From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755876AbYFLTAp (ORCPT ); Thu, 12 Jun 2008 15:00:45 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758311AbYFLTAc (ORCPT ); Thu, 12 Jun 2008 15:00:32 -0400 Received: from g4t0014.houston.hp.com ([15.201.24.17]:1972 "EHLO g4t0014.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753739AbYFLTAa (ORCPT ); Thu, 12 Jun 2008 15:00:30 -0400 Subject: Re: [PATCH] undo the brd.c part of ramfs-and-ram-disk-pages-are-unevictable.patch From: Lee Schermerhorn To: Rik van Riel Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, Nick Piggin In-Reply-To: <20080612135353.2d17436a@cuia.bos.redhat.com> References: <20080612135353.2d17436a@cuia.bos.redhat.com> Content-Type: text/plain Organization: HP/OSLO Date: Thu, 12 Jun 2008 15:00:57 -0400 Message-Id: <1213297257.6240.15.camel@lts-notebook> Mime-Version: 1.0 X-Mailer: Evolution 2.22.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2008-06-12 at 13:53 -0400, Rik van Riel wrote: > Undo the brd.c part of ramfs-and-ram-disk-pages-are-unevictable.patch. > The brd pages do not live on the LRU at all, so there is no need to > play these tricks. Does this mean that these pages cannot be migrated? E.g., to evacuate memory for hotplug? Looks like all paths to migrate_pages() construct a list of pages to migrate by isolating them from the lru [isolate_lru_page()]. Any pages not found in the lru are skipped. Lee > > Debugged-by: Nick Piggin > Signed-off-by: Rik van Riel > > --- > drivers/block/brd.c | 13 ------------- > 1 file changed, 13 deletions(-) > > Index: linux-2.6.26-rc5-mm2/drivers/block/brd.c > =================================================================== > --- linux-2.6.26-rc5-mm2.orig/drivers/block/brd.c 2008-06-11 14:39:43.000000000 -0400 > +++ linux-2.6.26-rc5-mm2/drivers/block/brd.c 2008-06-12 13:49:18.000000000 -0400 > @@ -374,21 +374,8 @@ static int brd_ioctl(struct inode *inode > return error; > } > > -/* > - * brd_open(): > - * Just mark the mapping as containing unevictable pages > - */ > -static int brd_open(struct inode *inode, struct file *filp) > -{ > - struct address_space *mapping = inode->i_mapping; > - > - mapping_set_unevictable(mapping); > - return 0; > -} > - > static struct block_device_operations brd_fops = { > .owner = THIS_MODULE, > - .open = brd_open, > .ioctl = brd_ioctl, > #ifdef CONFIG_BLK_DEV_XIP > .direct_access = brd_direct_access, >