Commit 82fa3c77 authored by KY Srinivasan's avatar KY Srinivasan Committed by David S. Miller

hv_netvsc: Use the xmit_more skb flag to optimize signaling the host

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: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9eea9222
......@@ -743,6 +743,7 @@ static inline int netvsc_send_pkt(
u64 req_id;
int ret;
struct hv_page_buffer *pgbuf;
u32 ring_avail = hv_ringbuf_avail_percent(&out_channel->outbound);
nvmsg.hdr.msg_type = NVSP_MSG1_TYPE_SEND_RNDIS_PKT;
if (packet->is_data_pkt) {
......@@ -769,32 +770,42 @@ static inline int netvsc_send_pkt(
if (out_channel->rescind)
return -ENODEV;
/*
* It is possible that once we successfully place this packet
* on the ringbuffer, we may stop the queue. In that case, we want
* to notify the host independent of the xmit_more flag. We don't
* need to be precise here; in the worst case we may signal the host
* unnecessarily.
*/
if (ring_avail < (RING_AVAIL_PERCENT_LOWATER + 1))
packet->xmit_more = false;
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_DATA_PACKET_FLAG_COMPLETION_REQUESTED,
!packet->xmit_more);
} else {
ret = vmbus_sendpacket(
out_channel, &nvmsg,
sizeof(struct nvsp_message),
req_id,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
ret = vmbus_sendpacket_ctl(out_channel, &nvmsg,
sizeof(struct nvsp_message),
req_id,
VM_PKT_DATA_INBAND,
VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED,
!packet->xmit_more);
}
if (ret == 0) {
atomic_inc(&net_device->num_outstanding_sends);
atomic_inc(&net_device->queue_sends[q_idx]);
if (hv_ringbuf_avail_percent(&out_channel->outbound) <
RING_AVAIL_PERCENT_LOWATER) {
netif_tx_stop_queue(netdev_get_tx_queue(
ndev, q_idx));
if (ring_avail < RING_AVAIL_PERCENT_LOWATER) {
netif_tx_stop_queue(netdev_get_tx_queue(ndev, q_idx));
if (atomic_read(&net_device->
queue_sends[q_idx]) < 1)
......
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