Re: [PATCH 05/10] x86/intel_rdt: Add support for Cache Allocation detection

From: Vikas Shivappa <vikas.shivappa@intel.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com>,
	linux-kernel@vger.kernel.org, vikas.shivappa@intel.com,
	x86@kernel.org, hpa@zytor.com, tglx@linutronix.de,
	mingo@kernel.org, matt.fleming@intel.com, will.auld@intel.com,
	linux-rdt@eclists.intel.com
Subject: Re: [PATCH 05/10] x86/intel_rdt: Add support for Cache Allocation detection
Date: Mon, 15 Jun 2015 10:04:31 -0700 (PDT)	[thread overview]
Message-ID: <alpine.DEB.2.10.1506150952530.3447@vshiva-Udesk> (raw)
In-Reply-To: <20150615124852.GC3644@twins.programming.kicks-ass.net>

On Mon, 15 Jun 2015, Peter Zijlstra wrote:

> On Fri, Jun 12, 2015 at 11:17:12AM -0700, Vikas Shivappa wrote:
>> +	/* Additional Intel-defined flags: level 0x00000010 */
>> +	if (c->cpuid_level >= 0x00000010) {
>> +		u32 eax, ebx, ecx, edx;
>> +
>> +		cpuid_count(0x00000010, 0, &eax, &ebx, &ecx, &edx);
>> +		c->x86_capability[13] = ebx;
>> +
>> +		if (cpu_has(c, X86_FEATURE_CAT_L3)) {
>> +
>> +			cpuid_count(0x00000010, 1, &eax, &ebx, &ecx, &edx);
>> +			c->x86_rdt_max_closid = edx + 1;
>> +			c->x86_rdt_max_cbm_len = eax + 1;
>> +		}
>> +	}
>
> I'm still annoyed by the whole RDT/CAT thing, so the above reads a CAT
> leaf and puts the values in an RDT variable.

Will fix. Was confusing as the closid is generic for rdt but just that its 
enumerated for each leaf ..

>
> That's inconsistent.
>