I agree with your assessment Tim, it is definitely misleading and should be improved!
On Wed, Nov 26, 2025 at 1:17 PM Tim Hardisty <[email protected]> wrote: > OK - but see here: > https://nuttx.apache.org/docs/latest/reference/user/02_task_scheduling.html > > Hardly a "default" if you have to read the help of Kconfig to see what's > going on? > > I know the documentation is, um, lacking...so if it can be improved here > let's do it! > > > On 26/11/2025 18:12, Alan C. Assis wrote: > > 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! >> > >> >> > >> >
