From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B4226C43381 for ; Fri, 22 Mar 2019 09:04:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 89C8C218E2 for ; Fri, 22 Mar 2019 09:04:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727836AbfCVJD7 (ORCPT ); Fri, 22 Mar 2019 05:03:59 -0400 Received: from mx2.suse.de ([195.135.220.15]:55220 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725981AbfCVJD6 (ORCPT ); Fri, 22 Mar 2019 05:03:58 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 8EF74AC32; Fri, 22 Mar 2019 09:03:57 +0000 (UTC) Subject: Re: [PATCH 2/2] PM / arch: x86: MSR_IA32_ENERGY_PERF_BIAS sysfs interface To: "Rafael J. Wysocki" , x86 Cc: LKML , Len Brown , Linux PM , Srinivas Pandruvada , Laura Abbott , Thomas Gleixner , Peter Zijlstra , Ingo Molnar , Simon Schricker , Borislav Petkov References: <1637073.gl2OfxWTjI@aspire.rjw.lan> <1762575.ER2xjzr9E1@aspire.rjw.lan> From: Hannes Reinecke Message-ID: <1fa29c73-c756-6942-76e5-0273efefd446@suse.de> Date: Fri, 22 Mar 2019 10:03:57 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <1762575.ER2xjzr9E1@aspire.rjw.lan> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/21/19 11:20 PM, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > The Performance and Energy Bias Hint (EPB) is expected to be set by > user space through the generic MSR interface, but that interface is > not particularly nice and there are security concerns regarding it, > so it is not always available. > > For this reason, add a sysfs interface for reading and updating the > EPB, in the form of a new attribute, energy_perf_bias, located > under /sys/devices/system/cpu/cpu#/power/ for online CPUs that > support the EPB feature. > > Signed-off-by: Rafael J. Wysocki > --- > Documentation/ABI/testing/sysfs-devices-system-cpu | 18 ++++ > Documentation/admin-guide/pm/intel_epb.rst | 27 ++++++ > arch/x86/kernel/cpu/intel_epb.c | 93 ++++++++++++++++++++- > 3 files changed, 134 insertions(+), 4 deletions(-) > Reviewed-by: Hannes Reinecke Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Mary Higgins, Sri Rasiah HRB 21284 (AG Nürnberg)