From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754018AbZKIDoE (ORCPT ); Sun, 8 Nov 2009 22:44:04 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753571AbZKIDoE (ORCPT ); Sun, 8 Nov 2009 22:44:04 -0500 Received: from out01.mta.xmission.com ([166.70.13.231]:47656 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753248AbZKIDoC (ORCPT ); Sun, 8 Nov 2009 22:44:02 -0500 To: Arnd Bergmann Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, David Miller , Stephen Rothwell Subject: Re: [PATCH 00/23] Removal of binary sysctl support References: <200911081306.20201.arnd@arndb.de> From: ebiederm@xmission.com (Eric W. Biederman) Date: Sun, 08 Nov 2009 19:44:02 -0800 In-Reply-To: <200911081306.20201.arnd@arndb.de> (Arnd Bergmann's message of "Sun\, 8 Nov 2009 13\:06\:20 +0000") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-XM-SPF: eid=;;;mid=;;;hst=in02.mta.xmission.com;;;ip=76.21.114.89;;;frm=ebiederm@xmission.com;;;spf=neutral X-SA-Exim-Connect-IP: 76.21.114.89 X-SA-Exim-Mail-From: ebiederm@xmission.com X-SA-Exim-Version: 4.2.1 (built Thu, 25 Oct 2007 00:26:12 +0000) X-SA-Exim-Scanned: No (on in02.mta.xmission.com); Unknown failure Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Arnd Bergmann writes: > On Sunday 08 November 2009 12:16:43 Eric W. Biederman wrote: >> This patchset reimplements sys_sysctl as a compatibility wrapper >> around /proc/sys. After which it removes all of the code to all over >> the kernel that is used today to implement the binary sysctls. >> >> I am posting this patchset to give everyone a heads up what is in >> flight. >> >> I intend to carry all of these patches in my sysctl tree. > > Very nice patches again! > > Looking at what you did, I had two ideas how to move on from there, > which may be part of your plans already: > > 1. Make it possible to build sysctl_binary.c as a loadable module > so you can get a smaller kernel without losing the option to use > binary sysctl altogether. This of course requires a small portion > to remain in the kernel, to provide the actual syscall entry point > and load the module on demand. I can see how this could make sense from a distribution perspective. > 2. On top of that, put the same code into glibc so that you don't > even have to load the module when you're running a new glibc version. > Since the binary sysctl ABI is stable (as in stiff and dead), there > should be no need to synchronize any extensions to it betwen kernel > and libc. I don't expect we will need to move this to glibc. There are so few users of sys_sysctl now, that I hardly expect it to be worth it to move this code out of the kernel. For me the big problem with sys_sysctl is solved by this patchset. It no longer constitutes a maintenance burden on the rest of the sysctl code, and the other sysctl users. Now the implementation of /proc/sys can be implemented and optimized without dealing with any sys_sysctl baggage. All of that said if someone is interested in tweaking sysctl_binary.c to make it easier to deal with sys_sysctl going away I don't have any problems. Eric