Re: [PATCH] cpu_pm: replace raw_notifier to atomic_notifier

From: Alex Shi
Date: Sat Jul 08 2017 - 03:25:50 EST




On 07/07/2017 06:25 PM, Sebastian Andrzej Siewior wrote:
> On 2017-07-06 16:47:46 [+0800], Alex Shi wrote:
>> This patch replace a rwlock and raw notifier by atomic notifier which
> + is
>> protected by spin_lock and rcu.
> â
>> Sebastian suggested using atomic_notifier instead of rwlock, which is not
>> only removing the sleeping in idle, but also getting better latency
>> improvement.
>
> Did you measure this / have numbers or did you write this because this
> is what RCU does in general?

Uh, I have no number on the performance. The benefit is in the theory.
https://lwn.net/Articles/263130/
But above article give some comparison data of rwlock and RCU.

>
> Acked-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
>

Thanks a lot!

Regards
Alex