Function sq_ring_needs_enter

src/queue.c:17–40

* Returns true if we're not using SQ thread (thus nobody submits but us) * or if IORING_SQ_NEED_WAKEUP is set, so submit thread must be explicitly * awakened. For the latter case, we set the thread wakeup flag. * If no SQEs are ready for submission, returns false. */

 * If no SQEs are ready for submission, returns false.
 */
static inline bool sq_ring_needs_enter(struct io_uring *ring,
				       unsigned submit,
				       unsigned *flags)
{
	if (!submit)
		return false;

	if (!(ring->flags & IORING_SETUP_SQPOLL))
		return true;

	/*
	 * Ensure the kernel can see the store to the SQ tail before we read
	 * the flags.
	 */
	io_uring_smp_mb();

	if (uring_unlikely(IO_URING_READ_ONCE(*ring->sq.kflags) &
			   IORING_SQ_NEED_WAKEUP)) {
		*flags |= IORING_ENTER_SQ_WAKEUP;
		return true;
	}

	return false;
}

static inline bool cq_ring_needs_flush(struct io_uring *ring)
{