[heap] Simplify and scale ResourceConstraints::ConfigureDefaults.

src/heap/heap.h

 // 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.
 
 #ifndef V8_HEAP_HEAP_H_
 #define V8_HEAP_HEAP_H_
 
 #include <cmath>
 #include <vector>
 
@@ skipping 596 matching lines @@
 
 #if V8_OS_ANDROID
   // Don't apply pointer multiplier on Android since it has no swap space and
   // should instead adapt it's heap size based on available physical memory.
   static const int kPointerMultiplier = 1;
 #else
   static const int kPointerMultiplier = i::kPointerSize / 4;
 #endif
 
   // The new space size has to be a power of 2. Sizes are in MB.
-  static const int kMaxSemiSpaceSizeLowMemoryDevice = 1 * kPointerMultiplier;
-  static const int kMaxSemiSpaceSizeMediumMemoryDevice = 4 * kPointerMultiplier;
-  static const int kMaxSemiSpaceSizeHighMemoryDevice = 8 * kPointerMultiplier;
-  static const int kMaxSemiSpaceSizeHugeMemoryDevice = 8 * kPointerMultiplier;
+  static const int kMinSemiSpaceSize = 1 * kPointerMultiplier;
+  static const int kMaxSemiSpaceSize = 8 * kPointerMultiplier;
 
   // The old space size has to be a multiple of Page::kPageSize.
   // Sizes are in MB.
-  static const int kMaxOldSpaceSizeLowMemoryDevice = 128 * kPointerMultiplier;
-  static const int kMaxOldSpaceSizeMediumMemoryDevice =
-      256 * kPointerMultiplier;
-  static const int kMaxOldSpaceSizeHighMemoryDevice = 512 * kPointerMultiplier;
-  static const int kMaxOldSpaceSizeHugeMemoryDevice = 1024 * kPointerMultiplier;
+  static const int kMinOldSpaceSize = 128 * kPointerMultiplier;
+  static const int kMaxOldSpaceSize = 1024 * kPointerMultiplier;
 
   static const int kTraceRingBufferSize = 512;
   static const int kStacktraceBufferSize = 512;
 
   V8_EXPORT_PRIVATE static const double kMinHeapGrowingFactor;
   V8_EXPORT_PRIVATE static const double kMaxHeapGrowingFactor;
   static const double kMaxHeapGrowingFactorMemoryConstrained;
   static const double kMaxHeapGrowingFactorIdle;
   static const double kConservativeHeapGrowingFactor;
   static const double kTargetMutatorUtilization;
@@ skipping 305 matching lines @@
 
   bool HasLowAllocationRate();
   bool HasHighFragmentation();
   bool HasHighFragmentation(size_t used, size_t committed);
 
   void ActivateMemoryReducerIfNeeded();
 
   bool ShouldOptimizeForMemoryUsage();
 
   bool IsLowMemoryDevice() {
+    const int kMaxOldSpaceSizeLowMemoryDevice = 128 * kPointerMultiplier;

[Hannes Payer (out of office), 2017/05/19 11:39:57]

I will remove these two methods in a follow-up CL. I am keeping the constants
until then local in these methods.

     return max_old_generation_size_ <= kMaxOldSpaceSizeLowMemoryDevice;
   }
 
   bool IsMemoryConstrainedDevice() {
+    const int kMaxOldSpaceSizeMediumMemoryDevice = 256 * kPointerMultiplier;
     return max_old_generation_size_ <= kMaxOldSpaceSizeMediumMemoryDevice;
   }
 
   bool HighMemoryPressure() {
     return memory_pressure_level_.Value() != MemoryPressureLevel::kNone;
   }
 
   size_t HeapLimitForDebugging() {
     const size_t kDebugHeapSizeFactor = 4;
     size_t max_limit = std::numeric_limits<size_t>::max() / 4;
@@ skipping 1669 matching lines @@
   friend class PagedSpace;
   DISALLOW_COPY_AND_ASSIGN(AllocationObserver);
 };
 
 V8_EXPORT_PRIVATE const char* AllocationSpaceName(AllocationSpace space);
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_HEAP_H_