On Wed, Sep 06, 2017 at 10:56:08AM +0200, Peter Zijlstra wrote: > Right, but even if it was a coherent patch, I'm not sure it makes sense. > > futex_wait() / futex_wake() don't make ordering guarantees and in > general you don't get to have wakeup preemption if you don't run a > PREEMPT kernel. > > So what makes this wakeup so special? Any changelog would need to have a > convincing argument.
Also, even on !PREEMPT, if that wakeup sets NEED_RESCHED, the return to userspace after futex_wake() should reschedule. So I'm really not getting it.
