From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zhu Yanjun Subject: [PATCHv3 1/1] IB/rxe: remove unnecessary skb_clone Date: Wed, 14 Feb 2018 05:36:40 -0500 Message-ID: <1518604600-4425-1-git-send-email-yanjun.zhu@oracle.com> References: <20180213112124.GA6991@yuvallap> Return-path: In-Reply-To: <20180213112124.GA6991@yuvallap> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: monis-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org, dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, jgg-uk2M96/98Pc@public.gmane.org, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, yuval.shaia-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org List-Id: linux-rdma@vger.kernel.org In send_atomic_ack function, it is not necessary to make a skb_clone. To gain better performance (high throughput and low latency), this skb_clone is removed. The following tests are made. server client --------- --------- |1.1.1.1|<----rxe-channel--->|1.1.1.2| --------- --------- On server: rping -s -a 1.1.1.1 -v -C 1000 -S 512 On client: rping -c -a 1.1.1.1 -v -C 1000 -S 512 The kernel config CONFIG_DEBUG_KMEMLEAK is enabled on both server and client. This test runs for several hours. There is no memory leak and the whole system can work well. As the above network, the following tests are made. Server: ibv_rc_pingpong -d rxe0 -g 1 Client: ibv_rc_pingpong -d rxe0 -g 1 1.1.1.1 The result on Server(10 tests are made). Before: Throughput is 137.07 Mbit/sec Latency is 517.76 usec/iter After: Throughput is 148.85 Mbit/sec Latency is 476.64 usec/iter The throughput is enhanced and the latency is reduced. CC: Srinivas Eeda CC: Junxiao Bi Signed-off-by: Zhu Yanjun --- V2-->V3: Fix typo errors. V1-->V2: 10 tests are made. From throughput and latency, the performance is better. --- drivers/infiniband/sw/rxe/rxe_resp.c | 18 +++--------------- 1 file changed, 3 insertions(+), 15 deletions(-) diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c index d37bb9b..2ebb07c 100644 --- a/drivers/infiniband/sw/rxe/rxe_resp.c +++ b/drivers/infiniband/sw/rxe/rxe_resp.c @@ -969,7 +969,6 @@ static int send_atomic_ack(struct rxe_qp *qp, struct rxe_pkt_info *pkt, int rc = 0; struct rxe_pkt_info ack_pkt; struct sk_buff *skb; - struct sk_buff *skb_copy; struct rxe_dev *rxe = to_rdev(qp->ibqp.device); struct resp_res *res; @@ -981,15 +980,6 @@ static int send_atomic_ack(struct rxe_qp *qp, struct rxe_pkt_info *pkt, goto out; } - skb_copy = skb_clone(skb, GFP_ATOMIC); - if (skb_copy) - rxe_add_ref(qp); /* for the new SKB */ - else { - pr_warn("Could not clone atomic response\n"); - rc = -ENOMEM; - goto out; - } - res = &qp->resp.resources[qp->resp.res_head]; free_rd_atomic_resource(qp, res); rxe_advance_resp_resource(qp); @@ -998,18 +988,16 @@ static int send_atomic_ack(struct rxe_qp *qp, struct rxe_pkt_info *pkt, memset((unsigned char *)SKB_TO_PKT(skb) + sizeof(ack_pkt), 0, sizeof(skb->cb) - sizeof(ack_pkt)); + refcount_inc(&skb->users); res->type = RXE_ATOMIC_MASK; res->atomic.skb = skb; res->first_psn = ack_pkt.psn; res->last_psn = ack_pkt.psn; res->cur_psn = ack_pkt.psn; - rc = rxe_xmit_packet(rxe, qp, &ack_pkt, skb_copy); - if (rc) { + rc = rxe_xmit_packet(rxe, qp, &ack_pkt, skb); + if (rc) pr_err_ratelimited("Failed sending ack\n"); - rxe_drop_ref(qp); - kfree_skb(skb_copy); - } out: return rc; -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html