sched_ext: Use IRQ_WORK_INIT_HARD() to initialize rq->scx.kick_cpus_irq_work

For PREEMPT_RT kernels, the kick_cpus_irq_workfn() be invoked in
the per-cpu irq_work/* task context and there is no rcu-read critical
section to protect. this commit therefore use IRQ_WORK_INIT_HARD() to
initialize the per-cpu rq->scx.kick_cpus_irq_work in the
init_sched_ext_class().

Signed-off-by: Zqiang <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>

Author: Zqiang

kernel/sched/ext.c

@@ -5322,7 +5322,7 @@ void __init init_sched_ext_class(void)
 		BUG_ON(!zalloc_cpumask_var_node(&rq->scx.cpus_to_preempt, GFP_KERNEL, n));
 		BUG_ON(!zalloc_cpumask_var_node(&rq->scx.cpus_to_wait, GFP_KERNEL, n));
 		rq->scx.deferred_irq_work = IRQ_WORK_INIT_HARD(deferred_irq_workfn);
-		init_irq_work(&rq->scx.kick_cpus_irq_work, kick_cpus_irq_workfn);
+		rq->scx.kick_cpus_irq_work = IRQ_WORK_INIT_HARD(kick_cpus_irq_workfn);
 
 		if (cpu_online(cpu))
 			cpu_rq(cpu)->scx.flags |= SCX_RQ_ONLINE;