Tweak default max heap size constants for platforms with swap.

Configure platforms with swap memory with larger heap size by default. Also
introduce an additional "bucket" between 1GB-2GBs.

BUG=None
R=hpayer@chromium.org, jkummerow@chromium.org

Review URL: https://codereview.chromium.org/24978006

Patch from Ross McIlroy <rmcilroy@chromium.org>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17081 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/defaults.cc

@@ -33,6 +33,14 @@
 
 namespace v8 {
 
+
+#if V8_OS_ANDROID
+const bool kOsHasSwap = false;
+#else
+const bool kOsHasSwap = true;
+#endif
+
+
 bool ConfigureResourceConstraintsForCurrentPlatform(
     ResourceConstraints* constraints) {
   if (constraints == NULL) {
@@ -44,18 +52,22 @@ bool ConfigureResourceConstraintsForCurrentPlatform(
 
   // The young_space_size should be a power of 2 and old_generation_size should
   // be a multiple of Page::kPageSize.
-  if (physical_memory > 2ul * i::GB) {
+  if (physical_memory <= 512ul * i::MB) {
+    constraints->set_max_young_space_size(2 * lump_of_memory);
+    constraints->set_max_old_space_size(128 * lump_of_memory);
+    constraints->set_max_executable_size(96 * lump_of_memory);
+  } else if (physical_memory <= (kOsHasSwap ? 768ul * i::MB : 1ul * i::GB)) {
+    constraints->set_max_young_space_size(8 * lump_of_memory);
+    constraints->set_max_old_space_size(256 * lump_of_memory);
+    constraints->set_max_executable_size(192 * lump_of_memory);
+  } else if (physical_memory <= (kOsHasSwap ? 1ul * i::GB : 2ul * i::GB)) {
+    constraints->set_max_young_space_size(16 * lump_of_memory);
+    constraints->set_max_old_space_size(512 * lump_of_memory);
+    constraints->set_max_executable_size(256 * lump_of_memory);
+  } else {
     constraints->set_max_young_space_size(16 * lump_of_memory);
     constraints->set_max_old_space_size(700 * lump_of_memory);
     constraints->set_max_executable_size(256 * lump_of_memory);
-  } else if (physical_memory > 512ul * i::MB) {
-    constraints->set_max_young_space_size(8 * lump_of_memory);
-    constraints->set_max_old_space_size(192 * lump_of_memory);
-    constraints->set_max_executable_size(192 * lump_of_memory);
-  } else /* (physical_memory <= 512GB) */ {
-    constraints->set_max_young_space_size(2 * lump_of_memory);
-    constraints->set_max_old_space_size(96 * lump_of_memory);
-    constraints->set_max_executable_size(96 * lump_of_memory);
   }
   return true;
 }
@@ -68,4 +80,4 @@ bool SetDefaultResourceConstraintsForCurrentPlatform() {
   return SetResourceConstraints(&constraints);
 }
 
-}  // namespace v8::internal
+}  // namespace v8