What kernel do you use? And what scheduling configuration? As it is a timing application, and sensible to jitter, I would suggest to use a real-time kernel (e.g. Preempt RT) [1].
Usually one can find pre-built kernels with PreempRT-support for boards like the RPi etc. on the internet. If you use a real-time kernel, and have it configured that your application of choice (in this case ntp) has real-time priority, the 16% cpu usage won't be a problem any more. Other workloads like IRQs or task scheduling may have much worse effects on application jitter (even on real-time systems). Interestingly, more CPU usage can even be better for jitter-sensitive applications: low cpu usage might enable power-saving functions, which in turn might lead to longer reaction times once an application needs to be handled. regards, Wolfgang [1] https://www.osadl.org/Realtime-Linux.projects-realtime-linux.0.html On 03/22/2015 08:46 AM, David J Taylor wrote: > David: > On the BBB, were you running the fully loaded release, or the minimum > "console" version of the OS? > Which specific version of the OS? > > Thanks, > --- Graham > ================================= > > Graham, > > The download was: > > bone-debian-7.8-lxde-4gb-armhf-2015-03-01-4gb.img.xz (547,024,548 bytes) > > which was from the "Recommended Debian Images" from: > http://beagleboard.org/latest-images. Perhaps there are some services > or background tasks I can disable to reduce the CPU steady load from its > present 16% average level? > > 73, > David GM8ARV _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.