Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753074AbbHaNyG (ORCPT ); Mon, 31 Aug 2015 09:54:06 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:38787 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752110AbbHaNyE (ORCPT ); Mon, 31 Aug 2015 09:54:04 -0400 Message-ID: <55E45C76.3070704@roeck-us.net> Date: Mon, 31 Aug 2015 06:53:58 -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: Peter Zijlstra CC: Borislav Petkov , Ingo Molnar , Huang Rui , Borislav Petkov , Jean Delvare , Andy Lutomirski , Andreas Herrmann , Thomas Gleixner , "Rafael J. Wysocki" , Len Brown , John Stultz , =?windows-1252?Q?Fr=E9d=E9ric_Weisbecker?= , 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> <55E455E8.1060208@roeck-us.net> <20150831133809.GM19282@twins.programming.kicks-ass.net> In-Reply-To: <20150831133809.GM19282@twins.programming.kicks-ass.net> Content-Type: text/plain; charset=windows-1252; 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: 1747 Lines: 42 On 08/31/2015 06:38 AM, Peter Zijlstra wrote: > On Mon, Aug 31, 2015 at 06:26:00AM -0700, Guenter Roeck wrote: >> On 08/31/2015 01:38 AM, Peter Zijlstra wrote: >>> On Sun, Aug 30, 2015 at 05:53:22PM +0200, Borislav Petkov wrote: >>>> On Sat, Aug 29, 2015 at 11:19:14AM +0200, Ingo Molnar wrote: >>>>> So let me withdraw my ack: the much more important question that I >>>>> missed first time around, why is this reporting feature living in >>>>> hwmon, not in perf? We have energy reporting facilities in perf that >>>>> this should be synced to. >>>> >>>> Because there's already fam15h_power driver which is exactly for that. >>>> Making it part of perf is then a question of cat-ting the same sysfs >>>> file twice, at the beginning and at the end of the trace, which is >>>> trivial. >>> >>> That don't make sense. >>> >>> 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 >>> -- which is all hwmon seems capable of. >>> >> >> Is it ? Why ? > > Dunno, because there's that big old loop iterating all cpus? > What does that have to do with 'hwmon' ? The current implementation in the driver may not be a good idea, and maybe for good reasons; I can not comment on that. However, you concluded from that implementation that hwmon, the subsystem, would not be able to support 'much finer grained measurements than system wide'. I would like to understand how you reached that conclusion. 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/