From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752498Ab0CQC2d (ORCPT ); Tue, 16 Mar 2010 22:28:33 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:42990 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752130Ab0CQC2c (ORCPT ); Tue, 16 Mar 2010 22:28:32 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Mel Gorman Subject: Re: [PATCH 04/11] Allow CONFIG_MIGRATION to be set without CONFIG_NUMA or memory hot-remove Cc: kosaki.motohiro@jp.fujitsu.com, Andrew Morton , Andrea Arcangeli , Christoph Lameter , Adam Litke , Avi Kivity , David Rientjes , Rik van Riel , linux-kernel@vger.kernel.org, linux-mm@kvack.org In-Reply-To: <1268412087-13536-5-git-send-email-mel@csn.ul.ie> References: <1268412087-13536-1-git-send-email-mel@csn.ul.ie> <1268412087-13536-5-git-send-email-mel@csn.ul.ie> Message-Id: <20100317110748.4C94.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Wed, 17 Mar 2010 11:28:26 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > CONFIG_MIGRATION currently depends on CONFIG_NUMA or on the architecture > being able to hot-remove memory. The main users of page migration such as > sys_move_pages(), sys_migrate_pages() and cpuset process migration are > only beneficial on NUMA so it makes sense. > > As memory compaction will operate within a zone and is useful on both NUMA > and non-NUMA systems, this patch allows CONFIG_MIGRATION to be set if the > user selects CONFIG_COMPACTION as an option. > > Signed-off-by: Mel Gorman > Reviewed-by: Christoph Lameter > Reviewed-by: Rik van Riel > Reviewed-by: KAMEZAWA Hiroyuki > --- > mm/Kconfig | 20 ++++++++++++++++---- > 1 files changed, 16 insertions(+), 4 deletions(-) > > diff --git a/mm/Kconfig b/mm/Kconfig > index 9c61158..04e241b 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -172,17 +172,29 @@ config SPLIT_PTLOCK_CPUS > default "4" > > # > +# support for memory compaction > +config COMPACTION > + bool "Allow for memory compaction" > + def_bool y > + select MIGRATION > + depends on EXPERIMENTAL && HUGETLBFS && MMU > + help > + Allows the compaction of memory for the allocation of huge pages. > + If select MIGRATION works, we can remove "depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE" line from config MIGRATION. > +# > # support for page migration > # > config MIGRATION > bool "Page migration" > def_bool y > - depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE > + depends on NUMA || ARCH_ENABLE_MEMORY_HOTREMOVE || COMPACTION > help > Allows the migration of the physical location of pages of processes > - while the virtual addresses are not changed. This is useful for > - example on NUMA systems to put pages nearer to the processors accessing > - the page. > + while the virtual addresses are not changed. This is useful in > + two situations. The first is on NUMA systems to put pages nearer > + to the processors accessing. The second is when allocating huge > + pages as migration can relocate pages to satisfy a huge page > + allocation instead of reclaiming. > > config PHYS_ADDR_T_64BIT > def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT > -- > 1.6.5 >