From: Jon Paul Maloy Date: Fri, 13 Mar 2015 20:08:09 +0000 (-0400) Subject: tipc: eliminate unnecessary call to broadcast ack function X-Git-Tag: v4.14-rc1~5592^2~243^2~2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=2cdf3918e47e98c8f34f7a64455ea9fd433756e7;p=platform%2Fkernel%2Flinux-rpi.git tipc: eliminate unnecessary call to broadcast ack function The unicast packet header contains a broadcast acknowledge sequence number, that may need to be conveyed to the broadcast link for proper treatment. Currently, the function tipc_rcv(), which is on the most critical data path, calls the function tipc_bclink_acknowledge() to have this done. This call is made for each received packet, and results in the unconditional grabbing of the broadcast link spinlock. This is unnecessary, since we can see directly from tipc_rcv() if the acknowledged number differs from what has been previously acked from the node in question. In the vast majority of cases the numbers won't differ, and there is nothing to update. We now make the call to tipc_bclink_acknowledge() conditional to that the two ack values differ. Reviewed-by: Erik Hugne Reviewed-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: David S. Miller --- diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c index 3e41704..5ee5076 100644 --- a/net/tipc/bcast.c +++ b/net/tipc/bcast.c @@ -215,7 +215,11 @@ void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked) struct net *net = n_ptr->net; struct tipc_net *tn = net_generic(net, tipc_net_id); + if (unlikely(!n_ptr->bclink.recv_permitted)) + return; + tipc_bclink_lock(net); + /* Bail out if tx queue is empty (no clean up is required) */ skb = skb_peek(&tn->bcl->outqueue); if (!skb) diff --git a/net/tipc/link.c b/net/tipc/link.c index 56c39b1..2652c32 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -1117,7 +1117,7 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr) ackd = msg_ack(msg); /* Release acked messages */ - if (likely(n_ptr->bclink.recv_permitted)) + if (unlikely(n_ptr->bclink.acked != msg_bcast_ack(msg))) tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg)); released = 0;