There is not a checkbox to ROUND ROBIN in the menuconfig: [image: image.png]
Only for Sporadic scheduling. The the <Help> for the RR timeslice explains it: │ The round robin timeslice will be set this number of milliseconds; │ │ Round robin scheduling (SCHED_RR) is enabled by setting this │ │ interval to a positive, non-zero value. On Wed, Nov 26, 2025 at 3:07 PM Matteo Golin <[email protected]> wrote: > I suppose I would agree, that does seem misleading if the default is RR. > Does the RR scheduling on NuttX have priority-based preemption/priority > inversion avoidance mechanisms? Maybe that could be the reasoning for > the wording. > > On Wed, Nov 26, 2025 at 1:00 PM Tim Hardisty <[email protected]> > wrote: > > > That's what I inferred (yet to try it) - so is the documentation > > misleading since the default CONFIG_RR_INTERVAL=200 forces RR scheduling > > rather than the stated "strict priority scheduling"? > > > > On 26/11/2025 17:54, Alan C. Assis wrote: > > > CONFIG_RR_INTERVAL=0 > > > > > > On Wed, Nov 26, 2025 at 2:22 PM Tim Hardisty <[email protected]> > > > wrote: > > > > > >> Apologies if this isn't really a NuttX question... > > >> > > >> Documentation says "By default, NuttX performs strict priority > > scheduling". > > >> > > >> Default CONFIG_RR_INTERVAL is 200ms. > > >> > > >> I have multiple threads, but have not set any scheduling parameters, > but > > >> it seems threads are being scheduled every 200ms rather on a priority > > >> basis. > > >> > > >> What *should* I be doing, please, to get all my threads scheduled by > > >> priority? > > >> > > >> Thanks, > > >> > > >> TimH > > >> > > >> PS - yes I have thrown myself in the deep end without a life jacket > with > > >> my project. And I'm no doubt up ****-creek without a paddle. But I am > > >> always learning! > > >> > > >
