From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <43A3C461.2030900@yahoo.com.au> Date: Sat, 17 Dec 2005 18:55:13 +1100 From: Nick Piggin MIME-Version: 1.0 Subject: Re: [PATCH 1/12]: MUTEX: Implement mutexes References: <200512162313.jBGND7g4019623@warthog.cambridge.redhat.com> <1134791914.13138.167.camel@localhost.localdomain> In-Reply-To: <1134791914.13138.167.camel@localhost.localdomain> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit To: Steven Rostedt Cc: David Howells , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, mingo@redhat.com, akpm@osdl.org, torvalds@osdl.org List-ID: Steven Rostedt wrote: > On Fri, 2005-12-16 at 23:13 +0000, David Howells wrote: >>This patch set does the following: >> >> (1) Renames DECLARE_MUTEX and DECLARE_MUTEX_LOCKED to be DECLARE_SEM_MUTEX and >> DECLARE_SEM_MUTEX_LOCKED for counting semaphores. >> > > > Could we really get rid of that "MUTEX" part. A counting semaphore is > _not_ a mutex, although a mutex _is_ a counting semaphore. As is a Jack > Russell is a dog, but a dog is not a Jack Russell. > Really? A Jack Russell is a dog because anything you say about a dog can also be said about a Jack Russell. A counting semaphore is a mutex for the same reason (and observe that 99% of users use the semaphore as a mutex). A mutex definitely is not a counting semaphore. David's implementation of mutexes don't count at all. If you want to use a semaphore as a mutex, DECLARE_SEM_MUTEX isn't a terrible name. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com