Dynamic scheduling

[Manuel Coutinho]

RTEMS has fixed-priority scheduling. RTEMS does not support dynamic
scheduling.

Actually, the rate monotonic that is referred only makes tasks to be
periodic. It does not implement the Rate Monotonic Scheduler. The
application must correctly assign the tasks priorities in order for the Rate
Monotonic Scheduler to work.

Note that is good that RTEMS does this because other scheduler variants can
be easily implemented (e.g Deadline Monotonic). Also, there are system
models, for example, non-preemptive or in which the task releases are well
defined, in which the Rate Monotonic Scheduler is NOT the optimal scheduler.

Hope this helps
Regards
Manuel Coutinho

> -----Original Message-----
> From: rtems-users-bounces at rtems.org [mailto:rtems-users-bounces at rtems.org]
> On Behalf Of Nasim Zehra
> Sent: Friday, July 17, 2009 7:58 AM
> To: Thomas Doerfler
> Cc: rtems-users at rtems.org
> Subject: RE: Dynamic scheduling
> 
>  like EDF, Minimum Laxity first.Actually i m having observation that rtems
> has only rate monotonic .static scheduling scheme, manager.May be it does
> not support dynamic one?I guess timer or clock directives are helpful in
> this regard, but i am having problem using timer directive..that what
> should be written in place of *user_data when timer is fired.Moreover
> whether should we create timer directive in main "init" function or should
> we create and delete then like rate monotonic periods inside the task
> ,mentioned in the example of rate monotonic manager.
> 
> nasim
> ________________________________________
> From: Thomas Doerfler [Thomas.Doerfler at embedded-brains.de]
> Sent: Friday, July 17, 2009 12:49 PM
> To: Nasim Zehra
> Cc: rtems-users at rtems.org
> Subject: Re: Dynamic scheduling
> 
> Hi,
> 
> what exactly do you call "dynamic scheduling"? The term seems a bit
> "open" to me, but maybe I am simpy ignorant :-)
> 
> wkr,
> Thomas.
> 
> Nasim Zehra wrote:
> > Does rtems support dynamic scheduling??if yes what managers are useful
> for this purpose?
> >
> > nasim
> > _______________________________________________
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> > rtems-users at rtems.org
> > http://www.rtems.org/mailman/listinfo/rtems-users
> 
> 
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