Queued up in a TIP branch ahead of the Linux 6.19 merge window opening in about one month’s time is optimizing the Restartable Sequences “RSEQ” code for its exit to user-space code path.
Intel Fellow Thomas Gleixner of Linutronix worked on a set of patches recently for optimizing the exit to user-space path for Restartable Sequences, the functionality for efficient access and manipulation of per-CPU data structures by user-space.
The last line in the summary in the post should be accessible. It just optimizes managing data in the kernel from user space (i.e. not using privileged kernel access).