A Dijous, 20 de febrer de 2014, Gilles Chanteperdrix va escriure: > On 02/20/2014 01:23 PM, Leopold Palomo-Avellaneda wrote: > > A Dijous, 20 de febrer de 2014, Gilles Chanteperdrix va escriure: > >> On 02/20/2014 11:09 AM, Leopold Palomo-Avellaneda wrote: > >>> A Dijous, 20 de febrer de 2014, Gilles Chanteperdrix va escriure: > >>>> On 02/20/2014 12:41 AM, Leopold Palomo-Avellaneda wrote: > >>>>> Well, > >>>>> > >>>>> please, correct me if I'm wrong in some of this sentences. I > >>>>> will try to rewrite my email in a more clear terminology. > >>>>> > >>>>> Following [1] I understand that a realtime task is scheduled by > >>>>> the > >>> Xenomai > >>>>> scheduler and a non-realtime by the Linux scheduler. I can use > >>>>> the terms "thread" and "task" in the same meaning. > >>>> > >>>> Again: the terms "real-time" and "non real-time" are ambiguous. > >>>> Please stick to the terms "task with a shadow", "task without a > >>>> shadow" and "primary mode" or "secondary mode". > >>>> > >>> :-( > >>> > >>> Ok, > >>> > >>> I agree with you that the nomenclature is important to define > >>> correctly but please don't be so strict. > >> > >> I'm in the open source world since long time ago, > >>> and I understand perfectly that the main developers of a projects > >>> are tired of dummy questions, or not clear mails, etc. But, I think > >>> that the relatime world is a complex thing, and not so easy when > >>> you are learning, or having troubles. > >>> > >>> And although that there's a lot documentation, it's difficult to > >>> find the document that fits all your doubts. > >>> > >>> So, again, please, correct me if I'm wrong in some of this > >>> sentences. I will try to rewrite my email in a more clear > >>> terminology. > >>> > >>> Following [1] and [2] I understand that a realtime thread is > >>> executed in primary mode and scheduled by the Xenomai scheduler. > >> > >> Listen, there are three cases: > >> 1- thread with a shadow running in primary mode > >> 2- thread with a shadow running in secondary mode > >> 3- thread without a shadow > >> > >> and you want to use two words "real-time thread" and "non real-time > >> thread". 1 is obviously a real-time thread, 3 is obviously a > >> non-real-time thread. What do you make of 2? If you consider "being > >> real-time" a "static" property, then 2 is a real-time thread. If you > >> consider it a run-time property, a state of a task, then 2 is a > >> non-real-time thread. > > > > For me real-time is a dynamic property. So, when a thread with a shadow is > > executed in primary mode I call it real-time. When the same thread is executed > > in secondary mode, it loses the real-time property. > > > > I find it more natural to think of real-time threads as the ones with a > shadow (and a priority higher than 0). Sure, they can be in secondary > mode temporarily, but they can still access the "primary mode only" > services, it will simply cause them to switch to primary mode. > > > > >>> If this RT thread call a non-RT primitive, then RT-Nucleus move > >>> this RT-Thread to the Linux queue and this thread is controlled by > >>> the Linux scheduler. A Non-RT thread is executed in secondary mode > >>> and controlled by the Linux scheduler. > >> > >> If 2 is with 3 (which would make your first assertion right), here you > >> are wrong. Only a thread with a shadow can run in secondary mode, > >> there is no primary or secondary mode for threads without a shadow. > > > > This is something that I don't understand yet. Then, what's the difference > > (practical) between a thread with a shadow running in secondary mode and a > > thread without a shadow. > > A thread without a shadow.... does not have a shadow, some, if not most > Xenomai services are reserved to threads with a shadow, so, the > difference is that it will get -EPERM when calling these services, which > would have worked if it had had a shadow. >
I'm sorry if I insist, but I still have a doubt: I have always understood that all Linux tasks were executed in secondary mode, and reading you I understand that this is not true. So, "where" is Linux running its tasks? Secondary mode? No mode, it's another domain, you cannot map this domain as mode? Leopold -- -- Linux User 152692 Catalonia -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 198 bytes Desc: This is a digitally signed message part. URL: <http://www.xenomai.org/pipermail/xenomai/attachments/20140220/f6ee66b0/attachment.sig> _______________________________________________ Xenomai mailing list [email protected] http://www.xenomai.org/mailman/listinfo/xenomai
