On Sat, Feb 01, 2025 at 10:22:08PM -0500, Steven Rostedt wrote: > And before seeing Peter's use of yield(), I was reluctant to use it for > the very same reasons you mentioned above. In my test programs, I was > simply using getuid(), as that was one of the quickest syscalls. Is getuid() guaranteed to issue a syscall? It feels like the kind of information that a tricksy libc could cache. Traditionally, I think we've used getppid() as the canonical "very cheap syscall" as no layer can cache that information.