Messages in this thread | | | Date | Wed, 10 Dec 2014 01:26:19 +0100 | From | Oleg Nesterov <> | Subject | Re: [PATCH v3] CPU hotplug: active_writer not woken up in some cases - deadlock |
| |
On 12/09, Paul E. McKenney wrote: > > Would wait_event()/wake_up() work for the wakeup-writer case?
Yes, and in this case we could probably kill this puts_pending logic and avoid cpu_hotplug.lock in put_online_cpus() altogether? Can't we just make cpu_hotplug.refcount atomic_t?
Anyway, this makes me think again that this code should use percpu_rwsem. Perhaps I'll try to make a patch next week...
(we need down_write_recursive_readers(), and probably rcusync patches).
Oleg.
| |