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

Alan Cox
2005-12-13T13:09:56Z

On Maw, 2005-12-13 at 13:47 +0100, Oliver Neukum wrote:
> > spinlock to do the cmpxchg. This means that there wont be one single
> > global spinlock to emulate cmpxchg, but the mutex's own spinlock can be
> > used for it.
>
> Can't you use the pointer as a hash input?

Some platforms already do this for certain sets of operations like
atomic_t. The downside however is that you no longer control the lock
contention or cache line bouncing. It becomes a question of luck rather
than science as to how well it scales.