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.
Basically performance boost to make it more in line with how libc works now.