Trim arenas for JIT

Moved arena pool into the runtime. Added arena trimming to arena
pool. When called, this madvises the used memory.

Changed the JIT compiler to trim arenas after compilation. Changed
the arena mmap name to dalvik-LinearAlloc.

Native PSS before:
  80353 kB: Native
  80775 kB: Native
  78116 kB: Native
After:
  73357 kB: Native
  70181 kB: Native
  70306 kB: Native

Bug: 17950037
Bug: 17643507
Bug: 19264997

Change-Id: I63e7a898fd6e909c2c677fa57b5917a7b1398930

1 files changed, 4 insertions, 2 deletions

diff --git a/compiler/jit/jit_compiler.cc b/compiler/jit/jit_compiler.cc
index 04efa21f4e..a63e14a980 100644
--- a/compiler/jit/jit_compiler.cc
+++ b/compiler/jit/jit_compiler.cc
@@ -103,7 +103,7 @@ JitCompiler::~JitCompiler() {
 }
 
 bool JitCompiler::CompileMethod(Thread* self, mirror::ArtMethod* method) {
-  uint64_t start_time = NanoTime();
+  const uint64_t start_time = NanoTime();
   StackHandleScope<2> hs(self);
   self->AssertNoPendingException();
   Runtime* runtime = Runtime::Current();
@@ -130,6 +130,8 @@ bool JitCompiler::CompileMethod(Thread* self, mirror::ArtMethod* method) {
     }
   }
   CompiledMethod* compiled_method(compiler_driver_->CompileMethod(self, h_method.Get()));
+  // Trim maps to reduce memory usage, TODO: measure how much this increases compile time.
+  runtime->GetArenaPool()->TrimMaps();
   if (compiled_method == nullptr) {
     return false;
   }
@@ -137,7 +139,7 @@ bool JitCompiler::CompileMethod(Thread* self, mirror::ArtMethod* method) {
   // Don't add the method if we are supposed to be deoptimized.
   bool result = false;
   if (!runtime->GetInstrumentation()->AreAllMethodsDeoptimized()) {
-    const void* code = Runtime::Current()->GetClassLinker()->GetOatMethodQuickCodeFor(
+    const void* code = runtime->GetClassLinker()->GetOatMethodQuickCodeFor(
         h_method.Get());
     if (code != nullptr) {
       // Already have some compiled code, just use this instead of linking.