diff --git a/sys/amd64/amd64/mp_machdep.c b/sys/amd64/amd64/mp_machdep.c
index 862b5ca42a18..e09730dafbbb 100644
--- a/sys/amd64/amd64/mp_machdep.c
+++ b/sys/amd64/amd64/mp_machdep.c
@@ -771,7 +771,6 @@ init_secondary(void)
 	if (smp_cpus == mp_ncpus) {
 		/* enable IPI's, tlb shootdown, freezes etc */
 		atomic_store_rel_int(&smp_started, 1);
-		smp_active = 1;	 /* historic */
 	}
 
 	/*
diff --git a/sys/amd64/amd64/vm_machdep.c b/sys/amd64/amd64/vm_machdep.c
index 12f49789369c..ae0a003e0ae4 100644
--- a/sys/amd64/amd64/vm_machdep.c
+++ b/sys/amd64/amd64/vm_machdep.c
@@ -597,7 +597,7 @@ cpu_reset()
 	cpuset_t map;
 	u_int cnt;
 
-	if (smp_active) {
+	if (smp_started) {
 		map = all_cpus;
 		CPU_CLR(PCPU_GET(cpuid), &map);
 		CPU_NAND(&map, &stopped_cpus);
diff --git a/sys/arm/arm/mp_machdep.c b/sys/arm/arm/mp_machdep.c
index 2e5e1d31e3b0..cebbd728843b 100644
--- a/sys/arm/arm/mp_machdep.c
+++ b/sys/arm/arm/mp_machdep.c
@@ -212,7 +212,6 @@ init_secondary(int cpu)
 	if (smp_cpus == mp_ncpus) {
 		/* enable IPI's, tlb shootdown, freezes etc */
 		atomic_store_rel_int(&smp_started, 1);
-		smp_active = 1;
 	}
 
 	mtx_unlock_spin(&ap_boot_mtx);
diff --git a/sys/i386/i386/mp_machdep.c b/sys/i386/i386/mp_machdep.c
index 53ac6dffbf3a..222e8e286c55 100644
--- a/sys/i386/i386/mp_machdep.c
+++ b/sys/i386/i386/mp_machdep.c
@@ -805,7 +805,6 @@ init_secondary(void)
 	if (smp_cpus == mp_ncpus) {
 		/* enable IPI's, tlb shootdown, freezes etc */
 		atomic_store_rel_int(&smp_started, 1);
-		smp_active = 1;	 /* historic */
 	}
 
 	mtx_unlock_spin(&ap_boot_mtx);
diff --git a/sys/i386/i386/vm_machdep.c b/sys/i386/i386/vm_machdep.c
index ef99b7694bf4..50c643335cc1 100644
--- a/sys/i386/i386/vm_machdep.c
+++ b/sys/i386/i386/vm_machdep.c
@@ -619,7 +619,7 @@ cpu_reset()
 	cpuset_t map;
 	u_int cnt;
 
-	if (smp_active) {
+	if (smp_started) {
 		map = all_cpus;
 		CPU_CLR(PCPU_GET(cpuid), &map);
 		CPU_NAND(&map, &stopped_cpus);
diff --git a/sys/i386/xen/mp_machdep.c b/sys/i386/xen/mp_machdep.c
index 1bc6572f7ab3..165b319bd6ae 100644
--- a/sys/i386/xen/mp_machdep.c
+++ b/sys/i386/xen/mp_machdep.c
@@ -655,7 +655,6 @@ init_secondary(void)
 	if (smp_cpus == mp_ncpus) {
 		/* enable IPI's, tlb shootdown, freezes etc */
 		atomic_store_rel_int(&smp_started, 1);
-		smp_active = 1;	 /* historic */
 	}
 
 	mtx_unlock_spin(&ap_boot_mtx);
diff --git a/sys/ia64/ia64/mp_machdep.c b/sys/ia64/ia64/mp_machdep.c
index a8868fae4a55..4d41dbb62668 100644
--- a/sys/ia64/ia64/mp_machdep.c
+++ b/sys/ia64/ia64/mp_machdep.c
@@ -455,7 +455,7 @@ cpu_mp_unleash(void *dummy)
 		    mp_ncpus, cpus, smp_cpus);
 	}
 
-	smp_active = 1;
+	/* XXX Atomic set operation? */
 	smp_started = 1;
 
 	/*
diff --git a/sys/kern/kern_cpu.c b/sys/kern/kern_cpu.c
index 6df4d3f12e14..b0de2a23f892 100644
--- a/sys/kern/kern_cpu.c
+++ b/sys/kern/kern_cpu.c
@@ -268,7 +268,7 @@ cf_set_method(device_t dev, const struct cf_level *level, int priority)
 	 * switching the main CPU.  XXXTODO: Need to think more about how to
 	 * handle having different CPUs at different frequencies.  
 	 */
-	if (mp_ncpus > 1 && !smp_active) {
+	if (mp_ncpus > 1 && !smp_started) {
 		device_printf(dev, "rejecting change, SMP not started yet\n");
 		error = ENXIO;
 		goto out;
diff --git a/sys/kern/subr_smp.c b/sys/kern/subr_smp.c
index 5425a4504df7..122fc4c5fede 100644
--- a/sys/kern/subr_smp.c
+++ b/sys/kern/subr_smp.c
@@ -59,6 +59,9 @@ cpuset_t logical_cpus_mask;
 
 void (*cpustop_restartfunc)(void);
 #endif
+
+static int sysctl_kern_smp_active(SYSCTL_HANDLER_ARGS);
+
 /* This is used in modules that need to work in both SMP and UP. */
 cpuset_t all_cpus;
 
@@ -78,9 +81,8 @@ SYSCTL_INT(_kern_smp, OID_AUTO, maxid, CTLFLAG_RD|CTLFLAG_CAPRD, &mp_maxid, 0,
 SYSCTL_INT(_kern_smp, OID_AUTO, maxcpus, CTLFLAG_RD|CTLFLAG_CAPRD, &mp_maxcpus,
     0, "Max number of CPUs that the system was compiled for.");
 
-int smp_active = 0;	/* are the APs allowed to run? */
-SYSCTL_INT(_kern_smp, OID_AUTO, active, CTLFLAG_RW, &smp_active, 0,
-    "Number of Auxillary Processors (APs) that were successfully started");
+SYSCTL_PROC(_kern_smp, OID_AUTO, active, CTLFLAG_RD | CTLTYPE_INT, NULL, 0,
+    sysctl_kern_smp_active, "I", "Indicates system is running in SMP mode");
 
 int smp_disabled = 0;	/* has smp been disabled? */
 SYSCTL_INT(_kern_smp, OID_AUTO, disabled, CTLFLAG_RDTUN|CTLFLAG_CAPRD,
@@ -831,3 +833,15 @@ quiesce_all_cpus(const char *wmesg, int prio)
 
 	return quiesce_cpus(all_cpus, wmesg, prio);
 }
+
+/* Extra care is taken with this sysctl because the data type is volatile */
+static int
+sysctl_kern_smp_active(SYSCTL_HANDLER_ARGS)
+{
+	int error, active;
+
+	active = smp_started;
+	error = SYSCTL_OUT(req, &active, sizeof(active));
+	return (error);
+}
+
diff --git a/sys/mips/mips/mp_machdep.c b/sys/mips/mips/mp_machdep.c
index 2a6bbb4be350..9f989091e072 100644
--- a/sys/mips/mips/mp_machdep.c
+++ b/sys/mips/mips/mp_machdep.c
@@ -317,7 +317,6 @@ smp_init_secondary(u_int32_t cpuid)
 
 	if (smp_cpus == mp_ncpus) {
 		atomic_store_rel_int(&smp_started, 1);
-		smp_active = 1;
 	}
 
 	mtx_unlock_spin(&ap_boot_mtx);
diff --git a/sys/powerpc/powerpc/mp_machdep.c b/sys/powerpc/powerpc/mp_machdep.c
index 772cd5eec679..555daf17489e 100644
--- a/sys/powerpc/powerpc/mp_machdep.c
+++ b/sys/powerpc/powerpc/mp_machdep.c
@@ -267,7 +267,7 @@ cpu_mp_unleash(void *dummy)
 	/* Let the APs get into the scheduler */
 	DELAY(10000);
 
-	smp_active = 1;
+	/* XXX Atomic set operation? */
 	smp_started = 1;
 }
 
diff --git a/sys/sparc64/sparc64/mp_machdep.c b/sys/sparc64/sparc64/mp_machdep.c
index 8d2282ebdb44..0f977b3e3921 100644
--- a/sys/sparc64/sparc64/mp_machdep.c
+++ b/sys/sparc64/sparc64/mp_machdep.c
@@ -291,7 +291,6 @@ cpu_mp_start(void)
 	KASSERT(!isjbus || mp_ncpus <= IDR_JALAPENO_MAX_BN_PAIRS,
 	    ("%s: can only IPI a maximum of %d JBus-CPUs",
 	    __func__, IDR_JALAPENO_MAX_BN_PAIRS));
-	smp_active = 1;
 }
 
 static void
diff --git a/sys/sys/smp.h b/sys/sys/smp.h
index fed12bfb7a5b..42cb8df058ce 100644
--- a/sys/sys/smp.h
+++ b/sys/sys/smp.h
@@ -71,7 +71,6 @@ struct cpu_group *smp_topo_2level(int l2share, int l2count, int l1share,
 struct cpu_group *smp_topo_find(struct cpu_group *top, int cpu);
 
 extern void (*cpustop_restartfunc)(void);
-extern int smp_active;
 extern int smp_cpus;
 extern volatile cpuset_t started_cpus;
 extern volatile cpuset_t stopped_cpus;
@@ -141,7 +140,7 @@ cpu_next(int i)
  * cpu_mp_start() will be called so that MP can be enabled.  This function
  * should do things such as startup secondary processors.  It should also
  * setup mp_ncpus, all_cpus, and smp_cpus.  It should also ensure that
- * smp_active and smp_started are initialized at the appropriate time.
+ * smp_started is initialized at the appropriate time.
  * Once cpu_mp_start() returns, machine independent MP startup code will be
  * executed and a simple message will be output to the console.  Finally,
  * cpu_mp_announce() will be called so that machine dependent messages about