Re: 32-bit dma allocations on 64-bit platforms

From: Arjan van de Ven
Date: Thu Jun 24 2004 - 01:20:01 EST


On Wed, 2004-06-23 at 23:46, Andi Kleen wrote:

> The VM should be able to handle this, but it may still require
> some tuning. It would need some generic changes, but not too bad.
> Still would need a decision on how big GFP_BIGDMA should be.
> I suspect 4GB would be too big again.

What is the problem again, can't the driver us the dynamic pci mapping
API which does allow more memory to be mapped even on crippled machines
without iommu ?
And isn't this a problem that will vanish since PCI Express and PCI X
both *require* support for 64 bit addressing, so all higher speed cards
are going to be ok in principle ?

Attachment: signature.asc
Description: This is a digitally signed message part