[heap] Simplify and scale ResourceConstraints::ConfigureDefaults.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 330174e79a2f6c4fd73aa1d22e6b2194b244bd2e..8cdb651443f55cb16c3be82db1d69374ed5965d7 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -69,6 +69,7 @@
 #include "src/tracing/trace-event.h"
 #include "src/trap-handler/trap-handler.h"
 #include "src/unicode-inl.h"
+#include "src/utils.h"
 #include "src/v8.h"
 #include "src/v8threads.h"
 #include "src/value-serializer.h"
@@ -874,38 +875,9 @@ ResourceConstraints::ResourceConstraints()
 
 void ResourceConstraints::ConfigureDefaults(uint64_t physical_memory,
                                             uint64_t virtual_memory_limit) {
-#if V8_OS_ANDROID
-  // Android has higher physical memory requirements before raising the maximum
-  // heap size limits since it has no swap space.
-  const uint64_t low_limit = 512ul * i::MB;
-  const uint64_t medium_limit = 1ul * i::GB;
-  const uint64_t high_limit = 2ul * i::GB;
-#else
-  const uint64_t low_limit = 512ul * i::MB;
-  const uint64_t medium_limit = 768ul * i::MB;
-  const uint64_t high_limit = 1ul  * i::GB;
-#endif
-
-  if (physical_memory <= low_limit) {
-    set_max_semi_space_size(i::Heap::kMaxSemiSpaceSizeLowMemoryDevice);
-    set_max_old_space_size(i::Heap::kMaxOldSpaceSizeLowMemoryDevice);
-    set_max_zone_pool_size(i::AccountingAllocator::kMaxPoolSizeLowMemoryDevice);
-  } else if (physical_memory <= medium_limit) {
-    set_max_semi_space_size(i::Heap::kMaxSemiSpaceSizeMediumMemoryDevice);
-    set_max_old_space_size(i::Heap::kMaxOldSpaceSizeMediumMemoryDevice);
-    set_max_zone_pool_size(
-        i::AccountingAllocator::kMaxPoolSizeMediumMemoryDevice);
-  } else if (physical_memory <= high_limit) {
-    set_max_semi_space_size(i::Heap::kMaxSemiSpaceSizeHighMemoryDevice);
-    set_max_old_space_size(i::Heap::kMaxOldSpaceSizeHighMemoryDevice);
-    set_max_zone_pool_size(
-        i::AccountingAllocator::kMaxPoolSizeHighMemoryDevice);
-  } else {
-    set_max_semi_space_size(i::Heap::kMaxSemiSpaceSizeHugeMemoryDevice);
-    set_max_old_space_size(i::Heap::kMaxOldSpaceSizeHugeMemoryDevice);
-    set_max_zone_pool_size(
-        i::AccountingAllocator::kMaxPoolSizeHugeMemoryDevice);
-  }
+  set_max_semi_space_size(ComputeMaxSemiSpaceSize(physical_memory));
+  set_max_old_space_size(ComputeMaxOldGenerationSize(physical_memory));
+  set_max_zone_pool_size(i::AccountingAllocator::kMaxPoolSize);
 
   if (virtual_memory_limit > 0 && i::kRequiresCodeRange) {
     // Reserve no more than 1/8 of the memory for the code range, but at most
@@ -916,6 +888,24 @@ void ResourceConstraints::ConfigureDefaults(uint64_t physical_memory,
   }
 }
 
+int ResourceConstraints::ComputeMaxOldGenerationSize(uint64_t physical_memory) {
+  const int old_space_physical_memory_factor = 4;
+  int value = i::Max(i::Min(static_cast<int>(physical_memory / i::MB /
+                                             old_space_physical_memory_factor *
+                                             i::Heap::kPointerMultiplier),
+                            i::Heap::kMaxOldSpaceSize),
+                     i::Heap::kMinOldSpaceSize);
+  return value;
+}
+
+int ResourceConstraints::ComputeMaxSemiSpaceSize(uint64_t physical_memory) {
+  const uint64_t semi_space_physical_memory_factor = 512;
+  return i::Max(i::Min(static_cast<int>(physical_memory / i::MB /
+                                        semi_space_physical_memory_factor *
+                                        i::Heap::kPointerMultiplier),
+                       i::Heap::kMaxSemiSpaceSize),
+                i::Heap::kMinSemiSpaceSize);
+}
 
 void SetResourceConstraints(i::Isolate* isolate,
                             const ResourceConstraints& constraints) {