From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261443AbVGTSkH (ORCPT ); Wed, 20 Jul 2005 14:40:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261448AbVGTSkH (ORCPT ); Wed, 20 Jul 2005 14:40:07 -0400 Received: from rgminet02.oracle.com ([148.87.122.31]:53165 "EHLO rgminet02.oracle.com") by vger.kernel.org with ESMTP id S261443AbVGTSkE (ORCPT ); Wed, 20 Jul 2005 14:40:04 -0400 Date: Wed, 20 Jul 2005 11:39:38 -0700 From: Joel Becker To: linux clustering Cc: "Walker, Bruce J (HP-Labs)" , David Teigland , linux-kernel@vger.kernel.org, ocfs2-devel@oss.oracle.com, clusters_sig@lists.osdl.org Subject: Re: [Clusters_sig] RE: [Linux-cluster] Re: [Ocfs2-devel] [RFC] nodemanager, ocfs2, dlm Message-ID: <20050720183938.GM16618@ca-server1.us.oracle.com> Mail-Followup-To: linux clustering , "Walker, Bruce J (HP-Labs)" , David Teigland , linux-kernel@vger.kernel.org, ocfs2-devel@oss.oracle.com, clusters_sig@lists.osdl.org References: <3689AF909D816446BA505D21F1461AE404167CFB@cacexc04.americas.cpqcorp.net> <20050720180918.GU5416@marowsky-bree.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050720180918.GU5416@marowsky-bree.de> X-Burt-Line: Trees are cool. X-Red-Smith: Ninety feet between bases is perhaps as close as man has ever come to perfection. User-Agent: Mutt/1.5.9i X-Brightmail-Tracker: AAAAAQAAAAI= X-Whitelist: TRUE Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 20, 2005 at 08:09:18PM +0200, Lars Marowsky-Bree wrote: > On 2005-07-20T09:55:31, "Walker, Bruce J (HP-Labs)" wrote: > > > Like Lars, I too was under the wrong impression about this configfs > > "nodemanager" kernel component. Our discussions in the cluster > > meeting Monday and Tuesday were assuming it was a general service that > > other kernel components could/would utilize and possibly also > > something that could send uevents to non-kernel components wanting a > > std. way to see membership information/events. > > Let me clarify that this was something we briefly touched on in > Walldorf: The node manager would (re-)export the current data via sysfs > (which would result in uevents being sent, too), and not something we > dreamed up just Monday ;-) In turn, let me clarify a little where configfs fits in to things. Configfs is merely a convenient and transparent method to communicate configuration to kernel objects. It's not a place for uevents, for netlink sockets, or for fancy communication. It allows userspace to create an in-kernel object and set/get values on that object. It also allows userspace and kernelspace to share the same representation of that object and its values. For more complex interaction, sysfs and procfs are often more appropriate. While you might "configure" all known nodes in configfs, the node up/down state might live in sysfs. A netlink socket for up/down events might live in procfs. And so on. Joel -- "But all my words come back to me In shades of mediocrity. Like emptiness in harmony I need someone to comfort me." Joel Becker Senior Member of Technical Staff Oracle E-mail: joel.becker@oracle.com Phone: (650) 506-8127