"trace progress of the incremental marking")
DEFINE_bool(track_gc_object_stats, false,
"track object counts and memory usage")
-DEFINE_bool(parallel_sweeping, false, "enable parallel sweeping")
-DEFINE_bool(concurrent_sweeping, true, "enable concurrent sweeping")
+DEFINE_bool(parallel_sweeping, true, "enable parallel sweeping")
+DEFINE_bool(concurrent_sweeping, false, "enable concurrent sweeping")
DEFINE_int(sweeper_threads, 0,
"number of parallel and concurrent sweeping threads")
#ifdef VERIFY_HEAP