Can multi-memory tier support more than 256GB cache memory

[tangliisu]

According to some previous discussion(#193), we can't support more than 256GB cache memory. I saw there are some to-do on multi-memory tier support that each tier could have 128GB and we can create multiple tier (

CacheLib/cachelib/allocator/memory/CompressedPtr.h

Line 46 in 94907cc

// In multi-tier design:

). does it means in multi-tier memory setting, we can have more than 256GB cache memory in future?

[haowu14]

Unfortunately no. We have a maximum of 2 tiers.

As you see in that discussion #193, the best way to address more memory is to increase the smallest addressable unit.