Re: [RFC PATCH 1/3] mm/memory-tiers Add functions for tier memory usage in a cgroup

[Aneesh Kumar K.V]

Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx> writes:

 +unsigned long mem_cgroup_toptier_usage(struct mem_cgroup *memcg)
> +{
> +	struct memory_tier *top_tier;
> +
> +	top_tier = list_first_entry(&memory_tiers, struct memory_tier, list);
> +	if (top_tier)
> +		return mem_cgroup_memtier_usage(memcg, top_tier);
> +	else
> +		return 0;
> +}

As discussed here, we would want to consider all memory tiers that got
compute as top tier.

https://lore.kernel.org/linux-mm/11f94e0c50f17f4a6a2f974cb69a1ae72853e2be.camel@xxxxxxxxx

V6 patchset actually walk the full memory tier hierarchy reverse and consider any
memory tier with higher or equal rank value than the first memory tier with CPU as top tier.

https://lore.kernel.org/linux-mm/20220610135229.182859-12-aneesh.kumar@xxxxxxxxxxxxx

-aneesh