Re: [PATCH v2 2/5] sched/fair: Remove unnecessary comparison with -1

From: Vincent Guittot
Date: Fri Aug 25 2017 - 09:40:42 EST


On 25 August 2017 at 12:16, Brendan Jackman <brendan.jackman@xxxxxxx> wrote:
> Since commit 83a0a96a5f26 ("sched/fair: Leverage the idle state info
> when choosing the "idlest" cpu") find_idlest_grou_cpu (formerly
> find_idlest_cpu) no longer returns -1.
>
> Signed-off-by: Brendan Jackman <brendan.jackman@xxxxxxx>
> Cc: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
> Cc: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
> Cc: Josef Bacik <josef@xxxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Morten Rasmussen <morten.rasmussen@xxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>

Reviewed-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>

> ---
> kernel/sched/fair.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index f6e277c65235..4ccecbf825bf 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -5583,7 +5583,7 @@ static inline int find_idlest_cpu(struct sched_domain *sd, struct task_struct *p
> }
>
> new_cpu = find_idlest_group_cpu(group, p, cpu);
> - if (new_cpu == -1 || new_cpu == cpu) {
> + if (new_cpu == cpu) {
> /* Now try balancing at a lower domain level of cpu */
> sd = sd->child;
> continue;
> --
> 2.14.1
>