Re: First cut of PowerPC support in NPTL

[Jakub Jelinek <jakub redhat com>]

On Fri, Mar 07, 2003 at 11:20:16AM +1100, Paul Mackerras wrote:
> +/* We have a separate internal lock implementation which is not tied
> +   to binary compatibility.  */
> +
> +/* Type for lock object.  */
> +typedef int lll_lock_t;
> +
> +/* Initializers for lock.  */
> +#define LLL_LOCK_INITIALIZER		(1)
> +#define LLL_LOCK_INITIALIZER_LOCKED	(0)

Is there any gain on PPC (or s390) to have separate lll_mutex_* and lll_*
implementations instead of using just one (lll_mutex_*) for both?

On IA-32 lll_lock is one insn faster than lll_mutex_lock, which is why I
believe Ulrich did this, but on s390 with compare_and_swap it
really doesn't matter if you increment or decrement and what the
unlocked value is.

	Jakub