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, 10 insertions, 0 deletions

diff --git a/runtime/runtime.h b/runtime/runtime.h
index 5078b7f1d6..4cddb5c255 100644
--- a/runtime/runtime.h
+++ b/runtime/runtime.h
@@ -28,6 +28,7 @@
 
 #include "arch/instruction_set.h"
 #include "base/allocator.h"
+#include "base/arena_allocator.h"
 #include "base/macros.h"
 #include "compiler_callbacks.h"
 #include "gc_root.h"
@@ -545,6 +546,13 @@ class Runtime {
 
   void CreateJit();
 
+  ArenaPool* GetArenaPool() {
+    return arena_pool_.get();
+  }
+  const ArenaPool* GetArenaPool() const {
+    return arena_pool_.get();
+  }
+
  private:
   static void InitPlatformSignalHandlers();
 
@@ -608,6 +616,8 @@ class Runtime {
 
   gc::Heap* heap_;
 
+  std::unique_ptr<ArenaPool> arena_pool_;
+
   // The number of spins that are done before thread suspension is used to forcibly inflate.
   size_t max_spins_before_thin_lock_inflation_;
   MonitorList* monitor_list_;