Re: [Xenomai-core] Overcoming the "foreign" stack

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

Jan Kiszka wrote:
> Am 05.10.2010 12:32, Gilles Chanteperdrix wrote:
>> Jan Kiszka wrote:
>>>  - consistent view on the system (if current is always valid, there are
>>>    no more confusions between current Linux vs. Xenomai task)
>> That is inherently incompatible with the co-kernel approach. Xenomai
>> will always be able to preempt Linux at a place where the state is not
>> consistent.
> 
> Depends on what state the trace examines and what it derives from it.
> The current task or the current preemption counter are definitely not
> critical and can easily be provided in a way that make tracer output
> consistent. In the end, shadow tasks are Linux tasks in a special mode.

To summarize what I was trying to say: the more you want to use Linux
infrastructures, the more you will want to have consistent state, the
more you will need to patch things around. This will incur overhead, to
the point where the modifications have influence on the results, and
this will also mean spaghetti-like troubles.

-- 
					    Gilles.