From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753486Ab3KDOK4 (ORCPT ); Mon, 4 Nov 2013 09:10:56 -0500 Received: from mail-ea0-f171.google.com ([209.85.215.171]:63457 "EHLO mail-ea0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752554Ab3KDOKz (ORCPT ); Mon, 4 Nov 2013 09:10:55 -0500 Date: Mon, 4 Nov 2013 15:10:51 +0100 From: Ingo Molnar To: Josh Boyer Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , prarit@redhat.com, x86@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] x86: Allow NR_CPUS=1024 Message-ID: <20131104141051.GA19355@gmail.com> References: <20131101141148.GH8652@hansolo.jdub.homelinux.org> <20131103101825.GA6605@gmail.com> <20131103102132.GA6807@gmail.com> <20131103155729.GB9944@hansolo.jdub.homelinux.org> <20131104065343.GC13030@gmail.com> <20131104140141.GC9944@hansolo.jdub.homelinux.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131104140141.GC9944@hansolo.jdub.homelinux.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Josh Boyer wrote: > > Why touch MAXSMP at all? It's really just a shortcut for 'configure > > the kernel silly large', via a single option, nothing else. You are > > not forced to use it and it should not affect configurability of > > NR_CPUS. > > > > What we _really_ want here is to fix NR_CPUS setting: to extend its > > range and to enforce that NR_CPUS cannot be set larger than 512 > > without setting CONFIG_CPUMASK_OFFSTACK. > > OK. I was just thinking that if we've come to the conclusion that 4096 > CPUs isn't silly large anymore, we should make MAXSMP be something we > consider silly large. [...] MAXSMP is also supposed to track the real hardware max as well on x86 - i.e. we should only increase it to 8192 etc. if such hardware exists. Thanks, Ingo