Re: [tip:locking/urgent] locking/static_key: Fix concurrent static_key_slow_inc()

[Paolo Bonzini]

> > > Isn't that what we have static_key_enable() for? Which btw also uses
> > > static_key_count() outside of the mutex.
> > 
> > Yes, they should be fixed and net/ can then use static_key_enable.
> 
> Right, let me try and fix _enable().

Here is what I scribbled before leaving the office.  (What was missing:
documentation for how to use static_key_enabled/count, testing).