LinuxSA Mailing list archives

  From: David Newall <davidn@rebel.net.au>
  To  : Daryl Tester <Daryl.Tester@steadycom.com.au>
  Date: Wed, 31 Mar 1999 15:48:33 +0930 (CST)

Re: Linux in real time (was More Meeting Information)

On Wed, 31 Mar 1999, Daryl Tester wrote:
> Linux (and possibly BSD) has real time extensions that enable
> you to adjust the scheduling policy of a process.  man 2
> sched_setscheduler for a plethora of information ...

It's not really real time.  It's really a higher-priority scheduling
class: "real time" processes are run before other classes of process;
so if a "real time" process wants to be a hog, nothing else runs.
This is something I first saw in Unix SVR4 (it has three classes:
Unix, Real Time and Kernel.)  The important consideration is that
these processes are not real-time, for example there is no guarantee
that a process will run within a specified time frame, which is the
fundamental guarantee provided by a real real time operating system.

-- 
Check out the LinuxSA web pages at http://www.linuxsa.org.au/
To unsubscribe from the LinuxSA list:
  mail linuxsa-request@linuxsa.org.au with "unsubscribe" as the subject