Re: linux-2.5.18: DRM + cmpxchg issues
Keith Whitwell (firstname.lastname@example.org)
Wed, 29 May 2002 08:23:27 +0100
george anzinger wrote:
> Keith Whitwell wrote:
>>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.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to email@example.com
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/