diff --git a/[refs] b/[refs]
index 3b4caf9d5c00..ceb1cdac86e2 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 05efc67d100ff6c3364604b72729addf1a86fdab
+refs/heads/master: 4bbf39c29bc3409d6454faf0dfa1b3b0aa2ac2af
diff --git a/trunk/arch/s390/Kconfig b/trunk/arch/s390/Kconfig
index b66602ad7b33..b7ca5bf9acfc 100644
--- a/trunk/arch/s390/Kconfig
+++ b/trunk/arch/s390/Kconfig
@@ -80,6 +80,10 @@ config HOTPLUG_CPU
 	  can be controlled through /sys/devices/system/cpu/cpu#.
 	  Say N if you want to disable CPU hotplug.
 
+config DEFAULT_MIGRATION_COST
+	int
+	default "1000000"
+
 config MATHEMU
 	bool "IEEE FPU emulation"
 	depends on MARCH_G5
diff --git a/trunk/kernel/sched.c b/trunk/kernel/sched.c
index 66d957227de9..12d291bf3379 100644
--- a/trunk/kernel/sched.c
+++ b/trunk/kernel/sched.c
@@ -5058,7 +5058,18 @@ static void init_sched_build_groups(struct sched_group groups[], cpumask_t span,
 #define MAX_DOMAIN_DISTANCE 32
 
 static unsigned long long migration_cost[MAX_DOMAIN_DISTANCE] =
-		{ [ 0 ... MAX_DOMAIN_DISTANCE-1 ] = -1LL };
+		{ [ 0 ... MAX_DOMAIN_DISTANCE-1 ] =
+/*
+ * Architectures may override the migration cost and thus avoid
+ * boot-time calibration. Unit is nanoseconds. Mostly useful for
+ * virtualized hardware:
+ */
+#ifdef CONFIG_DEFAULT_MIGRATION_COST
+			CONFIG_DEFAULT_MIGRATION_COST
+#else
+			-1LL
+#endif
+};
 
 /*
  * Allow override of migration cost - in units of microseconds.