Re: [Xenomai-help] [RTnet-users] /proc/xenomai/affinity and T_CPU(n) in

Re: [Xenomai-help] [RTnet-users] /proc/xenomai/affinity and T_CPU(n) in

[M. Koehrer]

	rt_task_create
Cc: xenomai@xenomai.org, rtnet-users@domain.hid
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Hi Jan,

does this mean that the value of /proc/xenomai/affinity is only relevant fo=
r creation of a new task?
I.e., once it is created I can modify it without "destroying" anything in t=
he already created tasks?=20
If this is the case I think I get everything up and running following your =
hint.

Perhaps the word "affinity" does not exactly describe the behaviour here as=
 it is not only affinity but also=20
"allowed CPUs for new tasks"....

Thanks a lot.

Regards

Mathias



>=20
> Suggested procedure:
> 1. set global affinity for RTnet and start up the stack
> 2. set global affinity for your application (or open it) and start that
>    one up
>=20


--=20
Mathias Koehrer
mathias_koehrer@domain.hid


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Re: [Xenomai-help] [RTnet-users] /proc/xenomai/affinity and T_CPU(n) in

[Jan Kiszka]

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M. Koehrer wrote:
> Hi Jan,
> 
> does this mean that the value of /proc/xenomai/affinity is only relevant fo=
> r creation of a new task?
> I.e., once it is created I can modify it without "destroying" anything in t=
> he already created tasks?=20
> If this is the case I think I get everything up and running following your =
> hint.

If your worries are that modifying /proc/xenomai/affinity would force
running tasks to new CPUs: no, there is no such side effect. The
affinity mask only "burns" the CPU affinity into the task structure when
they are created. Later states of that mask do not impact existing tasks.

> 
> Perhaps the word "affinity" does not exactly describe the behaviour here as=
>  it is not only affinity but also=20
> "allowed CPUs for new tasks"....

Feel free to define the precise semantic of this feature e.g. in the
wiki :). In the end, expectations and associations always change the
meaning of terms in the eye of the user.

Jan


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