Re: [dpdk-dev] [RFC v2] eal: simplify the implementation of rte_ctrl_thread_create

[Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>]

<snip>
> >
> >>
> >> On 2021-08-24 23:30, Stephen Hemminger wrote:
> >>> On Tue, 24 Aug 2021 20:03:03 +0000
> >>> Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com> wrote:
> >>>
> >>>>> One difference between this implementation and the previous one is
> >>>>> this busy loop. rte_pause() relaxes the cpu, but will not make the
> >>>>> calling thread to sleep and wait for the sync event. So here we
> >>>>> can spin a quite long time until the other thread is scheduled by the OS.
> >>>> Yes, this is a difference. We could add a microsleep to allow for
> >>>> the OS to
> >> un-schedule the current thread.
> >>>
> >>> Why not use sched_yield() here?
> >>>
> >>
> >> The man page is not exactly encouraging the use sched_yield on CFS.
> > Sorry, what is CFS?
> > There are already several uses of sched_yield in the code.
> >
> 
> CFS is the Linux best-effort scheduler and default scheduling policy, and likely
> used by most DPDK applications.
Thanks, I read some of the issues. If sched_yield has to be used, the API needs to be implemented for Linux/Windows/FreeBSD. From my perspective, this API is called mostly during init time. I do not think it is worth duplicating the code and maintaining it. I would prefer to go with usleep.