mlx4_ib_poll_cq
while (mlx4_ib_poll_cq(ctx->cq, 1, &wc) == 1) {
.poll_cq = mlx4_ib_poll_cq,
int mlx4_ib_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc);