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Commit 4bb02e95 authored by Mike Marciniszyn's avatar Mike Marciniszyn Committed by Doug Ledford
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IB/hfi1: Use aborts to trigger RC throttling 



SDMA and pio flushes will cause a lot of packets to be transmitted
after a link has gone down, using a lot of CPU to retransmit
packets.

Fix for RC QPs by recognizing the flush status and:
- Forcing a timer start
- Putting the QP into a "send one" mode

Fixes: 77241056 ("IB/hfi1: add driver files")
Reviewed-by: default avatarKaike Wan <kaike.wan@intel.com>
Signed-off-by: default avatarMike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: default avatarDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
parent 9755f724

drivers/infiniband/hw/hfi1/rc.c

+30 −0
Original line number Diff line number Diff line
@@ -1701,6 +1701,36 @@ static void reset_sending_psn(struct rvt_qp *qp, u32 psn) 
	}

}



/**

 * hfi1_rc_verbs_aborted - handle abort status

 * @qp: the QP

 * @opah: the opa header

 *

 * This code modifies both ACK bit in BTH[2]

 * and the s_flags to go into send one mode.

 *

 * This serves to throttle the send engine to only

 * send a single packet in the likely case the

 * a link has gone down.

 */

void hfi1_rc_verbs_aborted(struct rvt_qp *qp, struct hfi1_opa_header *opah)

{

	struct ib_other_headers *ohdr = hfi1_get_rc_ohdr(opah);

	u8 opcode = ib_bth_get_opcode(ohdr);

	u32 psn;



	/* ignore responses */

	if ((opcode >= OP(RDMA_READ_RESPONSE_FIRST) &&

	     opcode <= OP(ATOMIC_ACKNOWLEDGE)) ||

	    opcode == TID_OP(READ_RESP) ||

	    opcode == TID_OP(WRITE_RESP))

		return;



	psn = ib_bth_get_psn(ohdr) | IB_BTH_REQ_ACK;

	ohdr->bth[2] = cpu_to_be32(psn);

	qp->s_flags |= RVT_S_SEND_ONE;

}



/*

 * This should be called with the QP s_lock held and interrupts disabled.

 */

drivers/infiniband/hw/hfi1/verbs.c

+6 −4
Original line number Diff line number Diff line
@@ -638,6 +638,8 @@ static void verbs_sdma_complete( 
		struct hfi1_opa_header *hdr;



		hdr = &tx->phdr.hdr;

		if (unlikely(status == SDMA_TXREQ_S_ABORTED))

			hfi1_rc_verbs_aborted(qp, hdr);

		hfi1_rc_send_complete(qp, hdr);

	}

	spin_unlock(&qp->s_lock);
@@ -1095,15 +1097,15 @@ int hfi1_verbs_send_pio(struct rvt_qp *qp, struct hfi1_pkt_state *ps, 
			       &ps->s_txreq->phdr.hdr, ib_is_sc5(sc5));



pio_bail:

	if (qp->s_wqe) {

	spin_lock_irqsave(&qp->s_lock, flags);

	if (qp->s_wqe) {

		rvt_send_complete(qp, qp->s_wqe, wc_status);

		spin_unlock_irqrestore(&qp->s_lock, flags);

	} else if (qp->ibqp.qp_type == IB_QPT_RC) {

		spin_lock_irqsave(&qp->s_lock, flags);

		if (unlikely(wc_status == IB_WC_GENERAL_ERR))

			hfi1_rc_verbs_aborted(qp, &ps->s_txreq->phdr.hdr);

		hfi1_rc_send_complete(qp, &ps->s_txreq->phdr.hdr);

		spin_unlock_irqrestore(&qp->s_lock, flags);

	}

	spin_unlock_irqrestore(&qp->s_lock, flags);



	ret = 0;

drivers/infiniband/hw/hfi1/verbs.h

+1 −0
Original line number Diff line number Diff line
@@ -416,6 +416,7 @@ void hfi1_rc_hdrerr( 


u8 ah_to_sc(struct ib_device *ibdev, struct rdma_ah_attr *ah_attr);



void hfi1_rc_verbs_aborted(struct rvt_qp *qp, struct hfi1_opa_header *opah);

void hfi1_rc_send_complete(struct rvt_qp *qp, struct hfi1_opa_header *opah);



void hfi1_ud_rcv(struct hfi1_packet *packet);