From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752169Ab0CSKRN (ORCPT ); Fri, 19 Mar 2010 06:17:13 -0400 Received: from gir.skynet.ie ([193.1.99.77]:59514 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751065Ab0CSKRM (ORCPT ); Fri, 19 Mar 2010 06:17:12 -0400 Date: Fri, 19 Mar 2010 10:16:51 +0000 From: Mel Gorman To: KOSAKI Motohiro Cc: Christoph Lameter , Andrew Morton , Andrea Arcangeli , Adam Litke , Avi Kivity , David Rientjes , Rik van Riel , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 04/11] Allow CONFIG_MIGRATION to be set without CONFIG_NUMA or memory hot-remove Message-ID: <20100319101651.GT12388@csn.ul.ie> References: <20100318085226.8726.A69D9226@jp.fujitsu.com> <20100318112414.GL12388@csn.ul.ie> <20100319152106.8775.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20100319152106.8775.A69D9226@jp.fujitsu.com> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 19, 2010 at 03:21:20PM +0900, KOSAKI Motohiro wrote: > > On Thu, Mar 18, 2010 at 08:56:23AM +0900, KOSAKI Motohiro wrote: > > > > On Wed, 17 Mar 2010, Mel Gorman wrote: > > > > > > > > > > If select MIGRATION works, we can remove "depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE" > > > > > > line from config MIGRATION. > > > > > > > > > > > > > > > > I'm not quite getting why this would be an advantage. COMPACTION > > > > > requires MIGRATION but conceivable both NUMA and HOTREMOVE can work > > > > > without it. > > > > > > > > Avoids having to add additional CONFIG_XXX on the page migration "depends" > > > > line in the future. > > > > > > Yes, Kconfig mess freqently shot ourself in past days. if we have a chance > > > to remove unnecessary dependency, we should do. that's my intention of the last mail. > > > > > > > But if the depends line is removed, it could be set without NUMA, memory > > hot-remove or compaction enabled. That wouldn't be very useful. I'm > > missing something obvious. > > Perhaps I'm missing something. > > my point is, force enabling useless config is not good idea (yes, i agree). but config > selectability doesn't cause any failure. IOW, usefulness and dependency aren't > related so much. personally I dislike _unnecessary_ dependency. > > If my opinion cause any bad thing, I'll withdraw it. of course. > I've changed the MIGRATION entry to config MIGRATION bool "Page migration" def_bool y depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE i.e. it no longer depends on COMPACTION because the "select MIGRATION" in that line is enough. I've left NUMA and HOTREMOVE because migration is an optional feature for those configurations. -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id E94606B00C8 for ; Fri, 19 Mar 2010 06:17:11 -0400 (EDT) Date: Fri, 19 Mar 2010 10:16:51 +0000 From: Mel Gorman Subject: Re: [PATCH 04/11] Allow CONFIG_MIGRATION to be set without CONFIG_NUMA or memory hot-remove Message-ID: <20100319101651.GT12388@csn.ul.ie> References: <20100318085226.8726.A69D9226@jp.fujitsu.com> <20100318112414.GL12388@csn.ul.ie> <20100319152106.8775.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20100319152106.8775.A69D9226@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: Christoph Lameter , Andrew Morton , Andrea Arcangeli , Adam Litke , Avi Kivity , David Rientjes , Rik van Riel , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Fri, Mar 19, 2010 at 03:21:20PM +0900, KOSAKI Motohiro wrote: > > On Thu, Mar 18, 2010 at 08:56:23AM +0900, KOSAKI Motohiro wrote: > > > > On Wed, 17 Mar 2010, Mel Gorman wrote: > > > > > > > > > > If select MIGRATION works, we can remove "depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE" > > > > > > line from config MIGRATION. > > > > > > > > > > > > > > > > I'm not quite getting why this would be an advantage. COMPACTION > > > > > requires MIGRATION but conceivable both NUMA and HOTREMOVE can work > > > > > without it. > > > > > > > > Avoids having to add additional CONFIG_XXX on the page migration "depends" > > > > line in the future. > > > > > > Yes, Kconfig mess freqently shot ourself in past days. if we have a chance > > > to remove unnecessary dependency, we should do. that's my intention of the last mail. > > > > > > > But if the depends line is removed, it could be set without NUMA, memory > > hot-remove or compaction enabled. That wouldn't be very useful. I'm > > missing something obvious. > > Perhaps I'm missing something. > > my point is, force enabling useless config is not good idea (yes, i agree). but config > selectability doesn't cause any failure. IOW, usefulness and dependency aren't > related so much. personally I dislike _unnecessary_ dependency. > > If my opinion cause any bad thing, I'll withdraw it. of course. > I've changed the MIGRATION entry to config MIGRATION bool "Page migration" def_bool y depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE i.e. it no longer depends on COMPACTION because the "select MIGRATION" in that line is enough. I've left NUMA and HOTREMOVE because migration is an optional feature for those configurations. -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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/ . Don't email: email@kvack.org