On Tue, Mar 12, 2024 at 10:28:44PM +0100, Christoph Hellwig wrote: > On Sun, Mar 10, 2024 at 11:35:13AM +0200, Leon Romanovsky wrote: > > And you will need to have a way to instruct that pin_user_pages() variant > > to continue anyway, because you asked for FOLL_PCI_P2PDMA. Without that > > force, you will have !FOLL_PCI_P2PDMA behaviour. > > I don't understand what you mean. Jason talked about the need to call to pin_user_pages(..., gup_flags | FOLL_PCI_P2PDMA, ...), but in your proposal this call won't be possible anymore. > > > When you say "simplify the overall interface", which interface do you mean? > > Primarily the dma mapping interface. Secondarily also everything around > it. OK, thanks