Re: [patch v4 0/18] sched: simplified fork, release load avg andpower awareness scheduling

From: Alex Shi
Date: Mon Jan 28 2013 - 20:32:00 EST



>> then the above no_node-load_balance thing suffers a small-ish dip at 320
>> tasks, yeah.
>
> No no, that's not restricted to one node. It's just overloaded because
> I turned balancing off at the NODE domain level.
>
>> And AFAICR, the effect of disabling boosting will be visible in the
>> small count tasks cases anyway because if you saturate the cores with
>> tasks, the boosting algorithms tend to get the box out of boosting for
>> the simple reason that the power/perf headroom simply disappears due to
>> the SOC being busy.
>>
>>> 640 100294.8 98 38.7 570.9 2.6118
>>> 1280 115998.2 97 66.9 1132.8 1.5104
>>> 2560 125820.0 97 123.3 2256.6 0.8191
>>
>> I dunno about those. maybe this is expected with so many tasks or do we
>> want to optimize that case further?
>
> When using all 4 nodes properly, that's still scaling. Here, I

Without node regular balancing, only waking balance left in
select_task_rq_fair for aim7 testing, (I just assume you used shared
workfile, most of testing is cpu density and only few exec/fork load).

Since, waking balance just happened in same llc domain. guess that is
the reason for this.

> intentionally screwed up balancing to watch the low end. High end is
> expected wreckage.


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