Re: [PATCH RT] kernel/futex: don't deboost too early

From: Thomas Gleixner
Date: Fri Sep 30 2016 - 14:46:14 EST

On Fri, 30 Sep 2016, Steven Rostedt wrote:
> This looks awfully complex. Would something as simple as this work?
> What harm can happen by moving the holding of the lock after the
> wakeups for RT?

That's exactly bringing us back to the state before we added the delayed
wakeup so that the woken waiter will not be blocked on hb->lock right
away. That's 2 extra context switches for nothing.