On Tue, 5 May 2015 18:31:20 +0200 (CEST)
Thomas Gleixner <t...@linutronix.de> wrote:
> On Tue, 5 May 2015, Steven Rostedt wrote:
> > I got pulled onto other things so I never finished it, but one thing
> > that worried me about this fix is this:
> >
> > T1 - FIFO policy (prio = 10)
> > lock(rtmutex);
> >
> > T2 (prio = 20)
> > lock(rtmutex)
> > boost T1 (prio = 20)
> >
> > TI (prio = 20)
> > sys_sched_setscheduler(prio = 30)
> > TI (prio = 30)
> >
> > T1 (prio = 30)
> > sys_sched_setscheduler(SCHED_OTHER)
> > new_effective_prio = 20, oldprio = 30
> >
> > Before the code stopped at the rt_mutex_check_prio(), but now it
> > continues. Will having the policy change cause problems here?
>
> No, because it stays effective in the FIFO domain.
>
Ah, the policy passed in isn't used, so we are safe. But, but I also
found that we still call __setscheduler(), which does:
p->prio = normal_prio();
Isn't that going to null out the boosting?
-- Steve
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