Re: [PATCH V2] sched: Improve load balancing in the presence of idle CPUs

[Wanpeng Li]

Hi Srikar,
On Fri, Mar 27, 2015 at 11:09:07AM +0530, Srikar Dronamraju wrote:
>
>Yes, the need_resched() in nohz_idle_balance() would exit the
>nohz_idle_balance if it has something to run. However I wonder if we
>should move the need_resched check out of the for loop. i.e the
>need_resched check should probably be there with the idle check.
>
>With the current code when the ilb cpus are not free: 
>- We would be updating the nohz.next_balance even through we havent done
>  any load balance.
>- We might iterate thro the nohz.idle_cpus_mask()s to find balance_cpus.

Good idea, the nohz load balance will be delay since nohz.next_balance is 
updated inapposite when current ILB just be busy. I will send a patch to 
fix it. ;)

Regards,
Wanpeng Li 
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