On Tue, Jun 22, 2021 at 11:05 AM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > Huh? Last I checked, the fault_in_readable actually read a byte from > the page. It has to wait for the read to complete before that can > happen. Yeah, we don't have any kind of async fault-in model. I'm not sure how that would even look. I don't think it would necessarily be *impossible* (special marker in the exception table to let the fault code know that this is a "prepare" fault), but it would be pretty challenging. Linus