Re: RT patch acceptance

john cooper
2005-06-01T15:36:55Z

Andrea Arcangeli wrote:
> The reason I raise this topic is that the fact spin_lock_irq wasn't
> disabling irqs like it does in the non-RT configuration, sounded like
> the technique described in the patent and it's one technique I always
> considered not-usable. I possibly wrongly remembered that redefining the
> disable-interrupt operation not to disable irqs, was the crucial point
> of the patent. But as I've said I'm not a lawyer and so I may have
> misunderstood completely the technique that the rtlinux patent is
> covering (the way patents are written is not very readable to me).

FWIW the decoupling of interrupt mask levels from
spinlocks is a technique which predates the patent
under discussion by a decade or so. And yes IANAL
as well but it seems the patent would/should not
have been awarded if it conflicted/overlapped with
preexisting usage. I'd hazard this is a non-issue.

-john

--
john.cooper@timesys.com