Re: [RFC PATCH 1/5] numa: introduce per-cgroup numa balancing locality, statistic

From: Peter Zijlstra
Date: Tue Apr 23 2019 - 04:44:55 EST


On Mon, Apr 22, 2019 at 10:11:24AM +0800, çè wrote:
> +#ifdef CONFIG_NUMA_BALANCING
> +
> +enum memcg_numa_locality_interval {
> + PERCENT_0_9,
> + PERCENT_10_19,
> + PERCENT_20_29,
> + PERCENT_30_39,
> + PERCENT_40_49,
> + PERCENT_50_59,
> + PERCENT_60_69,
> + PERCENT_70_79,
> + PERCENT_80_89,
> + PERCENT_90_100,
> + NR_NL_INTERVAL,
> +};
> +
> +struct memcg_stat_numa {
> + u64 locality[NR_NL_INTERVAL];
> +};

If you make that 8 it fits a single cacheline. Do you really need the
additional resolution? If so, then 16 would be the next logical amount
of buckets. 10 otoh makes no sense what so ever.