Re: [RFC] memory tiering: use small chunk size and more tiers

[Michal Hocko]

On Mon 31-10-22 09:33:49, Huang, Ying wrote:
[...]
> In the upstream implementation, 4 tiers are possible below DRAM.  That's
> enough for now.  But in the long run, it may be better to define more.
> 100 possible tiers below DRAM may be too extreme.

I am just curious. Is any configurations with more than couple of tiers
even manageable? I mean applications have been struggling even with
regular NUMA systems for years and vast majority of them is largerly
NUMA unaware. How are they going to configure for a more complex system
when a) there is no resource access control so whatever you aim for
might not be available and b) in which situations there is going to be a
demand only for subset of tears (GPU memory?) ?

Thanks!

-- 
Michal Hocko
SUSE Labs