Commit 270a9833 authored by Mike Marciniszyn's avatar Mike Marciniszyn Committed by Jason Gunthorpe
Browse files

IB/hfi1: Add running average for adaptive pio 



The adaptive PIO implementation only considers the current packet size
when deciding between SDMA and pio for a packet.

This causes credit return forces if small and large packets are
interleaved.

Add a running average to avoid costly credit forces so that a large
sequence of small packets is required to go below the threshold that
chooses pio.

Reviewed-by: default avatarMichael J. Ruhl <michael.j.ruhl@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 avatarJason Gunthorpe <jgg@mellanox.com>
parent 19b1a294

drivers/infiniband/hw/hfi1/qp.c

+2 −0
Original line number Diff line number Diff line
@@ -742,6 +742,8 @@ void *qp_priv_alloc(struct rvt_dev_info *rdi, struct rvt_qp *qp) 
		iowait_wakeup,

		iowait_sdma_drained,

		hfi1_init_priority);

	/* Init to a value to start the running average correctly */

	priv->s_running_pkt_size = piothreshold / 2;

	return priv;

}

drivers/infiniband/hw/hfi1/verbs.c

+4 −3
Original line number Diff line number Diff line
@@ -1223,15 +1223,16 @@ static inline send_routine get_send_routine(struct rvt_qp *qp, 
	case IB_QPT_UD:

		break;

	case IB_QPT_UC:

	case IB_QPT_RC: {

	case IB_QPT_RC:

		priv->s_running_pkt_size =

			(tx->s_cur_size + priv->s_running_pkt_size) / 2;

		if (piothreshold &&

		    tx->s_cur_size <= min(piothreshold, qp->pmtu) &&

		    priv->s_running_pkt_size <= min(piothreshold, qp->pmtu) &&

		    (BIT(ps->opcode & OPMASK) & pio_opmask[ps->opcode >> 5]) &&

		    iowait_sdma_pending(&priv->s_iowait) == 0 &&

		    !sdma_txreq_built(&tx->txreq))

			return dd->process_pio_send;

		break;

	}

	default:

		break;

	}

drivers/infiniband/hw/hfi1/verbs.h

+1 −0
Original line number Diff line number Diff line
@@ -170,6 +170,7 @@ struct hfi1_qp_priv { 
	struct tid_flow_state flow_state;

	struct tid_rdma_qp_params tid_rdma;

	struct rvt_qp *owner;

	u16 s_running_pkt_size;

	u8 hdr_type; /* 9B or 16B */

	struct rvt_sge_state tid_ss;       /* SGE state pointer for 2nd leg */

	atomic_t n_requests;               /* # of TID RDMA requests in the */

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