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Subject: Re: [RFC PATCH v3 0/3] sched: simplify the select_task_rq_fair()
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Michael Wang <wangyun@linux.vnet.ibm.com>
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Date: Fri, 22 Feb 2013 09:21:10 +0100
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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.