Re: [RFC PATCH] sched: psi: Add psi events trace point

[Johannes Weiner]

On Thu, Aug 14, 2025 at 03:07:19PM +0800, Xuewen Yan wrote:
> Add trace point to psi triggers. This is useful to
> observe the psi events in the kernel space.
> 
> Signed-off-by: Xuewen Yan <xuewen.yan@xxxxxxxxxx>

Can you elaborate on a situation in which you would use this?

> ---
>  include/trace/events/sched.h | 5 +++++
>  kernel/sched/psi.c           | 2 ++
>  2 files changed, 7 insertions(+)
> 
> diff --git a/include/trace/events/sched.h b/include/trace/events/sched.h
> index 7b2645b50e78..c23cb2bc76fd 100644
> --- a/include/trace/events/sched.h
> +++ b/include/trace/events/sched.h
> @@ -896,6 +896,11 @@ DECLARE_TRACE(sched_set_need_resched,
>  	TP_PROTO(struct task_struct *tsk, int cpu, int tif),
>  	TP_ARGS(tsk, cpu, tif));
>  
> +struct psi_trigger *t

Missing ;

> +DECLARE_TRACE(psi_event,
> +	TP_PROTO(struct psi_trigger *t),
> +	TP_ARGS(t));
> +
>  #endif /* _TRACE_SCHED_H */
>  
>  /* This part must be outside protection */