[$] Multiple memory classes for address-space isolation

Brendan Jackman has been working to try to get ahead of the next hardware CPU
vulnerability
before it gets discovered. In January, he posted the second version of

a patch set that introduces

address-space isolation (ASI) as a way of
preventing future CPU vulnerabilities from leaking important
information. The core concept is to ensure that data that is not currently
needed is not present in memory, so that speculative execution cannot leak it.
The work is nowhere near ready to be incorporated into the mainline
kernel — not least of all because it has a large performance impact in its
current form — but it is likely to once again be a topic of discussion at the
2025

Linux Filesystem, Memory Management, and BPF Summit.