Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262392AbUK3WyO (ORCPT ); Tue, 30 Nov 2004 17:54:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262382AbUK3WyN (ORCPT ); Tue, 30 Nov 2004 17:54:13 -0500 Received: from fw.osdl.org ([65.172.181.6]:12697 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S262392AbUK3WwC (ORCPT ); Tue, 30 Nov 2004 17:52:02 -0500 Date: Tue, 30 Nov 2004 14:51:20 -0800 (PST) From: Linus Torvalds To: David Woodhouse cc: Alexandre Oliva , dhowells , Paul Mackerras , Greg KH , Matthew Wilcox , hch@infradead.org, linux-kernel@vger.kernel.org, libc-hacker@sources.redhat.com Subject: Re: [RFC] Splitting kernel headers and deprecating __KERNEL__ In-Reply-To: <1101854061.4574.4.camel@localhost.localdomain> Message-ID: References: <19865.1101395592@redhat.com> <20041125165433.GA2849@parcelfarce.linux.theplanet.co.uk> <1101406661.8191.9390.camel@hades.cambridge.redhat.com> <20041127032403.GB10536@kroah.com> <16810.24893.747522.656073@cargo.ozlabs.ibm.com> <8219.1101828816@redhat.com> <1101854061.4574.4.camel@localhost.localdomain> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1488 Lines: 45 On Tue, 30 Nov 2004, David Woodhouse wrote: > > That depends on your definition of 'break'. It should prevent abuse. Not really. It should prevent _future_ abuse. The notion of "preventing existing xxx" is insane. You can't "prevent" something that already happened unless you've come up with some new interesting theory of causality. > To pick a specific example, since you like them: where userland programs > are including atomic.h, and hence writing programs which don't compile > on some architectures, and which compile on others but silently give > non-atomic results, it's perfectly acceptable and indeed advisable to > prevent compilation across the board. > > Some people might call that breakage; I don't. I do. The thing is, the people who _notice_ the breakage are often the people who don't know what the hell to do about it. The way to prevent _future_ abuse is by adding something like #ifndef __KERNEL__ #warning "This really doesn't work" #endif which does that, and has the advantage of not breaking anything at all. In other words: if you want to move things around just to break things, THEN THAT IS INCREDIBLY STUPID. We don't do things to screw our users over. Feel free to send a patch. Linus - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/