From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from coco.kroah.org (kroah.org [198.145.64.141]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "coco.kroah.org", Issuer "Greg KH" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 21FD3B718B for ; Fri, 21 Jan 2011 04:27:03 +1100 (EST) Date: Thu, 20 Jan 2011 09:25:26 -0800 From: Greg KH To: Nathan Fontenot 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 In-Reply-To: <4D386820.5080902@austin.ibm.com> Cc: linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, KAMEZAWA Hiroyuki , Robin Holt List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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