Re: [PATCH] Futexes IV (Fast Lightweight Userspace Semaphores)

Rusty Russell
2002-03-13T02:57:38Z

In message <Pine.LNX.4.33.0203120905280.19167-100000@penguin.transmeta.com> you
write:
>
> On Tue, 12 Mar 2002, Rusty Russell wrote:
> > >
> > > You've convinced me.
> >
> > Damn. Because now I've been playing with a different approach.
>
> I don't think your current patch is very useful.

I agree. But your "Applied" EMail rushed me into posting it.

> It's obviously slower, and while it is an interesting approach for not
> just lock generation but also for synchronization points, it doesn't seem
> to actually _buy_ you anything. And since the cookie isn't guaranteed to
> be unique, you can't actually use it as a synchronization point on its
> own, but must always still have some shared memory location as a
> confirmation for whatever the synchronization was.

My original cookie was 128 bits. ie. unique.

> So: interesting approach, but in its current form pointless as far as I
> can see.

Yeah, I'm not sure what it's useful for either. But the code is out
there if someone gets inspired...

Thanks,
Rusty.
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.