From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S939189AbdAFAbu (ORCPT ); Thu, 5 Jan 2017 19:31:50 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:35016 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932094AbdAFAbl (ORCPT ); Thu, 5 Jan 2017 19:31:41 -0500 Date: Thu, 5 Jan 2017 16:07:48 -0800 From: Andrew Morton To: Alexey Dobriyan Cc: linux-kernel@vger.kernel.org, linux@rasmusvillemoes.dk Subject: Re: [PATCH] lib/vsprintf.c: remove %Z support Message-Id: <20170105160748.1f3696c51cd4e56de132243d@linux-foundation.org> In-Reply-To: <20170103230126.GA30170@avx2> References: <20170103230126.GA30170@avx2> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 4 Jan 2017 02:01:27 +0300 Alexey Dobriyan wrote: > Now that %z is standartised in C99 there is no reason to support %Z. > Unlike %L it doesn't even make format strings smaller. > > Use BUILD_BUG_ON in a couple ATM drivers. > > In case anyone didn't notice lib/vsprintf.o is about half of SLUB > which is in my opinion is quite an achievement. Hopefully this patch > inspires someone else to trim vsprintf.c more. There's a risk that more %Z uses will sneak into the tree during the 4.10 development cycle, and possibly even later. So I added a note-to-self to re-grep the tree before sending this upstream, but that won't prevent people adding new instances later on: code which was tested under earlier kernels which has %Z support. The best suggestion I have is to add a checkpatch rule to try to catch new %Z's being added.