sched/cpupri: Replace NR_CPUS arrays

Tejun reported that his resume was failing due to order-3 allocations
from sched_domain building.

Replace the NR_CPUS arrays in there with a dynamically allocated
array.

Reported-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-7cysnkw1gik45r864t1nkudh@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/cpupri.c

@@ -30,6 +30,7 @@
 #include <linux/gfp.h>
 #include <linux/sched.h>
 #include <linux/sched/rt.h>
+#include <linux/slab.h>
 #include "cpupri.h"
 
 /* Convert between a 140 based task->prio, and our 102 based cpupri */
@@ -218,8 +219,13 @@ int cpupri_init(struct cpupri *cp)
 			goto cleanup;
 	}
 
+	cp->cpu_to_pri = kcalloc(nr_cpu_ids, sizeof(int), GFP_KERNEL);
+	if (!cp->cpu_to_pri)
+		goto cleanup;
+
 	for_each_possible_cpu(i)
 		cp->cpu_to_pri[i] = CPUPRI_INVALID;
+
 	return 0;
 
 cleanup:
@@ -236,6 +242,7 @@ void cpupri_cleanup(struct cpupri *cp)
 {
 	int i;
 
+	kfree(cp->cpu_to_pri);
 	for (i = 0; i < CPUPRI_NR_PRIORITIES; i++)
 		free_cpumask_var(cp->pri_to_cpu[i].mask);
 }

kernel/sched/cpupri.h

@@ -17,7 +17,7 @@ struct cpupri_vec {
 
 struct cpupri {
 	struct cpupri_vec pri_to_cpu[CPUPRI_NR_PRIORITIES];
-	int               cpu_to_pri[NR_CPUS];
+	int *cpu_to_pri;
 };
 
 #ifdef CONFIG_SMP