Disable concurrent marking/sweeping, and background compilation on ARMv5TE

runtime/vm/flag_list.h

Index: runtime/vm/flag_list.h
diff --git a/runtime/vm/flag_list.h b/runtime/vm/flag_list.h
index cf476ca760f162d23294ddc775c004b5e3263379..5f5c1fb4344c0e2aa32c2a7cedb67df27aff2e59 100644
--- a/runtime/vm/flag_list.h
+++ b/runtime/vm/flag_list.h
@@ -11,25 +11,33 @@
 #define USING_DBC 0
 #endif
 
+// Disable background threads by default on armv5te. The relevant

[Ivan Posva, 2016/05/12 19:59:46]

Please move this into platform/globals.h instead of it hiding here in
flag_list.h.

[zra, 2016/05/12 20:12:25]

Done.

+// implementations are uniprocessors.
+#if defined(TARGET_ARCH_ARM_5TE)
+#define ARCH_IS_MULTI_CORE 0
+#else
+#define ARCH_IS_MULTI_CORE 1
+#endif
+
 // List of all flags in the VM.
 // Flags can be one of three categories:
 // * P roduct flags: Can be set in any of the deployment modes, including in
 //   production.
-// * D ebug flags: Can only be set in debug VMs, which also have assertions
-//   enabled.
 // * R elease flags: Generally available flags except when building product.
+// * D ebug flags: Can only be set in debug VMs, which also have C++ assertions
+//   enabled.
 // * pre C ompile flags: Generally available flags except when building product
 //   or precompiled runtime.
 //
 // Usage:
 //   P(name, type, default_value, comment)
-//   D(name, type, default_value, comment)
 //   R(name, product_value, type, default_value, comment)
+//   D(name, type, default_value, comment)
 //   C(name, precompiled_value, product_value, type, default_value, comment)
 #define FLAG_LIST(P, R, D, C)                                                  \
 P(always_megamorphic_calls, bool, false,                                       \
   "Instance call always as megamorphic.")                                      \
-P(background_compilation, bool, true,                                          \
+P(background_compilation, bool, ARCH_IS_MULTI_CORE,                            \
   "Run optimizing compilation in background")                                  \
 R(background_compilation_stop_alot, false, bool, false,                        \
   "Stress test system: stop background compiler often.")                       \
@@ -39,6 +47,8 @@ C(collect_code, false, true, bool, true,                                       \
   "Attempt to GC infrequently used code.")                                     \
 P(collect_dynamic_function_names, bool, true,                                  \
   "Collects all dynamic function names to identify unique targets")            \
+R(concurrent_sweep, ARCH_IS_MULTI_CORE, bool, ARCH_IS_MULTI_CORE,              \
+  "Concurrent sweep for old generation.")                                      \
 R(dedup_instructions, true, bool, false,                                       \
   "Canonicalize instructions when precompiling.")                              \
 C(deoptimize_alot, false, false, bool, false,                                  \
@@ -86,6 +96,11 @@ P(link_natives_lazily, bool, false,                                            \
   "Link native calls lazily")                                                  \
 C(load_deferred_eagerly, true, true, bool, false,                              \
   "Load deferred libraries eagerly.")                                          \
+R(log_marker_tasks, false, bool, false,                                        \
+  "Log debugging information for old gen GC marking tasks.")                   \
+R(marker_tasks, ARCH_IS_MULTI_CORE ? 2 : 0, int, ARCH_IS_MULTI_CORE ? 2 : 0,   \
+  "The number of tasks to spawn during old gen GC marking (0 means "           \
+  "perform all marking on main thread).")                                      \
 P(max_polymorphic_checks, int, 4,                                              \
   "Maximum number of polymorphic check, otherwise it is megamorphic.")         \
 P(max_equality_polymorphic_checks, int, 32,                                    \