From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261841AbTJGF0u (ORCPT ); Tue, 7 Oct 2003 01:26:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261850AbTJGF0u (ORCPT ); Tue, 7 Oct 2003 01:26:50 -0400 Received: from dyn-ctb-210-9-245-93.webone.com.au ([210.9.245.93]:17156 "EHLO chimp.local.net") by vger.kernel.org with ESMTP id S261841AbTJGF0s (ORCPT ); Tue, 7 Oct 2003 01:26:48 -0400 Message-ID: <3F824E66.7020006@cyberone.com.au> Date: Tue, 07 Oct 2003 15:25:58 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030827 Debian/1.4-3 X-Accept-Language: en MIME-Version: 1.0 To: maneesh@in.ibm.com CC: Patrick Mochel , Dipankar Sarma , Al Viro , Greg KH , LKML Subject: Re: [RFC 0/6] Backing Store for sysfs References: <20031006202656.GB9908@in.ibm.com> <20031007043157.GA9036@in.ibm.com> In-Reply-To: <20031007043157.GA9036@in.ibm.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Maneesh Soni wrote: >On Mon, Oct 06, 2003 at 01:29:20PM -0700, Patrick Mochel wrote: > >>Uh, that's about the same thing I suggested, though probably not as >>concisely: >> >>"As I said before, I don't know the right solution, but the directions to >>look in are related to attribute groups. Attributes definitely consume the >>most amount of memory (as opposed to the kobject hierachy), so delaying >>their creation would help, hopefully without making the interface too >>awkward. >> > >Ok.. attributes do consume maximum in sysfs. In the system I mentioned >leaf dentries are about 65% of the total. > > >>You can also use the assumption that an attribute group exists for all the >>kobjects in a kset, and that a kobject knows what kset it belongs to. And >> > >That's not correct... kobject corresponding to /sys/block/hda/queue >doesnot know which kset it belongs to and what are its attributes. Same >for /sys/block/hda/queue/iosched. > > >>that eventually, all attributes should be added as part of an attribute >>group.." >> >>Attributes are the leaf entries, and they don't need to always exist. But, >>you have easy access to them via the attribute groups of the ksets the >>kobjects belong to. >> >> > >Having backing store just for leaf dentries should be fine. But there is >_no_ easy access for attributes. For this also I see some data change required >as of now. The reasons are > - not all kobjects belong to a kset. For example, /sys/block/hda/queue > - not all ksets have attribute groups > > queue and iosched might not be good examples as they are somewhat broken wrt the block device scheme. Possibly they will be put in their own kset, with /sys/block/hda/queue symlinked to them.