Re: [PATCH v4 2/2] sched/uclamp: Use wrappers instead of open coding UCLAMP_FLAG_IDLE

[Kayra Cizmeci <kayracizmeci@gmail.com>]

On Thu, Oct 29, 2026 at 01:13:54PM +0000, Qais Yousef wrote:

Hi Qais,

> We already have uclamp_rq_is_idle(), but it wasn't used everywhere.
> Replace open coding with the function and add new wrapper to set and
> clear the flag which enhances readability.
> 
> Signed-off-by: Qais Yousef <qyousef@layalina.io>
> ---
>  kernel/sched/core.c  | 14 +++++++-------
>  kernel/sched/sched.h | 10 ++++++++++
>  2 files changed, 17 insertions(+), 7 deletions(-)
> 
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index c6780358a7975..a2035d66270b9 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -1626,7 +1626,7 @@ uclamp_idle_value(struct rq *rq, enum uclamp_id clamp_id,
>  	 * max-clamp.
>  	 */
>  	if (clamp_id == UCLAMP_MAX) {
> -		rq->uclamp_flags |= UCLAMP_FLAG_IDLE;
> +		uclamp_rq_set_idle(rq);
>  		return clamp_value;
>  	}
>  
> @@ -1637,7 +1637,7 @@ static inline void uclamp_idle_reset(struct rq *rq, enum uclamp_id clamp_id,
>  				     unsigned int clamp_value)
>  {
>  	/* Reset max-clamp retention only on idle exit */
> -	if (!(rq->uclamp_flags & UCLAMP_FLAG_IDLE))
> +	if (!uclamp_rq_is_idle(rq))
>  		return;
>  
>  	uclamp_rq_set(rq, clamp_id, clamp_value);
> @@ -1890,8 +1890,8 @@ static inline void uclamp_rq_inc(struct rq *rq, struct task_struct *p, int flags
>  		uclamp_rq_inc_id(rq, p, clamp_id);
>  
>  	/* Reset clamp idle holding when there is one RUNNABLE task */
> -	if (rq->uclamp_flags & UCLAMP_FLAG_IDLE)
> -		rq->uclamp_flags &= ~UCLAMP_FLAG_IDLE;
> +	if (uclamp_rq_is_idle(rq))
> +		uclamp_rq_clear_idle(rq);
>  }
>  
>  static inline void uclamp_rq_dec(struct rq *rq, struct task_struct *p)
> @@ -1930,8 +1930,8 @@ static inline void uclamp_rq_reinc_id(struct rq *rq, struct task_struct *p,
>  	 * Make sure to clear the idle flag if we've transiently reached 0
>  	 * active tasks on rq.
>  	 */
> -	if (clamp_id == UCLAMP_MAX && (rq->uclamp_flags & UCLAMP_FLAG_IDLE))
> -		rq->uclamp_flags &= ~UCLAMP_FLAG_IDLE;
> +	if (clamp_id == UCLAMP_MAX && uclamp_rq_is_idle(rq))
> +		uclamp_rq_clear_idle(rq);
>  }
>  
>  static inline void
> @@ -2122,7 +2122,7 @@ void init_uclamp_rq(struct rq *rq)
>  		};
>  	}
>  
> -	rq->uclamp_flags = UCLAMP_FLAG_IDLE;
> +	uclamp_rq_set_idle(rq);
>  }
>  
>  static void __init init_uclamp(void)
> diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
> index d87bdbd2121df..4706f73838a86 100644
> --- a/kernel/sched/sched.h
> +++ b/kernel/sched/sched.h
> @@ -3743,6 +3743,16 @@ static inline void uclamp_rq_set(struct rq *rq, enum uclamp_id clamp_id,
>  	WRITE_ONCE(rq->uclamp[clamp_id].value, value);
>  }
>  
> +static inline void uclamp_rq_set_idle(struct rq *rq)
> +{
> +	rq->uclamp_flags |= UCLAMP_FLAG_IDLE;
> +}
> +
> +static inline void uclamp_rq_clear_idle(struct rq *rq)
> +{
> +	rq->uclamp_flags &= ~UCLAMP_FLAG_IDLE;
> +}
> +
>  static inline bool uclamp_rq_is_idle(struct rq *rq)
>  {
>  	return rq->uclamp_flags & UCLAMP_FLAG_IDLE;
> -- 
> 2.53.0
> 

Looks good to me.


Reviewed-by: Kayra Cizmeci <kayracizmeci@gmail.com>


Thanks,

Kayra