Re: real-time priority

[Frank Rowand <frank.rowand@am.sony.com>]

Rodrigo Amestica wrote:
> yes, i forgot to include the link. now it goes.
> 
> http://www.ddj.com/linux-open-source/200900827
> 
> Rodrigo Amestica wrote:
>> Hi,
>>
>> general questions from somebody who's just starting to look into the
>> preempt patch.
>>
>> the article linked below makes direct reference to the behavior of the
>> preempt rt patch. The article was written in 2007. How much of that
>> still holds true in the current version of the patch?
>>
>> I'm basically wondering about the first sentences in the abstract of
>> that article. The big picture seems to be rather simple: calls to
>> specific linux services could break the performance of a real time
>> task by depending on lower priority tasks to complete that service.
>>
>> Does this mean that one must always be alert to which system services
>> are invoked during the execution of a real time task?

Yes.

>> Does the vanilla
>> kernel or the preempt-rt patch tries to somehow detect this condition
>> and alert somehow?

I am not aware of any such test, but it sounds like an interesting idea.

>>
>> thanks,
>> Rodrigo
>>