sched: Wrap scheduler p->cpus_allowed access

This task is preparatory for the migrate_disable() implementation, but
stands on its own and provides a cleanup.

It currently only converts those sites required for task-placement.
Kosaki-san once mentioned replacing cpus_allowed with a proper
cpumask_t instead of the NR_CPUS sized array it currently is, that
would also require something like this.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Link: http://lkml.kernel.org/n/tip-e42skvaddos99psip0vce41o@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 506db09..5c9e679 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -2183,7 +2183,7 @@
 
 		/* Skip over this group if it has no CPUs allowed */
 		if (!cpumask_intersects(sched_group_cpus(group),
-					&p->cpus_allowed))
+					tsk_cpus_allowed(p)))
 			continue;
 
 		local_group = cpumask_test_cpu(this_cpu,
@@ -2229,7 +2229,7 @@
 	int i;
 
 	/* Traverse only the allowed CPUs */
-	for_each_cpu_and(i, sched_group_cpus(group), &p->cpus_allowed) {
+	for_each_cpu_and(i, sched_group_cpus(group), tsk_cpus_allowed(p)) {
 		load = weighted_cpuload(i);
 
 		if (load < min_load || (load == min_load && i == this_cpu)) {
@@ -2273,7 +2273,7 @@
 		if (!(sd->flags & SD_SHARE_PKG_RESOURCES))
 			break;
 
-		for_each_cpu_and(i, sched_domain_span(sd), &p->cpus_allowed) {
+		for_each_cpu_and(i, sched_domain_span(sd), tsk_cpus_allowed(p)) {
 			if (idle_cpu(i)) {
 				target = i;
 				break;
@@ -2316,7 +2316,7 @@
 	int sync = wake_flags & WF_SYNC;
 
 	if (sd_flag & SD_BALANCE_WAKE) {
-		if (cpumask_test_cpu(cpu, &p->cpus_allowed))
+		if (cpumask_test_cpu(cpu, tsk_cpus_allowed(p)))
 			want_affine = 1;
 		new_cpu = prev_cpu;
 	}
@@ -2697,7 +2697,7 @@
 	 * 2) cannot be migrated to this CPU due to cpus_allowed, or
 	 * 3) are cache-hot on their current CPU.
 	 */
-	if (!cpumask_test_cpu(this_cpu, &p->cpus_allowed)) {
+	if (!cpumask_test_cpu(this_cpu, tsk_cpus_allowed(p))) {
 		schedstat_inc(p, se.statistics.nr_failed_migrations_affine);
 		return 0;
 	}
@@ -4087,7 +4087,7 @@
 			 * moved to this_cpu
 			 */
 			if (!cpumask_test_cpu(this_cpu,
-					      &busiest->curr->cpus_allowed)) {
+					tsk_cpus_allowed(busiest->curr))) {
 				raw_spin_unlock_irqrestore(&busiest->lock,
 							    flags);
 				all_pinned = 1;