Re: Wayland or X11, was: Re: Upcoming time boundary events

On 2025-06-18, Lawrence D'Oliveiro <ldo@nz.invalid> wrote:

On Thu, 19 Jun 2025 01:28:55 +0100, chrisq wrote:
>

Yes, thanks, know about devuan and others. Installed and looked at
it, but still remnants of systemd that can't be removed, even if we
are told it doesn't do anything. That's a compromise, not software
engineering.

>
Obviously you need to show us how it?s done, then.
>

Working in embedded real time, I like tight, efficient and lightweight
design, which modern Linux doesn't understand at all.

>
Oh yes it does. Look at what is being done with a Raspberry Pi, for
example.
>
Linux fits into a phone. What have you done that can compete with Android?

There is a massive difference between soft realtime and hard realtime.

How well does Linux meet the hard realtime requirements, even with the
recent realtime patches which have been added to it ?

For example, how well does Linux run code to toggle a GPIO line at
1000/1024 Hz, and what kind of jitter will you see with Linux compared
to dedicated hardware and software ?

What kind of hard realtime GPIO sampling rates can programs reliably
achieve under Linux and how much jitter will you see when sampling ?

Simon.

--
Simon Clubley, clubley@remove_me.eisner.decus.org-Earth.UFP
Walking destinations on a map are further away than they appear.