Re: Which version of preempt_realtime to use?

["Jürgen Mell" <mell@hedrich-winders.com>]

>
> Esben,
>
>   
>> I am going to suggest that we use preempt_realtime for a _real_ project
>> (i.e. costumers will depend on it). We will run on standeard x86 (maybe
>> x86_64) hardware and will only need serial interfaces for realtime
>> purposes. Security is not an issue. Which version of preempt_realtime
>> should I pick?
>>     
> The latest and greatest *and* most stable version is 2.6.24.7-rt26. As
> far as I know (but maybe others know better), there are no unresolved
> issues with this "Latest Stable". The kernel release 2.6.24 may not
> contain sufficient architecture support for PPC and ARM, but the large
> majority of x86 based processors and chipsets is well supported.
>
> Please report, if anything does not work as expected.
>   
The only thing which is missing for me from the 2.6.24.7-rt series is
the patch
"x86-fpu-fix-config_preempt-y-corruption-of-application-s-fpu-stack.patch"
, GIT commit
 870568b39064cab2dd971fe57969916036982862 from mainline 2.6.25. This
might cause trouble with applications which are using floating point
arithmetics. Otherwise I am using the 2.6.24.7-rt series on a machine
control for a 16 axes machine and it is working mostly well. There are
only some points where I get big delays (up to some milliseconds) with
my timer routine, where normally delays are below 50 microseconds. Up to
now I could not find the application ( X ??) which is causing this.

Bye,
           Jürgen

-- 
Jürgen Mell (Software-Entwicklung)           mell@hedrich.com
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