Re: [PATCH] RFC: Set irq thread to RT priority on creation

[Steven Rostedt <rostedt@goodmis.org>]

On Thu, 2013-05-30 at 14:12 +0200, Ivo Sieben wrote:

>  kernel/irq/manage.c |    6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
> index fa17855..0ffe37b 100644
> --- a/kernel/irq/manage.c
> +++ b/kernel/irq/manage.c
> @@ -950,6 +950,9 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
>  	 */
>  	if (new->thread_fn && !nested) {
>  		struct task_struct *t;
> +		static const struct sched_param param = {
> +			.sched_priority = MAX_USER_RT_PRIO/2,
> +		};
>  
>  		t = kthread_create(irq_thread, new, "irq/%d-%s", irq,
>  				   new->name);
> @@ -957,6 +960,9 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
>  			ret = PTR_ERR(t);
>  			goto out_mput;
>  		}
> +
> +		sched_setscheduler(t, SCHED_FIFO, &param);
> +

If you are adding this here, might as well remove the
sched_set_scheduler() from irq_thread() as well. No need to do it twice.

-- Steve

>  		/*
>  		 * We keep the reference to the task struct even if
>  		 * the thread dies to avoid that the interrupt code