Make from-space initially uncommitted for another 1Mbyte

improvement in boot time memory usage.
Review URL: http://codereview.chromium.org/9242008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10415 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/spaces.cc

@@ -1026,14 +1026,13 @@ bool NewSpace::SetUp(int reserved_semispace_capacity,
          2 * heap()->ReservedSemiSpaceSize());
   ASSERT(IsAddressAligned(chunk_base_, 2 * reserved_semispace_capacity, 0));
 
-  if (!to_space_.SetUp(chunk_base_,
-                       initial_semispace_capacity,
-                       maximum_semispace_capacity)) {
-    return false;
-  }
-  if (!from_space_.SetUp(chunk_base_ + reserved_semispace_capacity,
-                         initial_semispace_capacity,
-                         maximum_semispace_capacity)) {
+  to_space_.SetUp(chunk_base_,
+                  initial_semispace_capacity,
+                  maximum_semispace_capacity);
+  from_space_.SetUp(chunk_base_ + reserved_semispace_capacity,
+                    initial_semispace_capacity,
+                    maximum_semispace_capacity);
+  if (!to_space_.Commit()) {
     return false;
   }
 
@@ -1266,7 +1265,7 @@ void NewSpace::Verify() {
 // -----------------------------------------------------------------------------
 // SemiSpace implementation
 
-bool SemiSpace::SetUp(Address start,
+void SemiSpace::SetUp(Address start,
                       int initial_capacity,
                       int maximum_capacity) {
   // Creates a space in the young generation. The constructor does not
@@ -1285,8 +1284,6 @@ bool SemiSpace::SetUp(Address start,
   object_mask_ = address_mask_ | kHeapObjectTagMask;
   object_expected_ = reinterpret_cast<uintptr_t>(start) | kHeapObjectTag;
   age_mark_ = start_;
-
-  return Commit();
 }
 
 

src/spaces.h

@@ -1839,8 +1839,9 @@ class SemiSpace : public Space {
       anchor_(this),
       current_page_(NULL) { }
 
-  // Sets up the semispace using the given chunk.
-  bool SetUp(Address start, int initial_capacity, int maximum_capacity);
+  // Sets up the semispace using the given chunk.  After this, call Commit()
+  // to make the semispace usable.
+  void SetUp(Address start, int initial_capacity, int maximum_capacity);
 
   // Tear down the space.  Heap memory was not allocated by the space, so it
   // is not deallocated here.

test/cctest/test-mark-compact.cc

@@ -534,15 +534,15 @@ TEST(BootUpMemoryUse) {
     intptr_t booted_memory = MemoryInUse();
     if (sizeof(initial_memory) == 8) {
       if (v8::internal::Snapshot::IsEnabled()) {
-        CHECK_LE(booted_memory - initial_memory, 4700 * 1024);  // 4640.
+        CHECK_LE(booted_memory - initial_memory, 3700 * 1024);  // 3640.
       } else {
-        CHECK_LE(booted_memory - initial_memory, 4300 * 1024);  // 4276.
+        CHECK_LE(booted_memory - initial_memory, 3300 * 1024);  // 3276.
       }
     } else {
       if (v8::internal::Snapshot::IsEnabled()) {
-        CHECK_LE(booted_memory - initial_memory, 3300 * 1024);  // 3276.
+        CHECK_LE(booted_memory - initial_memory, 2300 * 1024);  // 2276.
       } else {
-        CHECK_LE(booted_memory - initial_memory, 3500 * 1024);  // 3416
+        CHECK_LE(booted_memory - initial_memory, 2500 * 1024);  // 2416
       }
     }
   }