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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,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 9EFAEC43381 for ; Thu, 21 Mar 2019 07:58:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 63471218D3 for ; Thu, 21 Mar 2019 07:58:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="w3VFws0F" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728116AbfCUH6W (ORCPT ); Thu, 21 Mar 2019 03:58:22 -0400 Received: from merlin.infradead.org ([205.233.59.134]:59252 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728097AbfCUH6T (ORCPT ); Thu, 21 Mar 2019 03:58:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=BCYTt+DVMwc6+hCDhi6nLX8WjMnsxzYSVrapY6kMfCw=; b=w3VFws0FH3JukYL56y7250J6z 2LM10/hp2jhDUc38Axbn2PKNOpkUQeMT0P/WTKiPhePL/zi4G0Lv7KQ0N9Zybi6dVaBxiFzVZg2WN tOYMF5qnyvMKMiBM0tzH5EQDaHtauIfYYwcb/5MtiCgDCJkABSxEb5XwjTPzWtnXZ95rAV2O1545z /LTbz0sajwVhd7VXeMvozwNnkHF4l3TIVSPkmwJisq7/OiMkx2J8JfTchi8ajxBydcnrGseZTswHi zx8bAykin2/87ozUTunMXMtLXLQHmzK615q5qbnFiNYTohEqu2y1SKcnTMn+oxRUwty+on6DlgCsf V+OWjlGoQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1h6saW-000832-Q7; Thu, 21 Mar 2019 07:58:09 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 55EDB2391A9A9; Thu, 21 Mar 2019 08:58:07 +0100 (CET) Date: Thu, 21 Mar 2019 08:58:07 +0100 From: Peter Zijlstra To: "Rafael J. Wysocki" Cc: x86 , LKML , Len Brown , Linux PM , Srinivas Pandruvada , Laura Abbott , Thomas Gleixner , Ingo Molnar , Simon Schricker , Borislav Petkov , Hannes Reinecke Subject: Re: [PATCH] PM / arch: x86: Rework the MSR_IA32_ENERGY_PERF_BIAS handling Message-ID: <20190321075807.GK6058@hirez.programming.kicks-ass.net> References: <2816566.rddYshD6lm@aspire.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2816566.rddYshD6lm@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 01:00:52AM +0100, Rafael J. Wysocki wrote: > + * The Performance and Energy Bias Hint (EPB) allows software to specify its > + * preference with respect to the power-performance tradeoffs present in the > + * processor. Generally, the EPB is expected to be set by user space through > + * the generic MSR interface (with the help of the x86_energy_perf_policy tool), > + * but there are two reasons for the kernel to touch it. So I hate /dev/msr with a passion. It is absolute atrocious crap. Please, just make a real interface for this if it is important.