Disable concurrent marking/sweeping, and background compilation on ARMv5TE

runtime/vm/gc_marker.cc

Index: runtime/vm/gc_marker.cc
diff --git a/runtime/vm/gc_marker.cc b/runtime/vm/gc_marker.cc
index cc5db20ce64187a265ec23cd2ad5d2cd8b2ecf5e..b0d30080ce61d49d9dbdc9277222c0fd446bf65a 100644
--- a/runtime/vm/gc_marker.cc
+++ b/runtime/vm/gc_marker.cc
@@ -25,7 +25,15 @@
 
 namespace dart {
 
-DEFINE_FLAG(int, marker_tasks, 2,
+// Disable concurrent marking by default on armv5te. The relevant
+// implementations are uniprocessors.
+#if defined(TARGET_ARCH_ARM_5TE)
+#define MARKER_TASKS 0
+#else
+#define MARKER_TASKS 2
+#endif
+
+DEFINE_FLAG(int, marker_tasks, MARKER_TASKS,

[Ivan Posva, 2016/05/12 17:19:46]

Can we please move these flags into the flag list?

[zra, 2016/05/12 19:54:21]

Done.

             "The number of tasks to spawn during old gen GC marking (0 means "
             "perform all marking on main thread).");
 DEFINE_FLAG(bool, log_marker_tasks, false,