Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932208Ab0DGAGm (ORCPT ); Tue, 6 Apr 2010 20:06:42 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:60512 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932211Ab0DGAGX (ORCPT ); Tue, 6 Apr 2010 20:06:23 -0400 Date: Tue, 6 Apr 2010 17:05:32 -0700 From: Andrew Morton To: Mel Gorman Cc: Andrea Arcangeli , Christoph Lameter , Adam Litke , Avi Kivity , David Rientjes , Minchan Kim , KAMEZAWA Hiroyuki , KOSAKI Motohiro , Rik van Riel , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 04/14] Allow CONFIG_MIGRATION to be set without CONFIG_NUMA or memory hot-remove Message-Id: <20100406170532.56c71031.akpm@linux-foundation.org> In-Reply-To: <1270224168-14775-5-git-send-email-mel@csn.ul.ie> References: <1270224168-14775-1-git-send-email-mel@csn.ul.ie> <1270224168-14775-5-git-send-email-mel@csn.ul.ie> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.9; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1384 Lines: 41 On Fri, 2 Apr 2010 17:02:38 +0100 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. > > ... > > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -172,6 +172,16 @@ 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. Seems strange to depend on hugetlbfs. Perhaps depending on HUGETLB_PAGE would be more logical. But hang on. I wanna use compaction to make my order-4 wireless skb allocations work better! Why do you hate me? -- 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/