On Wed, Oct 02, 2024 at 09:33:16AM -0600, Keith Busch wrote: > You remember right. I also explained the use cases for per-io hints are > to replace current passthrough users with generic read/write paths that > have all the memory guard rails, read/write stats, and other features > that you don't get with passthrough. This just lets you accomplish the > same placement hints with the nvme raw block device that you get with > the nvme char device. Yes, and as I said before we need an opt-in from the file_ops, because file systems can't support this. And I'm speaking that from a position of working on a file system that made the existing non-idea hints work (to all fairness Hans did the hard work, but I was part of it).