From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1754493AbcFPUoZ (ORCPT <rfc822;w@1wt.eu>);
	Thu, 16 Jun 2016 16:44:25 -0400
Received: from mail-io0-f194.google.com ([209.85.223.194]:32825 "EHLO
	mail-io0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1754094AbcFPUoY (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Thu, 16 Jun 2016 16:44:24 -0400
From: Vince Weaver <vincent.weaver@maine.edu>
X-Google-Original-From: Vince Weaver <vince@maine.edu>
Date: Thu, 16 Jun 2016 16:44:20 -0400 (EDT)
X-X-Sender: vince@macbook-air
To: Huang Rui <ray.huang@amd.com>
cc: Vince Weaver <vincent.weaver@maine.edu>, Borislav Petkov <bp@suse.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@kernel.org>,
        Andy Lutomirski <luto@amacapital.net>,
        Robert Richter <rric@kernel.org>, Jacob Shin <jacob.w.shin@gmail.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Kan Liang <kan.liang@intel.com>, linux-kernel@vger.kernel.org,
        x86@kernel.org, Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
        Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>,
        Borislav Petkov <bp@alien8.de>, Guenter Roeck <linux@roeck-us.net>,
        Fengguang Wu <fengguang.wu@intel.com>
Subject: Re: [REDO PATCH v7] perf/x86/amd/power: Add AMD accumulated power
 reporting mechanism
In-Reply-To: <20160616053802.GA7810@hr-amur2>
Message-ID: <alpine.DEB.2.20.1606161636530.2744@macbook-air>
References: <1457502306-2559-1-git-send-email-ray.huang@amd.com> <alpine.DEB.2.20.1606152104370.26137@macbook-air> <20160616053802.GA7810@hr-amur2>
User-Agent: Alpine 2.20 (DEB 67 2015-01-07)
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Thu, 16 Jun 2016, Huang Rui wrote:

> > 1.  In theory this should also work on an amd fam16h model 30h
> >     processor too, correct?  The current code limits things to fam15h
> >     even though the fam16mod30h has all the proper cpuid flags.
> > 
> 
> I was told this feature would be supported on fam15h 60h, 70h and
> later processors before. Just checked the fam16h model 30h BKDG, yes,
> it should be also supported. But I didn't test that platform, if you
> confirm it works in your side. We can enable it.

I can confirm I get power readings on my fam16hmod30h board once I apply a 
trivial patch to the driver.  I'll send the patch in a separate e-mail.

> PTSC's frequency is about 100Mhz, it shouldn't be overflow.

That's what I thought.  I'm trying to read the value using the /dev/msr 
interface from userspace and I get weird results.

i.e.:
	Jx: read 62d299b84
	PTSC MSR: read 72fe92
	
	sleep 5ms

	Jy: read 631b453b9
	PTSC MSR: read 46b25

this happens about half the time (PTSC going backwards).  Though 
admittedly the problem could somehow be in the MSR code I'm using.

> mWatts are for processor power not system power. Below data is
> calculated on fam15h model 60h which is low power platform. Even
> though the method has a minor mistake, the processor power should be
> in mWatts field.

I have an actual wall-mounted power meter hooked up to my system and the 
difference from idle to all-cores-busy is 20W, so I would think that that 
the results we find with perf should be >1W at least.

Vince