netvsc: keep track of some non-fatal overload conditions

Add ethtool statistics for case where send chimmeny buffer is
exhausted and driver has to fall back to doing scatter/gather
send. Also, add statistic for case where ring buffer is full and
receive completions are delayed.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index 3032637..9198dd1 100644 (file)
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -680,6 +680,8 @@ struct netvsc_ethtool_stats {
        unsigned long tx_no_space;
        unsigned long tx_too_big;
        unsigned long tx_busy;
+       unsigned long tx_send_full;
+       unsigned long rx_comp_busy;
 };
 
 struct netvsc_vf_pcpu_stats {

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index d9d7555..0530e7d 100644 (file)
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -883,7 +883,9 @@ int netvsc_send(struct net_device_context *ndev_ctx,
        } else if (pktlen + net_device->pkt_align <
                   net_device->send_section_size) {
                section_index = netvsc_get_next_send_section(net_device);
-               if (section_index != NETVSC_INVALID_INDEX) {
+               if (unlikely(section_index == NETVSC_INVALID_INDEX)) {
+                       ++ndev_ctx->eth_stats.tx_send_full;
+               } else {
                        move_pkt_msd(&msd_send, &msd_skb, msdp);
                        msd_len = 0;
                }
@@ -949,9 +951,10 @@ send_now:
 }
 
 /* Send pending recv completions */
-static int send_recv_completions(struct netvsc_channel *nvchan)
+static int send_recv_completions(struct net_device *ndev,
+                                struct netvsc_device *nvdev,
+                                struct netvsc_channel *nvchan)
 {
-       struct netvsc_device *nvdev = nvchan->net_device;
        struct multi_recv_comp *mrc = &nvchan->mrc;
        struct recv_comp_msg {
                struct nvsp_message_header hdr;
@@ -969,8 +972,12 @@ static int send_recv_completions(struct netvsc_channel *nvchan)
                msg.status = rcd->status;
                ret = vmbus_sendpacket(nvchan->channel, &msg, sizeof(msg),
                                       rcd->tid, VM_PKT_COMP, 0);
-               if (unlikely(ret))
+               if (unlikely(ret)) {
+                       struct net_device_context *ndev_ctx = netdev_priv(ndev);
+
+                       ++ndev_ctx->eth_stats.rx_comp_busy;
                        return ret;
+               }
 
                if (++mrc->first == nvdev->recv_completion_cnt)
                        mrc->first = 0;
@@ -1011,7 +1018,7 @@ static void enq_receive_complete(struct net_device *ndev,
        recv_comp_slot_avail(nvdev, mrc, &filled, &avail);
 
        if (unlikely(filled > NAPI_POLL_WEIGHT)) {
-               send_recv_completions(nvchan);
+               send_recv_completions(ndev, nvdev, nvchan);
                recv_comp_slot_avail(nvdev, mrc, &filled, &avail);
        }
 
@@ -1194,7 +1201,7 @@ int netvsc_poll(struct napi_struct *napi, int budget)
         * then re-enable host interrupts
         *     and reschedule if ring is not empty.
         */
-       if (send_recv_completions(nvchan) == 0 &&
+       if (send_recv_completions(ndev, net_device, nvchan) == 0 &&
            work_done < budget &&
            napi_complete_done(napi, work_done) &&
            hv_end_read(&channel->inbound)) {

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 873c83a..b33f050 100644 (file)
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -1112,6 +1112,8 @@ static const struct {
        { "tx_no_space",  offsetof(struct netvsc_ethtool_stats, tx_no_space) },
        { "tx_too_big",   offsetof(struct netvsc_ethtool_stats, tx_too_big) },
        { "tx_busy",      offsetof(struct netvsc_ethtool_stats, tx_busy) },
+       { "tx_send_full", offsetof(struct netvsc_ethtool_stats, tx_send_full) },
+       { "rx_comp_busy", offsetof(struct netvsc_ethtool_stats, rx_comp_busy) },
 }, vf_stats[] = {
        { "vf_rx_packets", offsetof(struct netvsc_vf_pcpu_stats, rx_packets) },
        { "vf_rx_bytes",   offsetof(struct netvsc_vf_pcpu_stats, rx_bytes) },