From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262328AbTJFRjU (ORCPT ); Mon, 6 Oct 2003 13:39:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262336AbTJFRjU (ORCPT ); Mon, 6 Oct 2003 13:39:20 -0400 Received: from mtagate6.uk.ibm.com ([195.212.29.139]:35495 "EHLO mtagate6.uk.ibm.com") by vger.kernel.org with ESMTP id S262328AbTJFRjL (ORCPT ); Mon, 6 Oct 2003 13:39:11 -0400 Date: Mon, 6 Oct 2003 23:11:08 +0530 From: Dipankar Sarma To: Greg KH Cc: Maneesh Soni , Al Viro , Patrick Mochel , LKML Subject: Re: [RFC 1/6] sysfs-kobject.patch Message-ID: <20031006174108.GB1788@in.ibm.com> Reply-To: dipankar@in.ibm.com References: <20031006085915.GE4220@in.ibm.com> <20031006090003.GF4220@in.ibm.com> <20031006161639.GC4125@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20031006161639.GC4125@us.ibm.com> User-Agent: Mutt/1.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 06, 2003 at 09:16:40AM -0700, Greg KH wrote: > On Mon, Oct 06, 2003 at 02:30:03PM +0530, Maneesh Soni wrote: > > diff -puN include/linux/kobject.h~sysfs-kobject include/linux/kobject.h > > --- linux-2.6.0-test6/include/linux/kobject.h~sysfs-kobject 2003-10-06 11:48:37.000000000 +0530 > > +++ linux-2.6.0-test6-maneesh/include/linux/kobject.h 2003-10-06 11:48:51.000000000 +0530 > > @@ -32,6 +32,12 @@ struct kobject { > > struct kset * kset; > > struct kobj_type * ktype; > > struct dentry * dentry; > > + struct list_head k_sibling; > > + struct list_head k_children; > > + struct list_head attr; > > + struct list_head attr_group; > > + struct rw_semaphore k_rwsem; > > + char *k_symlink; > > }; > > Ouch. Like Al said, this is too bloated. Remember, not all kobjects That is not what LowFree numbers after mounting sysfs says. Sure you add some 48 bytes to kobject, but you are no longer pinning 256-byte(??) dentries and possibly bigger inodes for kobjects. Doesn't that count ? > are registered for use in sysfs. This makes the overhead for such > usages pretty high :( The only way to confirm this is with numbers. Maneesh posted some numbers that clearly show that memory usage is lower even with the added fields in kobjects. Now, the question is are there scenerios where kobject size increase in overhead. It will be nice to have some numbers to demonstrate that. Thanks Dipankar