From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757425AbZEHGjo (ORCPT ); Fri, 8 May 2009 02:39:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753435AbZEHGjf (ORCPT ); Fri, 8 May 2009 02:39:35 -0400 Received: from vpn.id2.novell.com ([195.33.99.129]:46912 "EHLO vpn.id2.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751516AbZEHGje convert rfc822-to-8bit (ORCPT ); Fri, 8 May 2009 02:39:34 -0400 Message-Id: <4A03F016.76EA.0078.0@novell.com> X-Mailer: Novell GroupWise Internet Agent 8.0.0 Date: Fri, 08 May 2009 07:40:54 +0100 From: "Jan Beulich" To: "H. Peter Anvin" Cc: , , Subject: Re: [PATCH] x86-64: improve e820_search_gap() References: <4A0199B8.76EA.0078.0@novell.com> <4A03BC1A.9060605@zytor.com> In-Reply-To: <4A03BC1A.9060605@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>> "H. Peter Anvin" 08.05.09 06:59 >>> >Jan Beulich wrote: >> Impact: bug fix >> >> Blindly putting the gap close after max_pfn is in conflict with that >> same memory range potentially being used by hotplugged memory. >> >> Also, make the function static to ensure there are no other users that >> could depend on the previous behavior regarding the way start_addr gets >> specified. >> >> Signed-off-by: Jan Beulich >> > >So blindly locate it somewhere else? How is that inherently better? >Wouldn't a machine with hotplug memory (which doesn't bother advertising >that fact so we can reserve the address space) be just as likely to use >a sparse memory space, since one can hardly expect the hardware to pack >the space (packing in hardware is why PCs generally have a >mostly-contiguous RAM space) when the memory is hotplugged? Why blindly? Aren't hotpluggable memory ranges supposed to be reserved in the E820 map? Jan