On 10/19/2018 10:37 AM, Andy Lutomirski wrote: >> I think it's much more straightforward to just not enforce pkeys. >> Having this "phantom" value could cause a very odd, nearly >> undebuggable I/O failure. > But now we have the reverse. The IO can work if it’s truly async but, > if the kernel decides to synchronously complete IO (with GUP or > copy_to_user), it’ll fail, right. This isn’t exactly friendly > either. Yeah, but a synchronous I/O failure is really straightforward to debug because you get an immediate error message about it. This is certainly not the weirdest behavior or asymmetry that we would see from synchronous vs. async I/O.
