Implement committed physical memory stats for Linux.

src/spaces.h

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 489 matching lines @@
   static const intptr_t kLiveBytesOffset =
      kSizeOffset + kPointerSize + kPointerSize + kPointerSize +
      kPointerSize + kPointerSize +
      kPointerSize + kPointerSize + kPointerSize + kIntSize;
 
   static const size_t kSlotsBufferOffset = kLiveBytesOffset + kIntSize;
 
   static const size_t kWriteBarrierCounterOffset =
       kSlotsBufferOffset + kPointerSize + kPointerSize;
 
-  static const size_t kHeaderSize = kWriteBarrierCounterOffset + kPointerSize;
+  static const size_t kHeaderSize =
+      kWriteBarrierCounterOffset + kPointerSize + kPointerSize;
 
   static const int kBodyOffset =
     CODE_POINTER_ALIGN(MAP_POINTER_ALIGN(kHeaderSize + Bitmap::kSize));
 
   // The start offset of the object area in a page. Aligned to both maps and
   // code alignment to be suitable for both.  Also aligned to 32 words because
   // the marking bitmap is arranged in 32 bit chunks.
   static const int kObjectStartAlignment = 32 * kPointerSize;
   static const int kObjectStartOffset = kBodyOffset - 1 +
       (kObjectStartAlignment - (kBodyOffset - 1) % kObjectStartAlignment);
@@ skipping 91 matching lines @@
     ASSERT(slots_buffer_ == NULL);
     ClearFlag(EVACUATION_CANDIDATE);
   }
 
   Address area_start() { return area_start_; }
   Address area_end() { return area_end_; }
   int area_size() {
     return static_cast<int>(area_end() - area_start());
   }
 
+  // Approximate amount of physical memory committed for this chunk.
+  size_t CommittedPhysicalMemory() {
+    return high_water_mark_;
+  }
+
+  static inline void UpdateHighWaterMark(Address mark);
+
  protected:
   MemoryChunk* next_chunk_;
   MemoryChunk* prev_chunk_;
   size_t size_;
   intptr_t flags_;
 
   // Start and end of allocatable memory on this chunk.
   Address area_start_;
   Address area_end_;
 
   // If the chunk needs to remember its memory reservation, it is stored here.
   VirtualMemory reservation_;
   // The identity of the owning space.  This is tagged as a failure pointer, but
   // no failure can be in an object, so this can be distinguished from any entry
   // in a fixed array.
   Address owner_;
   Heap* heap_;
   // Used by the store buffer to keep track of which pages to mark scan-on-
   // scavenge.
   int store_buffer_counter_;
   // Count of bytes marked black on page.
   int live_byte_count_;
   SlotsBuffer* slots_buffer_;
   SkipList* skip_list_;
   intptr_t write_barrier_counter_;
+  // Assuming the initial allocation on a page is sequential,
+  // count highest number of bytes ever allocated on the page.
+  int high_water_mark_;
 
   static MemoryChunk* Initialize(Heap* heap,
                                  Address base,
                                  size_t size,
                                  Address area_start,
                                  Address area_end,
                                  Executability executable,
                                  Space* owner);
 
   friend class MemoryAllocator;
@@ skipping 829 matching lines @@
   // Prepares for a mark-compact GC.
   virtual void PrepareForMarkCompact();
 
   // Current capacity without growing (Size() + Available()).
   intptr_t Capacity() { return accounting_stats_.Capacity(); }
 
   // Total amount of memory committed for this space.  For paged
   // spaces this equals the capacity.
   intptr_t CommittedMemory() { return Capacity(); }
 
+  // Approximate amount of physical memory committed for this space.
+  size_t CommittedPhysicalMemory();
+
   // Sets the capacity, the available space and the wasted space to zero.
   // The stats are rebuilt during sweeping by adding each page to the
   // capacity and the size when it is encountered.  As free spaces are
   // discovered during the sweeping they are subtracted from the size and added
   // to the available and wasted totals.
   void ClearStats() {
     accounting_stats_.ClearSizeWaste();
   }
 
   // Available bytes without growing.  These are the bytes on the free list.
@@ skipping 40 matching lines @@
   }
 
   void ResetFreeList() {
     free_list_.Reset();
   }
 
   // Set space allocation info.
   void SetTop(Address top, Address limit) {
     ASSERT(top == limit ||
            Page::FromAddress(top) == Page::FromAddress(limit - 1));
+    MemoryChunk::UpdateHighWaterMark(allocation_info_.top);
     allocation_info_.top = top;
     allocation_info_.limit = limit;
   }
 
   void Allocate(int bytes) {
     accounting_stats_.AllocateBytes(bytes);
   }
 
   void IncreaseCapacity(int size) {
     accounting_stats_.ExpandSpace(size);
@@ skipping 386 matching lines @@
   // Returns the maximum capacity of the semi space.
   int MaximumCapacity() { return maximum_capacity_; }
 
   // Returns the initial capacity of the semi space.
   int InitialCapacity() { return initial_capacity_; }
 
   SemiSpaceId id() { return id_; }
 
   static void Swap(SemiSpace* from, SemiSpace* to);
 
+  // Approximate amount of physical memory committed for this space.
+  size_t CommittedPhysicalMemory();
+
  private:
   // Flips the semispace between being from-space and to-space.
   // Copies the flags into the masked positions on all pages in the space.
   void FlipPages(intptr_t flags, intptr_t flag_mask);
 
   NewSpacePage* anchor() { return &anchor_; }
 
   // The current and maximum capacity of the space.
   int capacity_;
   int maximum_capacity_;
@@ skipping 177 matching lines @@
     ASSERT(to_space_.Capacity() == from_space_.Capacity());
     return to_space_.Capacity();
   }
 
   // Return the total amount of memory committed for new space.
   intptr_t CommittedMemory() {
     if (from_space_.is_committed()) return 2 * Capacity();
     return Capacity();
   }
 
+  // Approximate amount of physical memory committed for this space.
+  size_t CommittedPhysicalMemory();
+
   // Return the available bytes without growing.
   intptr_t Available() {
     return Capacity() - Size();
   }
 
   // Return the maximum capacity of a semispace.
   int MaximumCapacity() {
     ASSERT(to_space_.MaximumCapacity() == from_space_.MaximumCapacity());
     return to_space_.MaximumCapacity();
   }
@@ skipping 347 matching lines @@
   }
 
   virtual intptr_t SizeOfObjects() {
     return objects_size_;
   }
 
   intptr_t CommittedMemory() {
     return Size();
   }
 
+  // Approximate amount of physical memory committed for this space.
+  size_t CommittedPhysicalMemory();
+
   int PageCount() {
     return page_count_;
   }
 
   // Finds an object for a given address, returns Failure::Exception()
   // if it is not found. The function iterates through all objects in this
   // space, may be slow.
   MaybeObject* FindObject(Address a);
 
   // Finds a large object page containing the given address, returns NULL
@@ skipping 132 matching lines @@
   }
   // Must be small, since an iteration is used for lookup.
   static const int kMaxComments = 64;
 };
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_SPACES_H_