On 2023-05-13 09:22:31, jeremy ardley via Dng wrote:
>
> On 13/5/23 09:00, onefang wrote:
> >
> > Linux has a RT kernel, I use it on my Devuan desktop for music
> > production. Did I bring this back on topic? B-)
> >
> >
> The linux kernel is pretty snappy but it's not possible get 'true'
> deterministic performance for a user space applcation.
>
> I use linux all the time for 'real time' applications such as audio
> streaming and processing. If you use a soft SIP phone so are you.
>
> The problem comes down to microsecond timed control of hardware such as
> setting an output bit at a precise time. Linux does not guarantee that so
> you have to rely on hardware or run some clunky real time OS such as RTOS.
>
> Luckily the vast majority of applications don't need that precision. I gave
> the example of ArduPilot that is a highly complex system interfacing to many
> sensors and data sources and sinks and relying in precise timing. It did not
> use RTOS (I think some later versions may). It just required intelligent
> coding and the use of hardware for the precision operations.
>
> If you stick with linux you have pthreads for any conceivably complex
> application architecture - though any application that needs more than two
> threads per core is almost certainly badly designed.
>
> I also think RTOS and equivalents are highly obsolete these days and seem
> mainly used by legacy developers keen to keep themselves in a niche job.

It always boils down to "how hard RT do you actually need?".

--
A big old stinking pile of genius that no one wants
coz there are too many silver coated monkeys in the world.