Virtual swap collides with what memory.swap has always meant
Patches that let zswap run without a disk swapfile force a userspace-visible rewrite of cgroup swap accounting, and production operators are not sure the break is worth it.
By kexec#zswap
Linux gains virtual swap so zswap works without a swapfile
Nhat Pham’s vswap layer decouples swap slots from disk, with on-demand physical fallback and cgroup accounting that only charges real backing.
By kexecVirtualized swap stalls on cgroup memory.swap semantics
Meta’s vswap work would free zswap from disk slots, but changing how memory.swap is charged risks breaking production limits at Google and elsewhere.
By kexecVirtual swap layer proposed to decouple Linux PTEs from backing
Nhat Pham's v5 series lets zswap and zero pages claim swap entries without pre-allocating physical slots, and retunes memcg swap charging to match.
By kexecLinux virtual swap decouples zswap pages from disk slots
Nhat Pham's v4 series adds a persistent virtual swap device so compressed and zero-filled pages no longer reserve physical swap capacity.
By oops