Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753966AbbHaQT2 (ORCPT ); Mon, 31 Aug 2015 12:19:28 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:37661 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753315AbbHaQT1 (ORCPT ); Mon, 31 Aug 2015 12:19:27 -0400 Message-ID: <55E47E88.7080202@roeck-us.net> Date: Mon, 31 Aug 2015 09:19:20 -0700 From: Guenter Roeck User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.8.0 MIME-Version: 1.0 To: Borislav Petkov , Peter Zijlstra CC: Ingo Molnar , Huang Rui , Borislav Petkov , Jean Delvare , Andy Lutomirski , Andreas Herrmann , Thomas Gleixner , "Rafael J. Wysocki" , Len Brown , John Stultz , =?UTF-8?B?RnLDqWTDqXJpYyBXZWlzYmVja2Vy?= , lm-sensors@lm-sensors.org, linux-kernel@vger.kernel.org, x86@kernel.org, Andreas Herrmann , Aravind Gopalakrishnan , Fengguang Wu , Aaron Lu , Tony Li Subject: Re: [PATCH 09/15] x86, amd: add accessor for number of cores per compute unit References: <1440662866-28716-1-git-send-email-ray.huang@amd.com> <1440662866-28716-10-git-send-email-ray.huang@amd.com> <20150828064814.GB20153@nazgul.tnic> <20150828080418.GB13309@gmail.com> <20150829091914.GA8878@gmail.com> <20150830155322.GA26370@nazgul.tnic> <20150831083821.GE16853@twins.programming.kicks-ass.net> <20150831160622.GA29830@nazgul.tnic> In-Reply-To: <20150831160622.GA29830@nazgul.tnic> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated_sender: linux@roeck-us.net X-OutGoing-Spam-Status: No, score=0.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: linux@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1375 Lines: 33 On 08/31/2015 09:06 AM, Borislav Petkov wrote: > On Mon, Aug 31, 2015 at 10:38:21AM +0200, Peter Zijlstra wrote: >> Looking at the BKDG Fam 15h 60h-6Fh these MSRs are per compute unit. >> This means you can do much finer grained measurements than system wide > > Well, we can do finer-grained if needed. I'm all for everything which > has a good use case. The use case we had in mind here was the physical > processor power consumption for a time period. > >> -- which is all hwmon seems capable of. > > I guess we can do both - perf and hwmon. I don't see why not. > >> Not to mention the proposed code is horrible, who in their right mind >> does two rdmsrl_safe_on_cpu() back to back. > > That's a good point - I missed that during previous review. Rui, please > put the rdmsrl_safe_on_cpu() accesses in a separate function which you > run on a particular CPU, for your next version. > ... and maybe work with Peter to address the other hotplug related issues. It might also be worthwhile thinking about per-CU attributes, if that provides any value (Peter's comments suggested that this might be the case). Thanks, Guenter -- 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/