Re: [Xenomai] kconfig CONFIG_XENO_OPT_TIMING_PERIODIC=y/n

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

Le 02/02/2013 22:30, Gilles Chanteperdrix a écrit :
> Le 02/02/2013 21:19, John Morris a écrit :
>>
>>
>> On 01/29/2013 06:54 AM, Michael Haberler wrote:
>>> I'm testing linuxcnc with John's 3.5.7 - 2.6.2.1 kernel and found an
>>> issue with the deprecated linuxcnc xenomai-kernel threads version
>>> (the userland threads version is fine; both using native skin). I
>>> traced that back to rt_timer_ticks2ns(30000) returning zero.
>>>
>>> The config difference I see is: CONFIG_XENO_OPT_TIMING_PERIODIC=y on
>>> 3.5.7, unset on 3.2.21
>>
>> The periodic timing option =y made it into my kernel
>> script-kiddie-style:  I copied it directly from Gilles's config without
>> trying to understand every option.
>>
>>>
>>> The way I read back messages I'd think that should be unset for
>>> native and Posix skins; these are compiled in:
>>>
>>> CONFIG_XENO_SKIN_NATIVE=y
>>> CONFIG_XENO_SKIN_POSIX=y
>>> CONFIG_XENO_SKIN_PSOS=m
>>> CONFIG_XENO_SKIN_UITRON=m
>>> CONFIG_XENO_SKIN_VRTX=m
>>> CONFIG_XENO_SKIN_VXWORKS=m
>>> CONFIG_XENO_SKIN_RTDM=y
>>
>> Now that I've gone back and read, I don't understand either.  Native and
>> posix styles need periodic timing unset.
>
> No, since xenomai 2.5, each skin decides whether it uses a periodic or
> aperiodic timing.
>
> without CONFIG_XENO_OPT_TIMING_PERIODIC, only the aperiodic timer is
> available, with this option set, the user has the choice.
>
> Each skin has:
> - a pre-set timer period in micro-seconds (which should be 0 by default
> for the native and posix skin, meaning the default aperiodic mode)
> - a module parameter "tick_arg" allowing to override the compiled-in
> pre-set timer period.
>
> So, enabling this option is what makes the most sense for a "generic"
> configuration. Now, what you observe with rt_timer_ticks2ns is
> undoubtely a bug.
>


-- 
Gilles.