Re: [PATCH 3/5] locking/rwsem: Enable reader optimistic lock stealing

[Davidlohr Bueso]

On Tue, 17 Nov 2020, Waiman Long wrote:

> If the optimistic spinning queue is empty and the rwsem does not have
> the handoff or write-lock bits set, it is actually not necessary to
> call rwsem_optimistic_spin() to spin on it. Instead, it can steal the
> lock directly as its reader bias is in the count already.  If it is
> the first reader in this state, it will try to wake up other readers
> in the wait queue.
>
> Signed-off-by: Waiman Long <longman@xxxxxxxxxx>

Reviewed-by: Davidlohr Bueso <dbueso@xxxxxxx>