[$] Code tagging and memory-allocation profiling

The code-tagging mechanism proposed last
year by Suren Baghdasaryan and Kent Overstreet has been the subject of a
number of (sometimes tense) discussions. That conversation came to the
memory-management track at the 2023 Linux
Storage, Filesystem, Memory-Management and BPF Summit, where its
developers (Baghdasaryan attending in-person and Overstreet remotely) tried
to convince the attendees that its benefits justify its cost.