Re: Minutes from Feb 21 LSE Call

Val Henson
2003-02-24T06:25:33Z

On Sun, Feb 23, 2003 at 06:57:09PM -0500, Bill Davidsen wrote:
> On Sat, 22 Feb 2003, Larry McVoy wrote:
> >
> > But that's a false promise because by definition, fine grained threading
> > adds more bus traffic. It's kind of hard to not have that happen, the
> > caches have to stay coherent somehow.
>
> Clearly. And things which require more locking will pay some penalty for
> this. But a quick scan of this list on keyword "lockless' will show that
> people are thinking about this.

Lockless algorithms still generate bus traffic when you do the atomic
compare-and-swap or load-linked or whatever hardware instruction you
use to implement your lockless algorithm. Caches still have to stay
coherent, lock or no lock.

-VAL