From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266884AbUH1VDR (ORCPT ); Sat, 28 Aug 2004 17:03:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267864AbUH1VDK (ORCPT ); Sat, 28 Aug 2004 17:03:10 -0400 Received: from ns.virtualhost.dk ([195.184.98.160]:39574 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S266884AbUH1VCn (ORCPT ); Sat, 28 Aug 2004 17:02:43 -0400 Date: Sat, 28 Aug 2004 22:59:34 +0200 From: Jens Axboe To: Andrew Morton Cc: Adrian Bunk , mrmacman_g4@mac.com, linux-kernel@vger.kernel.org Subject: Re: [2.6 patch][1/3] ipc/ BUG -> BUG_ON conversions Message-ID: <20040828205933.GC8716@suse.de> References: <20040828151137.GA12772@fs.tum.de> <20040828151544.GB12772@fs.tum.de> <098EB4E1-F90C-11D8-A7C9-000393ACC76E@mac.com> <20040828162633.GG12772@fs.tum.de> <20040828125816.206ef7fa.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040828125816.206ef7fa.akpm@osdl.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Aug 28 2004, Andrew Morton wrote: > Adrian Bunk wrote: > > > > > Anything you put in BUG_ON() must *NOT* have side effects. > > >... > > > > I'd have said exactly the same some time ago, but I was convinced by > > Arjan that if done correctly, a BUG_ON() with side effects is possible > > with no extra cost even if you want to make BUG configurably do nothing. > > Nevertheless, I think I'd prefer that we not move code which has > side-effects into BUG_ONs. For some reason it seems neater that way. > > Plus one would like to be able to do > > BUG_ON(strlen(str) > 22); > > and have strlen() not be evaluated if BUG_ON is disabled. > > A minor distinction, but one which it would be nice to preserve. Precisely, I fully agree (even though BUG_ON() will never be defined away, if you should not do the check kill it completely). -- Jens Axboe