Enable concurrent sweep for ia32.

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/compiler_stats.h"
 #include "vm/gc_marker.h"
 #include "vm/gc_sweeper.h"
@@ skipping 16 matching lines @@
             "Print free list statistics after a GC");
 DEFINE_FLAG(bool, collect_code, true,
             "Attempt to GC infrequently used code.");
 DEFINE_FLAG(int, code_collection_interval_in_us, 30000000,
             "Time between attempts to collect unused code.");
 DEFINE_FLAG(bool, log_code_drop, false,
             "Emit a log message when pointers to unused code are dropped.");
 DEFINE_FLAG(bool, always_drop_code, false,
             "Always try to drop code if the function's usage counter is >= 0");
 #if defined(TARGET_ARCH_IA32)
-DEFINE_FLAG(bool, concurrent_sweep, false,
+DEFINE_FLAG(bool, concurrent_sweep, true,
             "Concurrent sweep for old generation.");
 #else  // TARGET_ARCH_IA32
 DEFINE_FLAG(bool, concurrent_sweep, false,
             "Concurrent sweep for old generation.");
 #endif  // TARGET_ARCH_IA32
 DEFINE_FLAG(bool, log_growth, false, "Log PageSpace growth policy decisions.");
 
 HeapPage* HeapPage::Initialize(VirtualMemory* memory, PageType type) {
   ASSERT(memory->size() > VirtualMemory::PageSize());
   bool is_executable = (type == kExecutable);
@@ skipping 948 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