Measure incremental marking speed in bytes per millisecond based on pure incremental marking steps.

src/heap/gc-tracer.h

 // Copyright 2014 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.
 
 #ifndef V8_HEAP_GC_TRACER_H_
 #define V8_HEAP_GC_TRACER_H_
 
 namespace v8 {
 namespace internal {
 
@@ skipping 179 matching lines @@
 
     // Cumulative duration of incremental marking steps since creation of
     // tracer. (value at start of event)
     double cumulative_incremental_marking_duration;
 
     // Duration of incremental marking steps since
     // - last event for SCAVENGER events
     // - last MARK_COMPACTOR event for MARK_COMPACTOR events
     double incremental_marking_duration;
 
+    // Cumulative pure duration of incremental marking steps since creation of
+    // tracer. (value at start of event)
+    double cumulative_pure_incremental_marking_duration;
+
+    // Duration of pure incremental marking steps since
+    // - last event for SCAVENGER events
+    // - last MARK_COMPACTOR event for MARK_COMPACTOR events
+    double pure_incremental_marking_duration;
+
     // Longest incremental marking step since start of marking.
     // (value at start of event)
     double longest_incremental_marking_step;
 
     // Amounts of time spent in different scopes during GC.
     double scopes[Scope::NUMBER_OF_SCOPES];
   };
 
   static const int kRingBufferMaxSize = 10;
 
@@ skipping 102 matching lines @@
   // Cumulative number of incremental marking steps since creation of tracer.
   int cumulative_incremental_marking_steps_;
 
   // Cumulative size of incremental marking steps (in bytes) since creation of
   // tracer.
   intptr_t cumulative_incremental_marking_bytes_;
 
   // Cumulative duration of incremental marking steps since creation of tracer.
   double cumulative_incremental_marking_duration_;
 
+  // Cumulative duration of pure incremental marking steps since creation of
+  // tracer.
+  double cumulative_pure_incremental_marking_duration_;
+
   // Longest incremental marking step since start of marking.
   double longest_incremental_marking_step_;
 
   // Total marking time.
   // This timer is precise when run with --print-cumulative-gc-stat
   double cumulative_marking_duration_;
 
   // Total sweeping time on the main thread.
   // This timer is precise when run with --print-cumulative-gc-stat
   // TODO(hpayer): Account for sweeping time on sweeper threads. Add a
   // different field for that.
   // TODO(hpayer): This timer right now just holds the sweeping time
   // of the initial atomic sweeping pause. Make sure that it accumulates
   // all sweeping operations performed on the main thread.
   double cumulative_sweeping_duration_;
 
   DISALLOW_COPY_AND_ASSIGN(GCTracer);
 };
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_GC_TRACER_H_