Add heap growing strategy details to --trace-gc-verbose.

src/heap/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/bits.h"
 #include "src/base/once.h"
@@ skipping 311 matching lines @@
                          ", available: %6" V8_PTR_PREFIX "d KB\n",
                isolate_->memory_allocator()->Size() / KB,
                isolate_->memory_allocator()->Available() / KB);
   PrintIsolate(isolate_, "New space,          used: %6" V8_PTR_PREFIX
                          "d KB"
                          ", available: %6" V8_PTR_PREFIX
                          "d KB"
                          ", committed: %6" V8_PTR_PREFIX "d KB\n",
                new_space_.Size() / KB, new_space_.Available() / KB,
                new_space_.CommittedMemory() / KB);
-  PrintIsolate(isolate_, "Old space,       used: %6" V8_PTR_PREFIX
+  PrintIsolate(isolate_, "Old space,          used: %6" V8_PTR_PREFIX
                          "d KB"
                          ", available: %6" V8_PTR_PREFIX
                          "d KB"
                          ", committed: %6" V8_PTR_PREFIX "d KB\n",
                old_space_->SizeOfObjects() / KB, old_space_->Available() / KB,
                old_space_->CommittedMemory() / KB);
   PrintIsolate(isolate_, "Code space,         used: %6" V8_PTR_PREFIX
                          "d KB"
                          ", available: %6" V8_PTR_PREFIX
                          "d KB"
@@ skipping 4916 matching lines @@
     max_factor = 2;
   }
 
   // If there are many freed global handles, then the next full GC will
   // likely collect a lot of garbage. Choose the heap growing factor
   // depending on freed global handles.
   // TODO(ulan, hpayer): Take into account mutator utilization.
   // TODO(hpayer): The idle factor could make the handles heuristic obsolete.
   // Look into that.
   double factor;
+  double idle_factor;
   if (freed_global_handles <= kMinHandles) {
     factor = max_factor;
   } else if (freed_global_handles >= kMaxHandles) {
     factor = min_factor;
   } else {
     // Compute factor using linear interpolation between points
     // (kMinHandles, max_factor) and (kMaxHandles, min_factor).
     factor = max_factor -
              (freed_global_handles - kMinHandles) * (max_factor - min_factor) /
                  (kMaxHandles - kMinHandles);
   }
 
   if (FLAG_stress_compaction ||
       mark_compact_collector()->reduce_memory_footprint_) {
     factor = min_factor;
   }
 
+  idle_factor = Min(factor, idle_max_factor);
+
   old_generation_allocation_limit_ =
       CalculateOldGenerationAllocationLimit(factor, old_gen_size);
-  idle_old_generation_allocation_limit_ = CalculateOldGenerationAllocationLimit(
-      Min(factor, idle_max_factor), old_gen_size);
+  idle_old_generation_allocation_limit_ =
+      CalculateOldGenerationAllocationLimit(idle_factor, old_gen_size);
+
+  if (FLAG_trace_gc_verbose) {
+    PrintIsolate(
+        isolate_,
+        "Grow: old size: %" V8_PTR_PREFIX "d KB, new limit: %" V8_PTR_PREFIX
+        "d KB (%.1f), new idle limit: %" V8_PTR_PREFIX "d KB (%.1f)\n",
+        old_gen_size / KB, old_generation_allocation_limit_ / KB, factor,
+        idle_old_generation_allocation_limit_ / KB, idle_factor);
+  }
 }
 
 
 void Heap::EnableInlineAllocation() {
   if (!inline_allocation_disabled_) return;
   inline_allocation_disabled_ = false;
 
   // Update inline allocation limit for new space.
   new_space()->UpdateInlineAllocationLimit(0);
 }
@@ skipping 1122 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   CODE_AGE_LIST_COMPLETE(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   MemCopy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   MemCopy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 }
 }  // namespace v8::internal