Re: RT patch acceptance

Esben Nielsen
2005-05-30T18:39:10Z

On Mon, 30 May 2005, Nick Piggin wrote:

> Esben Nielsen wrote:
>
> > I do like the idea of guest kernels - especially the ability to enforce a
> > strict seperation of RT and non-RT. But you can't use _any_ part of the
> > Linux kernel in your RT application - not even drivers. I know a lot of
>
> If you can't use the drivers, then presumably they're no good
> to be used as they are for realtime in Linux either, though :(
>
The driver is probably good enough but because you have to call into the
Linux kernel to use them. With a guest kernel setup you can forget about
realtime then. With PREEMPT_RT you get hard realtime behaviour out of the
box.

Ofcourse, there is a lot of buts to that. You have to check that the
driver doesn't take a call path which is nontermnistic in special cases
and the path between your application and the driver is deterministic.
A static code checker would be nice...

Esben