Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756795Ab1EBVZN (ORCPT ); Mon, 2 May 2011 17:25:13 -0400 Received: from e7.ny.us.ibm.com ([32.97.182.137]:48065 "EHLO e7.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753715Ab1EBVZM (ORCPT ); Mon, 2 May 2011 17:25:12 -0400 Subject: Re: [PATCH 1/4] mm: Remove dependency on CONFIG_FLATMEM from online_page() From: Dave Hansen To: Daniel Kiper Cc: ian.campbell@citrix.com, akpm@linux-foundation.org, andi.kleen@intel.com, haicheng.li@linux.intel.com, fengguang.wu@intel.com, jeremy@goop.org, konrad.wilk@oracle.com, dan.magenheimer@oracle.com, v.tolstov@selfip.ru, pasik@iki.fi, wdauchy@gmail.com, rientjes@google.com, xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org In-Reply-To: <20110502211915.GB4623@router-fw-old.local.net-space.pl> References: <20110502211915.GB4623@router-fw-old.local.net-space.pl> Content-Type: text/plain; charset="ISO-8859-1" Date: Mon, 02 May 2011 14:25:04 -0700 Message-ID: <1304371504.30823.45.camel@nimitz> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1243 Lines: 28 On Mon, 2011-05-02 at 23:19 +0200, Daniel Kiper wrote: > Memory hotplug code strictly depends on CONFIG_SPARSEMEM. > It means that code depending on CONFIG_FLATMEM in online_page() > is never compiled. Remove it because it is not needed anymore. It's subtle, but I don't think that's true. We had another hotplug mode for x86_64 before folks were comfortable turning SPARSEMEM on for the whole architecture. It was quite possible to have memory hotplug without sparsemem in that case. I think Keith Mannthey did some of that code if I remember right. But, I'm not sure how much of that stayed in distros versus made it upstream. In any case, you might want to chase down the X86_64_ACPI_NUMA bit to make sure it can't be used with FLATMEM ever. config MEMORY_HOTPLUG bool "Allow for memory hot-add" depends on SPARSEMEM || X86_64_ACPI_NUMA depends on HOTPLUG && ARCH_ENABLE_MEMORY_HOTPLUG depends on (IA64 || X86 || PPC_BOOK3S_64 || SUPERH || S390) -- Dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/