[Xenomai-help] SMP issues

[Xenomai-help] SMP issues

[Cédric Schaffter]

Hi List!

I'm trying to compare Xenomai performances with and without SMP on my 
Intel Core 2 duo.
So I built the linux kernel 2.6.25.11 (as described here : 
http://xenomai.org/index.php/Xenomai_quick_build_quide),
and I disabled the SMP support.

When I used dmesg and as I wanted, only one processor was activated... I 
performed some tests, increasing tasks
number and also their complexity...

And then, I rebuilt the kernel and specified SMP support and the dmesg 
command informed me that I have two
processors working. I launched the same applications that I used to test 
one core.

But the problem is that I get same results in both case... I thought 
tasks were automatically dispatched between
cores or cpu. Did I forget something?

Best regards,
Cédric

Re: [Xenomai-help] SMP issues

[Gilles Chanteperdrix]

Cédric Schaffter wrote:
> But the problem is that I get same results in both case... I thought 
> tasks were automatically dispatched between
> cores or cpu. Did I forget something?

Linux does that. With xenomai, tasks never migrate, choosing what task
runs on what processor is part of the design of your application.
Migrations kill determinism.

-- 
                                                 Gilles.

Re: [Xenomai-help] SMP issues

[Cédric Schaffter]

Cédric Schaffter a écrit :
> Gilles Chanteperdrix a écrit :
>> Cédric Schaffter wrote:
>>  
>>> But the problem is that I get same results in both case... I thought 
>>> tasks were automatically dispatched between
>>> cores or cpu. Did I forget something?
>>>     
>>
>> Linux does that. With xenomai, tasks never migrate, choosing what task
>> runs on what processor is part of the design of your application.
>> Migrations kill determinism.
>>
>>   
> So I have to specify which task runs on which core, using the flag 
> T_CPU(x) during the task creation?
>

[Xenomai-help] Window Resize issue

[stefano.franzoni]

Dear experts

we have 2 systems with Ubuntu Linux 2.6.25.11 and Xenomai 2.4.4.

One has an Intel(R) Pentium(R) M processor 1.73GHz and the other one has
Pentium III (Coppermine) 1GHz.
The Xenomai installation seems to be ok and also native application tests
give right results.

The issue, on both the systems, is that if I run, for example,
trivial-periodic sample in a windows and I resize the window the rt task
aborts and the application exits.

Any suggestion?
Thanks in advance

Stefano

Re: [Xenomai-help] Window Resize issue

[Gilles Chanteperdrix]

stefano.franzoni@domain.hid wrote:
> Dear experts
> 
> we have 2 systems with Ubuntu Linux 2.6.25.11 and Xenomai 2.4.4.
> 
> One has an Intel(R) Pentium(R) M processor 1.73GHz and the other one has
> Pentium III (Coppermine) 1GHz.
> The Xenomai installation seems to be ok and also native application tests
> give right results.
> 
> The issue, on both the systems, is that if I run, for example,
> trivial-periodic sample in a windows and I resize the window the rt task
> aborts and the application exits.
> 
> Any suggestion?

When resizing a terminal, the SIGWINCH signal is sent to the running
application. Unfortunately, SIGWINCH is also used internally by Xenomai.
A simple workaround is to recompile Xenomai to use another signal by
replacing the define in asm-generic/syscall.h. However, your choices are
limited if you want a signal that does not interfere with gdb.

-- 
					    Gilles.