noble (3) io_uring_submit.3.gz

NAME

       io_uring_submit - submit requests to the submission queue

SYNOPSIS

       #include <liburing.h>

       int io_uring_submit(struct io_uring *ring);

DESCRIPTION

       The io_uring_submit(3) function submits the next events to the submission queue belonging to the ring.

       After  the  caller retrieves a submission queue entry (SQE) with io_uring_get_sqe(3) and prepares the SQE
       using one of the provided helpers, it can be submitted with io_uring_submit(3).

RETURN VALUE

       On success io_uring_submit(3) returns the number of submitted submission queue entries, if SQPOLL is  not
       used.   If SQPOLL is used, the return value may report a higher number of submitted entries than actually
       submitted. If the the user requires accurate information about how many  submission  queue  entries  have
       been  successfully  submitted,  while  using  SQPOLL,  the user must fall back to repeatedly submitting a
       single submission queue entry. On failure it returns -errno.

NOTES

       For any request that passes in data in a struct, that data must remain valid until the request  has  been
       successfully submitted. It need not remain valid until completion. Once a request has been submitted, the
       in-kernel state is stable. Very early kernels (5.4 and earlier) required state to  be  stable  until  the
       completion  occurred. Applications can test for this behavior by inspecting the IORING_FEAT_SUBMIT_STABLE
       flag passed back from io_uring_queue_init_params(3).  In general, the man pages for the  individual  prep
       helpers will have a note mentioning this fact as well, if required for the given command.

SEE ALSO

       io_uring_get_sqe(3), io_uring_submit_and_wait(3), io_uring_submit_and_wait_timeout(3)