Re: [PATCH] Replace completions with semaphores

From: Ingo Molnar
Date: Sun Apr 13 2008 - 03:09:18 EST



* Matthew Wilcox <matthew@xxxxxx> wrote:

> Yes, that text appears in the URL I provided in the mail that started
> this thread ;-)
>
> The semaphore rewrite I did does not have this problem (it's less
> efficient than the hand-optimised assembler, but much more
> maintainable). You're supposed to be using mutexes if you want
> efficiency anyway.

but semaphores will be _removed_, _completely_. Rewriting them in
generic C code is just the first step towards that - it consolidates all
the myriads of semaphore implementations that Linux has spread out.

your proposed change to change completions to semaphores is totally
backwards and prolongs an API we want to get rid of. Did you miss this
aspect of the mutex rewrite, of the semaphore-to-mutex,
semaphore-to-completions and semaphore-to-rwsem conversions?

Ingo
--
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/