Index: sys/kern/subr_smp.c
===================================================================
--- sys/kern/subr_smp.c	(revision 223034)
+++ sys/kern/subr_smp.c	(working copy)
@@ -142,7 +142,7 @@
 	/* Probe for MP hardware. */
 	if (smp_disabled != 0 || cpu_mp_probe() == 0) {
 		mp_ncpus = 1;
-		all_cpus = PCPU_GET(cpumask);
+		CPU_SETOF(PCPU_GET(cpuid), &all_cpus);
 		return;
 	}
 
@@ -708,7 +708,7 @@
 {
 	mp_ncpus = 1;
 	mp_maxid = PCPU_GET(cpuid);
-	all_cpus = PCPU_GET(cpumask);
+	CPU_SETOF(mp_maxid, &all_cpus);
 	KASSERT(PCPU_GET(cpuid) == 0, ("UP must have a CPU ID of zero"));
 }
 SYSINIT(cpu_mp_setvariables, SI_SUB_TUNABLES, SI_ORDER_FIRST,
Index: sys/kern/subr_kdb.c
===================================================================
--- sys/kern/subr_kdb.c	(revision 223034)
+++ sys/kern/subr_kdb.c	(working copy)
@@ -211,9 +211,12 @@
 void
 kdb_panic(const char *msg)
 {
-	
 #ifdef SMP
-	stop_cpus_hard(PCPU_GET(other_cpus));
+	cpuset_t other_cpus;
+
+	other_cpus = all_cpus;
+	CPU_CLR(PCPU_GET(cpuid), &other_cpus);
+	stop_cpus_hard(other_cpus);
 #endif
 	printf("KDB: panic\n");
 	panic("%s", msg);
@@ -414,7 +417,7 @@
 #if defined(SMP) && defined(KDB_STOPPEDPCB)
 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu)  {
 		if (pc->pc_curthread == thr &&
-		    CPU_OVERLAP(&stopped_cpus, &pc->pc_cpumask))
+		    CPU_ISSET(pc->pc_cpuid, &stopped_cpus))
 			return (KDB_STOPPEDPCB(pc));
 	}
 #endif
@@ -501,6 +504,7 @@
 	struct kdb_dbbe *be;
 	register_t intr;
 #ifdef SMP
+	cpuset_t other_cpus;
 	int did_stop_cpus;
 #endif
 	int handled;
@@ -516,8 +520,11 @@
 	intr = intr_disable();
 
 #ifdef SMP
-	if ((did_stop_cpus = kdb_stop_cpus) != 0)
-		stop_cpus_hard(PCPU_GET(other_cpus));
+	if ((did_stop_cpus = kdb_stop_cpus) != 0) {
+		other_cpus = all_cpus;
+		CPU_CLR(PCPU_GET(cpuid), &other_cpus);
+		stop_cpus_hard(other_cpus);
+	}
 #endif
 
 	kdb_active++;
Index: sys/kern/sched_4bsd.c
===================================================================
--- sys/kern/sched_4bsd.c	(revision 223034)
+++ sys/kern/sched_4bsd.c	(working copy)
@@ -951,8 +951,7 @@
 	if (td->td_flags & TDF_IDLETD) {
 		TD_SET_CAN_RUN(td);
 #ifdef SMP
-		/* Spinlock held here, assume no migration. */
-		CPU_NAND(&idle_cpus_mask, PCPU_PTR(cpumask));
+		CPU_CLR(PCPU_GET(cpuid), &idle_cpus_mask);
 #endif
 	} else {
 		if (TD_IS_RUNNING(td)) {
@@ -1026,7 +1025,7 @@
 
 #ifdef SMP
 	if (td->td_flags & TDF_IDLETD)
-		CPU_OR(&idle_cpus_mask, PCPU_PTR(cpumask));
+		CPU_SET(PCPU_GET(cpuid), &idle_cpus_mask);
 #endif
 	sched_lock.mtx_lock = (uintptr_t)td;
 	td->td_oncpu = PCPU_GET(cpuid);
@@ -1055,7 +1054,8 @@
 forward_wakeup(int cpunum)
 {
 	struct pcpu *pc;
-	cpuset_t dontuse, id, map, map2, me;
+	cpuset_t dontuse, map, map2;
+	u_int id, me;
 	int iscpuset;
 
 	mtx_assert(&sched_lock, MA_OWNED);
@@ -1073,27 +1073,24 @@
 	/*
 	 * Check the idle mask we received against what we calculated
 	 * before in the old version.
-	 *
-	 * Also note that sched_lock is held now, thus no migration is
-	 * expected.
 	 */
-	me = PCPU_GET(cpumask);
+	me = PCPU_GET(cpuid);
 
 	/* Don't bother if we should be doing it ourself. */
-	if (CPU_OVERLAP(&me, &idle_cpus_mask) &&
-	    (cpunum == NOCPU || CPU_ISSET(cpunum, &me)))
+	if (CPU_ISSET(me, &idle_cpus_mask) &&
+	    (cpunum == NOCPU || me == cpunum))
 		return (0);
 
-	dontuse = me;
+	CPU_SETOF(me, &dontuse);
 	CPU_OR(&dontuse, &stopped_cpus);
 	CPU_OR(&dontuse, &hlt_cpus_mask);
 	CPU_ZERO(&map2);
 	if (forward_wakeup_use_loop) {
 		STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
-			id = pc->pc_cpumask;
-			if (!CPU_OVERLAP(&id, &dontuse) &&
+			id = pc->pc_cpuid;
+			if (!CPU_ISSET(id, &dontuse) &&
 			    pc->pc_curthread == pc->pc_idlethread) {
-				CPU_OR(&map2, &id);
+				CPU_SET(id, &map2);
 			}
 		}
 	}
@@ -1125,11 +1122,11 @@
 	if (!CPU_EMPTY(&map)) {
 		forward_wakeups_delivered++;
 		STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
-			id = pc->pc_cpumask;
-			if (!CPU_OVERLAP(&map, &id))
+			id = pc->pc_cpuid;
+			if (!CPU_ISSET(id, &map))
 				continue;
 			if (cpu_idle_wakeup(pc->pc_cpuid))
-				CPU_NAND(&map, &id);
+				CPU_CLR(id, &map);
 		}
 		if (!CPU_EMPTY(&map))
 			ipi_selected(map, IPI_AST);
@@ -1147,7 +1144,7 @@
 	int cpri;
 
 	pcpu = pcpu_find(cpuid);
-	if (CPU_OVERLAP(&idle_cpus_mask, &pcpu->pc_cpumask)) {
+	if (CPU_ISSET(cpuid, &idle_cpus_mask)) {
 		forward_wakeups_delivered++;
 		if (!cpu_idle_wakeup(cpuid))
 			ipi_cpu(cpuid, IPI_AST);
@@ -1205,10 +1202,10 @@
 sched_add(struct thread *td, int flags)
 #ifdef SMP
 {
-	cpuset_t idle, me, tidlemsk;
+	cpuset_t tidlemsk;
 	struct td_sched *ts;
+	u_int cpu, cpuid;
 	int forwarded = 0;
-	int cpu;
 	int single_cpu = 0;
 
 	ts = td->td_sched;
@@ -1271,23 +1268,17 @@
 		ts->ts_runq = &runq;
 	}
 
-	if (single_cpu && (cpu != PCPU_GET(cpuid))) {
+	cpuid = PCPU_GET(cpuid);
+	if (single_cpu && cpu != cpuid) {
 	        kick_other_cpu(td->td_priority, cpu);
 	} else {
 		if (!single_cpu) {
+			tidlemsk = idle_cpus_mask;
+			CPU_NAND(&tidlemsk, &hlt_cpus_mask);
+			CPU_CLR(cpuid, &tidlemsk);
 
-			/*
-			 * Thread spinlock is held here, assume no
-			 * migration is possible.
-			 */
-			me = PCPU_GET(cpumask);
-			idle = idle_cpus_mask;
-			tidlemsk = idle;
-			CPU_AND(&idle, &me);
-			CPU_OR(&me, &hlt_cpus_mask);
-			CPU_NAND(&tidlemsk, &me);
-
-			if (CPU_EMPTY(&idle) && ((flags & SRQ_INTR) == 0) &&
+			if (!CPU_ISSET(cpuid, &idle_cpus_mask) &&
+			    ((flags & SRQ_INTR) == 0) &&
 			    !CPU_EMPTY(&tidlemsk))
 				forwarded = forward_wakeup(cpu);
 		}
Index: sys/kern/kern_rmlock.c
===================================================================
--- sys/kern/kern_rmlock.c	(revision 223034)
+++ sys/kern/kern_rmlock.c	(working copy)
@@ -263,7 +263,7 @@
 	pc = pcpu_find(curcpu);
 
 	/* Check if we just need to do a proper critical_exit. */
-	if (!CPU_OVERLAP(&pc->pc_cpumask, &rm->rm_writecpus)) {
+	if (!CPU_ISSET(pc->pc_cpuid, &rm->rm_writecpus)) {
 		critical_exit();
 		return (1);
 	}
@@ -325,7 +325,7 @@
 
 	critical_enter();
 	pc = pcpu_find(curcpu);
-	CPU_NAND(&rm->rm_writecpus, &pc->pc_cpumask);
+	CPU_CLR(pc->pc_cpuid, &rm->rm_writecpus);
 	rm_tracker_add(pc, tracker);
 	sched_pin();
 	critical_exit();
@@ -367,7 +367,7 @@
 	 * conditional jump.
 	 */
 	if (0 == (td->td_owepreempt |
-	    CPU_OVERLAP(&rm->rm_writecpus,  &pc->pc_cpumask)))
+	    CPU_ISSET(pc->pc_cpuid, &rm->rm_writecpus)))
 		return (1);
 
 	/* We do not have a read token and need to acquire one. */
Index: sys/dev/xen/control/control.c
===================================================================
--- sys/dev/xen/control/control.c	(revision 223034)
+++ sys/dev/xen/control/control.c	(working copy)
@@ -197,6 +197,7 @@
 static void
 xctrl_suspend()
 {
+	u_int cpuid;
 	int i, j, k, fpp;
 	unsigned long max_pfn, start_info_mfn;
 
@@ -210,11 +211,11 @@
 	thread_lock(td);
 	sched_bind(td, 0);
 	thread_unlock(td);
-	KASSERT(PCPU_GET(cpuid) == 0, ("xen_suspend: not running on cpu 0"));
+	cpuid = PCPU_GET(cpuid);
+	KASSERT(cpuid == 0, ("xen_suspend: not running on cpu 0"));
 
-	sched_pin();
-	map = PCPU_GET(other_cpus);
-	sched_unpin();
+	map = all_cpus;
+	CPU_CLR(cpuid, &map);
 	CPU_NAND(&map, &stopped_cpus);
 	if (!CPU_EMPTY(&map))
 		stop_cpus(map);
Index: powerpc/booke/pmap.c
===================================================================
--- powerpc/booke/pmap.c	(revision 223106)
+++ powerpc/booke/pmap.c	(working copy)
@@ -1826,6 +1826,7 @@
 mmu_booke_activate(mmu_t mmu, struct thread *td)
 {
 	pmap_t pmap;
+	u_int cpuid;
 
 	pmap = &td->td_proc->p_vmspace->vm_pmap;
 
@@ -1836,14 +1837,15 @@
 
 	mtx_lock_spin(&sched_lock);
 
-	CPU_OR_ATOMIC(&pmap->pm_active, PCPU_PTR(cpumask));
+	cpuid = PCPU_GET(cpuid);
+	CPU_SET_ATOMIC(cpuid, &pmap->pm_active);
 	PCPU_SET(curpmap, pmap);
 	
-	if (pmap->pm_tid[PCPU_GET(cpuid)] == TID_NONE)
+	if (pmap->pm_tid[cpuid] == TID_NONE)
 		tid_alloc(pmap);
 
 	/* Load PID0 register with pmap tid value. */
-	mtspr(SPR_PID0, pmap->pm_tid[PCPU_GET(cpuid)]);
+	mtspr(SPR_PID0, pmap->pm_tid[cpuid]);
 	__asm __volatile("isync");
 
 	mtx_unlock_spin(&sched_lock);
@@ -1865,9 +1867,7 @@
 	CTR5(KTR_PMAP, "%s: td=%p, proc = '%s', id = %d, pmap = 0x%08x",
 	    __func__, td, td->td_proc->p_comm, td->td_proc->p_pid, pmap);
 
-	sched_pin();
-	CPU_NAND_ATOMIC(&pmap->pm_active, PCPU_PTR(cpumask));
-	sched_unpin();
+	CPU_CLR_ATOMIC(PCPU_GET(cpuid), &pmap->pm_active);
 	PCPU_SET(curpmap, NULL);
 }
 
Index: powerpc/powerpc/mp_machdep.c
===================================================================
--- powerpc/powerpc/mp_machdep.c	(revision 223106)
+++ powerpc/powerpc/mp_machdep.c	(working copy)
@@ -175,9 +175,8 @@
 			pc->pc_cpuid = bsp.cr_cpuid;
 			pc->pc_bsp = 1;
 		}
-		CPU_SETOF(pc->pc_cpuid, &pc->pc_cpumask);
 		pc->pc_hwref = cpu.cr_hwref;
-		CPU_OR(&all_cpus, &pc->pc_cpumask);
+		CPU_SET(pc->pc_cpuid, &all_cpus);
 next:
 		error = platform_smp_next_cpu(&cpu);
 	}
@@ -215,8 +214,6 @@
 	smp_cpus = 0;
 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
 		cpus++;
-		pc->pc_other_cpus = all_cpus;
-		CPU_NAND(&pc->pc_other_cpus, &pc->pc_cpumask);
 		if (!pc->pc_bsp) {
 			if (bootverbose)
 				printf("Waking up CPU %d (dev=%x)\n",
@@ -278,7 +275,7 @@
 int
 powerpc_ipi_handler(void *arg)
 {
-	cpuset_t self;
+	u_int cpuid;
 	uint32_t ipimask;
 	int msg;
 
@@ -310,14 +307,14 @@
 			 */
 			CTR1(KTR_SMP, "%s: IPI_STOP or IPI_STOP_HARD (stop)",
 			    __func__);
-			savectx(&stoppcbs[PCPU_GET(cpuid)]);
-			self = PCPU_GET(cpumask);
+			cpuid = PCPU_GET(cpuid);
+			savectx(&stoppcbs[cpuid]);
 			savectx(PCPU_GET(curpcb));
-			CPU_OR_ATOMIC(&stopped_cpus, &self);
-			while (!CPU_OVERLAP(&started_cpus, &self))
+			CPU_SET_ATOMIC(cpuid, &stopped_cpus);
+			while (!CPU_ISSET(cpuid, &started_cpus))
 				cpu_spinwait();
-			CPU_NAND_ATOMIC(&started_cpus, &self);
-			CPU_NAND_ATOMIC(&stopped_cpus, &self);
+			CPU_CLR_ATOMIC(cpuid, &stopped_cpus);
+			CPU_CLR_ATOMIC(cpuid, &started_cpus);
 			CTR1(KTR_SMP, "%s: IPI_STOP (restart)", __func__);
 			break;
 		case IPI_HARDCLOCK:
@@ -350,7 +347,7 @@
 	struct pcpu *pc;
 
 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
-		if (CPU_OVERLAP(&cpus, &pc->pc_cpumask))
+		if (CPU_ISSET(pc->pc_cpuid, &cpus))
 			ipi_send(pc, ipi);
 	}
 }
Index: powerpc/aim/mmu_oea.c
===================================================================
--- powerpc/aim/mmu_oea.c	(revision 223106)
+++ powerpc/aim/mmu_oea.c	(working copy)
@@ -945,9 +945,7 @@
 	pm = &td->td_proc->p_vmspace->vm_pmap;
 	pmr = pm->pmap_phys;
 
-	sched_pin();
-	CPU_OR(&pm->pm_active, PCPU_PTR(cpumask));
-	sched_unpin();
+	CPU_SET(PCPU_GET(cpuid), &pm->pm_active);
 	PCPU_SET(curpmap, pmr);
 }
 
@@ -957,9 +955,7 @@
 	pmap_t	pm;
 
 	pm = &td->td_proc->p_vmspace->vm_pmap;
-	sched_pin();
-	CPU_NAND(&pm->pm_active, PCPU_PTR(cpumask));
-	sched_unpin();
+	CPU_CLR(PCPU_GET(cpuid), &pm->pm_active);
 	PCPU_SET(curpmap, NULL);
 }
 
Index: powerpc/aim/mmu_oea64.c
===================================================================
--- powerpc/aim/mmu_oea64.c	(revision 223106)
+++ powerpc/aim/mmu_oea64.c	(working copy)
@@ -998,9 +998,7 @@
 	pmap_t	pm;
 
 	pm = &td->td_proc->p_vmspace->vm_pmap;
-	sched_pin();
-	CPU_OR(&pm->pm_active, PCPU_PTR(cpumask));
-	sched_unpin();
+	CPU_SET(PCPU_GET(cpuid), &pm->pm_active);
 
 	#ifdef __powerpc64__
 	PCPU_SET(userslb, pm->pm_slb);
@@ -1015,9 +1013,7 @@
 	pmap_t	pm;
 
 	pm = &td->td_proc->p_vmspace->vm_pmap;
-	sched_pin();
-	CPU_NAND(&pm->pm_active, PCPU_PTR(cpumask));
-	sched_unpin();
+	CPU_CLR(PCPU_GET(cpuid), &pm->pm_active);
 	#ifdef __powerpc64__
 	PCPU_SET(userslb, NULL);
 	#else