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Date: Thu, 8 Sep 2016 11:40:17 +0200 (CEST)
From: Thomas Gleixner <tglx@linutronix.de>
To: Fenghua Yu <fenghua.yu@intel.com>
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Subject: Re: [PATCH v2 09/33] x86/intel_rdt: Add L3 cache capacity bitmask
 management
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On Thu, 8 Sep 2016, Fenghua Yu wrote:
>  
> +	for_each_online_cpu(i)
> +		rdt_cpumask_update(i);

The only reason why this does not blow up in your face is that at this
point the secondary cpus have been brought up already and user space is not
yet running, so cpu hotplug cannot happen in parallel. Protection by chance
is never a good idea.

Thanks,

	tglx