Re: [PATCH v0] add nano semaphore in kernel
From: Pavel Machek
Date: Tue Jan 04 2011 - 09:04:22 EST
Hi!
> +/*
> + * nano_semaphore_down - acquire the nano semaphore
> + * @s: the nano semaphore to be acquired
> + * @nano_secs: the nano seconds to wait if necessary,
> + * could be zero if want to wait as long as possible.
> + *
> + * Returns >0 if acquired successfully, <=0 otherwise.
> + *
> + * Note unlike down() in semaphore, nano_semaphore_down is not looping until
> + * the nano semaphore is hold, but simply reports the result. And the callers
> + * could, if they like, loop in simple manner, for instance,
> + * while (1 != nano_semaphore_down(s, 800));
> + * do_home_work();
> + * nano_semaphore_up(s);
But thats spinlock, not semaphore, right?
Also, your example does not use the API right -- according to
description, 42 is correct 'semaphore acquired' reply...
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/