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From: Vincent Guittot <vincent.guittot@linaro.org>
Date: Wed, 20 Dec 2023 14:59:01 +0100
Message-ID: <CAKfTPtCRoLULQkRTZcJfXvSSqZYV2oRN0a3_AFiuqD7k0LtL-Q@mail.gmail.com>
Subject: Re: [PATCH] sched: move access of avg_rt and avg_dl into existing
 helper functions
To: Shrikanth Hegde <sshegde@linux.vnet.ibm.com>
Cc: mingo@kernel.org, peterz@infradead.org, dietmar.eggemann@arm.com, 
	linux-kernel@vger.kernel.org, srikar@linux.vnet.ibm.com, yu.c.chen@intel.com, 
	tim.c.chen@linux.intel.com
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On Wed, 20 Dec 2023 at 07:55, Shrikanth Hegde
<sshegde@linux.vnet.ibm.com> wrote:
>
> This is a minor code simplification. There are helper functions called
> cpu_util_dl and cpu_util_rt which gives the average utilization of DL
> and RT respectively. But there are few places in code where these
> variables are used directly.
>
> Instead use the helper function so that code becomes simpler and easy to
> maintain later on.
>
> Signed-off-by: Shrikanth Hegde <sshegde@linux.vnet.ibm.com>
> ---
>  kernel/sched/fair.c | 12 +++++-------
>  1 file changed, 5 insertions(+), 7 deletions(-)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index bcea3d55d95d..02631060ca7e 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -9212,19 +9212,17 @@ static inline bool cfs_rq_has_blocked(struct cfs_rq *cfs_rq)
>
>  static inline bool others_have_blocked(struct rq *rq)
>  {
> -       if (READ_ONCE(rq->avg_rt.util_avg))
> +       if (cpu_util_rt(rq))
>                 return true;
>
> -       if (READ_ONCE(rq->avg_dl.util_avg))
> +       if (cpu_util_dl(rq))
>                 return true;
>
>         if (thermal_load_avg(rq))
>                 return true;
>
> -#ifdef CONFIG_HAVE_SCHED_AVG_IRQ
> -       if (READ_ONCE(rq->avg_irq.util_avg))
> +       if (cpu_util_irq(rq))

cpu_util_irq doesn't call READ_ONCE()


>                 return true;
> -#endif
>
>         return false;
>  }
> @@ -9481,8 +9479,8 @@ static unsigned long scale_rt_capacity(int cpu)
>          * avg_thermal.load_avg tracks thermal pressure and the weighted
>          * average uses the actual delta max capacity(load).
>          */
> -       used = READ_ONCE(rq->avg_rt.util_avg);
> -       used += READ_ONCE(rq->avg_dl.util_avg);
> +       used = cpu_util_rt(rq);
> +       used += cpu_util_dl(rq);
>         used += thermal_load_avg(rq);
>
>         if (unlikely(used >= max))
> --
> 2.39.3
>