commit 518b1646f8a31904ca637b8df0c1e31c34a7a3c2: IPoIB/cm: Fix SRQ WR leak introduced performance regression on Mellanox cards: keeping a QP in error state for extended periods of time, moves hardware to the slow path (until QP is destroyed). Fix this by posting a send WR on one of the QPs that are being flushed, instead of using a separate drain QP.
This fixes bug <https://bugs.openfabrics.org/show_bug.cgi?id=636> Reported and bisected by Scott Weitzenkamp at Cisco. Debugged by Sasha Mikheev at Voltaire. Signed-off-by: Michael S. Tsirkin <[EMAIL PROTECTED]> --- > How about using the send queue of the QP we're trying to flush? > I'll try to code this up tomorrow if no one beats me to the fix. diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c index f133b56..253ece1 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c @@ -69,8 +69,9 @@ static struct ib_qp_attr ipoib_cm_err_attr = { #define IPOIB_CM_RX_DRAIN_WRID 0x7fffffff -static struct ib_recv_wr ipoib_cm_rx_drain_wr = { - .wr_id = IPOIB_CM_RX_DRAIN_WRID +static struct ib_send_wr ipoib_cm_rx_drain_wr = { + .wr_id = IPOIB_CM_RX_DRAIN_WRID, + .opcode = IB_WR_SEND, }; static int ipoib_cm_tx_handler(struct ib_cm_id *cm_id, @@ -163,16 +164,22 @@ partial_error: static void ipoib_cm_start_rx_drain(struct ipoib_dev_priv* priv) { - struct ib_recv_wr *bad_wr; + struct ib_send_wr *bad_wr; + struct ipoib_cm_rx *p; - /* rx_drain_qp send queue depth is 1, so + /* We only reserved 1 extra slot in CQ for drain WRs, so * make sure we have at most 1 outstanding WR. */ if (list_empty(&priv->cm.rx_flush_list) || !list_empty(&priv->cm.rx_drain_list)) return; - if (ib_post_recv(priv->cm.rx_drain_qp, &ipoib_cm_rx_drain_wr, &bad_wr)) - ipoib_warn(priv, "failed to post rx_drain wr\n"); + /* + * QPs on flush list are error state. This way, a "flush + * error" WC will be immediately generated for each WR we post. + */ + p = list_entry(priv->cm.rx_flush_list.next, typeof(*p), list); + if (ib_post_send(p->qp, &ipoib_cm_rx_drain_wr, &bad_wr)) + ipoib_warn(priv, "failed to post drain wr\n"); list_splice_init(&priv->cm.rx_flush_list, &priv->cm.rx_drain_list); } @@ -199,10 +206,10 @@ static struct ib_qp *ipoib_cm_create_rx_qp(struct net_device *dev, struct ipoib_dev_priv *priv = netdev_priv(dev); struct ib_qp_init_attr attr = { .event_handler = ipoib_cm_rx_event_handler, - .send_cq = priv->cq, /* does not matter, we never send anything */ + .send_cq = priv->cq, /* For drain WR */ .recv_cq = priv->cq, .srq = priv->cm.srq, - .cap.max_send_wr = 1, /* FIXME: 0 Seems not to work */ + .cap.max_send_wr = 1, /* For drain WR */ .cap.max_send_sge = 1, /* FIXME: 0 Seems not to work */ .sq_sig_type = IB_SIGNAL_ALL_WR, .qp_type = IB_QPT_RC, @@ -242,6 +249,24 @@ static int ipoib_cm_modify_rx_qp(struct net_device *dev, ipoib_warn(priv, "failed to modify QP to RTR: %d\n", ret); return ret; } + + /* Mellanox firmware won't generate completions with error for drain WRs + * unless the QP has been moved to RTS first. This work-around leaves a + * window where a QP has moved to error asynchronously, but this will + * eventually get fixed in firmware, so let's not error out if modify QP + * fails. */ + qp_attr.qp_state = IB_QPS_RTS; + ret = ib_cm_init_qp_attr(cm_id, &qp_attr, &qp_attr_mask); + if (ret) { + ipoib_warn(priv, "failed to init QP attr for RTS: %d\n", ret); + return 0; + } + ret = ib_modify_qp(qp, &qp_attr, qp_attr_mask); + if (ret) { + ipoib_warn(priv, "failed to modify QP to RTS: %d\n", ret); + return 0; + } + return 0; } @@ -623,38 +648,11 @@ static void ipoib_cm_tx_completion(struct ib_cq *cq, void *tx_ptr) int ipoib_cm_dev_open(struct net_device *dev) { struct ipoib_dev_priv *priv = netdev_priv(dev); - struct ib_qp_init_attr qp_init_attr = { - .send_cq = priv->cq, /* does not matter, we never send anything */ - .recv_cq = priv->cq, - .cap.max_send_wr = 1, /* FIXME: 0 Seems not to work */ - .cap.max_send_sge = 1, /* FIXME: 0 Seems not to work */ - .cap.max_recv_wr = 1, - .cap.max_recv_sge = 1, /* FIXME: 0 Seems not to work */ - .sq_sig_type = IB_SIGNAL_ALL_WR, - .qp_type = IB_QPT_UC, - }; int ret; if (!IPOIB_CM_SUPPORTED(dev->dev_addr)) return 0; - priv->cm.rx_drain_qp = ib_create_qp(priv->pd, &qp_init_attr); - if (IS_ERR(priv->cm.rx_drain_qp)) { - printk(KERN_WARNING "%s: failed to create CM ID\n", priv->ca->name); - ret = PTR_ERR(priv->cm.rx_drain_qp); - return ret; - } - - /* - * We put the QP in error state directly. This way, a "flush - * error" WC will be immediately generated for each WR we post. - */ - ret = ib_modify_qp(priv->cm.rx_drain_qp, &ipoib_cm_err_attr, IB_QP_STATE); - if (ret) { - ipoib_warn(priv, "failed to modify drain QP to error: %d\n", ret); - goto err_qp; - } - priv->cm.id = ib_create_cm_id(priv->ca, ipoib_cm_rx_handler, dev); if (IS_ERR(priv->cm.id)) { printk(KERN_WARNING "%s: failed to create CM ID\n", priv->ca->name); @@ -676,8 +674,6 @@ err_listen: ib_destroy_cm_id(priv->cm.id); err_cm: priv->cm.id = NULL; -err_qp: - ib_destroy_qp(priv->cm.rx_drain_qp); return ret; } @@ -740,7 +736,6 @@ void ipoib_cm_dev_stop(struct net_device *dev) kfree(p); } - ib_destroy_qp(priv->cm.rx_drain_qp); cancel_delayed_work(&priv->cm.stale_task); } -- MST _______________________________________________ general mailing list general@lists.openfabrics.org http://lists.openfabrics.org/cgi-bin/mailman/listinfo/general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general
