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=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 EB572C3F2D1 for ; Thu, 5 Mar 2020 12:41:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C7B5320848 for ; Thu, 5 Mar 2020 12:41:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726243AbgCEMlI (ORCPT ); Thu, 5 Mar 2020 07:41:08 -0500 Received: from mail.cn.fujitsu.com ([183.91.158.132]:5700 "EHLO heian.cn.fujitsu.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725993AbgCEMlI (ORCPT ); Thu, 5 Mar 2020 07:41:08 -0500 X-IronPort-AV: E=Sophos;i="5.70,517,1574092800"; d="scan'208";a="85887893" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 05 Mar 2020 20:40:54 +0800 Received: from G08CNEXMBPEKD06.g08.fujitsu.local (unknown [10.167.33.206]) by cn.fujitsu.com (Postfix) with ESMTP id 80C6250A9962; Thu, 5 Mar 2020 20:31:02 +0800 (CST) Received: from [10.167.226.60] (10.167.226.60) by G08CNEXMBPEKD06.g08.fujitsu.local (10.167.33.206) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Thu, 5 Mar 2020 20:40:55 +0800 To: X86 ML , LKML CC: Thomas Gleixner , Ingo Molnar , Borislav Petkov From: Cao jin Subject: Is this code chunk in init_apic_mappings() superfluous? Message-ID: <978293b9-8e9f-55f6-6ec4-e2d66c4db0de@cn.fujitsu.com> Date: Thu, 5 Mar 2020 20:44:24 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.167.226.60] X-ClientProxiedBy: G08CNEXCHPEKD05.g08.fujitsu.local (10.167.33.203) To G08CNEXMBPEKD06.g08.fujitsu.local (10.167.33.206) X-yoursite-MailScanner-ID: 80C6250A9962.A3D38 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: caoj.fnst@cn.fujitsu.com Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, I am trying to figure the following code chunk out: if (x2apic_mode) { boot_cpu_physical_apicid = read_apic_id(); return; } As my understanding, even in x2APIC mode, boot_cpu_physical_apicid is also got via early_acpi_process_madt --> ... --> register_lapic_address, so, is it for any corner case I am not aware? -- Sincerely, Cao jin