From 99dae690255e90f5cbefcc76ad92b35cdf87d14d Mon Sep 17 00:00:00 2001 From: Zhu Yanjun Date: Wed, 21 Mar 2018 04:08:37 -0400 Subject: [PATCH] IB/rxe: optimize mcast recv process In mcast recv process, the function skb_clone is used. In fact, the refcount can be increased to replace cloning a new skb since the original skb will not be modified before it is freed. This can make the performance better and save the memory. CC: Srinivas Eeda CC: Junxiao Bi Signed-off-by: Zhu Yanjun Reviewed-by: Yuval Shaia Signed-off-by: Jason Gunthorpe --- drivers/infiniband/sw/rxe/rxe_recv.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/drivers/infiniband/sw/rxe/rxe_recv.c b/drivers/infiniband/sw/rxe/rxe_recv.c index 08ad9dc72205..dd80c7d9074a 100644 --- a/drivers/infiniband/sw/rxe/rxe_recv.c +++ b/drivers/infiniband/sw/rxe/rxe_recv.c @@ -276,7 +276,6 @@ static void rxe_rcv_mcast_pkt(struct rxe_dev *rxe, struct sk_buff *skb) { struct rxe_pkt_info *pkt = SKB_TO_PKT(skb); struct rxe_mc_grp *mcg; - struct sk_buff *skb_copy; struct rxe_mc_elem *mce; struct rxe_qp *qp; union ib_gid dgid; @@ -309,18 +308,14 @@ static void rxe_rcv_mcast_pkt(struct rxe_dev *rxe, struct sk_buff *skb) continue; /* if *not* the last qp in the list - * make a copy of the skb to post to the next qp + * increase the users of the skb then post to the next qp */ - skb_copy = (mce->qp_list.next != &mcg->qp_list) ? - skb_clone(skb, GFP_ATOMIC) : NULL; + if (mce->qp_list.next != &mcg->qp_list) + refcount_inc(&skb->users); pkt->qp = qp; rxe_add_ref(qp); rxe_rcv_pkt(rxe, pkt, skb); - - skb = skb_copy; - if (!skb) - break; } spin_unlock_bh(&mcg->mcg_lock); @@ -328,8 +323,7 @@ static void rxe_rcv_mcast_pkt(struct rxe_dev *rxe, struct sk_buff *skb) rxe_drop_ref(mcg); /* drop ref from rxe_pool_get_key. */ err1: - if (skb) - kfree_skb(skb); + kfree_skb(skb); } static int rxe_match_dgid(struct rxe_dev *rxe, struct sk_buff *skb)