Re: GFP_DMA32 and PAE x86 machines

[William Lee Irwin III <wli@holomorphy.com>]

On 5/31/07, Andi Kleen <ak@suse.de> wrote:
>> Please give a very very strong rationale why you want it. Did you actually
>> run into such a situation yourself yet?

On Thu, May 31, 2007 at 09:09:58AM +1000, Dave Airlie wrote:
> Funnily enough I have just today with an app I have which uses 1.2GB
> of textures :-)
> we are currently using GFP_DMA32 in the TTM allocator code, however
> what I really want on x86 non-PAE is GFP_HIGHMEM (as DMA32 does
> nothing) however on x86-PAE I don't want that I want a real GFP_DMA32,
> and on x86-64 I want the current GFP_DMA32,
> Therein lies my problems, the API sucks, but I suppose the DRM TTM is
> a special use case (AGP is the same) and I'll accept the fact that can
> just make it my own problem, my current solution would be to screw PAE
> machines giving them 1GB only and let non-PAE access all 4GB.

It's easy enough to spin kernels that allow 4GB-constrained highmem
allocations. The real question is whether it'll be merged.


-- wli