Re: [PATCH-tip v3 11/11] locking/rwsem: Optimize rwsem structure for uncontended lock acquisition

[Waiman Long]

On 04/03/2019 09:12 AM, Peter Zijlstra wrote:
> On Thu, Feb 28, 2019 at 02:09:41PM -0500, Waiman Long wrote:
>> For an uncontended rwsem, count and owner are the only fields a task
>> needs to touch when acquiring the rwsem. So they are put next to each
>> other to increase the chance that they will share the same cacheline.
> Did you try and micro-bench this?
>
I haven't tried to micro-bench that as the one that I used will have
both owner and count in the same cacheline. I need to construct one with
all sort of different cacheline offfset to see if that makes a
difference. I will do so.

Thanks,
Longman