Index: usr.bin/top/machine.c
===================================================================
--- usr.bin/top/machine.c
+++ usr.bin/top/machine.c
@@ -196,7 +196,7 @@
 static const char *ordernames[] = {
 	"cpu", "size", "res", "time", "pri", "threads",
 	"total", "read", "write", "fault", "vcsw", "ivcsw",
-	"jid", "swap", "pid", NULL
+	"jid", "swap", "core", "pid", NULL
 };
 
 /* Per-cpu time states */
@@ -214,6 +214,7 @@
 static int compare_jid(const void *a, const void *b);
 static int compare_pid(const void *a, const void *b);
 static int compare_tid(const void *a, const void *b);
+static int compare_core(const void *a, const void *b);
 static const char *format_nice(const struct kinfo_proc *pp);
 static void getsysctl(const char *name, void *ptr, size_t len);
 static int swapmode(int *retavail, int *retfree);
@@ -1276,6 +1277,21 @@
 		return (diff > 0 ? 1 : -1); \
 } while (0)
 
+#define ORDERKEY_CORE(a, b) do { \
+	int cpu1, cpu2; \
+	if ((int)(a)->ki_stat == SRUN && (int)(a)->ki_oncpu != NOCPU) \
+		cpu1 = (int)(a)->ki_oncpu; \
+	else \
+		cpu1 = (int)(a)->ki_lastcpu; \
+	if ((int)(b)->ki_stat == SRUN && (int)(b)->ki_oncpu != NOCPU) \
+		cpu2 = (int)(b)->ki_oncpu; \
+	else \
+		cpu2 = (int)(b)->ki_lastcpu; \
+	int diff = cpu2 - cpu1; \
+	if (diff != 0) \
+		return (diff > 0 ? 1 : -1); \
+} while (0)
+
 /* compare_cpu - the comparison function for sorting by cpu percentage */
 
 static int
@@ -1294,6 +1310,25 @@
 	return (0);
 }
 
+/* compare_core - the comparison function for sorting by cpu core number */
+
+static int
+compare_core(const void *arg1, const void *arg2)
+{
+	const struct kinfo_proc *p1 = *(const struct kinfo_proc * const *)arg1;
+	const struct kinfo_proc *p2 = *(const struct kinfo_proc * const *)arg2;
+
+	ORDERKEY_CORE(p1, p2);
+	ORDERKEY_PCTCPU(p1, p2);
+	ORDERKEY_CPTICKS(p1, p2);
+	ORDERKEY_STATE(p1, p2);
+	ORDERKEY_PRIO(p1, p2);
+	ORDERKEY_RSSIZE(p1, p2);
+
+	return(0);
+}
+
+
 /* compare_size - the comparison function for sorting by total memory usage */
 
 static int
@@ -1511,6 +1546,7 @@
 	compare_ivcsw,
 	compare_jid,
 	compare_swap,
+        compare_core,
 	NULL
 };
 
Index: usr.bin/top/top.1
===================================================================
--- usr.bin/top/top.1
+++ usr.bin/top/top.1
@@ -1,5 +1,5 @@
 .\" $FreeBSD$
-.Dd October 2, 2018
+.Dd December 10, 2018
 .Dt TOP 1
 .Os
 .Sh NAME
@@ -153,7 +153,7 @@
 \*(lqcpu\*(lq, \*(rqsize\*(lq, \*(rqres\*(lq, \*(rqtime\*(lq,
 \*(rqpri\*(lq, \*(rqthreads\*(lq, \*(lqtotal\*(lq, \*(rqread\*(lq,
 \*(rqwrite\*(lq, \*(rqfault\*(lq, \*(rqvcsw\*(lq, \*(rqivcsw\*(lq,
-\*(lqjid\*(lq, \*(rqswap\*(lq or \*(rqpid\*(lq.
+\*(lqjid\*(lq, \*(rqswap\*(lq, \*(rqcore\*(lq, or \*(rqpid\*(lq.
 .It Fl p Ar pid
 Show only the process
 .Ar pid .