From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261902AbULKB3J (ORCPT ); Fri, 10 Dec 2004 20:29:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261904AbULKB3J (ORCPT ); Fri, 10 Dec 2004 20:29:09 -0500 Received: from ylpvm43-ext.prodigy.net ([207.115.57.74]:21202 "EHLO ylpvm43.prodigy.net") by vger.kernel.org with ESMTP id S261902AbULKB3G (ORCPT ); Fri, 10 Dec 2004 20:29:06 -0500 From: David Brownell To: linux-usb-devel@lists.sourceforge.net Subject: Re: [linux-usb-devel] [RFC PATCH] debugfs - yet another in-kernel file system Date: Fri, 10 Dec 2004 17:29:01 -0800 User-Agent: KMail/1.7.1 Cc: Greg KH , linux-kernel@vger.kernel.org References: <20041210005055.GA17822@kroah.com> In-Reply-To: <20041210005055.GA17822@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit Content-Disposition: inline Message-Id: <200412101729.01155.david-b@pacbell.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thursday 09 December 2004 4:50 pm, Greg KH wrote: > What if there was a in-kernel filesystem that was explicitly just for > putting debugging stuff?  Some place other than proc and sysfs, and that > was easier than both of them to use.  Yet it needed to also be able to > handle complex stuff like seq file and raw file_ops if needed. The problem with sysfs here is: no seq_file support. Otherwise it solves the basic "where to put the debug files associated with "device X" or "driver Y" problems in a good non-confusing way: there are directories already set up for devices and for drivers. The problem with procfs here is that it doesn't have such a naming solution: there's no automatic mapping betwen a /proc/driver/...file and its device, or vice versa. That issue is shared with debugfs. Couldn't debugfs just be a thin shim on top of sysfs, adding seq_file support? Or on top of procfs, adding device/driver naming domains, and maybe file-per-value read/write support for drivers that want them? What I'd really want out of a debug file API is to resolve the naming issues, work with seq_file, and "softly and silently vanish away". I think this patch has the last two, but not the first one! - Dave