Re: [Question] Are "device exclusive non-swap entries" / "SVM atomics in Nouveau" still getting used in practice?

Jason Gunthorpe
2025-01-24T14:11:30Z

On Fri, Jan 24, 2025 at 11:44:28AM +0100, David Hildenbrand wrote:

> There are other concerns I have (what if the page is pinned and access
> outside of the user space page tables?). Maybe there was not need to handle
> these cases so far.

I think alot of this depends on userspace following some restrictions
so that the pages are always convertible. Presumably if the userspace
breaks things then their atomic using GPU kernels will fault.

So, from a kernel perspective, I'd suggest that creating a reasonable
set of conditions that userspace can follow to have it work reliably
is a reasonable goal.

Jason