Re: Enabling peer to peer device transactions for PCIe devices

From: Logan Gunthorpe
Date: Mon Nov 28 2016 - 16:37:05 EST

On 28/11/16 12:35 PM, Serguei Sagalovitch wrote:
> As soon as PeerDirect mapping is called then GPU must not "move" the
> such memory. It is by PeerDirect design. It is similar how it is works
> with system memory and RDMA MR: when "get_user_pages" is called then the
> memory is pinned.

We haven't touch this in a long time and perhaps it changed, but there
definitely was a call back in the PeerDirect API to allow the GPU to
invalidate the mapping. That's what we don't want.