diff --git a/sys/amd64/amd64/mp_machdep.c b/sys/amd64/amd64/mp_machdep.c
index 8e8dc67bdc1c..70ba466720f4 100644
--- a/sys/amd64/amd64/mp_machdep.c
+++ b/sys/amd64/amd64/mp_machdep.c
@@ -1428,6 +1428,22 @@ cpususpend_handler(void)
 	intr_restore(rf);
 }
 
+void
+md_assert_nopreempt(void)
+{
+#ifdef INVARIANTS
+	struct thread *td;
+	register_t rflags;
+
+	td = curthread;
+	rflags = read_rflags();
+
+	if ((rflags & PSL_I) != 0 && td->td_critnest <= 0)
+		panic("Preemption still allowed, thread %s\n",
+		    (td->td_pinned <= 0) ? "not pinned" : "pinned");
+#endif
+}
+
 /*
  * This is called once the rest of the system is up and running and we're
  * ready to let the AP's out of the pen.
diff --git a/sys/amd64/include/smp.h b/sys/amd64/include/smp.h
index ec107f931055..bafb349ced2f 100644
--- a/sys/amd64/include/smp.h
+++ b/sys/amd64/include/smp.h
@@ -64,6 +64,7 @@ void 	ipi_bitmap_handler(struct trapframe frame);
 void	ipi_cpu(int cpu, u_int ipi);
 int	ipi_nmi_handler(void);
 void	ipi_selected(cpumask_t cpus, u_int ipi);
+void	md_assert_nopreempt(void);
 u_int	mp_bootaddress(u_int);
 int	mp_grab_cpu_hlt(void);
 void	smp_cache_flush(void);
diff --git a/sys/i386/i386/mp_machdep.c b/sys/i386/i386/mp_machdep.c
index a07b06c53f75..f36bf1d5c0de 100644
--- a/sys/i386/i386/mp_machdep.c
+++ b/sys/i386/i386/mp_machdep.c
@@ -1486,6 +1486,22 @@ cpustop_handler(void)
 	}
 }
 
+void
+md_assert_nopreempt(void)
+{
+#ifdef INVARIANTS
+	struct thread *td;
+	register_t rflags;
+
+	td = curthread;
+	rflags = read_rflags();
+
+	if ((rflags & PSL_I) != 0 && td->td_critnest <= 0)
+		panic("Preemption still allowed, thread %s\n",
+		    (td->td_pinned <= 0) ? "not pinned" : "pinned");
+#endif
+}
+
 /*
  * This is called once the rest of the system is up and running and we're
  * ready to let the AP's out of the pen.
diff --git a/sys/i386/include/smp.h b/sys/i386/include/smp.h
index b512e00b4228..2e2ede4f66f1 100644
--- a/sys/i386/include/smp.h
+++ b/sys/i386/include/smp.h
@@ -65,6 +65,7 @@ void 	ipi_bitmap_handler(struct trapframe frame);
 void	ipi_cpu(int cpu, u_int ipi);
 int	ipi_nmi_handler(void);
 void	ipi_selected(cpumask_t cpus, u_int ipi);
+void	md_assert_nopreempt(void);
 u_int	mp_bootaddress(u_int);
 int	mp_grab_cpu_hlt(void);
 void	smp_cache_flush(void);
diff --git a/sys/i386/xen/mp_machdep.c b/sys/i386/xen/mp_machdep.c
index 6e0fa2338f88..845fa439d854 100644
--- a/sys/i386/xen/mp_machdep.c
+++ b/sys/i386/xen/mp_machdep.c
@@ -1241,6 +1241,22 @@ cpustop_handler(void)
 	}
 }
 
+void
+md_assert_nopreempt(void)
+{
+#ifdef INVARIANTS
+	struct thread *td;
+	register_t rflags;
+
+	td = curthread;
+	rflags = read_rflags();
+
+	if ((rflags & PSL_I) != 0 && td->td_critnest <= 0)
+		panic("Preemption still allowed, thread %s\n",
+		    (td->td_pinned <= 0) ? "not pinned" : "pinned");
+#endif
+}
+
 /*
  * This is called once the rest of the system is up and running and we're
  * ready to let the AP's out of the pen.