Re: [RFC 0/8] Copy Offload with Peer-to-Peer PCI Memory

From: Jason Gunthorpe
Date: Tue Apr 18 2017 - 17:23:29 EST


On Tue, Apr 18, 2017 at 02:11:33PM -0700, Dan Williams wrote:
> > I think this opens an even bigger can of worms..
>
> No, I don't think it does. You'd only shim when the target page is
> backed by a device, not host memory, and you can figure this out by a
> is_zone_device_page()-style lookup.

The bigger can of worms is how do you meaningfully stack dma_ops.

What does the p2p provider do when it detects a p2p page?

Jason