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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 DACC4C433E0 for ; Thu, 11 Mar 2021 11:49:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7598964FBA for ; Thu, 11 Mar 2021 11:49:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232690AbhCKLs4 (ORCPT ); Thu, 11 Mar 2021 06:48:56 -0500 Received: from mail.skyhub.de ([5.9.137.197]:49380 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232519AbhCKLsX (ORCPT ); Thu, 11 Mar 2021 06:48:23 -0500 Received: from zn.tnic (p200300ec2f0e1f0084acfb80b2ea2480.dip0.t-ipconnect.de [IPv6:2003:ec:2f0e:1f00:84ac:fb80:b2ea:2480]) (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 203261EC0402; Thu, 11 Mar 2021 12:48:22 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1615463302; 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=+T8jHdTHhTXNJ17K47mZybeuko0jgRMbn4SbH0sUdkg=; b=FRJ8cjgMaYtJEx1iTnulsaiaw7JRmDcl3bj7NpXHGkJa9VO6SX6482xP7lTZVYnwFqFMa4 qLLphuvhe0nTUJceNI9a9lVHnVXqyWE0ClqR+Tx2VsWiu1tSSZEnq9Rsa+f+o11NaJtkCP DD3GQbDidxWavPnaFxswc0lI3O27zZg= Date: Thu, 11 Mar 2021 12:48:14 +0100 From: Borislav Petkov To: kan.liang@linux.intel.com Cc: 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, Ricardo Neri , Andy Lutomirski , Dave Hansen , "Rafael J. Wysocki" , "Ravi V. Shankar" , Srinivas Pandruvada Subject: Re: [PATCH V2 2/25] x86/cpu: Add helper functions to get parameters of hybrid CPUs Message-ID: <20210311114814.GA5829@zn.tnic> References: <1615394281-68214-1-git-send-email-kan.liang@linux.intel.com> <1615394281-68214-3-git-send-email-kan.liang@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1615394281-68214-3-git-send-email-kan.liang@linux.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 10, 2021 at 08:37:38AM -0800, kan.liang@linux.intel.com wrote: > From: Ricardo Neri > > On processors with Intel Hybrid Technology (i.e., one having more than one > type of CPU in the same package), all CPUs support the same instruction > set and enumerate the same features on CPUID. Thus, all software can run > on any CPU without restrictions. However, there may be model-specific > differences among types of CPUs. For instance, each type of CPU may support > a different number of performance counters. Also, machine check error banks > may be wired differently. Even though most software will not care about > these differences, kernel subsystems dealing with these differences must > know. Add a new member to cpuinfo_x86 that subsystems can query to know ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ That is not the case anymore. And it looks like the IPIing is going away too, which is good. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette