Post Syndicated from original https://lwn.net/Articles/885818/

Restartable sequences, a Linux kernel feature that facilitates the writing
of lockless, per-CPU code in user space, has been around for some years,
but it only just received support in the GNU C
Library this month. Now that this barrier has been crossed, it would
seem that the time has come to start adding features. Mathieu Desnoyers
has responded to this challenge with a
patch set adding an extension mechanism and a new “virtual CPU ID”
feature.