Is IORING_REGISTER_IOWQ_AFF expected to work on 5.17.0?

[sharpobject]

Hello,

We tried using IORING_REGISTER_IOWQ_AFF today to set affinity to 02 and the resulting iou-wrk threads still have affinity 3f (which is all cores for us). Is this expected to work? Is this fixed in some later kernel? It is possible to use IORING_REGISTER_IOWQ_AFF to set the affinity of the worker threads to some mask that has no bits in common with the application's threads and no bits in common with the SQPOLL thread?

[sharpobject]

We're setting the SQPOLL thread to core 2 and we're running the application's main thread (the one that talks to io_uring) in a cpuset that includes only core 5. We're observing that the iou-wrk threads are always scheduled to core 2 even though their mask says they could run on other cores and other cores are idle.