From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264144AbUAOBh2 (ORCPT ); Wed, 14 Jan 2004 20:37:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264949AbUAOBh1 (ORCPT ); Wed, 14 Jan 2004 20:37:27 -0500 Received: from dp.samba.org ([66.70.73.150]:18823 "EHLO lists.samba.org") by vger.kernel.org with ESMTP id S264144AbUAOBh0 (ORCPT ); Wed, 14 Jan 2004 20:37:26 -0500 Date: Thu, 15 Jan 2004 10:20:48 +1100 From: Rusty Russell To: Adrian Bunk Cc: akpm@osdl.org, linux-kernel@vger.kernel.org, eike-kernel@sf-tec.de, rth@twiddle.net, torvalds@osdl.org Subject: Re: [2.6 patch] if ... BUG() -> BUG_ON() Message-Id: <20040115102048.4689664e.rusty@rustcorp.com.au> In-Reply-To: <20040113213230.GY9677@fs.tum.de> References: <20040113213230.GY9677@fs.tum.de> X-Mailer: Sylpheed version 0.9.7 (GTK+ 1.2.10; i386-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 X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 13 Jan 2004 22:32:30 +0100 Adrian Bunk wrote: > Hi Andrew, > > four months ago, Rolf Eike Beer sent a patch > against 2.6.0-test5-bk1 that converted several if ... BUG() to BUG_ON() > (this might in some cases result in slightly faster code). You know, I dislike this. The right fix is to hack gcc to allow functions (in this case, BUG()) to have an "unlikely" attribute, and therefore know that this branch is unlikely. Making code slightly less readable for minor (and hopefully temporary) optimizations is IMHO not a worthy use of your time. Quick! To the GCC sources! Run! Rusty. -- there are those who do and those who hang on and you don't see too many doers quoting their contemporaries. -- Larry McVoy