Need help in figuring out how a node gets its afffinity when it is created

[Richi Dubey]

>
> telling me earlier that by default a node/task/thread is allowed to
> execute on all the processors?

The thread's affinity is set to all processor when it gets initialized :
https://git.rtems.org/rtems/tree/cpukit/score/src/threadinitialize.c#n217

On Fri, Aug 14, 2020 at 5:58 PM Richi Dubey <richidubey at gmail.com> wrote:

> Hi,
>
> Follow up of my progress to this question:
>
> I 'stepped inside' the important functions to make the observation that
> the flow of code is actually:
>
> -------------------------------------
>
> _Scheduler_strong_APA_Node_initialize
>
> _Scheduler_Node_initialize
>
> _Thread_Initialize
>
> rtems_task_create
>
> _RTEMS_tasks_Initialize_user_task
>
> rtems_initialize_executive
>
> boot_card
>
> bsp_start_hook_0_done
>
> -------------------------------------
> (So, the thread corresponding to the Init task gets created and assigned a
> scheduler node which is then initialized and the Init task is started by
> calling rtems_task_start on it)
>
>
> So, is it okay if I set the Affinity (defined here
> <https://github.com/richidubey/rtems/blob/03650c47c537c1acd584c5a9c3db588ab49634ef/cpukit/include/rtems/score/schedulerstrongapa.h#L75>)
> of a node to all processors when it gets initialized (here
> <https://github.com/richidubey/rtems/blob/03650c47c537c1acd584c5a9c3db588ab49634ef/cpukit/score/src/schedulerstrongapa.c#L739>
> ) because I remember Mr. Huber telling me earlier that by default a
> node/task/thread is allowed to execute on all the processors?
>
>
>
>
> On Fri, Aug 14, 2020 at 3:26 PM Richi Dubey <richidubey at gmail.com> wrote:
>
>> Hi,
>>
>> My code is failing because its logic assumed (code here
>> <https://github.com/richidubey/rtems/blob/03650c47c537c1acd584c5a9c3db588ab49634ef/cpukit/score/src/schedulerstrongapa.c#L315>)
>> that it would never get a node with an empty affinity (i.e. no affinity to
>> any processor or a 0 affinity). This assumption proved wrong as I can see
>> from the gdb and the current flow of code observed is:
>>
>> ------------------------------------------------
>> _Scheduler_strong_APA_Get_lowest_scheduled
>>
>> _Scheduler_SMP_Enqueue
>>
>> _Scheduler_strong_APA_Enqueue
>>
>> _Scheduler_SMP_Unblock
>>
>> _Scheduler_strong_APA_Unblock
>>
>> _Scheduler_Unblock
>>
>> _Thread_Clear_state_locked
>>
>> _Thread_Start
>>
>> rtems_task_start
>>
>> _RTEMS_tasks_Initialize_user_task
>>
>> rtems_initialize_executive
>>
>> boot_card
>>
>> bsp_start_hook_0_done
>> ----------------------------------------------------
>>
>> Why is this happening? The Affinity variable (defined here
>> <https://github.com/richidubey/rtems/blob/03650c47c537c1acd584c5a9c3db588ab49634ef/cpukit/include/rtems/score/schedulerstrongapa.h#L75>)
>> gets set whenever the Set affinity operation corresponding to Strong_APA
>> scheduler (defined here
>> <https://github.com/richidubey/rtems/blob/03650c47c537c1acd584c5a9c3db588ab49634ef/cpukit/score/src/schedulerstrongapa.c#L770>)
>> gets called. So, why wasn't this function called before this happened? Any
>> help would be appreciated.
>>
>> Thanks,
>> Richi.
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.rtems.org/pipermail/devel/attachments/20200814/d452281d/attachment-0001.html>