Revert "Revert "Favor free list allocation to bump pointer allocation.""

runtime/vm/pages.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/pages.h"
 
 #include "platform/assert.h"
 #include "vm/gc_marker.h"
 #include "vm/gc_sweeper.h"
 #include "vm/object.h"
 #include "vm/virtual_memory.h"
 
 namespace dart {
 
 DEFINE_FLAG(int, heap_growth_space_ratio, 10,
             "The desired maximum percentage of free space after GC");
 DEFINE_FLAG(int, heap_growth_time_ratio, 3,
             "The desired maximum percentage of time spent in GC");
 DEFINE_FLAG(int, heap_growth_rate, 4,
             "The size the heap is grown, in heap pages");
+DEFINE_FLAG(bool, print_free_list_before_gc, false,
+            "Print free list statistics before a GC");
+DEFINE_FLAG(bool, print_free_list_after_gc, false,
+            "Print free list statistics after a GC");
 
 HeapPage* HeapPage::Initialize(VirtualMemory* memory, bool is_executable) {
   ASSERT(memory->size() > VirtualMemory::PageSize());
   memory->Commit(is_executable);
 
   HeapPage* result = reinterpret_cast<HeapPage*>(memory->address());
   result->memory_ = memory;
   result->next_ = NULL;
   result->used_ = 0;
   result->top_ = result->first_object_start();
@@ skipping 174 matching lines @@
 uword PageSpace::TryAllocate(intptr_t size) {
   return TryAllocate(size, kControlGrowth);
 }
 
 
 uword PageSpace::TryAllocate(intptr_t size, GrowthPolicy growth_policy) {
   ASSERT(size >= kObjectAlignment);
   ASSERT(Utils::IsAligned(size, kObjectAlignment));
   uword result = 0;
   if (size < kAllocatablePageSize) {
-    result = TryBumpAllocate(size);
+    result = freelist_.TryAllocate(size);
     if (result == 0) {
-      result = freelist_.TryAllocate(size);
+      result = TryBumpAllocate(size);
       if ((result == 0) &&
           (page_space_controller_.CanGrowPageSpace(size) ||
            growth_policy == kForceGrowth) &&
           CanIncreaseCapacity(kPageSize)) {
         AllocatePage();
         result = TryBumpAllocate(size);
         ASSERT(result != 0);
       }
     }
   } else {
@@ skipping 108 matching lines @@
 }
 
 
 void PageSpace::MarkSweep(bool invoke_api_callbacks) {
   // MarkSweep is not reentrant. Make sure that is the case.
   ASSERT(!sweeping_);
   sweeping_ = true;
   Isolate* isolate = Isolate::Current();
   NoHandleScope no_handles(isolate);
 
+  if (FLAG_print_free_list_before_gc) {
+    freelist_.Print();
+  }
+
   if (FLAG_verify_before_gc) {
     OS::PrintErr("Verifying before MarkSweep...");
     heap_->Verify();
     OS::PrintErr(" done.\n");
   }
 
   Timer timer(true, "MarkSweep");
   timer.Start();
   int64_t start = OS::GetCurrentTimeMillis();
 
@@ skipping 52 matching lines @@
   if (FLAG_verbose_gc) {
     const intptr_t KB2 = KB / 2;
     OS::PrintErr("Mark-Sweep[%d]: %lldus (%dK -> %dK, %dK)\n",
                  count_,
                  timer.TotalElapsedTime(),
                  (in_use_before + (KB2)) / KB,
                  (in_use + (KB2)) / KB,
                  (capacity_ + KB2) / KB);
   }
 
+  if (FLAG_print_free_list_after_gc) {
+    freelist_.Print();
+  }
+
   if (FLAG_verify_after_gc) {
     OS::PrintErr("Verifying after MarkSweep...");
     heap_->Verify();
     OS::PrintErr(" done.\n");
   }
 
   count_++;
   // Done, reset the marker.
   ASSERT(sweeping_);
   sweeping_ = false;
@@ skipping 107 matching lines @@
     return 0;
   } else {
     ASSERT(total_time >= gc_time);
     int result= static_cast<int>((static_cast<double>(gc_time) /
                              static_cast<double>(total_time)) * 100);
     return result;
   }
 }
 
 }  // namespace dart