Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752062Ab0BSOJ2 (ORCPT ); Fri, 19 Feb 2010 09:09:28 -0500 Received: from gir.skynet.ie ([193.1.99.77]:55353 "EHLO gir.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751328Ab0BSOJ0 (ORCPT ); Fri, 19 Feb 2010 09:09:26 -0500 Date: Fri, 19 Feb 2010 14:09:11 +0000 From: Mel Gorman To: KAMEZAWA Hiroyuki Cc: Andrea Arcangeli , Christoph Lameter , Adam Litke , Avi Kivity , David Rientjes , KOSAKI Motohiro , Rik van Riel , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 05/12] Allow CONFIG_MIGRATION to be set without CONFIG_NUMA or memory hot-remove Message-ID: <20100219140911.GH30258@csn.ul.ie> References: <1266516162-14154-1-git-send-email-mel@csn.ul.ie> <1266516162-14154-6-git-send-email-mel@csn.ul.ie> <20100219092111.ee280622.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20100219092111.ee280622.kamezawa.hiroyu@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 Content-Length: 3104 Lines: 89 On Fri, Feb 19, 2010 at 09:21:11AM +0900, KAMEZAWA Hiroyuki wrote: > On Thu, 18 Feb 2010 18:02:35 +0000 > Mel Gorman wrote: > > > 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 > But see below. > > > --- > > mm/Kconfig | 20 ++++++++++++++++---- > > 1 files changed, 16 insertions(+), 4 deletions(-) > > > > diff --git a/mm/Kconfig b/mm/Kconfig > > index 17b8947..b1c2781 100644 > > --- a/mm/Kconfig > > +++ b/mm/Kconfig > > @@ -168,17 +168,29 @@ 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 > > + help > > + Allows the compaction of memory for the allocation of huge pages. > > + > > I think > + depends on MMU > Agreed. Thanks > > +# > > # 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 > > > > -- > > 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 > > > -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- 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/