[PATCH V3 net-next 1/1] hv_netvsc: Use the xmit_more skb flag to optimize signaling the host
From: "K. Y. Srinivasan" <kys@microsoft.com>
Date: 2015-05-06 17:01:09
Also in:
lkml
Subsystem:
hyper-v/azure core and drivers, networking drivers, the rest · Maintainers:
"K. Y. Srinivasan", Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Based on the information given to this driver (via the xmit_more skb flag), we can defer signaling the host if more packets are on the way. This will help make the host more efficient since it can potentially process a larger batch of packets. Implement this optimization. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> --- v2: Fixed up indentation based on feedback from David Miller. v3: If the queue is stopped, deal with that condition: Eric Dumazet [off-list ref] drivers/net/hyperv/netvsc.c | 20 ++++++++++++-------- drivers/net/hyperv/netvsc_drv.c | 2 ++ 2 files changed, 14 insertions(+), 8 deletions(-)
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index ea091bc..36fef17 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c@@ -743,6 +743,7 @@ static inline int netvsc_send_pkt( u64 req_id; int ret; struct hv_page_buffer *pgbuf; + u32 vmbus_flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT; if (packet->is_data_pkt) {
@@ -772,19 +773,22 @@ static inline int netvsc_send_pkt( if (packet->page_buf_cnt) { pgbuf = packet->cp_partial ? packet->page_buf + packet->rmsg_pgcnt : packet->page_buf; - ret = vmbus_sendpacket_pagebuffer(out_channel, - pgbuf, - packet->page_buf_cnt, - &nvmsg, - sizeof(struct nvsp_message), - req_id); + ret = vmbus_sendpacket_pagebuffer_ctl(out_channel, + pgbuf, + packet->page_buf_cnt, + &nvmsg, + sizeof(struct + nvsp_message), + req_id, + vmbus_flags, + !packet->xmit_more); } else { - ret = vmbus_sendpacket( + ret = vmbus_sendpacket_ctl( out_channel, &nvmsg, sizeof(struct nvsp_message), req_id, VM_PKT_DATA_INBAND, - VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); + vmbus_flags, !packet->xmit_more); } if (ret == 0) {
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 5993c7e..4efaa6e 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c@@ -435,6 +435,8 @@ check_size: packet->page_buf = page_buf; packet->q_idx = skb_get_queue_mapping(skb); + if (netif_tx_queue_stopped(netdev_get_tx_queue(net, packet->q_idx))) + packet->xmit_more = false; packet->is_data_pkt = true; packet->total_data_buflen = skb->len;
--
1.7.4.1