[Xenomai-help] process on linux

[Xenomai-help] process on linux

[davide doninelli]

Hi 
i see in linux proces 3 xenomai processes per xenomai RT task .
I don't understand what are the first 2 process.
Is that right? What are used for? Tasks are like in envelope?
i don't find information about that.

#ps
....
 483 root     ./interrupt_xeno_userspacen 
  484 root     ./interrupt_xeno_userspacen 
  485 root     ./interrupt_xeno_userspacen 

# cat /proc/xenomai/stat 
CPU  PID    MSW        CSW        PF    STAT       %CPU  NAME
  0  0      0          71         0     00500080  100.0  ROOT
  0  485    0          47         0     00320184    0.0  mytask
  0  0      0          1984       0     00000000    0.0  IRQ26: [timer]




tanks in advance
Davide Doninelli

Re: [Xenomai-help] process on linux

[Gilles Chanteperdrix]

davide doninelli wrote:
> Hi 
> i see in linux proces 3 xenomai processes per xenomai RT task .
> I don't understand what are the first 2 process.
> Is that right? What are used for? Tasks are like in envelope?
> i don't find information about that.
> 
> #ps
> ....
>  483 root     ./interrupt_xeno_userspacen 
>   484 root     ./interrupt_xeno_userspacen 
>   485 root     ./interrupt_xeno_userspacen 

With the quantity of information you give us, we can only guess, but you
probably use a linuxthreads based libc, so:
- each thread appears as an entry in ps output
- there is a "manager" thread called when creating the first thread.

So, 483 is probably the main thread, 484 the manager thread, 485 is the
"mytask" thread.

Still guessing, I think you are confusing 2 + N with 3 * N, because you
only tested with N == 1.

-- 
					    Gilles.

Re: [Xenomai-help] process on linux

[davide doninelli]

ok, two more questions...
What's main thread and manager thread roles?
I looked on the web site for technical docs about schedulers interaction, have you some advice for any docs?

best regards
davide

Il giorno 1-apr-2011, alle ore 11.32, Gilles Chanteperdrix ha scritto:

> davide doninelli wrote:
>> Hi 
>> i see in linux proces 3 xenomai processes per xenomai RT task .
>> I don't understand what are the first 2 process.
>> Is that right? What are used for? Tasks are like in envelope?
>> i don't find information about that.
>> 
>> #ps
>> ....
>> 483 root     ./interrupt_xeno_userspacen 
>>  484 root     ./interrupt_xeno_userspacen 
>>  485 root     ./interrupt_xeno_userspacen 
> 
> With the quantity of information you give us, we can only guess, but you
> probably use a linuxthreads based libc, so:
> - each thread appears as an entry in ps output
> - there is a "manager" thread called when creating the first thread.
> 
> So, 483 is probably the main thread, 484 the manager thread, 485 is the
> "mytask" thread.
> 
> Still guessing, I think you are confusing 2 + N with 3 * N, because you
> only tested with N == 1.
> 
> -- 
> 					    Gilles.

Re: [Xenomai-help] process on linux

[Gilles Chanteperdrix]

davide doninelli wrote:
> ok, two more questions...
> What's main thread and manager thread roles?

The main thread is the one running the "main" function.

The manager thread is something internal to linuxthreads, so, if it is
documented somewhere, it must be in some documentation related to
linuxthreads.

Note that all this is not at all specific to Xenomain, so, this mailing
list is not the best place to ask these questions.

-- 
					    Gilles.