From: Manjunath Patil Date: Tue, 13 Apr 2021 18:36:05 +0000 (-0700) Subject: IB/ipoib: Improve latency in ipoib/cm connection formation X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=338a010cb616b6b257bd7fe615bd4a87ca575c3a;p=linux.git IB/ipoib: Improve latency in ipoib/cm connection formation Currently IPoIB connected mode queries the device to get the pkey table entry during connection formation. This will increase the time taken to form the connection, especially when limited pkeys are in use. This gets worse when multiple connection attempts are done in parallel. Since ipoib interfaces are locked to a single pkey, use the pkey index that was determined at link up time instead of searching for anything. This improved the latency from 500ms to 1ms on an internal setup. Link: https://lore.kernel.org/r/1618338965-16717-1-git-send-email-manjunath.b.patil@oracle.com Suggested-by: Jason Gunthorpe Signed-off-by: Manjunath Patil Signed-off-by: Jason Gunthorpe --- diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c index d5d592bdab358..9dbc85a6b702c 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c @@ -1122,12 +1122,8 @@ static int ipoib_cm_modify_tx_init(struct net_device *dev, struct ipoib_dev_priv *priv = ipoib_priv(dev); struct ib_qp_attr qp_attr; int qp_attr_mask, ret; - ret = ib_find_pkey(priv->ca, priv->port, priv->pkey, &qp_attr.pkey_index); - if (ret) { - ipoib_warn(priv, "pkey 0x%x not found: %d\n", priv->pkey, ret); - return ret; - } + qp_attr.pkey_index = priv->pkey_index; qp_attr.qp_state = IB_QPS_INIT; qp_attr.qp_access_flags = IB_ACCESS_LOCAL_WRITE; qp_attr.port_num = priv->port;