On Tue, Aug 23, 2016 at 02:46:20PM +0200, Peter Zijlstra wrote: > @@ -573,8 +600,14 @@ __mutex_lock_common(struct mutex *lock, > schedule_preempt_disabled(); > spin_lock_mutex(&lock->wait_lock, flags); > > + if (__mutex_owner(lock) == current) > + break; > + > if (__mutex_trylock(lock)) > break; > + > + if (__mutex_waiter_is_first(lock, &waiter)) > + __mutex_set_flag(lock, MUTEX_FLAG_HANDOFF); > } > __set_task_state(task, TASK_RUNNING); >
And 'obviously' we can add a spin-on-owner loop in there as well, as Waiman's patches did, but I didn't bother pulling that in for now.
