Re: drm + 4GB RAM + swiotlb = drm craps out

From: David Miller
Date: Mon Apr 02 2007 - 01:24:55 EST


From: "Dave Airlie" <airlied@xxxxxxxxx>
Date: Mon, 2 Apr 2007 15:15:48 +1000

> > Perhaps we'll have to create something ugly like vmalloc_nobounce().
> >
> > Remind me again why you're ending up with swiotlb'd pages?
> > vmalloc_32() uses GFP_KERNEL which should use entirely lowmem and thus
> > RAM below 4GB and not anything which should need bounce buffering.
>
> On a 64-bit machine GFP_KERNEL can give me any memory... it all works
> fine on 32-bit highmem kernel as I don't get highmem... I really need
> __GFP_DMA32 memory but we don't have a generic allocator that gives
> this out that I can see..

That clears things up thanks.

Perhaps the other uses of vmalloc_32() want GFP_32 semantics too,
although I didn't check.
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