diff options
| author | KY Srinivasan <kys@microsoft.com> | 2015-05-11 15:39:46 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-05-12 23:10:43 -0400 |
| commit | 82fa3c776e5abba7ed6e4b4f4983d14731c37d6a (patch) | |
| tree | cb52ac0c3e8ccd801c42d0ad6703dd7ffe4adf76 /drivers/net | |
| parent | 9eea92226407e7a117ef1ceef45380ebd000a0e2 (diff) | |
| download | linux-82fa3c776e5abba7ed6e4b4f4983d14731c37d6a.tar.bz2 | |
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: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/hyperv/netvsc.c | 43 |
1 files changed, 27 insertions, 16 deletions
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c index 2d9ef533cc48..1c4f265f4e7c 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 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) |