Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753175AbdL0Qtp (ORCPT ); Wed, 27 Dec 2017 11:49:45 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:36592 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753143AbdL0Qtl (ORCPT ); Wed, 27 Dec 2017 11:49:41 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Gleixner , Andy Lutomirski , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Josh Poimboeuf , Juergen Gross , Linus Torvalds , Peter Zijlstra , Ingo Molnar Subject: [PATCH 4.14 09/74] x86/Kconfig: Limit NR_CPUS on 32-bit to a sane amount Date: Wed, 27 Dec 2017 17:45:42 +0100 Message-Id: <20171227164614.480065102@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20171227164614.109898944@linuxfoundation.org> References: <20171227164614.109898944@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1641 Lines: 47 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Gleixner commit 7bbcbd3d1cdcbacd0f9f8dc4c98d550972f1ca30 upstream. The recent cpu_entry_area changes fail to compile on 32-bit when BIGSMP=y and NR_CPUS=512, because the fixmap area becomes too big. Limit the number of CPUs with BIGSMP to 64, which is already way to big for 32-bit, but it's at least a working limitation. We performed a quick survey of 32-bit-only machines that might be affected by this change negatively, but found none. Signed-off-by: Thomas Gleixner Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Dave Hansen Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Juergen Gross Cc: Linus Torvalds Cc: Peter Zijlstra Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/Kconfig | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -925,7 +925,8 @@ config MAXSMP config NR_CPUS int "Maximum number of CPUs" if SMP && !MAXSMP range 2 8 if SMP && X86_32 && !X86_BIGSMP - range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK + range 2 64 if SMP && X86_32 && X86_BIGSMP + range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK && X86_64 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64 default "1" if !SMP default "8192" if MAXSMP