On 2019-06-20 5:40 p.m., Dan Williams wrote: > This seems to be the most salient point. I was missing the fact that > this replaces custom hacks and "special" pages with an explicit "just > pass this pre-mapped address down the stack". It's functionality that > might plausibly be used outside of p2p, as long as the driver can > assert that it never needs to touch the data with the cpu before > handing it off to a dma-engine. Yup, that's a good way to put it. If I resend this patchset, I'll include wording like yours in the cover letter. Logan