Messages in this thread | | | Date | Mon, 25 Feb 2008 21:42:00 -0500 | From | Pavel Roskin <> | Subject | Re: [RFC] mmiotrace full patch, preview 1 |
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Quoting Christoph Hellwig <hch@infradead.org>:
> On Mon, Feb 25, 2008 at 02:49:22PM -0800, Andrew Morton wrote: >> the things which it finds. >> >> > +static DECLARE_MUTEX(kmmio_init_mutex); >> >> That's not a mutex. >> >> > + down(&kmmio_init_mutex); >> >> It's a semaphore. Please do convert it to a mutex. >> >> Andy, I'd say that addition of new semaphores is worth a warning - they're >> rarely legitimate. > > I'm not sure that any semaphore should be a warning, but the initializer > for semaphore used as binary mutex (DECLARE_MUTEX and init_MUTEX) are > worth it.
It looks like a mutex, it acts like a mutex, but it isn't a mutex, it's a trap for the unwary. Weird. I was annoyed by it before; now I see a fellow developer actually getting into that trap.
I'd say, rename DECLARE_MUTEX to DECLARE_SEMAPHORE and let external code be fixed one way or another (i.e. stick with the "mutex" name or stick with the semaphore functionality if it's really needed).
-- Regards, Pavel Roskin
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