Re: [patch] Real-Time Preemption, -RT-2.6.12-rc1-V0.7.43-00

Ingo Molnar
2005-04-05T05:34:34Z

* Esben Nielsen <simlo@phys.au.dk> wrote:

> > Now the question is, who will fix it? Preferably the maintainers, but I
> > don't know how much of a priority this is to them. I don't have the time
> > now to look at this and understand enough about the code to be able to
> > make a proper fix, and I'm sure you have other things to do too.
>
> How about adding a
> if(rt_task(current)) {
> WARN_ON(1);
> mutex_setprio(current, MAX_PRIO-1)
> }
> ?
>
> to find all calls to yields from rt-tasks. That will force the user
> (aka the real-time developer) to either stop calling the subsystems
> still using yield from his RT-tasks, or fix those subsystems.

i've added this to the -43-08 patch, so that we can see the scope of the
problem. But any yield() use could become a problem due to priority
inheritance. (which might eventually be expanded to userspace locking
too)

Ingo