Re: posix 4 extensions

Stephen C. Tweedie (
Tue, 30 Jul 1996 11:58:18 +0100


On 27 Jul 96 01:52:07 EDT, Mike Robinson <>

> I heard rumours some time ago that linux was going to include the
> posix 4 real time extensions in the next production release. I've
> had a quick look, and I've found some references in the 2.0.x code
> to real time scheduling policies, but the functions specified in the
> o'reilly posix 4 book don't seem to exist.

> Has linux implemented any of the posix 4 stuff, and particularly the
> real time scheduling stuff? If not, is any other real time support
> provided?

The posix.4 real time scheduling classes are supported in 2.0. Most
of the other posix.4 stuff requires real time signals, and doing that
would require too much change in the kernel to make so close to 2.0.
Hopefully you'll see it in 2.1. There was a BOF session at the Berlin
LinuxKongress where real time linux was discussed, btw.


Stephen Tweedie <>
Department of Computer Science, Edinburgh University, Scotland.