Shrinking of PagedSpace is done only by sweeper.

BUG=

Review URL: https://codereview.chromium.org/12313131

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13758 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap.cc

@@ -591,7 +591,6 @@ void Heap::CollectAllAvailableGarbage(const char* gc_reason) {
   mark_compact_collector()->SetFlags(kNoGCFlags);
   new_space_.Shrink();
   UncommitFromSpace();
-  Shrink();
   incremental_marking()->UncommitMarkingDeque();
 }
 
@@ -789,11 +788,6 @@ void Heap::EnsureFromSpaceIsCommitted() {
   if (new_space_.CommitFromSpaceIfNeeded()) return;
 
   // Committing memory to from space failed.
-  // Try shrinking and try again.
-  Shrink();
-  if (new_space_.CommitFromSpaceIfNeeded()) return;
-
-  // Committing memory to from space failed again.
   // Memory is exhausted and we will die.
   V8::FatalProcessOutOfMemory("Committing semi space failed.");
 }
@@ -822,7 +816,6 @@ void Heap::ClearJSFunctionResultCaches() {
 }
 
 
-
 void Heap::ClearNormalizedMapCaches() {
   if (isolate_->bootstrapper()->IsActive() &&
       !incremental_marking()->IsMarking()) {
@@ -6414,17 +6407,6 @@ void Heap::TearDown() {
 }
 
 
-void Heap::Shrink() {
-  // Try to shrink all paged spaces.
-  PagedSpaces spaces(this);
-  for (PagedSpace* space = spaces.next();
-       space != NULL;
-       space = spaces.next()) {
-    space->ReleaseAllUnusedPages();
-  }
-}
-
-
 void Heap::AddGCPrologueCallback(GCPrologueCallback callback, GCType gc_type) {
   ASSERT(callback != NULL);
   GCPrologueCallbackPair pair(callback, gc_type);

src/heap.h

@@ -1384,9 +1384,6 @@ class Heap {
   // Given an address occupied by a live code object, return that object.
   Object* FindCodeObject(Address a);
 
-  // Invoke Shrink on shrinkable spaces.
-  void Shrink();
-
   enum HeapState { NOT_IN_GC, SCAVENGE, MARK_COMPACT };
   inline HeapState gc_state() { return gc_state_; }
 

src/spaces.cc

@@ -1081,36 +1081,6 @@ void PagedSpace::ReleasePage(Page* page) {
 }
 
 
-void PagedSpace::ReleaseAllUnusedPages() {
-  PageIterator it(this);
-  while (it.has_next()) {
-    Page* page = it.next();
-    if (!page->WasSwept()) {
-      if (page->LiveBytes() == 0) ReleasePage(page);
-    } else {
-      HeapObject* obj = HeapObject::FromAddress(page->area_start());
-      if (obj->IsFreeSpace() &&
-          FreeSpace::cast(obj)->size() == AreaSize()) {
-        // Sometimes we allocate memory from free list but don't
-        // immediately initialize it (e.g. see PagedSpace::ReserveSpace
-        // called from Heap::ReserveSpace that can cause GC before
-        // reserved space is actually initialized).
-        // Thus we can't simply assume that obj represents a valid
-        // node still owned by a free list
-        // Instead we should verify that the page is fully covered
-        // by free list items.
-        FreeList::SizeStats sizes;
-        free_list_.CountFreeListItems(page, &sizes);
-        if (sizes.Total() == AreaSize()) {
-          ReleasePage(page);
-        }
-      }
-    }
-  }
-  heap()->FreeQueuedChunks();
-}
-
-
 #ifdef DEBUG
 void PagedSpace::Print() { }
 #endif

src/spaces.h

@@ -1698,9 +1698,6 @@ class PagedSpace : public Space {
   // Releases an unused page and shrinks the space.
   void ReleasePage(Page* page);
 
-  // Releases all of the unused pages.
-  void ReleaseAllUnusedPages();
-
   // The dummy page that anchors the linked list of pages.
   Page* anchor() { return &anchor_; }