Re: [PATCH v3 2/5] locking/rwsem: Limit # of null owner retries for handoff writer

[Waiman Long]

On 10/25/22 16:14, Peter Zijlstra wrote:
> On Tue, Oct 25, 2022 at 03:55:09PM -0400, Waiman Long wrote:
>
> > That is quite a number of changes spread over many different functions. That
> > is the kind of changes that may make it harder to backport to stable
> > releases.
> Yeah; don't care. it's the right thing to do. It also doesn't need to be
> reverted since it's a sane and good property for lock-ops to have.

I am sorry to confuse you. What I am saying is the original patch 2 of 
the series, not what you have proposed. I am fine about disabling 
preemption while running in the core rwsem code.

As a counter proposal, I will suggest modifying patch 2 to disable 
preemption for the reader rwsem code as the writer code already have 
preemption disabled in the most critical parts. Then I add another patch 
to complete the writer side conversion for symmetry. Are you OK with that?

Cheers,
Longman