commit c785344b87221f5e4e6473e5b762e4e61fe65dcf
author Mathieu Chartier <mathieuc@google.com> Fri Mar 27 14:35:38 2015 -0700
committer Mathieu Chartier <mathieuc@google.com> Fri Apr 10 12:57:27 2015 -0700
tree cd32ad2c2604596a18926f04d4c313dab255ecfd
parent a29d93b380c9aeb8270e281aefbdd0c77a430d43

Move ArtField to native

Add linear alloc. Moved ArtField to be native object. Changed image
writer to put ArtFields after the mirror section.

Savings:
2MB on low ram devices
4MB on normal devices

Total PSS measurements before (normal N5, 95s after shell start):
Image size: 7729152 bytes
23112 kB: .NonMoving
23212 kB: .NonMoving
22868 kB: .NonMoving
23072 kB: .NonMoving
22836 kB: .NonMoving
19618 kB: .Zygote
19850 kB: .Zygote
19623 kB: .Zygote
19924 kB: .Zygote
19612 kB: .Zygote
Avg: 42745.4 kB

After:
Image size: 7462912 bytes
17440 kB: .NonMoving
16776 kB: .NonMoving
16804 kB: .NonMoving
17812 kB: .NonMoving
16820 kB: .NonMoving
18788 kB: .Zygote
18856 kB: .Zygote
19064 kB: .Zygote
18841 kB: .Zygote
18629 kB: .Zygote
3499 kB: .LinearAlloc
3408 kB: .LinearAlloc
3424 kB: .LinearAlloc
3600 kB: .LinearAlloc
3436 kB: .LinearAlloc
Avg: 39439.4 kB

No reflection performance changes.

Bug: 19264997
Bug: 17643507

Change-Id: I10c73a37913332080aeb978c7c94713bdfe4fe1c

runtime/base/arena_allocator.cc

diff --git a/runtime/base/arena_allocator.cc b/runtime/base/arena_allocator.cc
index dd29404..59d38ad 100644
--- a/runtime/base/arena_allocator.cc
+++ b/runtime/base/arena_allocator.cc
@@ -132,11 +132,10 @@
   free(reinterpret_cast<void*>(memory_));
 }
 
-MemMapArena::MemMapArena(size_t size) {
+MemMapArena::MemMapArena(size_t size, bool low_4gb) {
   std::string error_msg;
-  map_.reset(
-      MemMap::MapAnonymous("dalvik-LinearAlloc", nullptr, size, PROT_READ | PROT_WRITE, false,
-                           false, &error_msg));
+  map_.reset(MemMap::MapAnonymous(
+      "LinearAlloc", nullptr, size, PROT_READ | PROT_WRITE, low_4gb, false, &error_msg));
   CHECK(map_.get() != nullptr) << error_msg;
   memory_ = map_->Begin();
   size_ = map_->Size();
@@ -156,8 +155,12 @@
   }
 }
 
-ArenaPool::ArenaPool(bool use_malloc)
-    : use_malloc_(use_malloc), lock_("Arena pool lock"), free_arenas_(nullptr) {
+ArenaPool::ArenaPool(bool use_malloc, bool low_4gb)
+    : use_malloc_(use_malloc), lock_("Arena pool lock", kArenaPoolLock), free_arenas_(nullptr),
+      low_4gb_(low_4gb) {
+  if (low_4gb) {
+    CHECK(!use_malloc) << "low4gb must use map implementation";
+  }
   if (!use_malloc) {
     MemMap::Init();
   }
@@ -182,7 +185,8 @@
     }
   }
   if (ret == nullptr) {
-    ret = use_malloc_ ? static_cast<Arena*>(new MallocArena(size)) : new MemMapArena(size);
+    ret = use_malloc_ ? static_cast<Arena*>(new MallocArena(size)) :
+        new MemMapArena(size, low_4gb_);
   }
   ret->Reset();
   return ret;
@@ -229,6 +233,17 @@
   return ArenaAllocatorStats::BytesAllocated();
 }
 
+size_t ArenaAllocator::BytesUsed() const {
+  size_t total = ptr_ - begin_;
+  if (arena_head_ != nullptr) {
+    for (Arena* cur_arena = arena_head_->next_; cur_arena != nullptr;
+         cur_arena = cur_arena->next_) {
+     total += cur_arena->GetBytesAllocated();
+    }
+  }
+  return total;
+}
+
 ArenaAllocator::ArenaAllocator(ArenaPool* pool)
   : pool_(pool),
     begin_(nullptr),