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=-5.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 94FE2C43381 for ; Mon, 25 Mar 2019 11:32:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5B6BD2087C for ; Mon, 25 Mar 2019 11:32:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="imDCoyYX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730977AbfCYLcT (ORCPT ); Mon, 25 Mar 2019 07:32:19 -0400 Received: from mail.skyhub.de ([5.9.137.197]:39086 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730941AbfCYLcN (ORCPT ); Mon, 25 Mar 2019 07:32:13 -0400 Received: from zn.tnic (p200300EC2F098000329C23FFFEA6A903.dip0.t-ipconnect.de [IPv6:2003:ec:2f09:8000:329c:23ff:fea6:a903]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 6B8631EC0987; Mon, 25 Mar 2019 12:32:11 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1553513531; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=icjgNOxhSK7v2Qt5wjRjWd2TnLg47U6UOFug1LLmZLs=; b=imDCoyYXxeRKemi6HbwA7yC1YTf2ARER1dDiOf7pz+yidXPFvRfoNFkAsdg73m1HLs6lP9 VfYLQ3APczUURTo79q7YRLaP4K5QwIkDL0wrxB9X1HB89aXDHL7K9SmsCNhRoRR01Fg1qm RexQoUbjpXj/yxZ1ORuhpR0vZ292I7M= Date: Mon, 25 Mar 2019 12:32:18 +0100 From: Borislav Petkov To: "Rafael J. Wysocki" Cc: x86 , LKML , Len Brown , Linux PM , Srinivas Pandruvada , Laura Abbott , Thomas Gleixner , Peter Zijlstra , Ingo Molnar , Simon Schricker , Borislav Petkov , Hannes Reinecke Subject: Re: [PATCH 2/2] PM / arch: x86: MSR_IA32_ENERGY_PERF_BIAS sysfs interface Message-ID: <20190325113218.GG12016@zn.tnic> References: <1637073.gl2OfxWTjI@aspire.rjw.lan> <1762575.ER2xjzr9E1@aspire.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1762575.ER2xjzr9E1@aspire.rjw.lan> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 21, 2019 at 11:20:17PM +0100, 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(-) Acked-by: Borislav Petkov -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.