From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755820AbaCNIot (ORCPT ); Fri, 14 Mar 2014 04:44:49 -0400 Received: from merlin.infradead.org ([205.233.59.134]:35465 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755374AbaCNIoq (ORCPT ); Fri, 14 Mar 2014 04:44:46 -0400 Date: Fri, 14 Mar 2014 09:44:29 +0100 From: Peter Zijlstra To: Venkatesh Srinivas Cc: linux-kernel@vger.kernel.org, eranian@google.com, mingo@elte.hu, ak@linux.intel.com, zheng.z.yan@intel.com Subject: Re: [PATCH] perf/x86/intel: Use rdmsrl_safe when initializing RAPL PMU. Message-ID: <20140314084429.GO27965@twins.programming.kicks-ass.net> References: <1394739386-22260-1-git-send-email-venkateshs@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1394739386-22260-1-git-send-email-venkateshs@google.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 13, 2014 at 12:36:26PM -0700, Venkatesh Srinivas wrote: > CPUs which should support the RAPL counters according to > Family/Model/Stepping may still issue #GP when attempting to access > the RAPL MSRs. This may happen when Linux is running under KVM and > we are passing-through host F/M/S data, for example. Use rdmsrl_safe > to first access the RAPL_POWER_UNIT MSR; if this fails, do not > attempt to use this PMU. This kvm thing is getting tedious :-(