Change 64 bit ArtMethod fields to be pointer sized
Changed the 64 bit entrypoint and gc map fields in ArtMethod to be
pointer sized. This saves a large amount of memory on 32 bit systems.
Reduces ArtMethod size by 16 bytes on 32 bit.
Total number of ArtMethod on low memory mako: 169957
Image size: 49203 methods -> 787248 image size reduction.
Zygote space size: 1070 methods -> 17120 size reduction.
App methods: ~120k -> 2 MB savings.
Savings per app on low memory mako: 125K+ per app
(less active apps -> more image methods per app).
Savings depend on how often the shared methods are on dirty pages vs
shared.
TODO in another CL, delete gc map field from ArtMethod since we
should be able to get it from the Oat method header.
Bug: 17643507
Change-Id: Ie9508f05907a9f693882d4d32a564460bf273ee8
(cherry picked from commit e832e64a7e82d7f72aedbd7d798fb929d458ee8f)
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index aaf2da7..68e20f2 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -243,7 +243,8 @@
portable_imt_conflict_trampoline_(nullptr),
quick_imt_conflict_trampoline_(nullptr),
quick_generic_jni_trampoline_(nullptr),
- quick_to_interpreter_bridge_trampoline_(nullptr) {
+ quick_to_interpreter_bridge_trampoline_(nullptr),
+ image_pointer_size_(sizeof(void*)) {
memset(find_array_class_cache_, 0, kFindArrayCacheSize * sizeof(mirror::Class*));
}
@@ -378,10 +379,9 @@
Handle<mirror::Class> java_lang_reflect_ArtMethod(hs.NewHandle(
AllocClass(self, java_lang_Class.Get(), mirror::ArtMethod::ClassSize())));
CHECK(java_lang_reflect_ArtMethod.Get() != nullptr);
- java_lang_reflect_ArtMethod->SetObjectSize(mirror::ArtMethod::InstanceSize());
+ java_lang_reflect_ArtMethod->SetObjectSize(mirror::ArtMethod::InstanceSize(sizeof(void*)));
SetClassRoot(kJavaLangReflectArtMethod, java_lang_reflect_ArtMethod.Get());
java_lang_reflect_ArtMethod->SetStatus(mirror::Class::kStatusResolved, self);
-
mirror::ArtMethod::SetClass(java_lang_reflect_ArtMethod.Get());
// Set up array classes for string, field, method
@@ -407,8 +407,7 @@
// DexCache instances. Needs to be after String, Field, Method arrays since AllocDexCache uses
// these roots.
CHECK_NE(0U, boot_class_path.size());
- for (size_t i = 0; i != boot_class_path.size(); ++i) {
- const DexFile* dex_file = boot_class_path[i];
+ for (const DexFile* dex_file : boot_class_path) {
CHECK(dex_file != nullptr);
AppendToBootClassPath(self, *dex_file);
}
@@ -1682,6 +1681,20 @@
// Set classes on AbstractMethod early so that IsMethod tests can be performed during the live
// bitmap walk.
mirror::ArtMethod::SetClass(GetClassRoot(kJavaLangReflectArtMethod));
+ size_t art_method_object_size = mirror::ArtMethod::GetJavaLangReflectArtMethod()->GetObjectSize();
+ if (!Runtime::Current()->IsCompiler()) {
+ // Compiler supports having an image with a different pointer size than the runtime. This
+ // happens on the host for compile 32 bit tests since we use a 64 bit libart compiler. We may
+ // also use 32 bit dex2oat on a system with 64 bit apps.
+ CHECK_EQ(art_method_object_size, mirror::ArtMethod::InstanceSize(sizeof(void*)))
+ << sizeof(void*);
+ }
+ if (art_method_object_size == mirror::ArtMethod::InstanceSize(4)) {
+ image_pointer_size_ = 4;
+ } else {
+ CHECK_EQ(art_method_object_size, mirror::ArtMethod::InstanceSize(8));
+ image_pointer_size_ = 8;
+ }
// Set entry point to interpreter if in InterpretOnly mode.
if (Runtime::Current()->GetInstrumentation()->InterpretOnly()) {
@@ -1695,7 +1708,7 @@
// reinit array_iftable_ from any array class instance, they should be ==
array_iftable_ = GcRoot<mirror::IfTable>(GetClassRoot(kObjectArrayClass)->GetIfTable());
- DCHECK(array_iftable_.Read() == GetClassRoot(kBooleanArrayClass)->GetIfTable());
+ DCHECK_EQ(array_iftable_.Read(), GetClassRoot(kBooleanArrayClass)->GetIfTable());
// String class root was set above
mirror::Reference::SetClass(GetClassRoot(kJavaLangRefReference));
mirror::ArtField::SetClass(GetClassRoot(kJavaLangReflectArtField));
@@ -5312,14 +5325,18 @@
} else {
klass->SetNumReferenceInstanceFields(num_reference_fields);
if (!klass->IsVariableSize()) {
- std::string temp;
- DCHECK_GE(size, sizeof(mirror::Object)) << klass->GetDescriptor(&temp);
- size_t previous_size = klass->GetObjectSize();
- if (previous_size != 0) {
- // Make sure that we didn't originally have an incorrect size.
- CHECK_EQ(previous_size, size) << klass->GetDescriptor(&temp);
+ if (klass->DescriptorEquals("Ljava/lang/reflect/ArtMethod;")) {
+ klass->SetObjectSize(mirror::ArtMethod::InstanceSize(sizeof(void*)));
+ } else {
+ std::string temp;
+ DCHECK_GE(size, sizeof(mirror::Object)) << klass->GetDescriptor(&temp);
+ size_t previous_size = klass->GetObjectSize();
+ if (previous_size != 0) {
+ // Make sure that we didn't originally have an incorrect size.
+ CHECK_EQ(previous_size, size) << klass->GetDescriptor(&temp);
+ }
+ klass->SetObjectSize(size);
}
- klass->SetObjectSize(size);
}
}
@@ -5372,7 +5389,6 @@
}
CHECK_EQ(current_ref_offset.Uint32Value(), end_ref_offset.Uint32Value());
}
-
return true;
}