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RDMA/cxgb3: Turn off RX coalescing for iWARP connections

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The HW by default has RX coalescing on.  For iWARP connections, this
causes a 100ms delay in connection establishement due to the ingress
MPA Start message being stalled in HW.  So explicitly turn RX
coalescing off when setting up iWARP connections.

This was causing very bad performance for NP64 gather operations using
Open MPI, due to the way it sets up connections on larger jobs.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Cc: <stable@kernel.org>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
This commit is contained in:
Steve Wise 2010-09-18 19:38:21 -05:00 committed by Roland Dreier
parent 32163f4b2c
commit bec658ff31
1 changed files with 4 additions and 2 deletions
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6
drivers/infiniband/hw/cxgb3/iwch_cm.c
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@ -463,7 +463,8 @@ static int send_connect(struct iwch_ep *ep)
V_MSS_IDX(mtu_idx) |
V_L2T_IDX(ep->l2t->idx) | V_TX_CHANNEL(ep->l2t->smt_idx);
opt0l = V_TOS((ep->tos >> 2) & M_TOS) | V_RCV_BUFSIZ(rcv_win>>10);
opt2 = V_FLAVORS_VALID(1) | V_CONG_CONTROL_FLAVOR(cong_flavor);
opt2 = F_RX_COALESCE_VALID | V_RX_COALESCE(0) | V_FLAVORS_VALID(1) |
V_CONG_CONTROL_FLAVOR(cong_flavor);
skb->priority = CPL_PRIORITY_SETUP;
set_arp_failure_handler(skb, act_open_req_arp_failure);
@ -1280,7 +1281,8 @@ static void accept_cr(struct iwch_ep *ep, __be32 peer_ip, struct sk_buff *skb)
V_MSS_IDX(mtu_idx) |
V_L2T_IDX(ep->l2t->idx) | V_TX_CHANNEL(ep->l2t->smt_idx);
opt0l = V_TOS((ep->tos >> 2) & M_TOS) | V_RCV_BUFSIZ(rcv_win>>10);
opt2 = V_FLAVORS_VALID(1) | V_CONG_CONTROL_FLAVOR(cong_flavor);
opt2 = F_RX_COALESCE_VALID | V_RX_COALESCE(0) | V_FLAVORS_VALID(1) |
V_CONG_CONTROL_FLAVOR(cong_flavor);
rpl = cplhdr(skb);
rpl->wr.wr_hi = htonl(V_WR_OP(FW_WROPCODE_FORWARD));