From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753349AbYLFTf4 (ORCPT ); Sat, 6 Dec 2008 14:35:56 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752356AbYLFTfs (ORCPT ); Sat, 6 Dec 2008 14:35:48 -0500 Received: from zeniv.linux.org.uk ([195.92.253.2]:33583 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752192AbYLFTfs (ORCPT ); Sat, 6 Dec 2008 14:35:48 -0500 Date: Sat, 6 Dec 2008 19:35:41 +0000 From: Al Viro To: Nick Andrew Cc: Joe Perches , Andrew Morton , Linux Kernel Mailing List , Linus Torvalds , Tejun Heo , Takashi Iwai Subject: Re: [RFC] Recursive printk Message-ID: <20081206193541.GQ28946@ZenIV.linux.org.uk> References: <20081206065922.29149.63380.stgit@marcab.local.tull.net> <20081205232016.366765e2.akpm@linux-foundation.org> <1228549357.13046.618.camel@localhost> <20081206084038.GG5957@mail.local.tull.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081206084038.GG5957@mail.local.tull.net> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Dec 06, 2008 at 07:40:38PM +1100, Nick Andrew wrote: > The basic problem is that subsystems want to prepend or append their > own data to kernel messages generated by subsystem code, and they > both want to use printf-type strings. How to combine them into a > single kernel log message without using extra memory, or double > handling of strings? The basic problem with your approach is that printk interpretation of arguments becomes dependent on more than its first (and hopefully an explicit constant) argument.