8314599: [GenShen] Couple adaptive tenuring and generation size budgeting

src/hotspot/share/gc/shenandoah/heuristics/shenandoahOldHeuristics.cpp

@@ -141,7 +141,7 @@ bool ShenandoahOldHeuristics::prime_collection_set(ShenandoahCollectionSet* coll
     // If region r is evacuated to fragmented memory (to free memory within a partially used region), then we need
     // to decrease the capacity of the fragmented memory by the scaled loss.
 
-    size_t live_data_for_evacuation = r->get_live_data_bytes();
+    const size_t live_data_for_evacuation = r->get_live_data_bytes();
     size_t lost_available = r->free();
 
     if ((lost_available > 0) && (excess_fragmented_available > 0)) {
@@ -169,7 +169,9 @@ bool ShenandoahOldHeuristics::prime_collection_set(ShenandoahCollectionSet* coll
       // We were not able to account for the lost free memory within fragmented memory, so we need to take this
       // allocation out of unfragmented memory.  Unfragmented memory does not need to account for loss of free.
       if (live_data_for_evacuation > unfragmented_available) {
-        // There is not room to evacuate this region or any that come after it in within the candidates array.
+        // There is no room to evacuate this region or any that come after it in within the candidates array.
+        log_debug(gc, cset)("Not enough unfragmented memory (%zu) to hold evacuees (%zu) from region: (%zu)",
+                            unfragmented_available, live_data_for_evacuation, r->index());
         break;
       } else {
         unfragmented_available -= live_data_for_evacuation;
@@ -187,7 +189,9 @@ bool ShenandoahOldHeuristics::prime_collection_set(ShenandoahCollectionSet* coll
         evacuation_need = 0;
       }
       if (evacuation_need > unfragmented_available) {
-        // There is not room to evacuate this region or any that come after it in within the candidates array.
+        // There is no room to evacuate this region or any that come after it in within the candidates array.
+        log_debug(gc, cset)("Not enough unfragmented memory (%zu) to hold evacuees (%zu) from region: (%zu)",
+                            unfragmented_available, live_data_for_evacuation, r->index());
         break;
       } else {
         unfragmented_available -= evacuation_need;

src/hotspot/share/gc/shenandoah/shenandoahAgeCensus.cpp

@@ -181,6 +181,19 @@ void ShenandoahAgeCensus::update_census(size_t age0_pop) {
 }
 
 
+size_t ShenandoahAgeCensus::get_tenurable_bytes(const uint tenuring_threshold) const {
+  assert(_epoch < MAX_SNAPSHOTS, "Out of bounds");
+  size_t total = 0;
+  const AgeTable* pv = _global_age_tables[_epoch];
+  for (uint i = 0; i < MAX_COHORTS; i++) {
+    if (i >= tenuring_threshold) {
+      total += pv->sizes[i];
+    }
+  }
+  return total * HeapWordSize;
+}
+
+
 // Reset the epoch for the global age tables,
 // clearing all history.
 void ShenandoahAgeCensus::reset_global() {

src/hotspot/share/gc/shenandoah/shenandoahAgeCensus.hpp

@@ -211,6 +211,12 @@ class ShenandoahAgeCensus: public CHeapObj<mtGC> {
   // allocated when the concurrent marking was in progress.
   void update_census(size_t age0_pop);
 
+  // Return the total size of the population above the given threshold for the current epoch
+  size_t get_tenurable_bytes(uint tenuring_threshold) const;
+
+  // As above, but use the current tenuring threshold by default
+  size_t get_tenurable_bytes() const { return get_tenurable_bytes(tenuring_threshold()); }
+
   // Reset the epoch, clearing accumulated census history
   // Note: this isn't currently used, but reserved for planned
   // future usage.

src/hotspot/share/gc/shenandoah/shenandoahCollectionSet.cpp

@@ -225,9 +225,9 @@ void ShenandoahCollectionSet::summarize(size_t total_garbage, size_t immediate_g
                  count());
 
     if (garbage() > 0) {
-      const size_t young_evac_bytes = get_young_bytes_reserved_for_evacuation();
-      const size_t promote_evac_bytes = get_young_bytes_to_be_promoted();
-      const size_t old_evac_bytes = get_old_bytes_reserved_for_evacuation();
+      const size_t young_evac_bytes = get_live_bytes_in_untenurable_regions();
+      const size_t promote_evac_bytes = get_live_bytes_in_tenurable_regions();
+      const size_t old_evac_bytes = get_live_bytes_in_old_regions();
       const size_t total_evac_bytes = young_evac_bytes + promote_evac_bytes + old_evac_bytes;
       ls.print_cr("Evacuation Targets: "
                   "YOUNG: " PROPERFMT ", " "PROMOTE: " PROPERFMT ", " "OLD: " PROPERFMT ", " "TOTAL: " PROPERFMT,

src/hotspot/share/gc/shenandoah/shenandoahCollectionSet.hpp

@@ -109,14 +109,14 @@ class ShenandoahCollectionSet : public CHeapObj<mtGC> {
   // Prints a summary of the collection set when gc+ergo=info
   void summarize(size_t total_garbage, size_t immediate_garbage, size_t immediate_regions) const;
 
-  // Returns the amount of live bytes in young regions in the collection set. It is not known how many of these bytes will be promoted.
-  inline size_t get_young_bytes_reserved_for_evacuation() const;
+  // Returns the amount of live bytes in young regions with an age below the tenuring threshold.
+  inline size_t get_live_bytes_in_untenurable_regions() const;
 
   // Returns the amount of live bytes in old regions in the collection set.
-  inline size_t get_old_bytes_reserved_for_evacuation() const;
+  inline size_t get_live_bytes_in_old_regions() const;
 
   // Returns the amount of live bytes in young regions with an age above the tenuring threshold.
-  inline size_t get_young_bytes_to_be_promoted() const;
+  inline size_t get_live_bytes_in_tenurable_regions() const;
 
   // Returns the amount of free bytes in young regions in the collection set.
   size_t get_young_available_bytes_collected() const { return _young_available_bytes_collected; }
@@ -125,7 +125,7 @@ class ShenandoahCollectionSet : public CHeapObj<mtGC> {
   inline size_t get_old_garbage() const;
 
   bool is_preselected(size_t region_idx) {
-    assert(_preselected_regions != nullptr, "Missing etsablish after abandon");
+    assert(_preselected_regions != nullptr, "Missing establish after abandon");
     return _preselected_regions[region_idx];
   }
 

src/hotspot/share/gc/shenandoah/shenandoahCollectionSet.inline.hpp

@@ -54,15 +54,15 @@ bool ShenandoahCollectionSet::is_in_loc(void* p) const {
   return _biased_cset_map[index] == 1;
 }
 
-size_t ShenandoahCollectionSet::get_old_bytes_reserved_for_evacuation() const {
+size_t ShenandoahCollectionSet::get_live_bytes_in_old_regions() const {
   return _old_bytes_to_evacuate;
 }
 
-size_t ShenandoahCollectionSet::get_young_bytes_reserved_for_evacuation() const {
+size_t ShenandoahCollectionSet::get_live_bytes_in_untenurable_regions() const {
   return _young_bytes_to_evacuate - _young_bytes_to_promote;
 }
 
-size_t ShenandoahCollectionSet::get_young_bytes_to_be_promoted() const {
+size_t ShenandoahCollectionSet::get_live_bytes_in_tenurable_regions() const {
   return _young_bytes_to_promote;
 }