Re: [PATCH] sched/fair: Care divide error in update_task_scan_period()

[Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>]

(2014/10/09 1:54), Peter Zijlstra wrote:
> On Wed, Oct 08, 2014 at 12:42:24PM -0400, Rik van Riel wrote:
>> On 10/08/2014 02:43 AM, Yasuaki Ishimatsu wrote:
>>
>>>    The divide error is rare case because the trigger is node offline.
>>>    By this patch, when both of private and shared are set to 0, diff
>>>    is just set to 0, not calculating the division.
>>
>> How about a simple
>>
>>      if (private + shared) == 0)
>>            return;
>>
>> higher up in the function, to avoid adding an extra
>> layer of indentation and confusion to the main part
>> of the function?
>
> At which point we'll have 3 different return semantics. Should we not
> clear numa_faults_localityp[], even in this case?
>

I'm not familiar with Numa balancing feature. So I want to know it too.
If it's not necessary to clear numa_faults_locality[], I'll apply the idea.

Thanks,
Yasuaki Ishimatsu