Re: [PATCH v2 7/7] sched: Change task_struct::state

[Daniel Bristot de Oliveira]

On 6/11/21 10:28 AM, Peter Zijlstra wrote:
> --- a/kernel/sched/deadline.c
> +++ b/kernel/sched/deadline.c
> @@ -348,10 +348,10 @@ static void task_non_contending(struct t
>  	if ((zerolag_time < 0) || hrtimer_active(&dl_se->inactive_timer)) {
>  		if (dl_task(p))
>  			sub_running_bw(dl_se, dl_rq);
> -		if (!dl_task(p) || p->state == TASK_DEAD) {
> +		if (!dl_task(p) || READ_ONCE(p->__state) == TASK_DEAD) {
>  			struct dl_bw *dl_b = dl_bw_of(task_cpu(p));
>  
> -			if (p->state == TASK_DEAD)
> +			if (READ_ONCE(p->__state) == TASK_DEAD)
>  				sub_rq_bw(&p->dl, &rq->dl);
>  			raw_spin_lock(&dl_b->lock);
>  			__dl_sub(dl_b, p->dl.dl_bw, dl_bw_cpus(task_cpu(p)));
> @@ -1355,10 +1355,10 @@ static enum hrtimer_restart inactive_tas
>  	sched_clock_tick();
>  	update_rq_clock(rq);
>  
> -	if (!dl_task(p) || p->state == TASK_DEAD) {
> +	if (!dl_task(p) || READ_ONCE(p->__state) == TASK_DEAD) {
>  		struct dl_bw *dl_b = dl_bw_of(task_cpu(p));
>  
> -		if (p->state == TASK_DEAD && dl_se->dl_non_contending) {
> +		if (READ_ONCE(p->__state) == TASK_DEAD && dl_se->dl_non_contending) {
>  			sub_running_bw(&p->dl, dl_rq_of_se(&p->dl));
>  			sub_rq_bw(&p->dl, dl_rq_of_se(&p->dl));
>  			dl_se->dl_non_contending = 0;
> @@ -1722,7 +1722,7 @@ static void migrate_task_rq_dl(struct ta
>  {
>  	struct rq *rq;
>  
> -	if (p->state != TASK_WAKING)
> +	if (READ_ONCE(p->__state) != TASK_WAKING)
>  		return;
>  
>  	rq = task_rq(p);

Reviewed-by: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>

Feel free to add it to the other patches as well.

Thanks!
-- Daniel