Index: sys/kern/sched_ule.c
===================================================================
--- sys/kern/sched_ule.c
+++ sys/kern/sched_ule.c
@@ -1423,6 +1423,45 @@
 }
 
 #ifdef SMP
+static void
+sched_format_topo(struct sbuf *sb, char cpusetbuf[__min_size(CPUSETBUFSIZ)],
+    int level, const struct cpu_group *cg)
+{
+	int i, children;
+
+	sbuf_printf(sb, "%*scount %d, children %d, level %d, flags 0x%02x, "
+	    "cpuset %s\n", level * 4, "", cg->cg_count, (int)cg->cg_children,
+	    (int)cg->cg_level, (int)cg->cg_flags,
+	    cpusetobj_strprint(cpusetbuf, &cg->cg_mask));
+
+	children = cg->cg_children;
+	for (i = 0, cg = cg->cg_child; i < children; cg++, i++)
+		sched_format_topo(sb, cpusetbuf, level + 1, cg);
+}
+
+static void
+sched_print_topo(void)
+{
+#ifndef	PRINTF_BUFR_SIZE
+#define	PRINTF_BUFR_SIZE	64
+#endif
+	char cpusetbuf[CPUSETBUFSIZ];
+	char bufr[PRINTF_BUFR_SIZE];
+	struct sbuf sb, *sbp __unused;
+
+	sbp = sbuf_new(&sb, bufr, sizeof(bufr), SBUF_FIXEDLEN);
+	KASSERT(sbp != NULL, ("sbuf_new misused?"));
+
+	sbuf_set_drain(&sb, sbuf_printf_drain, NULL);
+
+	sbuf_cat(&sb, "Sched CPU Groups:\n");
+	sched_format_topo(&sb, cpusetbuf, 0, cpu_top);
+
+	sbuf_nl_terminate(&sb);
+	sbuf_finish(&sb);
+	sbuf_delete(&sb);
+}
+
 static void
 sched_setup_smp(void)
 {
@@ -1430,6 +1469,8 @@
 	int i;
 
 	cpu_top = smp_topo();
+	if (bootverbose)
+		sched_print_topo();
 	CPU_FOREACH(i) {
 		tdq = DPCPU_ID_PTR(i, tdq);
 		tdq_setup(tdq, i);
Index: sys/kern/subr_smp.c
===================================================================
--- sys/kern/subr_smp.c
+++ sys/kern/subr_smp.c
@@ -806,24 +806,29 @@
 struct cpu_group *
 smp_topo_find(struct cpu_group *top, int cpu)
 {
-	struct cpu_group *cg;
+	struct cpu_group *cg, *best;
 	cpuset_t mask;
 	int children;
 	int i;
 
 	CPU_SETOF(cpu, &mask);
 	cg = top;
-	for (;;) {
+	for (best = NULL;;) {
+		/*
+		 * If the CPU cannot be found in the set, return the best (most
+		 * specific) match we've seen.
+		 */
 		if (!CPU_OVERLAP(&cg->cg_mask, &mask))
-			return (NULL);
+			return (best);
 		if (cg->cg_children == 0)
 			return (cg);
+		best = cg;
 		children = cg->cg_children;
 		for (i = 0, cg = cg->cg_child; i < children; cg++, i++)
 			if (CPU_OVERLAP(&cg->cg_mask, &mask))
 				break;
 	}
-	return (NULL);
+	return (best);
 }
 #else /* !SMP */
 
Index: sys/x86/x86/mp_x86.c
===================================================================
--- sys/x86/x86/mp_x86.c
+++ sys/x86/x86/mp_x86.c
@@ -679,9 +679,11 @@
 void
 cpu_mp_announce(void)
 {
-	struct topo_node *node;
+	struct topo_node *node, *t;
 	const char *hyperthread;
 	struct topo_analysis topology;
+	char cpusetbuf[CPUSETBUFSIZ];
+	int level;
 
 	printf("FreeBSD/SMP: ");
 	if (topo_analyze(&topo_root, 1, &topology)) {
@@ -730,12 +732,30 @@
 		return;
 
 	TOPO_FOREACH(node, &topo_root) {
+		level = 0;
+		for (t = node; t != NULL && t != &topo_root; t = t->parent)
+			level++;
+
+		printf("%*s", 4 * level, "");
+
 		switch (node->type) {
+		case TOPO_TYPE_SYSTEM:
+			printf("System HW ID =");
+			break;
+		case TOPO_TYPE_GROUP:
+			printf("Group HW ID =");
+			break;
+		case TOPO_TYPE_NODE:
+			printf("Node HW ID =");
+			break;
+		case TOPO_TYPE_CACHE:
+			printf("Cache L%jd HW ID =", (intmax_t)node->subtype);
+			break;
 		case TOPO_TYPE_PKG:
-			printf("Package HW ID = %u\n", node->hwid);
+			printf("Package HW ID =");
 			break;
 		case TOPO_TYPE_CORE:
-			printf("\tCore HW ID = %u\n", node->hwid);
+			printf("Core HW ID =");
 			break;
 		case TOPO_TYPE_PU:
 			if (cpu_info[node->hwid].cpu_hyperthread)
@@ -744,19 +764,24 @@
 				hyperthread = "";
 
 			if (node->subtype == 0)
-				printf("\t\tCPU (AP%s): APIC ID: %u"
-				    "(disabled)\n", hyperthread, node->hwid);
+				printf("CPU (AP%s): APIC ID:", hyperthread);
 			else if (node->id == 0)
-				printf("\t\tCPU0 (BSP): APIC ID: %u\n",
-				    node->hwid);
+				printf("CPU0 (BSP): APIC ID:");
 			else
-				printf("\t\tCPU%u (AP%s): APIC ID: %u\n",
-				    node->id, hyperthread, node->hwid);
+				printf("CPU%u (AP%s): APIC ID:", node->id,
+				    hyperthread);
 			break;
 		default:
-			/* ignored */
+			printf("Unknown (%d) HW ID =", (int)node->type);
 			break;
 		}
+
+		printf(" %u", node->hwid);
+
+		if (node->type == TOPO_TYPE_PU && node->subtype == 0)
+			printf(" (disabled)");
+
+		printf(" [%s]\n", cpusetobj_strprint(cpusetbuf, &node->cpuset));
 	}
 }
 
@@ -817,6 +842,7 @@
 	while (node != NULL) {
 		if ((node->type != TOPO_TYPE_GROUP &&
 		    node->type != TOPO_TYPE_CACHE) ||
+		    CPU_EMPTY(&node->cpuset) ||
 		    (root->type != TOPO_TYPE_SYSTEM &&
 		    CPU_CMP(&node->cpuset, &root->cpuset) == 0)) {
 			node = topo_next_node(root, node);
@@ -838,6 +864,7 @@
 	while (node != NULL) {
 		if ((node->type != TOPO_TYPE_GROUP &&
 		    node->type != TOPO_TYPE_CACHE) ||
+		    CPU_EMPTY(&node->cpuset) ||
 		    (root->type != TOPO_TYPE_SYSTEM &&
 		    CPU_CMP(&node->cpuset, &root->cpuset) == 0)) {
 			node = topo_next_node(root, node);