Re: [PATCH 1/19] MUTEX: Introduce simple mutex implementation

Thomas Gleixner
2005-12-15T00:03:21Z

On Wed, 2005-12-14 at 18:57 -0500, Mark Lord wrote:
> >>Leaving up()/down() as-is is really the most sensible option.
> >
> ...
> >Doing a s/down/lock_mutex/ s/up/unlock_mutex/ - or whatever naming
> > convention we want to use - all over the place for mutexes while keeping
> > the up/down for counting semaphores is an one time issue.
> >
> > After the conversion every code breaks at compile time which tries to do
> > up/down(mutex_type).
> >
> > So the out of tree drivers have a clear indication what to fix. This is
> > also a one time issue.
> >
> > So where is the problem - except for fixing "huge" amounts of out of
> > kernel code once ?
>
> Pointless API breakage. The same functions continue to exist,
> the old names CANNOT be reused for some (longish) time,
> so there's no point in renaming them. It just breaks an API
> for no good reason whatsoever.

Well, depends on the POV. A counting sempahore is a different beast than
a mutex. At least as far as my limited knowledge of concurrency controls
goes.

The API breakage was introduced by using up/down for mutexes and not by
correcting this to a sane API.

tglx