Re: [PATCH v6 12/16] sched: Add deadline tracepoints

[Juri Lelli <juri.lelli@redhat.com>]

Hello,

On 25/02/26 10:51, Gabriele Monaco wrote:
> Add the following tracepoints:
> 
> * sched_dl_throttle(dl_se, cpu, type):
>     Called when a deadline entity is throttled
> * sched_dl_replenish(dl_se, cpu, type):
>     Called when a deadline entity's runtime is replenished
> * sched_dl_update(dl_se, cpu, type):
>     Called when a deadline entity updates without throttle or replenish
> * sched_dl_server_start(dl_se, cpu, type):
>     Called when a deadline server is started
> * sched_dl_server_stop(dl_se, cpu, type):
>     Called when a deadline server is stopped
> 
> Those tracepoints can be useful to validate the deadline scheduler with
> RV and are not exported to tracefs.
> 
> Reviewed-by: Phil Auld <pauld@redhat.com>
> Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
> ---
> 
> Notes:
>     V6:
>     * Add dl_se type to differentiate between fair and ext servers
>     * Add event to track dl_update_curr not firing other events
>     V3:
>     * Rename dl argument to dl_se in tracepoints
> 
>  include/trace/events/sched.h | 26 ++++++++++++++++++++++++++
>  kernel/sched/core.c          |  4 ++++
>  kernel/sched/deadline.c      | 25 ++++++++++++++++++++++++-
>  3 files changed, 54 insertions(+), 1 deletion(-)
> 
> diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
> index 5844147ec5fd..944d65750a64 100644
> --- a/include/trace/events/sched.h
> +++ b/include/trace/events/sched.h
> @@ -904,6 +904,32 @@ DECLARE_TRACE(sched_dequeue,
>  	TP_PROTO(struct task_struct *tsk, int cpu),
>  	TP_ARGS(tsk, cpu));
>  
> +#define DL_OTHER 0
> +#define DL_TASK 1
> +#define DL_SERVER_FAIR 2
> +#define DL_SERVER_EXT 3
> +
> +DECLARE_TRACE(sched_dl_throttle,
> +	TP_PROTO(struct sched_dl_entity *dl_se, int cpu, uint8_t type),
> +	TP_ARGS(dl_se, cpu, type));
> +
> +DECLARE_TRACE(sched_dl_replenish,
> +	TP_PROTO(struct sched_dl_entity *dl_se, int cpu, uint8_t type),
> +	TP_ARGS(dl_se, cpu, type));
> +
> +/* Call to update_curr_dl_se not involving throttle or replenish */
> +DECLARE_TRACE(sched_dl_update,
> +	TP_PROTO(struct sched_dl_entity *dl_se, int cpu, uint8_t type),
> +	TP_ARGS(dl_se, cpu, type));
> +
> +DECLARE_TRACE(sched_dl_server_start,
> +	TP_PROTO(struct sched_dl_entity *dl_se, int cpu, uint8_t type),
> +	TP_ARGS(dl_se, cpu, type));
> +
> +DECLARE_TRACE(sched_dl_server_stop,
> +	TP_PROTO(struct sched_dl_entity *dl_se, int cpu, uint8_t type),
> +	TP_ARGS(dl_se, cpu, type));
> +
>  #endif /* _TRACE_SCHED_H */
>  
>  /* This part must be outside protection */
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 4ca79ff58fca..b5bb2eb112bf 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -124,6 +124,10 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(sched_exit_tp);
>  EXPORT_TRACEPOINT_SYMBOL_GPL(sched_set_need_resched_tp);
>  EXPORT_TRACEPOINT_SYMBOL_GPL(sched_enqueue_tp);
>  EXPORT_TRACEPOINT_SYMBOL_GPL(sched_dequeue_tp);
> +EXPORT_TRACEPOINT_SYMBOL_GPL(sched_dl_throttle_tp);
> +EXPORT_TRACEPOINT_SYMBOL_GPL(sched_dl_replenish_tp);
> +EXPORT_TRACEPOINT_SYMBOL_GPL(sched_dl_server_start_tp);
> +EXPORT_TRACEPOINT_SYMBOL_GPL(sched_dl_server_stop_tp);

Don't we need to export sched_dl_update_tp as well?

>  DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
>  DEFINE_PER_CPU(struct rnd_state, sched_rnd_state);

...

> @@ -1532,7 +1551,8 @@ static void update_curr_dl_se(struct rq *rq, struct sched_dl_entity *dl_se, s64
>  
>  		if (!is_leftmost(dl_se, &rq->dl))
>  			resched_curr(rq);
> -	}
> +	} else
> +		trace_sched_dl_update_tp(dl_se, cpu_of(rq), dl_get_type(dl_se, rq));

This wants braces even if it's a single statement.

>  
>  	/*
>  	 * The dl_server does not account for real-time workload because it

Thanks,
Juri