Re: [PATCH v5 6/7] sched/deadline: Deferrable dl server

From: Daniel Bristot de Oliveira
Date: Mon Nov 06 2023 - 12:06:03 EST


On 11/6/23 15:55, Peter Zijlstra wrote:
> On Sat, Nov 04, 2023 at 11:59:23AM +0100, Daniel Bristot de Oliveira wrote:
>
>> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
>> index b15f7f376a67..399237cd9f59 100644
>> --- a/kernel/sched/fair.c
>> +++ b/kernel/sched/fair.c
>> @@ -1201,6 +1201,8 @@ static void update_curr(struct cfs_rq *cfs_rq)
>> account_group_exec_runtime(curtask, delta_exec);
>> if (curtask->server)
>> dl_server_update(curtask->server, delta_exec);
>> + else
>> + dl_server_update(&rq_of(cfs_rq)->fair_server, delta_exec);
>> }
>>
>> account_cfs_rq_runtime(cfs_rq, delta_exec);
>
> @@ -1195,8 +1196,17 @@ static void update_curr(struct cfs_rq *c
> update_deadline(cfs_rq, curr);
> update_min_vruntime(cfs_rq);
>
> - if (entity_is_task(curr))
> - update_curr_task(task_of(curr), delta_exec);
> + if (entity_is_task(curr)) {
> + struct task_struct *p = task_of(curr);
> + update_curr_task(p, delta_exec);
> + /*
> + * Any fair task that runs outside of fair_server should
> + * account against fair_server such that it can account for
> + * this time and possible avoid running this period.
> + */
> + if (p->dl_server != &rq->fair_server)
> + dl_server_update(&rq->fair_server, delta_exec);
aren't we missing:
else
dl_server_update(&rq_of(cfs_rq)->fair_server, delta_exec);

or am I missing something? :-)

> + }
>
> account_cfs_rq_runtime(cfs_rq, delta_exec);
> }