size,
          assert(result == NULL, "must be NULL if gc_locked() is true");
          continue;  // retry and/or stall as necessary
       }
+
+      // Allocation has failed and a collection
+      // has been done.  If the gc time limit was exceeded the
+      // this time, return NULL so that an out-of-memory
+      // will be thrown.  Clear gc_overhead_limit_exceeded
+      // so that the overhead exceeded does not persist.
+
+      const bool limit_exceeded = size_policy()->gc_overhead_limit_exceeded();
+      const bool softrefs_clear = all_soft_refs_clear();
+      assert(!limit_exceeded || softrefs_clear, "Should have been cleared");
+      if (limit_exceeded && softrefs_clear) {
+        *gc_overhead_limit_was_exceeded = true;
+        size_policy()->set_gc_overhead_limit_exceeded(false);
+        if (op.result() != NULL) {
+          CollectedHeap::fill_with_object(op.result(), size);
+        }
+        return NULL;
+      }
       assert(result == NULL || gch->is_in_reserved(result),
              "result not in heap");
       return result;
@@ -688,6 +710,9 @@ HeapWord* GenCollectorPolicy::satisfy_failed_allocation(size_t size,
     return result;
   }
 
+  assert(!should_clear_all_soft_refs(),
+    "Flag should have been handled and cleared prior to this point");
+
   // What else?  We might try synchronous finalization later.  If the total
   // space available is large enough for the allocation, then a more
   // complete compaction phase than we've tried so far might be

hotspot/src/share/vm/memory/collectorPolicy.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -69,12 +69,28 @@ class CollectorPolicy : public CHeapObj {
   size_t _min_alignment;
   size_t _max_alignment;
 
+  // The sizing of the heap are controlled by a sizing policy.
+  AdaptiveSizePolicy* _size_policy;
+
+  // Set to true when policy wants soft refs cleared.
+  // Reset to false by gc after it clears all soft refs.
+  bool _should_clear_all_soft_refs;
+  // Set to true by the GC if the just-completed gc cleared all
+  // softrefs.  This is set to true whenever a gc clears all softrefs, and
+  // set to false each time gc returns to the mutator.  For example, in the
+  // ParallelScavengeHeap case the latter would be done toward the end of
+  // mem_allocate() where it returns op.result()
+  bool _all_soft_refs_clear;
+
   CollectorPolicy() :
     _min_alignment(1),
     _max_alignment(1),
     _initial_heap_byte_size(0),
     _max_heap_byte_size(0),
-    _min_heap_byte_size(0)
+    _min_heap_byte_size(0),
+    _size_policy(NULL),
+    _should_clear_all_soft_refs(false),
+    _all_soft_refs_clear(false)
   {}
 
  public:
@@ -98,6 +114,19 @@ class CollectorPolicy : public CHeapObj {
     G1CollectorPolicyKind
   };
 
+  AdaptiveSizePolicy* size_policy() { return _size_policy; }
+  bool should_clear_all_soft_refs() { return _should_clear_all_soft_refs; }
+  void set_should_clear_all_soft_refs(bool v) { _should_clear_all_soft_refs = v; }
+  // Returns the current value of _should_clear_all_soft_refs.
+  // _should_clear_all_soft_refs is set to false as a side effect.
+  bool use_should_clear_all_soft_refs(bool v);
+  bool all_soft_refs_clear() { return _all_soft_refs_clear; }
+  void set_all_soft_refs_clear(bool v) { _all_soft_refs_clear = v; }
+
+  // Called by the GC after Soft Refs have been cleared to indicate
+  // that the request in _should_clear_all_soft_refs has been fulfilled.
+  void cleared_all_soft_refs();
+
   // Identification methods.
   virtual GenCollectorPolicy*           as_generation_policy()            { return NULL; }
   virtual TwoGenerationCollectorPolicy* as_two_generation_policy()        { return NULL; }
@@ -165,6 +194,22 @@ class CollectorPolicy : public CHeapObj {
 
 };
 
+class ClearedAllSoftRefs : public StackObj {
+  bool _clear_all_soft_refs;
+  CollectorPolicy* _collector_policy;
+ public:
+  ClearedAllSoftRefs(bool clear_all_soft_refs,
+                     CollectorPolicy* collector_policy) :
+    _clear_all_soft_refs(clear_all_soft_refs),
+    _collector_policy(collector_policy) {}
+
+  ~ClearedAllSoftRefs() {
+    if (_clear_all_soft_refs) {
+      _collector_policy->cleared_all_soft_refs();
+    }
+  }
+};
+
 class GenCollectorPolicy : public CollectorPolicy {
  protected:
   size_t _min_gen0_size;
@@ -173,10 +218,6 @@ class GenCollectorPolicy : public CollectorPolicy {
 
   GenerationSpec **_generations;
 
-  // The sizing of the different generations in the heap are controlled
-  // by a sizing policy.
-  AdaptiveSizePolicy* _size_policy;
-
   // Return true if an allocation should be attempted in the older
   // generation if it fails in the younger generation.  Return
   // false, otherwise.
@@ -236,14 +277,11 @@ class GenCollectorPolicy : public CollectorPolicy {
   virtual size_t large_typearray_limit();
 
   // Adaptive size policy
-  AdaptiveSizePolicy* size_policy() { return _size_policy; }
   virtual void initialize_size_policy(size_t init_eden_size,
                                       size_t init_promo_size,
                                       size_t init_survivor_size);
-
 };
 
-
 // All of hotspot's current collectors are subtypes of this
 // class. Currently, these collectors all use the same gen[0],
 // but have different gen[1] types. If we add another subtype

hotspot/src/share/vm/memory/defNewGeneration.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2008 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -594,6 +594,10 @@ void DefNewGeneration::collect(bool   full,
     _tenuring_threshold =
       age_table()->compute_tenuring_threshold(to()->capacity()/HeapWordSize);
 
+    // A successful scavenge should restart the GC time limit count which is
+    // for full GC's.
+    AdaptiveSizePolicy* size_policy = gch->gen_policy()->size_policy();
+    size_policy->reset_gc_overhead_limit_count();
     if (PrintGC && !PrintGCDetails) {
       gch->print_heap_change(gch_prev_used);
     }

hotspot/src/share/vm/memory/genCollectedHeap.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2000-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -428,7 +428,8 @@ void GenCollectedHeap::do_collection(bool  full,
   assert(my_thread->is_VM_thread() ||
          my_thread->is_ConcurrentGC_thread(),
          "incorrect thread type capability");
-  assert(Heap_lock->is_locked(), "the requesting thread should have the Heap_lock");
+  assert(Heap_lock->is_locked(),
+         "the requesting thread should have the Heap_lock");
   guarantee(!is_gc_active(), "collection is not reentrant");
   assert(max_level < n_gens(), "sanity check");
 
@@ -436,6 +437,11 @@ void GenCollectedHeap::do_collection(bool  full,
     return; // GC is disabled (e.g. JNI GetXXXCritical operation)
   }
 
+  const bool do_clear_all_soft_refs = clear_all_soft_refs ||
+                          collector_policy()->should_clear_all_soft_refs();
+
+  ClearedAllSoftRefs casr(do_clear_all_soft_refs, collector_policy());
+
   const size_t perm_prev_used = perm_gen()->used();
 
   if (PrintHeapAtGC) {
@@ -560,11 +566,11 @@ void GenCollectedHeap::do_collection(bool  full,
           if (rp->discovery_is_atomic()) {
             rp->verify_no_references_recorded();
             rp->enable_discovery();
-            rp->setup_policy(clear_all_soft_refs);
+            rp->setup_policy(do_clear_all_soft_refs);
           } else {
             // collect() below will enable discovery as appropriate
           }
-          _gens[i]->collect(full, clear_all_soft_refs, size, is_tlab);
+          _gens[i]->collect(full, do_clear_all_soft_refs, size, is_tlab);
           if (!rp->enqueuing_is_done()) {
             rp->enqueue_discovered_references();
           } else {

hotspot/src/share/vm/memory/genMarkSweep.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2009 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2001-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -29,6 +29,13 @@ void GenMarkSweep::invoke_at_safepoint(int level, ReferenceProcessor* rp,
   bool clear_all_softrefs) {
   assert(SafepointSynchronize::is_at_safepoint(), "must be at a safepoint");
 
+  GenCollectedHeap* gch = GenCollectedHeap::heap();
+#ifdef ASSERT
+  if (gch->collector_policy()->should_clear_all_soft_refs()) {
+    assert(clear_all_softrefs, "Policy should have been checked earlier");
+  }
+#endif
+
   // hook up weak ref data so it can be used during Mark-Sweep
   assert(ref_processor() == NULL, "no stomping");
   assert(rp != NULL, "should be non-NULL");
@@ -44,7 +51,6 @@ void GenMarkSweep::invoke_at_safepoint(int level, ReferenceProcessor* rp,
 
   // Increment the invocation count for the permanent generation, since it is
   // implicitly collected whenever we do a full mark sweep collection.
-  GenCollectedHeap* gch = GenCollectedHeap::heap();
   gch->perm_gen()->stat_record()->invocations++;
 
   // Capture heap size before collection for printing.

hotspot/src/share/vm/services/g1MemoryPool.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2007 Sun Microsystems, Inc.  All Rights Reserved.
+ * Copyright 2007-2010 Sun Microsystems, Inc.  All Rights Reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -45,7 +45,7 @@ size_t G1MemoryPoolSuper::eden_space_committed(G1CollectedHeap* g1h) {
 
 // See the comment at the top of g1MemoryPool.hpp
 size_t G1MemoryPoolSuper::eden_space_used(G1CollectedHeap* g1h) {
-  size_t young_list_length = g1h->young_list_length();
+  size_t young_list_length = g1h->young_list()->length();
   size_t eden_used = young_list_length * HeapRegion::GrainBytes;
   size_t survivor_used = survivor_space_used(g1h);
   eden_used = subtract_up_to_zero(eden_used, survivor_used);