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Date: Sun, 16 Oct 2016 15:50:39 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: Imre Palik <imrep.amz@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
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        Alexander Kozyrev <alexander.kozyrev@intel.com>,
        Artyom Kuanbekov <artyom.kuanbekov@intel.com>,
        Imre Palik <imrep@amazon.de>, Matt Wilson <msw@amazon.com>
Subject: Re: [RFC PATCH] perf: honouring the cpuid for number of fixed
 counters in hypervisors
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On Thu, Oct 13, 2016 at 01:28:09AM -0700, Imre Palik wrote:
> +	if (version > 1) {
> +		unsigned int ecx = cpuid_ecx(1);
> +
> +		if (ecx >> 31)

What is this magic, undocumented gunk doing? Is that supposed to be
static_cpu_has(X86_FEATURE_HYPERVISOR) ?