Index: compiler-rt/trunk/test/asan/lit.cfg
===================================================================
--- compiler-rt/trunk/test/asan/lit.cfg
+++ compiler-rt/trunk/test/asan/lit.cfg
@@ -212,5 +212,8 @@
 if config.host_os not in ['Linux', 'Darwin', 'FreeBSD', 'SunOS', 'Windows']:
   config.unsupported = True
 
-if config.host_os == 'Darwin' and config.target_arch in ["x86_64", "x86_64h"]:
-  config.parallelism_group = "darwin-64bit-sanitizer"
+if config.host_os == 'Darwin':
+  if config.target_arch in ["x86_64", "x86_64h"]:
+    config.parallelism_group = "darwin-64bit-sanitizer"
+  elif config.ios and not config.iossim:
+    config.parallelism_group = "darwin-ios-device-sanitizer"
Index: compiler-rt/trunk/test/lit.common.cfg
===================================================================
--- compiler-rt/trunk/test/lit.common.cfg
+++ compiler-rt/trunk/test/lit.common.cfg
@@ -291,6 +291,14 @@
 if platform.system() == 'Darwin':
   lit_config.parallelism_groups["darwin-64bit-sanitizer"] = 3
 
+# The current implementation of the tools in sanitizer_common/ios_comamnds
+# do not support parallel execution so force sequential execution of the
+# tests on iOS devices.
+if config.host_os == 'Darwin' and config.ios and not config.iossim:
+  lit_config.warning("iOS device test cases being run sequentially")
+  lit_config.parallelism_groups["darwin-ios-device-sanitizer"] = 1
+
+
 if config.host_os == 'Darwin':
   config.substitutions.append( ("%ld_flags_rpath_exe", '-Wl,-rpath,@executable_path/ %dynamiclib') )
   config.substitutions.append( ("%ld_flags_rpath_so", '-install_name @rpath/`basename %dynamiclib`') )
Index: compiler-rt/trunk/test/tsan/lit.cfg
===================================================================
--- compiler-rt/trunk/test/tsan/lit.cfg
+++ compiler-rt/trunk/test/tsan/lit.cfg
@@ -85,5 +85,8 @@
 if config.android:
   config.unsupported = True
 
-if config.host_os == 'Darwin' and config.target_arch in ["x86_64", "x86_64h"]:
-  config.parallelism_group = "darwin-64bit-sanitizer"
+if config.host_os == 'Darwin':
+  if config.target_arch in ["x86_64", "x86_64h"]:
+    config.parallelism_group = "darwin-64bit-sanitizer"
+  elif config.ios and not config.iossim:
+    config.parallelism_group = "darwin-ios-device-sanitizer"