On Wed, Mar 24, 2021 at 2:53 PM Gregory Nutt <spudan...@gmail.com> wrote: > > > > The way the logic in clock_nanosleep() is written, the minimum delay > > ends up being 2 such ticks. I don't remember why and I can't seem to > > find it in the code right now, but I know this because I checked into > > it recently and found out that that's how it works. > > See https://cwiki.apache.org/confluence/display/NUTTX/Short+Time+Delays > > This is a translation. It does not effect the accuracy, it effects the > mean delay. The accuracy is still 10 MS. The quantization error will > lie in the range of 0 to +10 MS. If you did not add one tick, the error > would be in the range of -1 to 0 MS which is unacceptable.
Thanks > > It does not make sense to change the tick interval to a higher > > resolution (shorter time) because then the OS will spend a > > significantly increasing amount of time in useless interrupts etc. > > Unless you use Tickless mode then it is easy to get very high resolution > (1 uS range) with no CPU overhead. Is the Tickless mode considered stable enough for production use now? IIRC it had some caveats when I last looked into it and I haven't had a chance to study it again. Nathan
