Index: bin/ps/extern.h
===================================================================
--- bin/ps/extern.h
+++ bin/ps/extern.h
@@ -48,6 +48,7 @@
 char	 *arguments(KINFO *, VARENT *);
 char	 *command(KINFO *, VARENT *);
 char	 *cputime(KINFO *, VARENT *);
+char	 *cpunum(KINFO *, VARENT *);
 int	 donlist(void);
 char	 *elapsed(KINFO *, VARENT *);
 char	 *elapseds(KINFO *, VARENT *);
Index: bin/ps/keyword.c
===================================================================
--- bin/ps/keyword.c
+++ bin/ps/keyword.c
@@ -83,8 +83,7 @@
 	    CHAR, NULL, 0},
 	{"cow", "COW", NULL, "copy-on-write-faults", 0, kvar, KOFF(ki_cow),
 	    UINT, "u", 0},
-	{"cpu", "CPU", NULL, "cpu-usage", 0, kvar, KOFF(ki_estcpu), UINT, "d",
-	    0},
+	{"cpu", "C", NULL, "on-cpu", 0, cpunum, 0, CHAR, NULL, 0},
 	{"cputime", "", "time", NULL, 0, NULL, 0, CHAR, NULL, 0},
 	{"dsiz", "DSIZ", NULL, "data-size", 0, kvar, KOFF(ki_dsize), PGTOK,
 	    "ld", 0},
Index: bin/ps/print.c
===================================================================
--- bin/ps/print.c
+++ bin/ps/print.c
@@ -550,6 +550,19 @@
 	return (printtime(k, ve, secs, psecs));
 }
 
+char *
+cpunum(KINFO *k, VARENT *ve __unused)
+{
+        char *cpu;
+
+        if (k->ki_p->ki_stat == SRUN && k->ki_p->ki_oncpu != NOCPU) {
+                asprintf(&cpu, "%d", k->ki_p->ki_oncpu);
+        } else {
+                asprintf(&cpu, "%d", k->ki_p->ki_lastcpu);
+        }
+        return (cpu);
+}
+
 char *
 systime(KINFO *k, VARENT *ve)
 {
Index: bin/ps/ps.1
===================================================================
--- bin/ps/ps.1
+++ bin/ps/ps.1
@@ -312,6 +312,9 @@
 be very young) it is possible for the sum of all
 .Cm %cpu
 fields to exceed 100%.
+.It Cm cpu
+The processor number on which the process is executing (visible only on SMP
+systems).
 .It Cm %mem
 The percentage of real memory used by this process.
 .It Cm class
@@ -544,8 +547,6 @@
 command and arguments
 .It Cm cow
 number of copy-on-write faults
-.It Cm cpu
-short-term CPU usage factor (for scheduling)
 .It Cm dsiz
 data size (in Kbytes)
 .It Cm emul