Index: sys/kern/subr_pcu.c
===================================================================
RCS file: /home/netbsd/src/sys/kern/subr_pcu.c,v
retrieving revision 1.21
diff -p -u -r1.21 subr_pcu.c
--- sys/kern/subr_pcu.c	16 Oct 2017 15:03:57 -0000	1.21
+++ sys/kern/subr_pcu.c	15 Dec 2019 13:47:48 -0000
@@ -110,6 +110,10 @@ pcu_switchpoint(lwp_t *l)
 			continue;
 		}
 		struct cpu_info * const pcu_ci = l->l_pcu_cpu[id];
+#ifndef MULTIPROCESSOR /* XXX */
+		if (pcu_ci == NULL)
+			continue;
+#endif
 		if (pcu_ci == l->l_cpu) {
 			KASSERT(pcu_ci->ci_pcu_curlwp[id] == l);
 			continue;