Commit 23cd4716 authored by Vennila Megavannan's avatar Vennila Megavannan Committed by Doug Ledford
Browse files

staging/rdma/hfi1: Allow a fair scheduling of QPs 



This patch fixes the fairness issues in QP scheduling
- the timeout for cond_resched is changed to a ratio of
qp->timeout_jiffies
- workqueue_congested is used to determine if qp needs to
reschedule itself

Reviewed-by: default avatarMike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: default avatarVennila Megavannan <vennila.megavannan@intel.com>
Signed-off-by: default avatarJubin John <jubin.john@intel.com>
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
parent f1bf2963

drivers/staging/rdma/hfi1/ruc.c

+38 −14
Original line number Diff line number Diff line
@@ -822,29 +822,42 @@ void _hfi1_do_send(struct work_struct *work) 
void hfi1_do_send(struct rvt_qp *qp)

{

	struct hfi1_pkt_state ps;

	struct hfi1_qp_priv *priv = qp->priv;

	int (*make_req)(struct rvt_qp *qp);

	unsigned long flags;

	unsigned long timeout;

	unsigned long timeout_int;

	int cpu;



	ps.dev = to_idev(qp->ibqp.device);

	ps.ibp = to_iport(qp->ibqp.device, qp->port_num);

	ps.ppd = ppd_from_ibp(ps.ibp);



	if ((qp->ibqp.qp_type == IB_QPT_RC ||

	     qp->ibqp.qp_type == IB_QPT_UC) &&

	    !loopback &&

	    (qp->remote_ah_attr.dlid & ~((1 << ps.ppd->lmc) - 1)) ==

	    ps.ppd->lid) {

	switch (qp->ibqp.qp_type) {

	case IB_QPT_RC:

		if (!loopback && ((qp->remote_ah_attr.dlid & ~((1 << ps.ppd->lmc

								) - 1)) ==

				 ps.ppd->lid)) {

			ruc_loopback(qp);

			return;

		}



	if (qp->ibqp.qp_type == IB_QPT_RC)

		make_req = hfi1_make_rc_req;

	else if (qp->ibqp.qp_type == IB_QPT_UC)

		timeout_int = (qp->timeout_jiffies);

		break;

	case IB_QPT_UC:

		if (!loopback && ((qp->remote_ah_attr.dlid & ~((1 << ps.ppd->lmc

								) - 1)) ==

				 ps.ppd->lid)) {

			ruc_loopback(qp);

			return;

		}

		make_req = hfi1_make_uc_req;

	else

		timeout_int = SEND_RESCHED_TIMEOUT;

		break;

	default:

		make_req = hfi1_make_ud_req;

		timeout_int = SEND_RESCHED_TIMEOUT;

	}



	spin_lock_irqsave(&qp->s_lock, flags);
@@ -858,7 +871,9 @@ void hfi1_do_send(struct rvt_qp *qp) 


	spin_unlock_irqrestore(&qp->s_lock, flags);



	timeout = jiffies + SEND_RESCHED_TIMEOUT;

	timeout = jiffies + (timeout_int) / 8;

	cpu = priv->s_sde ? priv->s_sde->cpu :

			cpumask_first(cpumask_of_node(ps.ppd->dd->node));

	do {

		/* Check for a constructed packet to be sent. */

		if (qp->s_hdrwords != 0) {
@@ -874,9 +889,18 @@ void hfi1_do_send(struct rvt_qp *qp) 


		/* allow other tasks to run */

		if (unlikely(time_after(jiffies, timeout))) {

			if (workqueue_congested(cpu, ps.ppd->hfi1_wq)) {

				spin_lock_irqsave(&qp->s_lock, flags);

				qp->s_flags &= ~RVT_S_BUSY;

				hfi1_schedule_send(qp);

				spin_unlock_irqrestore(&qp->s_lock,

						       flags);

				this_cpu_inc(*ps.ppd->dd->send_schedule);

				return;

			}

			cond_resched();

			this_cpu_inc(*ps.ppd->dd->send_schedule);

			timeout = jiffies + SEND_RESCHED_TIMEOUT;

			timeout = jiffies + (timeout_int) / 8;

		}

	} while (make_req(qp));

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE