[RFC PATCH v3 1/4] RDMA/umem: Support importing dma-buf as user memory region

[Jason Gunthorpe]

On Tue, Oct 06, 2020 at 11:22:14AM +0200, Daniel Vetter wrote:
> 
> For reinstanting the pages you need:
> 
> - dma_resv_lock, this prevents anyone else from issuing new moves or
>   anything like that
> - dma_resv_get_excl + dma_fence_wait to wait for any pending moves to
>   finish. gpus generally don't wait on the cpu, but block the dependent
>   dma operations from being scheduled until that fence fired. But for rdma
>   odp I think you need the cpu wait in your worker here.

Reinstating is not really any different that the first insertion, so
then all this should be needed in every case?

Jason