Merge tag 'io_uring-futex-2023-10-30' of git://git.kernel.dk/linux

Pull io_uring futex support from Jens Axboe:
 "This adds support for using futexes through io_uring - first futex
  wake and wait, and then the vectored variant of waiting, futex waitv.

  For both wait/wake/waitv, we support the bitset variant, as the
  'normal' variants can be easily implemented on top of that.

  PI and requeue are not supported through io_uring, just the above
  mentioned parts. This may change in the future, but in the spirit of
  keeping this small (and based on what people have been asking for),
  this is what we currently have.

  Wake support is pretty straight forward, most of the thought has gone
  into the wait side to avoid needing to offload wait operations to a
  blocking context. Instead, we rely on the usual callbacks to retry and
  post a completion event, when appropriate.

  As far as I can recall, the first request for futex support with
  io_uring came from Andres Freund, working on postgres. His aio ...