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Re: [PATCH 4/8] x86/intel_rdt/mba: Memory b/w allocation feature detect

From Thomas Gleixner <tglx@linutronix.de>
Newsgroups linux.kernel
Subject Re: [PATCH 4/8] x86/intel_rdt/mba: Memory b/w allocation feature detect
Date 2017-01-16 15:00 +0100
Message-ID <t0fZg-186-25@gated-at.bofh.it> (permalink)
References <sYaqZ-5m6-3@gated-at.bofh.it> <sYaqZ-5m6-5@gated-at.bofh.it>
Organization linux.* mail to news gateway

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On Tue, 10 Jan 2017, Vikas Shivappa wrote:

> Detect MBA feature if CPUID.(EAX=10H, ECX=0):EBX.L2[bit 3] = 1.
> Add supporting data structures to detect feature details which is done
> in later patch using CPUID with EAX=10H, ECX= 3.

So why is the $subject of this patch claiming that it provides the feature
detection?

> -/* CPUID.(EAX=10H, ECX=ResID=1).EDX */
> +/* CPUID.(EAX=10H, ECX=ResID=3).EAX */
> +union cpuid_0x10_3_eax {
> +	struct {
> +		unsigned int max_delay:12;
> +	} split;

And the point of this struct is?

> +	unsigned int full;
> +};

> +	if (boot_cpu_has(X86_FEATURE_MBA)) {
> +		ret = true;
> +	}

Pointless brackets.

Thanks,

	tglx

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Thread

[PATCH 4/8] x86/intel_rdt/mba: Memory b/w allocation feature detect Vikas Shivappa <vikas.shivappa@linux.intel.com> - 2017-01-10 20:40 +0100
  Re: [PATCH 4/8] x86/intel_rdt/mba: Memory b/w allocation feature  detect Thomas Gleixner <tglx@linutronix.de> - 2017-01-16 15:00 +0100
    Re: [PATCH 4/8] x86/intel_rdt/mba: Memory b/w allocation feature  detect Peter Zijlstra <peterz@infradead.org> - 2017-01-16 15:50 +0100
      Re: [PATCH 4/8] x86/intel_rdt/mba: Memory b/w allocation feature  detect Thomas Gleixner <tglx@linutronix.de> - 2017-01-16 17:20 +0100

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