On Thu, Jan 31, 2019 at 09:02:03AM +0100, Christoph Hellwig wrote: > On Wed, Jan 30, 2019 at 01:50:27PM -0500, Jerome Glisse wrote: > > I do not see how VMA changes are any different than using struct page > > in respect to userspace exposure. Those vma callback do not need to be > > set by everyone, in fact expectation is that only handful of driver > > will set those. > > > > How can we do p2p between RDMA and GPU for instance, without exposure > > to userspace ? At some point you need to tell userspace hey this kernel > > does allow you to do that :) > > To do RDMA on a memory region you need struct page backіng to start > with.. No you do not with this patchset and there is no reason to tie RDMA to struct page it does not provide a single feature we would need. So as it can be done without and they are not benefit of using one i do not see why we should use one. Cheers, Jérôme
