Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932563AbVLPXXH (ORCPT ); Fri, 16 Dec 2005 18:23:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932559AbVLPXXH (ORCPT ); Fri, 16 Dec 2005 18:23:07 -0500 Received: from 213-239-205-147.clients.your-server.de ([213.239.205.147]:6093 "EHLO mail.tglx.de") by vger.kernel.org with ESMTP id S932550AbVLPXXF (ORCPT ); Fri, 16 Dec 2005 18:23:05 -0500 Subject: Re: [PATCH 1/19] MUTEX: Introduce simple mutex implementation From: Thomas Gleixner Reply-To: tglx@linutronix.de To: Linus Torvalds Cc: Geert Uytterhoeven , Steven Rostedt , Andrew Morton , linux-arch@vger.kernel.org, Linux Kernel Development , matthew@wil.cx, arjan@infradead.org, Christoph Hellwig , mingo@elte.hu, Alan Cox , nikita@clusterfs.com, pj@sgi.com, dhowells@redhat.com In-Reply-To: References: <20051215085602.c98f22ef.pj@sgi.com> <20051213143147.d2a57fb3.pj@sgi.com> <43A0AD54.6050109@rtr.ca> <20051214155432.320f2950.akpm@osdl.org> <17313.29296.170999.539035@gargle.gargle.HOWL> <1134658579.12421.59.camel@localhost.localdomain> <4743.1134662116@warthog.cambridge.redhat.com> <7140.1134667736@warthog.cambridge.redhat.com> <20051215112115.7c4bfbea.akpm@osdl.org> <1134678532.13138.44.camel@localhost.localdomain> <1134769269.2806.17.camel@tglx.tec.linutronix.de> <1134770778.2806.31.camel@tglx.tec.linutronix.de> <1134772964.2806.50.camel@tglx.tec.linutronix.de> Content-Type: text/plain Organization: linutronix Date: Sat, 17 Dec 2005 00:29:59 +0100 Message-Id: <1134775799.2806.82.camel@tglx.tec.linutronix.de> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 976 Lines: 26 On Fri, 2005-12-16 at 14:41 -0800, Linus Torvalds wrote: > > You can still implement (chose a mechanism) a mutex on top - or in case > > of lack of priority inheritance or debugging with exactly the same - > > mechanism as a semaphore, but this does not change the semantical > > difference at all. > > "Friends don't let friends use priority inheritance". > > Just don't do it. If you really need it, your system is broken anyway. We are not talking about priority inheritance and its usefulness at all. Fact is that you can implement two semanticaly different concurrency controls with or on top of the same mechanism under given circumstances (no debugging, no ...). But the reverse attempt is wrong by defintion. tglx - 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/