From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965056AbWFTM3u (ORCPT ); Tue, 20 Jun 2006 08:29:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965067AbWFTM3t (ORCPT ); Tue, 20 Jun 2006 08:29:49 -0400 Received: from thunk.org ([69.25.196.29]:36244 "EHLO thunker.thunk.org") by vger.kernel.org with ESMTP id S965056AbWFTM3s (ORCPT ); Tue, 20 Jun 2006 08:29:48 -0400 Date: Tue, 20 Jun 2006 08:29:52 -0400 From: Theodore Tso To: Steven Whitehouse Cc: linux-kernel@vger.kernel.org Subject: Re: [RFC] [PATCH 1/8] inode_diet: Replace inode.u.generic_ip with inode.i_private Message-ID: <20060620122952.GB26030@thunk.org> Mail-Followup-To: Theodore Tso , Steven Whitehouse , linux-kernel@vger.kernel.org References: <20060619152003.830437000@candygram.thunk.org> <20060619153108.418349000@candygram.thunk.org> <1150796596.3856.1333.camel@quoit.chygwyn.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1150796596.3856.1333.camel@quoit.chygwyn.com> User-Agent: Mutt/1.5.11 X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@thunk.org X-SA-Exim-Scanned: No (on thunker.thunk.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 20, 2006 at 10:43:16AM +0100, Steven Whitehouse wrote: > As a further suggestion, I wonder do we really need i_private at all? > Since we have sb->s_op->alloc_inode and inode->i_sb->s_op->destroy_inode > if all filesystems did something along the following lines: > > struct myfs_inode { > struct inode i_inode; > ... > }; > > #define MYFS_I(inode) container_of((inode), struct myfs_inode, i_inode) That would work for filesystems but we would also need some solution for device inodes. (And at that point, yes, we could move it into device-specific union, but as I've already noted, that doesn't buy us anything currently.) It's worth thinking about, but for that amount of effort it might be have better ROI to work on moving the address space out of the inode given that many/most inodes in memory are caching stat information, not pages. - Ted