Add support for a target new space size

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 43 matching lines @@
 Heap::Heap()
     : amount_of_external_allocated_memory_(0),
       amount_of_external_allocated_memory_at_last_global_gc_(0),
       isolate_(NULL),
       code_range_size_(0),
       // semispace_size_ should be a power of 2 and old_generation_size_ should
       // be a multiple of Page::kPageSize.
       reserved_semispace_size_(8 * (kPointerSize / 4) * MB),
       max_semi_space_size_(8 * (kPointerSize / 4) * MB),
       initial_semispace_size_(Page::kPageSize),
+      target_semispace_size_(Page::kPageSize),
       max_old_generation_size_(700ul * (kPointerSize / 4) * MB),
       max_executable_size_(256ul * (kPointerSize / 4) * MB),
       // Variables set based on semispace_size_ and old_generation_size_ in
       // ConfigureHeap.
       // Will be 4 * reserved_semispace_size_ to ensure that young
       // generation can be aligned to its size.
       maximum_committed_(0),
       survived_since_last_expansion_(0),
       sweep_generation_(0),
       always_allocate_scope_depth_(0),
@@ skipping 4863 matching lines @@
       base::bits::RoundUpToPowerOfTwo32(max_semi_space_size_);
   reserved_semispace_size_ =
       base::bits::RoundUpToPowerOfTwo32(reserved_semispace_size_);
 
   if (FLAG_min_semi_space_size > 0) {
     int initial_semispace_size = FLAG_min_semi_space_size * MB;
     if (initial_semispace_size > max_semi_space_size_) {
       initial_semispace_size_ = max_semi_space_size_;
       if (FLAG_trace_gc) {
         PrintPID(
-            "Min semi-space size cannot be more than the maximum"
+            "Min semi-space size cannot be more than the maximum "
             "semi-space size of %d MB\n",
-            max_semi_space_size_);
+            max_semi_space_size_ / MB);
       }
     } else {
       initial_semispace_size_ = initial_semispace_size;
     }
   }
 
   initial_semispace_size_ = Min(initial_semispace_size_, max_semi_space_size_);
 
+  if (FLAG_target_semi_space_size > 0) {
+    int target_semispace_size = FLAG_target_semi_space_size * MB;
+    if (target_semispace_size < initial_semispace_size_) {
+      target_semispace_size_ = initial_semispace_size_;
+      if (FLAG_trace_gc) {
+        PrintPID(
+            "Target semi-space size cannot be less than the minimum "
+            "semi-space size of %d MB\n",
+            initial_semispace_size_ / MB);
+      }
+    } else if (target_semispace_size > max_semi_space_size_) {
+      target_semispace_size_ = max_semi_space_size_;
+      if (FLAG_trace_gc) {
+        PrintPID(
+            "Target semi-space size cannot be less than the maximum "
+            "semi-space size of %d MB\n",
+            max_semi_space_size_ / MB);
+      }
+    } else {
+      target_semispace_size_ = target_semispace_size;
+    }
+  }
+
+  target_semispace_size_ = Max(initial_semispace_size_, target_semispace_size_);
+
   // The old generation is paged and needs at least one page for each space.
   int paged_space_count = LAST_PAGED_SPACE - FIRST_PAGED_SPACE + 1;
   max_old_generation_size_ =
       Max(static_cast<intptr_t>(paged_space_count * Page::kPageSize),
           max_old_generation_size_);
 
   // We rely on being able to allocate new arrays in paged spaces.
   DCHECK(Page::kMaxRegularHeapObjectSize >=
          (JSArray::kSize +
           FixedArray::SizeFor(JSObject::kInitialMaxFastElementArray) +
@@ skipping 1236 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