From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nick Piggin Subject: Re: [PATCH -mm 14/24] Ramfs and Ram Disk pages are unevictable Date: Thu, 12 Jun 2008 10:54:18 +1000 References: <20080611184214.605110868@redhat.com> <20080611184339.693975681@redhat.com> In-Reply-To: <20080611184339.693975681@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200806121054.19253.nickpiggin@yahoo.com.au> Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: linux-kernel@vger.kernel.org, Andrew Morton , Lee Schermerhorn , Kosaki Motohiro , linux-mm@kvack.org, Eric Whitney List-ID: On Thursday 12 June 2008 04:42, Rik van Riel wrote: > From: Lee Schermerhorn > > Christoph Lameter pointed out that ram disk pages also clutter the > LRU lists. When vmscan finds them dirty and tries to clean them, > the ram disk writeback function just redirties the page so that it > goes back onto the active list. Round and round she goes... > Index: linux-2.6.26-rc5-mm2/drivers/block/brd.c > =================================================================== > --- linux-2.6.26-rc5-mm2.orig/drivers/block/brd.c 2008-06-10 > 10:46:18.000000000 -0400 +++ > linux-2.6.26-rc5-mm2/drivers/block/brd.c 2008-06-10 16:47:23.000000000 > -0400 @@ -374,8 +374,21 @@ 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, This isn't the case for brd any longer. It doesn't use the buffer cache as its backing store, so the buffer cache is reclaimable. -- 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