From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 12 May 2005 15:41:48 +0900 (JST) Message-Id: <20050512.154148.52902091.taka@valinux.co.jp> Subject: Re: [PATCH 2.6.12-rc3 4/8] mm: manual page migration-rc2 -- add-sys_migrate_pages-rc2.patch From: Hirokazu Takahashi In-Reply-To: <4282115C.40207@engr.sgi.com> References: <20050511043821.10876.47127.71762@jackhammer.engr.sgi.com> <20050511.222314.10910241.taka@valinux.co.jp> <4282115C.40207@engr.sgi.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: raybry@engr.sgi.com Cc: raybry@sgi.com, marcelo.tosatti@cyclades.com, ak@suse.de, haveblue@us.ibm.com, hch@infradead.org, linux-mm@kvack.org, nathans@sgi.com, raybry@austin.rr.com, lhms-devel@lists.sourceforge.net List-ID: Hi, > > BTW, I'm not sure whether it's enough that migrate_vma() can only > > migrate currently mapped pages. This may leave some pages in the > > page-cache if they're not mapped to the process address spaces yet. > > > > Thanks, > > Hirokazu Takahashi. > > If the page isn't mapped, there is no good way to match it up with > a particular process id, is there? :-) I just thought of the page, belonging to some file which is mmap()ed to the target process to be migrated. The page may not be accessed and the associated PTE isn't set yet. if vma->vm_file->f_mapping equals page_mapping(page), the page should be migrated. Pages in the swap-cache have the same problem since the related PTEs may be clean. But these cases may be rare and your approach seems to be good enough in most cases. > We've handled that separately in the actual migration application, > by sync'ing the system and then freeing clean page cache pages > before the migrate_pages() system call is invoked. > > -- > Best Regards, > Ray Thanks, Hirokazu Takahashi. -- 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: aart@kvack.org