On Thu, Jan 05, 2017 at 01:39:29PM -0500, Jerome Glisse wrote: > 1) peer-to-peer because of userspace specific API like NVidia GPU > direct (AMD is pushing its own similar API i just can't remember > marketing name). This does not happen through a vma, this happens > through specific device driver call going through device specific > ioctl on both side (GPU and RDMA). So both kernel driver are aware > of each others.
Today you can only do user-initiated RDMA operations in conjection with a VMA. We'd need a really big and strong reason to create an entirely new non-VMA based memory handle scheme for RDMA. So my inclination is to just completely push back on this idea. You need a VMA to do RMA. GPUs need to create VMAs for the memory they want to RDMA from, even if the VMA handle just causes SIGBUS for any CPU access. Jason
