On 2018/3/19 4:19, Yuval Shaia wrote:
On Sat, Mar 17, 2018 at 10:21:30PM -0400, Zhu Yanjun wrote:
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@xxxxxxxxxx>
CC: Junxiao Bi <junxiao.bi@xxxxxxxxxx>
Signed-off-by: Zhu Yanjun <yanjun.zhu@xxxxxxxxxx>
---
drivers/infiniband/sw/rxe/rxe_recv.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/infiniband/sw/rxe/rxe_recv.c b/drivers/infiniband/sw/rxe/rxe_recv.c
index 4c3f899..5b8f293 100644
--- a/drivers/infiniband/sw/rxe/rxe_recv.c
+++ b/drivers/infiniband/sw/rxe/rxe_recv.c
@@ -309,10 +309,13 @@ 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
+ * make a reference of the skb to post to the next qp
*/
- skb_copy = (mce->qp_list.next != &mcg->qp_list) ?
- skb_clone(skb, GFP_ATOMIC) : NULL;
+ skb_copy = NULL;
+ if (mce->qp_list.next != &mcg->qp_list) {
+ skb_copy = skb;
+ refcount_inc(&skb->users);
+ }
Something with the code after the change doesn't make sense to me, you save
skb in skb_copy (bad name after the change) and then, few lines below skb
is set to skb_copy.
I think with this change we do not really need skb_copy, just do
refcount_inc.
No comments about the idea itself, just the code structure.
Not related to this proposal, while here, can you remove the "if (skb)" in
Sure. I agree with you. I will make a new patch to fix it.
Thanks a lot.
Zhu Yanjun
label err1? looks like kfree_skb takes care of it.
pkt->qp = qp;
rxe_add_ref(qp);
--
2.7.4
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