Re: [PATCH -next] sched/fair: Move update_nohz_stats() under CONFIG_NO_HZ_COMMON

From: Vincent Guittot
Date: Tue Mar 30 2021 - 08:23:02 EST


On Tue, 30 Mar 2021 at 14:06, Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> wrote:
>
> update_nohz_stats() only call _nohz_idle_balance() under CONFIG_NO_HZ_COMMON.

a similar patch has already been sent and reviewed :
20210329144029.29200-1-yuehaibing@xxxxxxxxxx

>
> Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
> ---
> kernel/sched/fair.c | 40 ++++++++++++++++++----------------------
> 1 file changed, 18 insertions(+), 22 deletions(-)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 6d73bdbb2d40..2a20ada83cbb 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -8395,28 +8395,6 @@ group_type group_classify(unsigned int imbalance_pct,
> return group_has_spare;
> }
>
> -static bool update_nohz_stats(struct rq *rq)
> -{
> -#ifdef CONFIG_NO_HZ_COMMON
> - unsigned int cpu = rq->cpu;
> -
> - if (!rq->has_blocked_load)
> - return false;
> -
> - if (!cpumask_test_cpu(cpu, nohz.idle_cpus_mask))
> - return false;
> -
> - if (!time_after(jiffies, READ_ONCE(rq->last_blocked_load_update_tick)))
> - return true;
> -
> - update_blocked_averages(cpu);
> -
> - return rq->has_blocked_load;
> -#else
> - return false;
> -#endif
> -}
> -
> /**
> * update_sg_lb_stats - Update sched_group's statistics for load balancing.
> * @env: The load balancing environment.
> @@ -10380,6 +10358,24 @@ void nohz_balance_enter_idle(int cpu)
> WRITE_ONCE(nohz.has_blocked, 1);
> }
>
> +static bool update_nohz_stats(struct rq *rq)
> +{
> + unsigned int cpu = rq->cpu;
> +
> + if (!rq->has_blocked_load)
> + return false;
> +
> + if (!cpumask_test_cpu(cpu, nohz.idle_cpus_mask))
> + return false;
> +
> + if (!time_after(jiffies, READ_ONCE(rq->last_blocked_load_update_tick)))
> + return true;
> +
> + update_blocked_averages(cpu);
> +
> + return rq->has_blocked_load;
> +}
> +
> /*
> * Internal function that runs load balance for all idle cpus. The load balance
> * can be a simple update of blocked load or a complete load balance with
> --
> 2.26.2
>