Re: [PATCH v3 1/6] rtmutex: Deboost before waking up the top waiter
From: Thomas Gleixner
Date: Mon Apr 18 2016 - 04:25:13 EST
On Thu, 14 Apr 2016, Xunlei Pang wrote:
> We should deboost before waking the high-prio task such that
> we don't run two tasks with the 'same' priority.
No. This is fundamentaly broken.
T1 (prio 0) lock(X)
T2 (prio 10) lock(X)
T1 (prio 10) unlock(X)
T3 (prio 5) ....
Classic priority inversion enabled by a mechanism to avoid it. Brilliant