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* [Xenomai] creating a user space task by RTDM library
@ 2014-06-10 13:32 ali hagigat
  2014-06-10 19:49 ` Gilles Chanteperdrix
  0 siblings, 1 reply; 6+ messages in thread
From: ali hagigat @ 2014-06-10 13:32 UTC (permalink / raw)
  To: xenomai

Regarding xenomai 2.6.3, how rtdm_task_init() can be used in user
space? and the types like rtdm_task_t. Compiling with rtdm/rtdm.h or
rtdm/rtdm_driver.h produces errors.


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [Xenomai] creating a user space task by RTDM library
  2014-06-10 13:32 [Xenomai] creating a user space task by RTDM library ali hagigat
@ 2014-06-10 19:49 ` Gilles Chanteperdrix
  2014-06-11  8:25   ` ali hagigat
  0 siblings, 1 reply; 6+ messages in thread
From: Gilles Chanteperdrix @ 2014-06-10 19:49 UTC (permalink / raw)
  To: ali hagigat, xenomai

On 06/10/2014 03:32 PM, ali hagigat wrote:
> Regarding xenomai 2.6.3, how rtdm_task_init() can be used in user
> space? and the types like rtdm_task_t. Compiling with rtdm/rtdm.h or
> rtdm/rtdm_driver.h produces errors.

RTDM is a kernel-space only skin.


-- 
                                                                Gilles.


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [Xenomai] creating a user space task by RTDM library
  2014-06-10 19:49 ` Gilles Chanteperdrix
@ 2014-06-11  8:25   ` ali hagigat
  2014-06-11 18:18     ` Gilles Chanteperdrix
  0 siblings, 1 reply; 6+ messages in thread
From: ali hagigat @ 2014-06-11  8:25 UTC (permalink / raw)
  To: Gilles Chanteperdrix; +Cc: xenomai

On 6/11/14, Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org> wrote:
> On 06/10/2014 03:32 PM, ali hagigat wrote:
>> Regarding xenomai 2.6.3, how rtdm_task_init() can be used in user
>> space? and the types like rtdm_task_t. Compiling with rtdm/rtdm.h or
>> rtdm/rtdm_driver.h produces errors.
>
> RTDM is a kernel-space only skin.
>
>
> --
>                                                                 Gilles.
>

The RTDM documentation and the code comments report that
rtdm_task_init() can be used in user space.


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [Xenomai] creating a user space task by RTDM library
  2014-06-11  8:25   ` ali hagigat
@ 2014-06-11 18:18     ` Gilles Chanteperdrix
  2014-06-15 13:42       ` ali hagigat
  0 siblings, 1 reply; 6+ messages in thread
From: Gilles Chanteperdrix @ 2014-06-11 18:18 UTC (permalink / raw)
  To: ali hagigat; +Cc: xenomai

On 06/11/2014 10:25 AM, ali hagigat wrote:
> On 6/11/14, Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org> wrote:
>> On 06/10/2014 03:32 PM, ali hagigat wrote:
>>> Regarding xenomai 2.6.3, how rtdm_task_init() can be used in user
>>> space? and the types like rtdm_task_t. Compiling with rtdm/rtdm.h or
>>> rtdm/rtdm_driver.h produces errors.
>>
>> RTDM is a kernel-space only skin.
>>
>>
>> --
>>                                                                 Gilles.
>>
> 
> The RTDM documentation and the code comments report that
> rtdm_task_init() can be used in user space.
> 
The documentation says that a "User space task" is a valid context to
call rtdm_task_init, but this means that a user-space task, currently
executing kernel code, is a valid context, not that the function may be
called from user-space. Really, RTDM is an API for writing drivers
residing in kernel-space, it makes no sense to use it in user-space.

-- 
                                                                Gilles.


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [Xenomai] creating a user space task by RTDM library
  2014-06-11 18:18     ` Gilles Chanteperdrix
@ 2014-06-15 13:42       ` ali hagigat
  2014-06-15 13:44         ` Gilles Chanteperdrix
  0 siblings, 1 reply; 6+ messages in thread
From: ali hagigat @ 2014-06-15 13:42 UTC (permalink / raw)
  To: Gilles Chanteperdrix; +Cc: xenomai

On 6/11/14, Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org> wrote:
> On 06/11/2014 10:25 AM, ali hagigat wrote:
>> On 6/11/14, Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
>> wrote:
>>> On 06/10/2014 03:32 PM, ali hagigat wrote:
>>>> Regarding xenomai 2.6.3, how rtdm_task_init() can be used in user
>>>> space? and the types like rtdm_task_t. Compiling with rtdm/rtdm.h or
>>>> rtdm/rtdm_driver.h produces errors.
>>>
>>> RTDM is a kernel-space only skin.
>>>
>>>
>>> --
>>>                                                                 Gilles.
>>>
>>
>> The RTDM documentation and the code comments report that
>> rtdm_task_init() can be used in user space.
>>
> The documentation says that a "User space task" is a valid context to
> call rtdm_task_init, but this means that a user-space task, currently
> executing kernel code, is a valid context, not that the function may be
> called from user-space. Really, RTDM is an API for writing drivers
> residing in kernel-space, it makes no sense to use it in user-space.
>
> --
>                                                                 Gilles.
>

How a user-space task can execute kernel code? I wonder if you could
write a short example. Thank you. (besides when a kernel code executes
the context is not user any more, the context is kernel)


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [Xenomai] creating a user space task by RTDM library
  2014-06-15 13:42       ` ali hagigat
@ 2014-06-15 13:44         ` Gilles Chanteperdrix
  0 siblings, 0 replies; 6+ messages in thread
From: Gilles Chanteperdrix @ 2014-06-15 13:44 UTC (permalink / raw)
  To: ali hagigat; +Cc: xenomai

On 06/15/2014 03:42 PM, ali hagigat wrote:
> On 6/11/14, Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org> wrote:
>> On 06/11/2014 10:25 AM, ali hagigat wrote:
>>> On 6/11/14, Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
>>> wrote:
>>>> On 06/10/2014 03:32 PM, ali hagigat wrote:
>>>>> Regarding xenomai 2.6.3, how rtdm_task_init() can be used in user
>>>>> space? and the types like rtdm_task_t. Compiling with rtdm/rtdm.h or
>>>>> rtdm/rtdm_driver.h produces errors.
>>>>
>>>> RTDM is a kernel-space only skin.
>>>>
>>>>
>>>> --
>>>>                                                                 Gilles.
>>>>
>>>
>>> The RTDM documentation and the code comments report that
>>> rtdm_task_init() can be used in user space.
>>>
>> The documentation says that a "User space task" is a valid context to
>> call rtdm_task_init, but this means that a user-space task, currently
>> executing kernel code, is a valid context, not that the function may be
>> called from user-space. Really, RTDM is an API for writing drivers
>> residing in kernel-space, it makes no sense to use it in user-space.
>>
>> --
>>                                                                 Gilles.
>>
> 
> How a user-space task can execute kernel code? I wonder if you could
> write a short example. Thank you. (besides when a kernel code executes
> the context is not user any more, the context is kernel)
> 

Every time a user-space task executes a syscall, some kernel-code is
executed on behalf of the user task. From Xenomai point of view, this
makes a difference whether the task is a kernel-space task or a
user-space task. For instance:
- current is valid
- xnshadow_thread(current) is non NULL.

This is the last answer I give to this stupid thread.

-- 
                                                                Gilles.


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2014-06-15 13:44 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-06-10 13:32 [Xenomai] creating a user space task by RTDM library ali hagigat
2014-06-10 19:49 ` Gilles Chanteperdrix
2014-06-11  8:25   ` ali hagigat
2014-06-11 18:18     ` Gilles Chanteperdrix
2014-06-15 13:42       ` ali hagigat
2014-06-15 13:44         ` Gilles Chanteperdrix

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