From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755510AbcFQPy0 (ORCPT ); Fri, 17 Jun 2016 11:54:26 -0400 Received: from mail-io0-f195.google.com ([209.85.223.195]:33966 "EHLO mail-io0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752818AbcFQPyZ (ORCPT ); Fri, 17 Jun 2016 11:54:25 -0400 From: Vince Weaver X-Google-Original-From: Vince Weaver Date: Fri, 17 Jun 2016 11:54:22 -0400 (EDT) X-X-Sender: vince@macbook-air To: Huang Rui cc: Borislav Petkov , Thomas Gleixner , Peter Zijlstra , Ingo Molnar , Andy Lutomirski , Robert Richter , Jacob Shin , Arnaldo Carvalho de Melo , Kan Liang , linux-kernel@vger.kernel.org, x86@kernel.org, Suravee Suthikulpanit , Aravind Gopalakrishnan , Borislav Petkov , Guenter Roeck , Fengguang Wu Subject: Re: [REDO PATCH v7] perf/x86/amd/power: Add AMD accumulated power reporting mechanism In-Reply-To: <20160617100306.GB13900@hr-amur2> Message-ID: References: <1457502306-2559-1-git-send-email-ray.huang@amd.com> <20160616053802.GA7810@hr-amur2> <20160617100306.GB13900@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: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 17 Jun 2016, Huang Rui wrote: > Can you try to read the MSR value two times with the same core > (rdmsrl_on_cpu)? I'm reading from userspace using the /dev/cpu/0/msr device so it should always be reading from cpu0. I guess I could code up a custom kernel module to debug this if necessary. It does look that for some reason the 0xc0010280 MSR is only returning the lower 24 bits of the PTSC, rather than the 40 bits that cpuid 80000008:ecx seems to think it should have. Vince