Re: [PATCH] locking/osq: Drop the overload of osq lock

[Peter Zijlstra]

On Sat, Jun 25, 2016 at 06:09:22PM +0200, Peter Zijlstra wrote:
> That works here, but it would not work for the need_resched() in
> mutex_spin_on_owner() and mutex_optimistic_spin() which need equal
> treatment.
> 
> Because those too we want to limit.
> 
> The count thing, while a little more cumbersome, is more widely
> applicable than just the one OSQ case where we happen to have a cpu
> number.

Although I suppose that mutex_spin_on_owner() (and with that the rsem
variant) could use task_cpu(lock->owner) once we've established that the
owner pointer is still valid.