diff --git a/runtime/observatory/lib/src/elements/heap_map.dart b/runtime/observatory/lib/src/elements/heap_map.dart
index 41e1e989d92..6e313e8a8ca 100644
--- a/runtime/observatory/lib/src/elements/heap_map.dart
+++ b/runtime/observatory/lib/src/elements/heap_map.dart
@@ -108,8 +108,12 @@ class HeapMapElement extends HtmlElement implements Renderable {
         new NavVMMenuElement(_vm, _events, queue: _r.queue),
         new NavIsolateMenuElement(_isolate, _events, queue: _r.queue),
         navMenu('heap map'),
-        new NavRefreshElement(label: 'GC', queue: _r.queue)
-          ..onRefresh.listen((_) => _refresh(gc: true)),
+        new NavRefreshElement(label: 'Mark-Compact', queue: _r.queue)
+          ..onRefresh.listen((_) => _refresh(gc: "mark-compact")),
+        new NavRefreshElement(label: 'Mark-Sweep', queue: _r.queue)
+          ..onRefresh.listen((_) => _refresh(gc: "mark-sweep")),
+        new NavRefreshElement(label: 'Scavenge', queue: _r.queue)
+          ..onRefresh.listen((_) => _refresh(gc: "scavenge")),
         new NavRefreshElement(queue: _r.queue)
           ..onRefresh.listen((_) => _refresh()),
         new NavNotifyElement(_notifications, queue: _r.queue)
@@ -279,11 +283,11 @@ class HeapMapElement extends HtmlElement implements Renderable {
     });
   }
 
-  Future _refresh({gc: false}) {
+  Future _refresh({String gc}) {
     final isolate = _isolate as S.Isolate;
     var params = {};
-    if (gc) {
-      params['gc'] = 'full';
+    if (gc != null) {
+      params['gc'] = gc;
     }
     return isolate
         .invokeRpc('_getHeapMap', params)
diff --git a/runtime/observatory/tests/service/get_heap_map_rpc_test.dart b/runtime/observatory/tests/service/get_heap_map_rpc_test.dart
index a566d64e8e7..f60135a6185 100644
--- a/runtime/observatory/tests/service/get_heap_map_rpc_test.dart
+++ b/runtime/observatory/tests/service/get_heap_map_rpc_test.dart
@@ -22,6 +22,45 @@ var tests = [
     expect(result['pages'][0]['objects'].length, isPositive);
     expect(result['pages'][0]['objects'][0], isPositive);
   },
+  (Isolate isolate) async {
+    var params = {'gc': 'scavenge'};
+    var result = await isolate.invokeRpcNoUpgrade('_getHeapMap', params);
+    expect(result['type'], equals('HeapMap'));
+    expect(result['freeClassId'], isPositive);
+    expect(result['unitSizeBytes'], isPositive);
+    expect(result['pageSizeBytes'], isPositive);
+    expect(result['classList'], isNotNull);
+    expect(result['pages'].length, isPositive);
+    expect(result['pages'][0]['objectStart'], new isInstanceOf<String>());
+    expect(result['pages'][0]['objects'].length, isPositive);
+    expect(result['pages'][0]['objects'][0], isPositive);
+  },
+  (Isolate isolate) async {
+    var params = {'gc': 'mark-sweep'};
+    var result = await isolate.invokeRpcNoUpgrade('_getHeapMap', params);
+    expect(result['type'], equals('HeapMap'));
+    expect(result['freeClassId'], isPositive);
+    expect(result['unitSizeBytes'], isPositive);
+    expect(result['pageSizeBytes'], isPositive);
+    expect(result['classList'], isNotNull);
+    expect(result['pages'].length, isPositive);
+    expect(result['pages'][0]['objectStart'], new isInstanceOf<String>());
+    expect(result['pages'][0]['objects'].length, isPositive);
+    expect(result['pages'][0]['objects'][0], isPositive);
+  },
+  (Isolate isolate) async {
+    var params = {'gc': 'mark-compact'};
+    var result = await isolate.invokeRpcNoUpgrade('_getHeapMap', params);
+    expect(result['type'], equals('HeapMap'));
+    expect(result['freeClassId'], isPositive);
+    expect(result['unitSizeBytes'], isPositive);
+    expect(result['pageSizeBytes'], isPositive);
+    expect(result['classList'], isNotNull);
+    expect(result['pages'].length, isPositive);
+    expect(result['pages'][0]['objectStart'], new isInstanceOf<String>());
+    expect(result['pages'][0]['objects'].length, isPositive);
+    expect(result['pages'][0]['objects'][0], isPositive);
+  },
 ];
 
 main(args) async => runIsolateTests(args, tests);
diff --git a/runtime/vm/heap.cc b/runtime/vm/heap.cc
index 9d29b1f9aa2..2cb66ffe738 100644
--- a/runtime/vm/heap.cc
+++ b/runtime/vm/heap.cc
@@ -386,7 +386,7 @@ void Heap::EvacuateNewSpace(Thread* thread, GCReason reason) {
     NOT_IN_PRODUCT(isolate()->class_table()->UpdatePromoted());
     RecordAfterGC(kNew);
     PrintStats();
-    NOT_IN_PRODUCT(PrintStatsToTimeline(&tds));
+    NOT_IN_PRODUCT(PrintStatsToTimeline(&tds, reason));
     EndNewSpaceGC();
   }
 }
@@ -404,7 +404,7 @@ void Heap::CollectNewSpaceGarbage(Thread* thread,
       NOT_IN_PRODUCT(isolate()->class_table()->UpdatePromoted());
       RecordAfterGC(kNew);
       PrintStats();
-      NOT_IN_PRODUCT(PrintStatsToTimeline(&tds));
+      NOT_IN_PRODUCT(PrintStatsToTimeline(&tds, reason));
       EndNewSpaceGC();
     }
     if ((reason == kNewSpace) && old_space_.NeedsGarbageCollection()) {
@@ -421,10 +421,11 @@ void Heap::CollectOldSpaceGarbage(Thread* thread,
     VMTagScope tagScope(thread, VMTag::kGCOldSpaceTagId);
     TIMELINE_FUNCTION_GC_DURATION_BASIC(thread, "CollectOldGeneration");
     NOT_IN_PRODUCT(UpdateClassHeapStatsBeforeGC(kOld));
-    old_space_.MarkSweep();
+    bool compact = (reason == kCompaction) || FLAG_use_compactor;
+    old_space_.CollectGarbage(compact);
     RecordAfterGC(kOld);
     PrintStats();
-    NOT_IN_PRODUCT(PrintStatsToTimeline(&tds));
+    NOT_IN_PRODUCT(PrintStatsToTimeline(&tds, reason));
     // Some Code objects may have been collected so invalidate handler cache.
     thread->isolate()->handler_info_cache()->Clear();
     thread->isolate()->catch_entry_state_cache()->Clear();
@@ -636,6 +637,8 @@ const char* Heap::GCReasonToString(GCReason gc_reason) {
       return "promotion";
     case kOldSpace:
       return "old space";
+    case kCompaction:
+      return "compaction";
     case kFull:
       return "full";
     case kIdle:
@@ -829,38 +832,39 @@ void Heap::PrintStats() {
 #endif  // !defined(PRODUCT)
 }
 
-void Heap::PrintStatsToTimeline(TimelineEventScope* event) {
+void Heap::PrintStatsToTimeline(TimelineEventScope* event, GCReason reason) {
 #if !defined(PRODUCT)
   if ((event == NULL) || !event->enabled()) {
     return;
   }
   intptr_t arguments = event->GetNumArguments();
-  event->SetNumArguments(arguments + 12);
-  event->FormatArgument(arguments + 0, "Before.New.Used (kB)", "%" Pd "",
+  event->SetNumArguments(arguments + 13);
+  event->CopyArgument(arguments + 0, "Reason", GCReasonToString(reason));
+  event->FormatArgument(arguments + 1, "Before.New.Used (kB)", "%" Pd "",
                         RoundWordsToKB(stats_.before_.new_.used_in_words));
-  event->FormatArgument(arguments + 1, "After.New.Used (kB)", "%" Pd "",
+  event->FormatArgument(arguments + 2, "After.New.Used (kB)", "%" Pd "",
                         RoundWordsToKB(stats_.after_.new_.used_in_words));
-  event->FormatArgument(arguments + 2, "Before.Old.Used (kB)", "%" Pd "",
+  event->FormatArgument(arguments + 3, "Before.Old.Used (kB)", "%" Pd "",
                         RoundWordsToKB(stats_.before_.old_.used_in_words));
-  event->FormatArgument(arguments + 3, "After.Old.Used (kB)", "%" Pd "",
+  event->FormatArgument(arguments + 4, "After.Old.Used (kB)", "%" Pd "",
                         RoundWordsToKB(stats_.after_.old_.used_in_words));
 
-  event->FormatArgument(arguments + 4, "Before.New.Capacity (kB)", "%" Pd "",
+  event->FormatArgument(arguments + 5, "Before.New.Capacity (kB)", "%" Pd "",
                         RoundWordsToKB(stats_.before_.new_.capacity_in_words));
-  event->FormatArgument(arguments + 5, "After.New.Capacity (kB)", "%" Pd "",
+  event->FormatArgument(arguments + 6, "After.New.Capacity (kB)", "%" Pd "",
                         RoundWordsToKB(stats_.after_.new_.capacity_in_words));
-  event->FormatArgument(arguments + 6, "Before.Old.Capacity (kB)", "%" Pd "",
+  event->FormatArgument(arguments + 7, "Before.Old.Capacity (kB)", "%" Pd "",
                         RoundWordsToKB(stats_.before_.old_.capacity_in_words));
-  event->FormatArgument(arguments + 7, "After.Old.Capacity (kB)", "%" Pd "",
+  event->FormatArgument(arguments + 8, "After.Old.Capacity (kB)", "%" Pd "",
                         RoundWordsToKB(stats_.after_.old_.capacity_in_words));
 
-  event->FormatArgument(arguments + 8, "Before.New.External (kB)", "%" Pd "",
+  event->FormatArgument(arguments + 9, "Before.New.External (kB)", "%" Pd "",
                         RoundWordsToKB(stats_.before_.new_.external_in_words));
-  event->FormatArgument(arguments + 9, "After.New.External (kB)", "%" Pd "",
+  event->FormatArgument(arguments + 10, "After.New.External (kB)", "%" Pd "",
                         RoundWordsToKB(stats_.after_.new_.external_in_words));
-  event->FormatArgument(arguments + 10, "Before.Old.External (kB)", "%" Pd "",
+  event->FormatArgument(arguments + 11, "Before.Old.External (kB)", "%" Pd "",
                         RoundWordsToKB(stats_.before_.old_.external_in_words));
-  event->FormatArgument(arguments + 11, "After.Old.External (kB)", "%" Pd "",
+  event->FormatArgument(arguments + 12, "After.Old.External (kB)", "%" Pd "",
                         RoundWordsToKB(stats_.after_.old_.external_in_words));
 #endif  // !defined(PRODUCT)
 }
diff --git a/runtime/vm/heap.h b/runtime/vm/heap.h
index aa4e4be42fe..b8bcf3a06a3 100644
--- a/runtime/vm/heap.h
+++ b/runtime/vm/heap.h
@@ -45,6 +45,7 @@ class Heap {
     kNewSpace,
     kPromotion,
     kOldSpace,
+    kCompaction,
     kFull,
     kIdle,
     kGCAtAlloc,
@@ -321,7 +322,7 @@ class Heap {
   void RecordAfterGC(Space space);
   void PrintStats();
   void UpdateClassHeapStatsBeforeGC(Heap::Space space);
-  void PrintStatsToTimeline(TimelineEventScope* event);
+  void PrintStatsToTimeline(TimelineEventScope* event, GCReason reason);
 
   // Updates gc in progress flags.
   bool BeginNewSpaceGC(Thread* thread);
diff --git a/runtime/vm/pages.cc b/runtime/vm/pages.cc
index 2b8fcb1fc8e..05a6dbb1826 100644
--- a/runtime/vm/pages.cc
+++ b/runtime/vm/pages.cc
@@ -865,7 +865,7 @@ bool PageSpace::ShouldPerformIdleMarkSweep(int64_t deadline) {
   return estimated_mark_completion <= deadline;
 }
 
-void PageSpace::MarkSweep() {
+void PageSpace::CollectGarbage(bool compact) {
   Thread* thread = Thread::Current();
   Isolate* isolate = heap_->isolate();
   ASSERT(isolate == Isolate::Current());
@@ -984,7 +984,7 @@ void PageSpace::MarkSweep() {
 
       mid3 = OS::GetCurrentMonotonicMicros();
 
-      if (FLAG_use_compactor) {
+      if (compact) {
         Compact(thread);
       } else if (FLAG_concurrent_sweep) {
         ConcurrentSweep(isolate);
@@ -1039,7 +1039,7 @@ void PageSpace::MarkSweep() {
     ml.NotifyAll();
   }
 
-  if (FLAG_use_compactor) {
+  if (compact) {
     // Const object tables are hashed by address: rehash.
     SafepointOperationScope safepoint(thread);
     thread->isolate()->RehashConstants();
diff --git a/runtime/vm/pages.h b/runtime/vm/pages.h
index 9ebc20f4429..ed4882402c0 100644
--- a/runtime/vm/pages.h
+++ b/runtime/vm/pages.h
@@ -270,8 +270,8 @@ class PageSpace {
   // code.
   bool ShouldCollectCode();
 
-  // Collect the garbage in the page space using mark-sweep.
-  void MarkSweep();
+  // Collect the garbage in the page space using mark-sweep or mark-compact.
+  void CollectGarbage(bool compact);
 
   void AddRegionsToObjectSet(ObjectSet* set) const;
 
diff --git a/runtime/vm/service.cc b/runtime/vm/service.cc
index f199bd69a1a..f5dd5b82450 100644
--- a/runtime/vm/service.cc
+++ b/runtime/vm/service.cc
@@ -3439,18 +3439,18 @@ static const MethodParameter* get_heap_map_params[] = {
 
 static bool GetHeapMap(Thread* thread, JSONStream* js) {
   Isolate* isolate = thread->isolate();
-  bool should_collect = false;
   if (js->HasParam("gc")) {
-    if (js->ParamIs("gc", "full")) {
-      should_collect = true;
+    if (js->ParamIs("gc", "scavenge")) {
+      isolate->heap()->CollectGarbage(Heap::kNew);
+    } else if (js->ParamIs("gc", "mark-sweep")) {
+      isolate->heap()->CollectGarbage(Heap::kOld, Heap::kOldSpace);
+    } else if (js->ParamIs("gc", "mark-compact")) {
+      isolate->heap()->CollectGarbage(Heap::kOld, Heap::kCompaction);
     } else {
       PrintInvalidParamError(js, "gc");
       return true;
     }
   }
-  if (should_collect) {
-    isolate->heap()->CollectAllGarbage();
-  }
   isolate->heap()->PrintHeapMapToJSONStream(isolate, js);
   return true;
 }