On Sat, Aug 12, 2023 at 02:40:31PM +0200, Martin Pieuchot wrote: > So do we want to keep the existing requirement of being able to execute > a thread on a CPU that has been removed from the scheduler? That's is > what smr_flush() currently needs. I find it surprising but I can add > that as a requirement for the upcoming scheduler. I don't know if other > options are possible or even attractive.
I think it is useful that the kernel can force a thread to run on a specific CPU even when general scheduling has been stopped. It is maybe a bit crude, but nonetheless effective and machine independent, way of synchronization. The kernel has a few current uses of sched_peg_curproc(). Perhaps the most prominent ones are interrupt barriers and the SMR grace wait mechanism.
