On Fri, 2016-10-06 at 03:51:28 UTC, Boqun Feng wrote:
> There is an ordering issue with spin_unlock_wait() on powerpc, because
> the spin_lock primitive is an ACQUIRE and an ACQUIRE is only ordering
> the load part of the operation with memory operations following it.
...
>
> Suggested-by: "Paul E
There is an ordering issue with spin_unlock_wait() on powerpc, because
the spin_lock primitive is an ACQUIRE and an ACQUIRE is only ordering
the load part of the operation with memory operations following it.
Therefore the following event sequence can happen:
CPU 1 CPU 2