On Wed, Feb 12, 2025 at 3:21 PM Keith Busch <kbusch@xxxxxxxxxx> wrote: > > On Wed, Feb 12, 2025 at 03:07:30PM -0800, Caleb Sander Mateos wrote: > > > > Yes, we completely agree. We are working on incorporating Keith's > > patchset now. It looks like there is still an open question about > > whether userspace will need to enforce ordering between the requests > > (either using linked operations or waiting for completions before > > submitting the subsequent operations). > > In its current form, my series depends on you *not* using linked > requests. I didn't think it would be a problem as it follows an existing > pattern from the IORING_OP_FILES_UPDATE operation. That has to complete > in its entirety before prepping any subsequent commands that reference > the index, and using links would get the wrong results. As implementers of a ublk server, we would also prefer the current interface in your patch series! Having to explicitly order the requests would definitely make the interface more cumbersome and probably less performant. I was just saying that Ming and Pavel had raised some concerns about guaranteeing the order in which io_uring issues SQEs. IORING_OP_FILES_UPDATE is a good analogy. Do we have any examples of how applications use it? Are they waiting for a completion, linking it, or relying on io_uring to issue it synchronously?
