Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757588AbaDWPOk (ORCPT ); Wed, 23 Apr 2014 11:14:40 -0400 Received: from mail-ob0-f181.google.com ([209.85.214.181]:49531 "EHLO mail-ob0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752692AbaDWPOe (ORCPT ); Wed, 23 Apr 2014 11:14:34 -0400 MIME-Version: 1.0 In-Reply-To: <20140423150912.GO11096@twins.programming.kicks-ass.net> References: <1394739386-22260-1-git-send-email-venkateshs@google.com> <20140423144538.GN11096@twins.programming.kicks-ass.net> <20140423150912.GO11096@twins.programming.kicks-ass.net> Date: Wed, 23 Apr 2014 17:14:33 +0200 Message-ID: Subject: Re: [PATCH] perf/x86/intel: Use rdmsrl_safe when initializing RAPL PMU. From: Stephane Eranian To: Peter Zijlstra Cc: Venkatesh Srinivas , LKML , "mingo@elte.hu" , "ak@linux.intel.com" , "Yan, Zheng" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 23, 2014 at 5:09 PM, Peter Zijlstra wrote: > On Wed, Apr 23, 2014 at 04:49:55PM +0200, Stephane Eranian wrote: >> On your machine, booted with 3.15-rc2, do you have /sys/devices/power? >> If not, and you have at least an SNB, you should have RAPL and that >> RAPL_UNIT MSR. >> >> Proof is that if you read that MSR using /dev/cpu/msr it works just fine: >> # modprobe msr >> # rdmsr 0x606 >> a1003 >> >> So something is broken somewhere. > > I've not got SNB+ class hardware (for testing). But I believe you that > there's something funny, I just do not understanding how *msr_safe() > could cause this. Or the logic of the test in rapl_cpu_prepare() is wrong, maybe? Wouldn't rdmsrl_safe() return 0 on success? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/