From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752168Ab1ARO3z (ORCPT ); Tue, 18 Jan 2011 09:29:55 -0500 Received: from mail-ey0-f174.google.com ([209.85.215.174]:54712 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750865Ab1ARO3y (ORCPT ); Tue, 18 Jan 2011 09:29:54 -0500 Message-ID: <4D35A3D6.4070801@monstr.eu> Date: Tue, 18 Jan 2011 15:29:42 +0100 From: Michal Simek Reply-To: monstr@monstr.eu User-Agent: Thunderbird 2.0.0.22 (X11/20090625) MIME-Version: 1.0 To: Andrea Arcangeli CC: linux-mm@kvack.org, Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, Marcelo Tosatti , Adam Litke , Avi Kivity , Hugh Dickins , Rik van Riel , Mel Gorman , Dave Hansen , Benjamin Herrenschmidt , Ingo Molnar , Mike Travis , KAMEZAWA Hiroyuki , Christoph Lameter , Chris Wright , bpicco@redhat.com, KOSAKI Motohiro , Balbir Singh , "Michael S. Tsirkin" , Peter Zijlstra , Johannes Weiner , Daisuke Nishimura , Chris Mason , Borislav Petkov Subject: Re: [PATCH 13 of 66] export maybe_mkwrite References: <15324c9c30081da3a740.1288798068@v2.random> <4D344EAF.1080401@petalogix.com> <20110117143345.GQ9506@random.random> In-Reply-To: <20110117143345.GQ9506@random.random> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andrea Arcangeli wrote: > Hi Michal, > > On Mon, Jan 17, 2011 at 03:14:07PM +0100, Michal Simek wrote: >> Andrea Arcangeli wrote: >>> From: Andrea Arcangeli >>> >>> huge_memory.c needs it too when it fallbacks in copying hugepages into regular >>> fragmented pages if hugepage allocation fails during COW. >>> >>> Signed-off-by: Andrea Arcangeli >>> Acked-by: Rik van Riel >>> Acked-by: Mel Gorman >> It wasn't good idea to do it. mm/memory.c is used only for system with >> MMU. System without MMU are broken. >> >> Not sure what the right fix is but anyway I think use one ifdef make >> sense (git patch in attachment). > > Can you show the build failure with CONFIG_MMU=n so I can understand > better? Other places in mm.h depends on pte_t/vm_area_struct/VM_WRITE > to be defined, if a system is without MMU nobody should call it > simply. Not saying your patch is wrong, but I'm trying to understand > how exactly it got broken and the gcc error would show it immediately. > > This is only called by memory.o and huge_memory.o and they both are > built only if MMU=y. Of course: Look for example at this page: http://www.monstr.eu/wiki/doku.php?id=log:2011-01-18_11_51_49#linux_next Thanks, Michal -- Michal Simek, Ing. (M.Eng) w: www.monstr.eu p: +42-0-721842854 Maintainer of Linux kernel 2.6 Microblaze Linux - http://www.monstr.eu/fdt/ Microblaze U-BOOT custodian From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id 071088D0039 for ; Tue, 18 Jan 2011 09:29:55 -0500 (EST) Received: by fxm12 with SMTP id 12so7383366fxm.14 for ; Tue, 18 Jan 2011 06:29:53 -0800 (PST) Message-ID: <4D35A3D6.4070801@monstr.eu> Date: Tue, 18 Jan 2011 15:29:42 +0100 From: Michal Simek Reply-To: monstr@monstr.eu MIME-Version: 1.0 Subject: Re: [PATCH 13 of 66] export maybe_mkwrite References: <15324c9c30081da3a740.1288798068@v2.random> <4D344EAF.1080401@petalogix.com> <20110117143345.GQ9506@random.random> In-Reply-To: <20110117143345.GQ9506@random.random> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Andrea Arcangeli Cc: linux-mm@kvack.org, Linus Torvalds , Andrew Morton , linux-kernel@vger.kernel.org, Marcelo Tosatti , Adam Litke , Avi Kivity , Hugh Dickins , Rik van Riel , Mel Gorman , Dave Hansen , Benjamin Herrenschmidt , Ingo Molnar , Mike Travis , KAMEZAWA Hiroyuki , Christoph Lameter , Chris Wright , bpicco@redhat.com, KOSAKI Motohiro , Balbir Singh , "Michael S. Tsirkin" , Peter Zijlstra , Johannes Weiner , Daisuke Nishimura , Chris Mason , Borislav Petkov List-ID: Andrea Arcangeli wrote: > Hi Michal, > > On Mon, Jan 17, 2011 at 03:14:07PM +0100, Michal Simek wrote: >> Andrea Arcangeli wrote: >>> From: Andrea Arcangeli >>> >>> huge_memory.c needs it too when it fallbacks in copying hugepages into regular >>> fragmented pages if hugepage allocation fails during COW. >>> >>> Signed-off-by: Andrea Arcangeli >>> Acked-by: Rik van Riel >>> Acked-by: Mel Gorman >> It wasn't good idea to do it. mm/memory.c is used only for system with >> MMU. System without MMU are broken. >> >> Not sure what the right fix is but anyway I think use one ifdef make >> sense (git patch in attachment). > > Can you show the build failure with CONFIG_MMU=n so I can understand > better? Other places in mm.h depends on pte_t/vm_area_struct/VM_WRITE > to be defined, if a system is without MMU nobody should call it > simply. Not saying your patch is wrong, but I'm trying to understand > how exactly it got broken and the gcc error would show it immediately. > > This is only called by memory.o and huge_memory.o and they both are > built only if MMU=y. Of course: Look for example at this page: http://www.monstr.eu/wiki/doku.php?id=log:2011-01-18_11_51_49#linux_next Thanks, Michal -- Michal Simek, Ing. (M.Eng) w: www.monstr.eu p: +42-0-721842854 Maintainer of Linux kernel 2.6 Microblaze Linux - http://www.monstr.eu/fdt/ Microblaze U-BOOT custodian -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org