Messages in this thread | | | Date | Wed, 29 May 2002 08:23:27 +0100 | From | Keith Whitwell <> | Subject | Re: linux-2.5.18: DRM + cmpxchg issues |
| |
george anzinger wrote: > Keith Whitwell wrote: > >>Adam, >> >>I expect the answer is that we need to dig out the old one. >> >>Previously I don't think the full cmpxchg semantics werere required unless the >>box is smp -- there's no case where atomic operations are required for >>hardware interaction, for example. ... >> >>Probably this changed with preempt, though, so we need one even on UP boxes... >> >> > I can not think of any reason to need a lock or atomic > operation because of preempt. Even the management of the > preempt on/off flags at most requires memory barriers, even > in SMP boxen. Do you have an example?
No, I was just pointing out grey areas in my own knowledge.
Keith
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |