From patchwork Wed Dec 6 12:56:08 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prarit Bhargava X-Patchwork-Id: 845172 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3ysJX16kwZz9sRV for ; Wed, 6 Dec 2017 23:56:17 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752142AbdLFM4P (ORCPT ); Wed, 6 Dec 2017 07:56:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60472 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750989AbdLFM4N (ORCPT ); Wed, 6 Dec 2017 07:56:13 -0500 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id EA27485541; Wed, 6 Dec 2017 12:56:12 +0000 (UTC) Received: from praritdesktop.bos.redhat.com (prarit-guest.khw.lab.eng.bos.redhat.com [10.16.186.145]) by smtp.corp.redhat.com (Postfix) with ESMTP id DB40278389; Wed, 6 Dec 2017 12:56:11 +0000 (UTC) From: Prarit Bhargava To: linux-kernel@vger.kernel.org Cc: Prarit Bhargava , Jakub Kicinski , netdev@vger.kernel.org, Clark Williams , Andi Kleen , x86@kernel.org, Thomas Gleixner Subject: [PATCH] arch/x86: Initialize __max_smt_threads to 1 Date: Wed, 6 Dec 2017 07:56:08 -0500 Message-Id: <20171206125608.4750-1-prarit@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Wed, 06 Dec 2017 12:56:13 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org A single socket, single core, single thread system has __max_smt_threads set to 0 since smp_callin() is not called. __max_smt_threads must be a minimum of 1. Fixes: b1cbacc8663a ("x86/smpboot: Do not use smp_num_siblings in __max_logical_packages calculation) Signed-off-by: Prarit Bhargava Cc: Jakub Kicinski Cc: netdev@vger.kernel.org Cc: "netdev@vger.kernel.org" Cc: Clark Williams Cc: Andi Kleen Cc: x86@kernel.org Cc: Thomas Gleixner Link: https://marc.info/?t=151246092100004&r=1&w=2 --- arch/x86/kernel/smpboot.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index eaee15fb7d8b..882c61e1d7a2 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -106,7 +106,7 @@ EXPORT_SYMBOL(__max_logical_packages); static unsigned int logical_packages __read_mostly; /* Maximum number of SMT threads on any online core */ -int __max_smt_threads __read_mostly; +int __read_mostly __max_smt_threads = 1; /* Flag to indicate if a complete sched domain rebuild is required */ bool x86_topology_update;