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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 38EA0C433E0 for ; Wed, 10 Mar 2021 22:26:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D5B4F64FC3 for ; Wed, 10 Mar 2021 22:26:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232991AbhCJW0R (ORCPT ); Wed, 10 Mar 2021 17:26:17 -0500 Received: from mga02.intel.com ([134.134.136.20]:11590 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230076AbhCJW0J (ORCPT ); Wed, 10 Mar 2021 17:26:09 -0500 IronPort-SDR: 9s2MadHV4EeEeTFcNjq4SAlwPbjI4q7DbQ4uk/pg/coorOyVtpyVw3+LV7Yjs0HNw6IydOYQAK +Ky1qRAj5lOA== X-IronPort-AV: E=McAfee;i="6000,8403,9919"; a="175680130" X-IronPort-AV: E=Sophos;i="5.81,238,1610438400"; d="scan'208";a="175680130" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Mar 2021 14:26:08 -0800 IronPort-SDR: DaCZbLZi7fkrqtJT63YDgJ9vtvM2pKT5MASD2FBLcCpMUXff05RJq3bf/LphX3vS87zmTdte7J UobTP9hAZUog== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.81,238,1610438400"; d="scan'208";a="372111578" Received: from ranerica-svr.sc.intel.com ([172.25.110.23]) by orsmga006.jf.intel.com with ESMTP; 10 Mar 2021 14:26:08 -0800 Date: Wed, 10 Mar 2021 14:25:48 -0800 From: Ricardo Neri To: Borislav Petkov Cc: Srinivas Pandruvada , kan.liang@linux.intel.com, peterz@infradead.org, mingo@kernel.org, linux-kernel@vger.kernel.org, acme@kernel.org, tglx@linutronix.de, namhyung@kernel.org, jolsa@redhat.com, ak@linux.intel.com, yao.jin@linux.intel.com, alexander.shishkin@linux.intel.com, adrian.hunter@intel.com, "Rafael J. Wysocki" , "Ravi V. Shankar" Subject: Re: [PATCH V2 1/25] x86/cpufeatures: Enumerate Intel Hybrid Technology feature bit Message-ID: <20210310222548.GA28393@ranerica-svr.sc.intel.com> References: <1615394281-68214-1-git-send-email-kan.liang@linux.intel.com> <1615394281-68214-2-git-send-email-kan.liang@linux.intel.com> <20210310165358.GI23521@zn.tnic> <20210310194644.GA1218@ranerica-svr.sc.intel.com> <20210310200147.GJ23521@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210310200147.GJ23521@zn.tnic> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 10, 2021 at 09:01:47PM +0100, Borislav Petkov wrote: > On Wed, Mar 10, 2021 at 11:46:44AM -0800, Ricardo Neri wrote: > > But this series provides the use case, right? Kan's patches handle PMU counters > > that may differ cross types of CPUs. In patch 2, get_hybrid_params() > > needs to check first if X86_FEATURE_HYBRID_CPU is enabled before > > querying the hybrid parameters. Otherwise, we would need to rely on the > > maximum level of CPUID, which may not be reliable. > > On Wed, Mar 10, 2021 at 11:33:54AM -0800, Srinivas Pandruvada wrote: > > We are working on changes to P-State driver for hybrid CPUs using this > > define. They are still work in progress. > > But this patch can be submitted later with our set of changes. > > Answering to both with a single mail: > > I don't have a problem with X86_FEATURE_HYBRID_CPU - I simply don't want > to show "hybrid_cpu" in /proc/cpuinfo unless there's a valid use case > for userspace to know that it is running on a hybrid CPU. Ah, I get your point now. You would like to see #define X86_FEATURE_HYBRID_CPU (18*32+15) /* "" This part has CPUs of more than one type */ Right? Now your first comment makes sense. Srinivas, Kan, I don't think we need to expose "hybrid_cpu" in /proc/cpuinfo, do we? Thanks and BR, Ricardo