diff --git a/src/heap/gc-tracer.cc b/src/heap/gc-tracer.cc
index c4a118afb7..0a023b7b90 100644
--- a/src/heap/gc-tracer.cc
+++ b/src/heap/gc-tracer.cc
@@ -559,6 +559,10 @@ void GCTracer::PrintNVP() const {
           "mark.prepare_code_flush=%.1f "
           "mark.roots=%.1f "
           "mark.weak_closure=%.1f "
+          "mark.weak_closure.ephemeral=%.1f "
+          "mark.weak_closure.weak_handles=%.1f "
+          "mark.weak_closure.weak_roots=%.1f "
+          "mark.weak_closure.harmony=%.1f "
           "sweep=%.1f "
           "sweep.code=%.1f "
           "sweep.map=%.1f "
@@ -628,6 +632,10 @@ void GCTracer::PrintNVP() const {
           current_.scopes[Scope::MC_MARK_PREPARE_CODE_FLUSH],
           current_.scopes[Scope::MC_MARK_ROOTS],
           current_.scopes[Scope::MC_MARK_WEAK_CLOSURE],
+          current_.scopes[Scope::MC_MARK_WEAK_CLOSURE_EPHEMERAL],
+          current_.scopes[Scope::MC_MARK_WEAK_CLOSURE_WEAK_HANDLES],
+          current_.scopes[Scope::MC_MARK_WEAK_CLOSURE_WEAK_ROOTS],
+          current_.scopes[Scope::MC_MARK_WEAK_CLOSURE_HARMONY],
           current_.scopes[Scope::MC_SWEEP],
           current_.scopes[Scope::MC_SWEEP_CODE],
           current_.scopes[Scope::MC_SWEEP_MAP],
diff --git a/src/heap/gc-tracer.h b/src/heap/gc-tracer.h
index 45e4dc61dc..4621f3a0f1 100644
--- a/src/heap/gc-tracer.h
+++ b/src/heap/gc-tracer.h
@@ -98,6 +98,10 @@ class GCTracer {
       MC_MARK_PREPARE_CODE_FLUSH,
       MC_MARK_ROOTS,
       MC_MARK_WEAK_CLOSURE,
+      MC_MARK_WEAK_CLOSURE_EPHEMERAL,
+      MC_MARK_WEAK_CLOSURE_WEAK_HANDLES,
+      MC_MARK_WEAK_CLOSURE_WEAK_ROOTS,
+      MC_MARK_WEAK_CLOSURE_HARMONY,
       MC_SWEEP,
       MC_SWEEP_CODE,
       MC_SWEEP_MAP,
diff --git a/src/heap/mark-compact.cc b/src/heap/mark-compact.cc
index affe13d873..cadb68834b 100644
--- a/src/heap/mark-compact.cc
+++ b/src/heap/mark-compact.cc
@@ -2142,7 +2142,12 @@ void MarkCompactCollector::MarkLiveObjects() {
     // The objects reachable from the roots are marked, yet unreachable
     // objects are unmarked.  Mark objects reachable due to host
     // application specific logic or through Harmony weak maps.
-    ProcessEphemeralMarking(&root_visitor, false);
+    {
+      GCTracer::Scope gc_scope(heap()->tracer(),
+                               GCTracer::Scope::MC_MARK_WEAK_CLOSURE_EPHEMERAL);
+      ProcessEphemeralMarking(&root_visitor, false);
+      ProcessMarkingDeque();
+    }
 
     // The objects reachable from the roots, weak maps or object groups
     // are marked. Objects pointed to only by weak global handles cannot be
@@ -2151,18 +2156,33 @@ void MarkCompactCollector::MarkLiveObjects() {
     //
     // First we identify nonlive weak handles and mark them as pending
     // destruction.
-    heap()->isolate()->global_handles()->IdentifyWeakHandles(
-        &IsUnmarkedHeapObject);
+    {
+      GCTracer::Scope gc_scope(
+          heap()->tracer(), GCTracer::Scope::MC_MARK_WEAK_CLOSURE_WEAK_HANDLES);
+      heap()->isolate()->global_handles()->IdentifyWeakHandles(
+          &IsUnmarkedHeapObject);
+      ProcessMarkingDeque();
+    }
     // Then we mark the objects.
-    heap()->isolate()->global_handles()->IterateWeakRoots(&root_visitor);
-    ProcessMarkingDeque();
+
+    {
+      GCTracer::Scope gc_scope(
+          heap()->tracer(), GCTracer::Scope::MC_MARK_WEAK_CLOSURE_WEAK_ROOTS);
+      heap()->isolate()->global_handles()->IterateWeakRoots(&root_visitor);
+      ProcessMarkingDeque();
+    }
 
     // Repeat Harmony weak maps marking to mark unmarked objects reachable from
     // the weak roots we just marked as pending destruction.
     //
     // We only process harmony collections, as all object groups have been fully
     // processed and no weakly reachable node can discover new objects groups.
-    ProcessEphemeralMarking(&root_visitor, true);
+    {
+      GCTracer::Scope gc_scope(heap()->tracer(),
+                               GCTracer::Scope::MC_MARK_WEAK_CLOSURE_HARMONY);
+      ProcessEphemeralMarking(&root_visitor, true);
+      ProcessMarkingDeque();
+    }
   }
 
   if (FLAG_print_cumulative_gc_stat) {
diff --git a/tools/eval_gc_time.sh b/tools/eval_gc_time.sh
index bad4d135e1..23f7a4f369 100755
--- a/tools/eval_gc_time.sh
+++ b/tools/eval_gc_time.sh
@@ -90,6 +90,10 @@ INTERESTING_OLD_GEN_KEYS="\
   mark.prepare_code_flush \
   mark.roots \
   mark.weak_closure \
+  mark.weak_closure.ephemeral \
+  mark.weak_closure.weak_handles \
+  mark.weak_closure.weak_roots \
+  mark.weak_closure.harmony \
   sweep \
   sweep.code \
   sweep.map \