Re: [PATCH 2/2] locking/pvqspinlock: Optionally store lock holder cpu into lock

[Peter Zijlstra]

On Mon, Jul 13, 2020 at 10:48:00PM -0400, Waiman Long wrote:
> Storing the cpu number into the lock can be useful for other reason too. It
> is not totally related to PPC support.

Well, the thing you did only works for 'small' (<253 CPU) systems.
There's a number of Power systems that's distinctly larger than that. So
it simply cannot work as anything other than a suggestion/hint. It must
not be a correctness thing.