On 03.12.2009, at 14:14, Gilles Chanteperdrix <gilles.chanteperd...@xenomai.org 
 > wrote:

> Wolfgang Mauerer wrote:
>> Hi,
>> Gilles Chanteperdrix wrote:
>>> Wolfgang Mauerer wrote:
>>>> So that means, in essence, that you would accept probabilistic
>>>> algorithms in realtime context?
>>> Ah, today's troll!
>> though it seems that I have to replace Jan this time ;-)
>>> As I think I explained, the use of a seqlock in real-time context  
>>> when
>>> the seqlock writer only happens in linux context is not  
>>> probabilistic.
>>> It will work every time the first pass.
>> I still don't see why it should succeed every time: What about
>> the case that the Linux kernel on CPU0 updates the data, while
>> Xenomai accesses them on another CPU? This can lead to
>> inconsistent data, and they must be reread on the Xenomai side.
> Yeah, right. I was not thinking about SMP. But admit that in this  
> case,
> there will be only one retry, there is nothing pathological.
>> I'm asking because if this case can not happen, then there's
>> nothing left to to as I have the code already at hand.
> You have reworked the nucleus timers handling to adapt to this new
> real-time clock ?

Nope. Sorry, I was a bit unclear: I'm just referring to the gtod  
syscall that does the timer handling, Not any other adaptions.

Thanks, Wolfgang

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