[$] Recent RCU changes

In a combined filesystem and memory-management session at the 2022 Linux Storage,
Filesystem, Memory-management and BPF Summit (LSFMM), Paul McKenney
gave an update on
the changes to the read-copy-update (RCU) subsystem that had been made over
the last several years. He started with a quick overview of what RCU is
and why it exists at all. He did not go into any
real depth, though, since many of the topics could take a 90-minute session of their
own, he said, but he did provide some descriptions of the work that has gone into
RCU recently.