[Xenomai-help] system() call allowed from within RT task ?

[Xenomai-help] system() call allowed from within RT task ?

[Jochen Behnke]

Hello,

within my application I use system() calls from within a xenomai task.
Is this allowed ?

The reason I'm asking this, is the following:
In my application I have multiple xenomai tasks. One of them is time critical (Task_A).
An other (non time critical) xenomai task (Task_B) is used to pass data back
and forth between Task_A and normal linux tasks. Task_B uses the system()-call
to accomplish certain requests.
I have set the T_WARNSW for Task_A in order to get a SIGXCPU, whenever it switches
to secondary mode. As long as Task_B is not executing a sytem() call, everything is fine.
But when for example Task_B executes a system("cp -R dirA dirB") the application terminates
due to a SIGXCPU signal.

I'm using 
- Linux Kernel 2.6.17 (I-PIPE 1.5-02)
- Xenomai 2.3.0
- Celeron 600MHz System


Regards

Jochen
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Re: [Xenomai-help] system() call allowed from within RT task ?

[Gilles Chanteperdrix]

Jochen Behnke wrote:
 > Hello,
 > 
 > within my application I use system() calls from within a xenomai task.
 > Is this allowed ?
 > 
 > The reason I'm asking this, is the following:
 > In my application I have multiple xenomai tasks. One of them is time critical (Task_A).
 > An other (non time critical) xenomai task (Task_B) is used to pass data back
 > and forth between Task_A and normal linux tasks. Task_B uses the system()-call
 > to accomplish certain requests.
 > I have set the T_WARNSW for Task_A in order to get a SIGXCPU, whenever it switches
 > to secondary mode. As long as Task_B is not executing a sytem() call, everything is fine.
 > But when for example Task_B executes a system("cp -R dirA dirB") the application terminates
 > due to a SIGXCPU signal.
 > 
 > I'm using 
 > - Linux Kernel 2.6.17 (I-PIPE 1.5-02)

I-pipe 1.5-02 is too old. only more recent I-pipe patches have the
necessary support to allow real-time applications to call fork (or
system).


-- 


					    Gilles.

Re: [Xenomai-help] system() call allowed from within RT task ?

[Jochen Behnke]

> -----Ursprüngliche Nachricht-----
> Von: "Gilles Chanteperdrix" <gilles.chanteperdrix@xenomai.org>
> Gesendet: 15.04.08 19:02:58
> An: Jochen Behnke <JK.Behnke@domain.hid>
> CC: xenomai@xenomai.org
> Betreff: Re: [Xenomai-help] system() call allowed from within RT task ?

Hello Gilles,

thanks four your quick response. 
Which I-pipe/Xenomai version would you recommend ?
(probably the latest )

Regards
Jochen

> 
> Jochen Behnke wrote:
>  > Hello,
>  > 
>  > within my application I use system() calls from within a xenomai task.
>  > Is this allowed ?
>  > 
>  > The reason I'm asking this, is the following:
>  > In my application I have multiple xenomai tasks. One of them is time critical (Task_A).
>  > An other (non time critical) xenomai task (Task_B) is used to pass data back
>  > and forth between Task_A and normal linux tasks. Task_B uses the system()-call
>  > to accomplish certain requests.
>  > I have set the T_WARNSW for Task_A in order to get a SIGXCPU, whenever it switches
>  > to secondary mode. As long as Task_B is not executing a sytem() call, everything is fine.
>  > But when for example Task_B executes a system("cp -R dirA dirB") the application terminates
>  > due to a SIGXCPU signal.
>  > 
>  > I'm using 
>  > - Linux Kernel 2.6.17 (I-PIPE 1.5-02)
> 
> I-pipe 1.5-02 is too old. only more recent I-pipe patches have the
> necessary support to allow real-time applications to call fork (or
> system).
> 
> 
> -- 
> 
> 
> 					    Gilles.
> 


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