Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756830AbXFSKFc (ORCPT ); Tue, 19 Jun 2007 06:05:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756207AbXFSKFL (ORCPT ); Tue, 19 Jun 2007 06:05:11 -0400 Received: from TYO201.gate.nec.co.jp ([202.32.8.193]:51514 "EHLO tyo201.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756147AbXFSKFI (ORCPT ); Tue, 19 Jun 2007 06:05:08 -0400 Message-ID: <4677AA3D.7010604@bx.jp.nec.com> Date: Tue, 19 Jun 2007 19:04:45 +0900 From: Keiichi KII User-Agent: Thunderbird 2.0.0.0 (Windows/20070326) MIME-Version: 1.0 To: Satyam Sharma CC: Matt Mackall , Andrew Morton , David Miller , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: [RFC][PATCH -mm take5 6/7] add ioctls for adding/removing target References: <466FC455.5060001@bx.jp.nec.com> <466FC76A.6050006@bx.jp.nec.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2147 Lines: 51 Hello Satyam, > *ugh*. I was wondering what a show-stopper this particular patch > was -- introduces a couple of ioctl()'s, exports a new structure to > userspace, adds a hitherto-unneeded header file, brings in > tty_struct/tty_operations and ends up adding so much complexity/ > bloat to netconsole.c. Not only that, it must live together (and > side-by-side) with the sysfs interface also, because the two of them > do different things: sysfs to be able to modify target parameters at > run-time and the ioctl()'s to dynamically add/remove targets. We > can't really mkdir(2) or rmdir(2) in sysfs so the ioctl()'s are needed. > > So may I suggest: > > Just lose *both* the sysfs and ioctl() interfaces and use _configfs_. > It is *precisely* the thing you need in your driver here -- the ability > to create / destroy kernel objects (or config_items in configfs lingo) > from _userspace_ via simple mkdir(2) and rmdir(2). And configfs > makes changing multiple configurable parameters atomically trivial > too, via rename(2) ... not to mention a sysfs+ioctls -> configfs > conversion would help your patchset lose some weight too :-) Stephen Hemminger previously advised me about the user interface such as the following messages. > Some other speculations: > 1. Would it be possible to add ioctl's to /dev/console? This would be more in > keeping with older Unix style model. > > 2. Using sysfs makes sense if there is a device object that exists to > add the sysfs attributes to. > > 3. Procfs is handy for summary type tables. > > 4. Netlink does feel like overkill for this. Although newer generic netlink > makes it easier. So, I implemented ioctls to add/remove port like this patch on the tty driver. But I'm going to search configfs. Thank you for you information. Thanks -- Keiichi KII NEC Corporation OSS Platform Development Division E-mail: k-keiichi@bx.jp.nec.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/