Re: [PATCH RFC 0/3] sched/fair: cpu time reserves for cgroups

Peter Zijlstra
2016-05-16T11:18:54Z

On Mon, May 16, 2016 at 12:36:19PM +0300, Konstantin Khlebnikov wrote:
> This feature allows to change cpu cgroup weight for a limited time.
>
> Cgroup interface:
> cpu.cfs_reserve_us - reserved time for each cpu.cfs_period_us
> cpu.cfs_reserve_shares - group weight during reserved time
>
> While cfs group consumes reserved cpu time it has different weight,
> thus it gets different vruntime penalty for that execution.
>
> ^ weight
> |
> |
> reserve |
> shares -------*
> | |
> | |
> | |
> shares - *-----------------*
> | |
> | |
> 0------|-----------------|-----------> time
> reserve quota
>
> Reserve can work as a "low limit": boost weight for "guaranteed" time,
> and as a "high limit": give normal weight for a limited time and allow
> utilize cpu when nobody else needs it.
>

You forgot to explain why I should care about this.