From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 29 May 2007 11:36:51 -0700 (PDT) From: Christoph Lameter 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 Sender: owner-linux-mm@kvack.org Return-Path: To: Mel Gorman Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kamezawa.hiroyu@jp.fujitsu.com List-ID: 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. > 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. -- 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