Re: [PATCH v6 0/6] lockinig/rwsem: Fix rwsem bugs & enable true lock handoff

[Peter Zijlstra]

On Thu, Nov 17, 2022 at 09:20:10PM -0500, Waiman Long wrote:

> Waiman Long (6):
>   locking/rwsem: Prevent non-first waiter from spinning in down_write() slowpath
>   locking/rwsem: Disable preemption at all down_read*() and up_read() code paths
>   locking/rwsem: Disable preemption at all down_write*() and up_write() code paths
>   locking/rwsem: Change waiter->hanodff_set to a handoff_state enum

After all these we still have down_read_non_owner() using
__rwsem_set_reader_owner() outside of the preempt_disable() region.

Now, let me go stare at this one:

>   locking/rwsem: Enable direct rwsem lock handoff