Re: [PATCH v10 0/6] mm/swap, memcg: Introduce swap tiers for cgroup based swap control

[Johannes Weiner]

Zswap is a first-order swap destination with writeback semantics. The
way the discussion around zswap has been going in this thread is
disappointing, and I don't feel comfortable adding permanent user
interfaces on this basis.

We will not be merging a memcg swap tier interface until the swap side
has a story for indirection and backend migration.