liburing: introduce io_uring_for_each_cqe() and io_uring_cq_advance()

io_uring_cqe_seen() contains write memory barrier (at least for !x86),
so calling it can be very expensive for a big number of cqes.

Would be better to have a loop over all available cqes and only then
advance the cq ring once, e.g.:

      struct io_uring_cqe *cqe;
      unsigned nr, head;

      nr = 0;
      io_uring_for_each_cqe(&ring, head, cqe) {

              /* handle cqe */

              if (++nr == max)
                      break;
      }
      io_uring_cq_advance(&ring, nr);

Signed-off-by: Roman Penyaev <rpenyaev@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

0 files changed, 0 insertions, 0 deletions