sched_ext: idle: use assign_cpu() to update the idle cpumask

Use the assign_cpu() helper to set or clear the CPU in the idle mask,
based on the idle condition.

Acked-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

Author: arighi

kernel/sched/ext.c

@@ -3654,10 +3654,7 @@ void __scx_update_idle(struct rq *rq, bool idle)
 			return;
 	}
 
-	if (idle)
-		cpumask_set_cpu(cpu, idle_masks.cpu);
-	else
-		cpumask_clear_cpu(cpu, idle_masks.cpu);
+	assign_cpu(cpu, idle_masks.cpu, idle);
 
 #ifdef CONFIG_SCHED_SMT
 	if (sched_smt_active()) {