hyperv: Enable sendbuf mechanism on the send path
We send packets using a copy-free mechanism (this is the Guest to Host transport
via VMBUS). While this is obviously optimal for large packets,
it may not be optimal for small packets. Hyper-V host supports
a second mechanism for sending packets that is "copy based". We implement that
mechanism in this patch.
In this version of the patch I have addressed a comment from David Miller.
With this patch (and all of the other offload and VRSS patches), we are now able
to almost saturate a 10G interface between Linux VMs on Hyper-V
on different hosts - close to 9 Gbps as measured via iperf.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index c76b665..939e3af 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -236,10 +236,11 @@
struct hv_netvsc_packet *packet = (struct hv_netvsc_packet *)context;
struct sk_buff *skb = (struct sk_buff *)
(unsigned long)packet->send_completion_tid;
+ u32 index = packet->send_buf_index;
kfree(packet);
- if (skb)
+ if (skb && (index == NETVSC_INVALID_INDEX))
dev_kfree_skb_any(skb);
}