From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261519AbUL3Nja (ORCPT ); Thu, 30 Dec 2004 08:39:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261642AbUL3Nhw (ORCPT ); Thu, 30 Dec 2004 08:37:52 -0500 Received: from e33.co.us.ibm.com ([32.97.110.131]:43763 "EHLO e33.co.us.ibm.com") by vger.kernel.org with ESMTP id S261519AbUL3Ngm (ORCPT ); Thu, 30 Dec 2004 08:36:42 -0500 Date: Thu, 30 Dec 2004 19:04:59 +0530 From: Maneesh Soni To: "Adam J. Richter" Cc: akpm@osdl.org, chrisw@osdl.org, greg@kroah.com, linux-kernel@vger.kernel.org, viro@parcelfarce.linux.theplanet.co.uk Subject: Re: [Fake patch] Make sysfs_dirent.s_type an unsigned short Message-ID: <20041230133459.GC3122@in.ibm.com> Reply-To: maneesh@in.ibm.com References: <200412030356.iB33uSg03460@adam.yggdrasil.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200412030356.iB33uSg03460@adam.yggdrasil.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 03, 2004 at 04:08:58AM +0000, Adam J. Richter wrote: > Here is a fake patch against my heavily hacked sysfs tree > to change sysfs_dirent.s_type from an int to an unsigned short. > It appears next to another unsigned short (s_mode), so it should > save 4 bytes per sysfs node. > > Note that this patch will not apply to a pristine 2.6.10-rc2-bk15 > tree, because I've moved the declaration of struct sysfs_dirent > from include/linux/sysfs.h to fs/sysfs/sysfs.h in a previous patch. > > By the way, I have to sheepishly admit that somehow I previously > underestimated the size of struct sysfs_dirent. Only now > with s_children and s_count removed and s_type shortened to 16 bits > does sysfs_dirent occupy 32 bytes, according to /proc/slabinfo. > This does not effect my previous statements about how much memory > is saved by each of the patches that I've posted. It just means > the original amount of memory being used was more. > Looks sane. Thanks Maneesh > --- linux.prev/fs/sysfs/sysfs.h 2004-12-03 11:51:19.000000000 +0800 > +++ linux/fs/sysfs/sysfs.h 2004-12-03 00:51:44.000000000 +0800 > @@ -13,7 +13,7 @@ > struct sysfs_dirent { > struct list_head s_sibling; > void * s_element; > - int s_type; > + unsigned short s_type; > umode_t s_mode; > struct dentry * s_dentry; > }; > - -- Maneesh Soni Linux Technology Center, IBM India Software Labs, Bangalore, India email: maneesh@in.ibm.com Phone: 91-80-25044990