Re: (reposting) how to get DMA'able memory within 4GB on 64-bit m

[Alan Cox]

> There are so many issues with 64-bit DAC support, that many of
> the people whining in this thread have not even considered, and

Such as ? - I can see the obvious ones

-	Its slower
-	Not all host bridges can hit all of RAM
-	You want to use SAC and IOMMU when possible

> resources".  How do you say "SAC is preferred for performance" with
> ia64's API?  You can't.

I doubt they worried about it, SAC isnt terribly useful on IA64 right now.

> This, almost with several other issues, need to be considered and
> handled by whatever API you come up with.  If it does not address
> all of these issues somehow, it is unacceptable.

Nod