On Mon, Mar 09, 2026 at 01:30:24PM +0100, Marek Szyprowski wrote: > My question here is if RDMA works on any non-coherent DMA systems?
The in kernel components do work, like storage, nvme over fabrics, netdev. The user API (uverbs) does not work at all, and has never worked. I think DRM has similar issues too where most of their DMA API usage is OK but some places where they interact win pin_user_pages() have the same issues as RDMA. This is why I'd like a new attribute DMA_ATTR_REQUIRE_COHERENCE that these special cases can use to fail instead of data corrupt. Jason
