Re: [PATCH 4/4] sched: bias to target cpu load to reduce task moving

[Alex Shi]

On 12/17/2013 11:38 PM, Peter Zijlstra wrote:
> On Tue, Dec 17, 2013 at 02:10:12PM +0000, Morten Rasmussen wrote:
>>> @@ -4135,7 +4141,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu)
>>>  			if (local_group)
>>>  				load = source_load(i);
>>>  			else
>>> -				load = target_load(i);
>>> +				load = target_load(i, sd->imbalance_pct);
>>
>> Don't you apply imbalance_pct twice here? Later on in
>> find_idlest_group() you have:
>>
>> 	if (!idlest || 100*this_load < imbalance*min_load)
>> 		return NULL;
>>
>> where min_load comes from target_load().
> 
> Yes! exactly! this doesn't make any sense.

Thanks a lot for review and comments!

I changed the patch to following shape. and push it under Fengguang's testing 
system monitor. Any testing are appreciated!

BTW, Seems lots of changes in scheduler come from kinds of scenarios/benchmarks
experience. But I still like to take any theoretical comments/suggestions.

-- 
Thanks
    Alex

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