> This patchset (against tip/master) fixes the problem that swiotlb
> exhausts ZONE_DMA:
>
>
http://lkml.org/lkml/2008/8/31/16
>
> The root problem is that swiotlb_alloc_coherent always use ZONE_DMA,
> which is fine for IA64 but not for x86_64.
>
> This patchset makes the callers set up the gfp flags so that
> swiotlb_alloc_coherent can stop playing with the gfp flags.
>
> I think that it would be better to remove the allocation code in
> swiotlb_alloc_coherent theoretically (what swiotlb should do is taking
> care of the swiotlb memory. And swiotlb_alloc_coherent is not useful
> since we use it only when we can't allocate memory reachable by the
> device or we are in out of memory). But that code works for both x86
> and IA64 so it's not so bad, I guess.
>
> #1 is for IA64, #2-4 for x86, and #5 is for swiotlb.
>
