Messages in this thread | | | Date | Tue, 14 Jun 2016 22:28:34 +0200 | From | Peter Zijlstra <> | Subject | Re: [RFC][PATCH 2/8] sched/rtmutex/deadline: Fix a PI crash for deadline tasks |
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On Tue, Jun 14, 2016 at 02:42:17PM -0400, Steven Rostedt wrote: > On Tue, 07 Jun 2016 21:56:37 +0200 > Peter Zijlstra <peterz@infradead.org> wrote: > > + /* > > + * We should deboost before waking the top waiter task such that > > + * we don't run two tasks with the 'same' priority. This however > > + * can lead to prio-inversion if we would get preempted after > > + * the deboost but before waking our high-prio task, hence the > > + * preempt_disable before unlock. Pairs with preempt_enable() in > > + * rt_mutex_postunlock(); > > + */ > > + preempt_disable(); > > + > > This looks like a possible maintenance nightmare. Can we add some more > comments at the start of the functions that state that > rt_mutex_slowunlock() calls must be paired with rt_mutex_postunlock()?
Please look at patches 4 and 5 that clean this up.
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