From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264012AbTJFSln (ORCPT ); Mon, 6 Oct 2003 14:41:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264013AbTJFSln (ORCPT ); Mon, 6 Oct 2003 14:41:43 -0400 Received: from mail.kroah.org ([65.200.24.183]:43741 "EHLO perch.kroah.org") by vger.kernel.org with ESMTP id S264012AbTJFSlf (ORCPT ); Mon, 6 Oct 2003 14:41:35 -0400 Date: Mon, 6 Oct 2003 11:34:05 -0700 From: Greg KH To: Dipankar Sarma Cc: Maneesh Soni , Al Viro , Patrick Mochel , LKML Subject: Re: [RFC 0/6] Backing Store for sysfs Message-ID: <20031006183403.GA6274@kroah.com> References: <20031006085915.GE4220@in.ibm.com> <20031006160846.GA4125@us.ibm.com> <20031006173111.GA1788@in.ibm.com> <20031006173858.GA4403@kroah.com> <20031006180119.GC1788@in.ibm.com> <20031006180907.GA4611@kroah.com> <20031006183132.GD1788@in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20031006183132.GD1788@in.ibm.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 07, 2003 at 12:01:32AM +0530, Dipankar Sarma wrote: > On Mon, Oct 06, 2003 at 11:09:07AM -0700, Greg KH wrote: > > On Mon, Oct 06, 2003 at 11:31:19PM +0530, Dipankar Sarma wrote: > > No. My main point is that for every hotplug event (which is caused by a > > kobject being created or destroyed), udev will run and look at the sysfs > > entry for the kobject (by using libsysfs which reads in all of the > > kobject information, including attributes). This is a normal event, so > > we have to care about what happens after running 'find' on the sysfs > > tree as that is basically what will always happen. > > > > Does that make more sense? We can't just look at what happens with this > > patch without actually accessing all of the sysfs tree, as that will be > > the "normal" case. > > That sounds odd. So, udev essentially results in a frequent and continuous > "find /sys" ? That doesn't sound good. You are unnecessarily adding > pressure on vfs (dcache specially). We will discuss this offline then > and see what needs to be done. No, not a 'find', we look up the kobject that was added, and its attributes. Doing a 'find' will emulate this for your tests, that's all. thanks, greg k-h