Re: [PATCH v2 2/3] sched/fair: Move hot load_avg into its own cacheline

Waiman Long
2015-12-04T20:19:25Z

On 12/03/2015 09:07 PM, Mike Galbraith wrote:
> On Thu, 2015-12-03 at 14:34 -0500, Waiman Long wrote:
>> On 12/02/2015 11:32 PM, Mike Galbraith wrote:
>>> Is that with the box booted skew_tick=1?
>> I haven't tried that kernel parameter. I will try it to see if it can
>> improve the situation. BTW, will there be other undesirable side effects
>> of using this other than the increased power consumption as said in the
>> kernel-parameters.txt file?
> Not that are known. I kinda doubt you'd notice the power, but you
> should see a notable performance boost. Who knows, with a big enough
> farm of busy big boxen, it may save power by needing fewer of them.
>
> -Mike
>

You are right. Use skew_tick=1 did improve performance and reduce the
overhead of clock tick processing rather significantly. I think it
should be the default for large SMP boxes. Thanks for the tip.

Cheers,
Longman