[resend PATCH 1/2] dim: make dim_calc_stats() inputs const pointers

[Xuan Zhuo]

On Wed, 30 Oct 2024 18:23:25 -0600, Caleb Sander Mateos <csander at purestorage.com> wrote:
> Make the start and end arguments to dim_calc_stats() const pointers
> to clarify that the function does not modify their values.
>
> Signed-off-by: Caleb Sander Mateos <csander at purestorage.com>


Reviewed-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>

> ---
>  include/linux/dim.h | 3 ++-
>  lib/dim/dim.c       | 3 ++-
>  2 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/dim.h b/include/linux/dim.h
> index 1b581ff25a15..84579a50ae7f 100644
> --- a/include/linux/dim.h
> +++ b/include/linux/dim.h
> @@ -349,11 +349,12 @@ void dim_park_tired(struct dim *dim);
>   *
>   * Calculate the delta between two samples (in data rates).
>   * Takes into consideration counter wrap-around.
>   * Returned boolean indicates whether curr_stats are reliable.
>   */
> -bool dim_calc_stats(struct dim_sample *start, struct dim_sample *end,
> +bool dim_calc_stats(const struct dim_sample *start,
> +		    const struct dim_sample *end,
>  		    struct dim_stats *curr_stats);
>
>  /**
>   *	dim_update_sample - set a sample's fields with given values
>   *	@event_ctr: number of events to set
> diff --git a/lib/dim/dim.c b/lib/dim/dim.c
> index 83b65ac74d73..97c3d084ebf0 100644
> --- a/lib/dim/dim.c
> +++ b/lib/dim/dim.c
> @@ -52,11 +52,12 @@ void dim_park_tired(struct dim *dim)
>  	dim->steps_left   = 0;
>  	dim->tune_state   = DIM_PARKING_TIRED;
>  }
>  EXPORT_SYMBOL(dim_park_tired);
>
> -bool dim_calc_stats(struct dim_sample *start, struct dim_sample *end,
> +bool dim_calc_stats(const struct dim_sample *start,
> +		    const struct dim_sample *end,
>  		    struct dim_stats *curr_stats)
>  {
>  	/* u32 holds up to 71 minutes, should be enough */
>  	u32 delta_us = ktime_us_delta(end->time, start->time);
>  	u32 npkts = BIT_GAP(BITS_PER_TYPE(u32), end->pkt_ctr, start->pkt_ctr);
> --
> 2.45.2
>