From: Zhu Yanjun <yanjun.zhu@oracle.com>
Date: Wed, 21 Mar 2018 04:08:37 -0400
Subject: IB/rxe: optimize mcast recv process
Patch-mainline: v4.17-rc1
Git-commit: 99dae690255e90f5cbefcc76ad92b35cdf87d14d
References: bsc#1103992 FATE#326009
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 <srinivas.eeda@oracle.com>
CC: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Zhu Yanjun <yanjun.zhu@oracle.com>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/infiniband/sw/rxe/rxe_recv.c | 14 ++++----------
1 file changed, 4 insertions(+), 10 deletions(-)
--- 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
{
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
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
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)