Hi Morten,
On 06/22/2016 10:03 AM, Morten Rasmussen wrote:
[...]
>
> +/*
> + * group_smaller_cpu_capacity: Returns true if sched_group sg has smaller
> + * per-cpu capacity than sched_group ref.
> + */
> +static inline bool
> +group_smaller_cpu_capacity(struct sched_group *sg, struct sched_group *ref)
> +{
> + return sg->sgc->max_capacity * capacity_margin <
> + ref->sgc->max_capacity * 1024;
> +}
> +
> static inline enum
> group_type group_classify(struct sched_group *group,
> struct sg_lb_stats *sgs)
> @@ -6892,6 +6903,19 @@ static bool update_sd_pick_busiest(struct lb_env *env,
> if (sgs->avg_load <= busiest->avg_load)
> return false;
>
> + if (!(env->sd->flags & SD_ASYM_CPUCAPACITY))
> + goto asym_packing;
> +
> + /* Candidate sg has no more than one task per cpu and has
> + * higher per-cpu capacity. Migrating tasks to less capable
> + * cpus may harm throughput. Maximize throughput,
> + * power/energy consequences are not considered.
> + */
> + if (sgs->sum_nr_running <= sgs->group_weight &&
> + group_smaller_cpu_capacity(sds->local, sg))
> + return false;
> +
> +asym_packing:
What about the case where IRQ/RT work reduces the capacity of some of these
bigger CPUs? sgc->max_capacity might not necessarily capture that case.
Thanks,
-Sai
