Momtchil Momtchev momtchil.momtchev at netasq.com
Wed Aug 10 11:41:01 GMT 2005

On Wednesday 10 August 2005 10:40, Bsderss wrote:
> Hi,
> I found this real-time OS based on BSD:
> http://www.sdcsystems.com/realtime-linux.htm#rtcorebsd
> I m wondering what technology they used to make
> FreeBSD as a real-time OS. I thought kqueue/kevent is
> a key component? any comment?

 No, kqueue/kevent is not realtime, as the whole FreeBSD kernel doesn't 
support hard real-time scheduling.
 In order to have hard real-time scheduling you should have a fully preemtible 
kernel, which schedules and preempts everything (even interrupt handlers).
 The RTCoreBSD uses a two-kernel approach with a real-time microkernel which 
runs the FreeBSD kernel as a process, providing a virtual interrupt 
 The real-time processes run directly on the microkernel and can't directly 
use the FreeBSD kernel services.

Momtchil Momtchev <momtchil.momtchev at netasq.com>
R&D Engineer

Netasq - Secure Internet Connectivity
Tel : +33 320 619 742
Fax : +33 320 619 639

More information about the freebsd-current mailing list