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Date: Fri, 22 Feb 2013 17:10:33 +0800
From: Michael Wang <wangyun@linux.vnet.ibm.com>
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To: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Mike Galbraith <efault@gmx.de>, Ingo Molnar <mingo@kernel.org>,
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        "Nikunj A. Dadhania" <nikunj@linux.vnet.ibm.com>,
        Namhyung Kim <namhyung@kernel.org>
Subject: Re: [RFC PATCH v3 0/3] sched: simplify the select_task_rq_fair()
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On 02/22/2013 04:21 PM, Peter Zijlstra wrote:
> On Fri, 2013-02-22 at 10:36 +0800, Michael Wang wrote:
>> According to my understanding, in the old world, wake_affine() will
>> only
>> be used if curr_cpu and prev_cpu share cache, which means they are in
>> one package, whatever search in llc sd of curr_cpu or prev_cpu, we
>> won't
>> have the chance to spread the task out of that package.
> 
> Nah, look at where SD_WAKE_AFFINE is set. Only 'remote/big' NUMA domains
> don't have it set, but 'small' NUMA systems will have it set over the
> entire domain tree.

Oh, I missed that point...

But I don't get the reason to make NUMA level affine, cpus in different
nodes share cache? doesn't make sense...

Regards,
Michael Wang

> 
> 
> 
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