Print PID and time since start when tracing idle notification events.

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 4684 matching lines @@
       isolate()->counters()->gc_idle_time_limit_undershot()->AddSample(
           static_cast<int>(deadline_difference));
     }
   } else {
     isolate()->counters()->gc_idle_time_limit_overshot()->AddSample(
         static_cast<int>(-deadline_difference));
   }
 
   if ((FLAG_trace_idle_notification && action.type > DO_NOTHING) ||
       FLAG_trace_idle_notification_verbose) {
+    PrintPID("%8.0f ms: ", isolate()->time_millis_since_init());
     PrintF(
         "Idle notification: requested idle time %.2f ms, used idle time %.2f "
         "ms, deadline usage %.2f ms [",
         idle_time_in_ms, idle_time_in_ms - deadline_difference,
         deadline_difference);
     action.Print();
     PrintF("]");
     if (FLAG_trace_idle_notification_verbose) {
       PrintF("[");
       heap_state.Print();
@@ skipping 1678 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