Re: [RFC PATCH v2 05/25] sched/rt: Move some functions from rt.c to sched.h

From: Juri Lelli
Date: Thu Aug 14 2025 - 04:51:16 EST


Hi!

On 31/07/25 12:55, Yuri Andriaccio wrote:
> From: luca abeni <luca.abeni@xxxxxxxxxxxxxxx>
>
> Make the following functions be non-static and move them in sched.h, so that
> they can be used also in other source files:
> - rt_task_of()
> - rq_of_rt_rq()
> - rt_rq_of_se()
> - rq_of_rt_se()
>
> There are no functional changes. This is needed by future patches.
>
> Signed-off-by: luca abeni <luca.abeni@xxxxxxxxxxxxxxx>
> Signed-off-by: Yuri Andriaccio <yurand2000@xxxxxxxxx>
> ---
> kernel/sched/rt.c | 52 --------------------------------------------
> kernel/sched/sched.h | 51 +++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 51 insertions(+), 52 deletions(-)
>
> diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
> index 945e3d705cc..3ea92b08a0e 100644
> --- a/kernel/sched/rt.c
> +++ b/kernel/sched/rt.c
> @@ -168,34 +168,6 @@ static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b)
>
> #define rt_entity_is_task(rt_se) (!(rt_se)->my_q)
>
> -static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)
> -{
> - WARN_ON_ONCE(!rt_entity_is_task(rt_se));
> -
> - return container_of(rt_se, struct task_struct, rt);
> -}
> -
> -static inline struct rq *rq_of_rt_rq(struct rt_rq *rt_rq)
> -{
> - /* Cannot fold with non-CONFIG_RT_GROUP_SCHED version, layout */
> - WARN_ON(!rt_group_sched_enabled() && rt_rq->tg != &root_task_group);
> - return rt_rq->rq;
> -}
> -
> -static inline struct rt_rq *rt_rq_of_se(struct sched_rt_entity *rt_se)
> -{
> - WARN_ON(!rt_group_sched_enabled() && rt_se->rt_rq->tg != &root_task_group);
> - return rt_se->rt_rq;
> -}
> -
> -static inline struct rq *rq_of_rt_se(struct sched_rt_entity *rt_se)
> -{
> - struct rt_rq *rt_rq = rt_se->rt_rq;
> -
> - WARN_ON(!rt_group_sched_enabled() && rt_rq->tg != &root_task_group);
> - return rt_rq->rq;
> -}

Looks like we are losing WARN_ON checks with the change? Why is that?

...

> diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
> index a8073d0824d..a1e6d2852ca 100644
> --- a/kernel/sched/sched.h
> +++ b/kernel/sched/sched.h
> @@ -3042,6 +3042,57 @@ extern void set_rq_offline(struct rq *rq);
>
> extern bool sched_smp_initialized;
>
> +#ifdef CONFIG_RT_GROUP_SCHED
> +static inline struct task_struct *rt_task_of(struct sched_rt_entity *rt_se)
> +{
> +#ifdef CONFIG_SCHED_DEBUG
> + WARN_ON_ONCE(rt_se->my_q);
> +#endif

And gaining this one above. :)

Thanks,
Juri