From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752861Ab1ATR1D (ORCPT ); Thu, 20 Jan 2011 12:27:03 -0500 Received: from kroah.org ([198.145.64.141]:44007 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752178Ab1ATR1C (ORCPT ); Thu, 20 Jan 2011 12:27:02 -0500 Date: Thu, 20 Jan 2011 09:25:26 -0800 From: Greg KH To: Nathan Fontenot Cc: linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, KAMEZAWA Hiroyuki , Robin Holt Subject: Re: [PATCH 0/4] De-couple sysfs memory directories from memory sections Message-ID: <20110120172526.GC21643@kroah.com> References: <4D386498.9080201@austin.ibm.com> <20110120164555.GA30922@kroah.com> <4D386820.5080902@austin.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4D386820.5080902@austin.ibm.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 20, 2011 at 10:51:44AM -0600, Nathan Fontenot wrote: > On 01/20/2011 10:45 AM, Greg KH wrote: > > On Thu, Jan 20, 2011 at 10:36:40AM -0600, Nathan Fontenot wrote: > >> The root of this issue is in sysfs directory creation. Every time > >> a directory is created a string compare is done against sibling > >> directories ( see sysfs_find_dirent() ) to ensure we do not create > >> duplicates. The list of directory nodes in sysfs is kept as an > >> unsorted list which results in this being an exponentially longer > >> operation as the number of directories are created. > > > > Again, are you sure about this? I thought we resolved this issue in the > > past, but you were going to check it. Did you? > > > > Yes, the string compare is still present in the sysfs code. There was > discussion around this sometime last year when I sent a patch out that > stored the directory entries in something other than a linked list. > That patch was rejected but it was agreed that something should be done. Ah, ok, thanks for verifying. greg k-h