On Wed, Jan 23, 2019 at 09:08:51PM +0800, Zhou Wang wrote:
>
> +/**
> + * hisi_qp_poll() - Poll current cqe to see if a task is finished.
> + * @qp: The qp which will poll.
> + *
> + * This function polls current cqe for a give qp to see if a task is finished.
> + * Return -ETIME if timeout.
> + */
> +int hisi_qp_poll(struct hisi_qp *qp)
> +{
> + struct qm_cqe *cqe = qp->cqe + qp->qp_status.cq_head;
> + struct qm_cqc *cqc = qp->cqc;
> + int retries = 1000;
> +
> + while (!(QM_CQE_PHASE(cqe) == (cqc->dw6 & 0x1))) {
> + dma_rmb();
> + if (!--retries) {
> + dev_err(&qp->qm->pdev->dev, "Poll cqe failed!\n");
> + return -ETIME;
> + }
> + udelay(10);
> + }
> +
> + qm_cq_head_update(qp);
> + atomic_dec(&qp->qp_status.used);
> +
> + qm_db(qp->qm, qp->qp_id, QM_DOORBELL_CMD_CQ, qp->qp_status.cq_head, 0);
> + /* set c_flag */
> + qm_db(qp->qm, qp->qp_id, QM_DOORBELL_CMD_CQ, qp->qp_status.cq_head, 1);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(hisi_qp_poll);
Polling in softirq context is unacceptable. Can't your hardware
send interrupts to signal completion? What is the average speed
of processing a single 1500-byte packet on your hardware?
Cheers,
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
