From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 29 May 2007 19:49:01 +0100 (IST) From: Mel Gorman Subject: Re: [PATCH 3/7] Allow CONFIG_MIGRATION to be set without CONFIG_NUMA In-Reply-To: Message-ID: References: <20070529173609.1570.4686.sendpatchset@skynet.skynet.ie> <20070529173710.1570.91203.sendpatchset@skynet.skynet.ie> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kamezawa.hiroyu@jp.fujitsu.com List-ID: On Tue, 29 May 2007, Christoph Lameter wrote: > On Tue, 29 May 2007, Mel Gorman wrote: > >>>> +config SYSCALL_MOVE_PAGES >>>> + def_bool y >>>> + depends on MIGRATION && NUMA >>>> + >>> >>> Do we really need the CONFIG_SYSCALL_MOVE_PAGES? I think you will directly >>> access the lower levels. So why have it? CONFIG_SYSCALL_MOVE_PAGES == >>> CONFIG_NUMA. >> >> Without SYSCALL_MOVE_PAGES, the check in migrate.h becomes >> >> #if defined(CONFIG_NUMA) && defined(CONFIG_MIGRATION) >> /* Check if a vma is migratable */ >> static inline int vma_migratable(struct vm_area_struct *vma) >> #endif > > Why do you need vma_migratable for the CONFIG_MIGRATION case? The use of > vma_migratable in a !NUMA sitation would not be working right as far as I > can tell. > > #ifdef CONFIG_NUMA > > is fine. > Makes sense. >> That in itself is fine but in mm/migrate.c I didn't want to define >> sys_move_pages() in the non-NUMA case. Whatever about the header file where >> SYSCALL_MOVE_PAGES obscures understanding, I think it makes sense to have >> SYSCALL_MOVE_PAGES for mm/migrate.c . What do you think? > > Why do you need sys_move_pages for the non-NUMA case? > > The low level function that I intended to be used by defrag is > migrate_pages and that one is outside of #ifdef CONFIG_NUMA. > Also make sense. It'll be fixed up in the next verion minus the SYSCALL_MOVE_PAGES dirt. It'll even simplify the patch. -- 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