Re: [PATCH 1/4] numa: introduce per-cgroup numa balancing locality, statistic

[Peter Zijlstra]

On Wed, Jul 03, 2019 at 11:28:10AM +0800, çè wrote:
> +#ifdef CONFIG_NUMA_BALANCING
> +
> +enum memcg_numa_locality_interval {
> +	PERCENT_0_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,
> +};

That's just daft; why not make 8 equal sized buckets.

> +struct memcg_stat_numa {
> +	u64 locality[NR_NL_INTERVAL];
> +};

> +	if (remote || local) {
> +		idx = ((local * 10) / (remote + local)) - 2;

		idx = (NR_NL_INTERVAL * local) / (remote + local);

> +	}
> +
> +	rcu_read_lock();
> +	memcg = mem_cgroup_from_task(p);
> +	if (idx != -1)
> +		this_cpu_inc(memcg->stat_numa->locality[idx]);
> +	rcu_read_unlock();
> +}
> +#endif