Index: sys/i386/i386/mp_machdep.c
===================================================================
--- sys/i386/i386/mp_machdep.c	(revision 211149)
+++ sys/i386/i386/mp_machdep.c	(working copy)
@@ -1411,8 +1411,10 @@
 	cpumask_t cpumask;
 	u_int cpu;
 
+	sched_pin();
 	cpu = PCPU_GET(cpuid);
 	cpumask = PCPU_GET(cpumask);
+	sched_unpin();
 
 	savectx(&stoppcbs[cpu]);
 
@@ -1586,10 +1588,14 @@
 #endif
 	int retval;
 
+#ifdef MP_WATCHDOG
+	sched_pin();
 	mask = PCPU_GET(cpumask);
-#ifdef MP_WATCHDOG
 	cpuid = PCPU_GET(cpuid);
+	sched_unpin();
 	ap_watchdog(cpuid);
+#else
+	mask = PCPU_GET(cpumask);
 #endif
 
 	retval = mask & hlt_cpus_mask;
Index: sys/amd64/amd64/mp_machdep.c
===================================================================
--- sys/amd64/amd64/mp_machdep.c	(revision 211149)
+++ sys/amd64/amd64/mp_machdep.c	(working copy)
@@ -1324,8 +1324,10 @@
 	cpumask_t cpumask;
 	u_int cpu;
 
+	sched_pin();
 	cpu = PCPU_GET(cpuid);
 	cpumask = PCPU_GET(cpumask);
+	sched_unpin();
 
 	savectx(&stoppcbs[cpu]);
 
@@ -1356,8 +1358,10 @@
 	register_t cr3, rf;
 	u_int cpu;
 
+	sched_pin();
 	cpu = PCPU_GET(cpuid);
 	cpumask = PCPU_GET(cpumask);
+	sched_unpin();
 
 	rf = intr_disable();
 	cr3 = rcr3();
@@ -1535,10 +1539,14 @@
 #endif
 	int retval;
 
+#ifdef MP_WATCHDOG
+	sched_pin();
 	mask = PCPU_GET(cpumask);
-#ifdef MP_WATCHDOG
 	cpuid = PCPU_GET(cpuid);
+	sched_unpin();
 	ap_watchdog(cpuid);
+#else
+	mask = PCPU_GET(cpumask);
 #endif
 
 	retval = mask & hlt_cpus_mask;