[ovs-dev] [PATCH v8] netdev-dpdk:Detailed packet drop statistics

Sriram Vatala sriram.v at altencalsoftlabs.com
Tue Sep 10 12:27:43 UTC 2019


Hi All,
I have addressed the comments given in patch v7. Please review the patch v8
and let me know your comments if any.

Thanks & Regards,
Sriram.

-----Original Message-----
From: Sriram Vatala <sriram.v at altencalsoftlabs.com> 
Sent: 08 September 2019 21:32
To: ovs-dev at openvswitch.org; i.maximets at samsung.com
Cc: ktraynor at redhat.com; ian.stokes at intel.com; Sriram Vatala
<sriram.v at altencalsoftlabs.com>
Subject: [PATCH v8] netdev-dpdk:Detailed packet drop statistics

OVS may be unable to transmit packets for multiple reasons and today there
is a single counter to track packets dropped due to any of those reasons.
The most common reason is that a VM is unable to read packets fast enough
causing the vhostuser port transmit queue on the OVS side to become full.
This manifests as a problem with VNFs not receiving all packets. Having a
separate drop counter to track packets dropped because the transmit queue is
full will clearly indicate that the problem is on the VM side and not in
OVS. Similarly maintaining separate counters for all possible drops helps in
indicating sensible cause for packet drops.

This patch adds custom software stats counters to track packets dropped at
port level and these counters are displayed along with other stats in
"ovs-vsctl get interface <iface> statistics"
command. The detailed stats will be available for both dpdk and vhostuser
ports.

Signed-off-by: Sriram Vatala <sriram.v at altencalsoftlabs.com>
---
Changes since v7 :
Defined structure netdev_dpdk_sw_stats and moved all custom stats into it.
Placed a pointer to netdev_dpdk_sw_stats structure in netdev_dpdk strucure.
stats are reported with prefix with netdev_dpdk
---
 include/openvswitch/netdev.h                  |  14 +++
 lib/netdev-dpdk.c                             | 109 +++++++++++++++---
 utilities/bugtool/automake.mk                 |   3 +-
 utilities/bugtool/ovs-bugtool-get-port-stats  |  25 ++++
 .../plugins/network-status/openvswitch.xml    |   1 +
 vswitchd/vswitch.xml                          |  24 ++++
 6 files changed, 156 insertions(+), 20 deletions(-)  create mode 100755
utilities/bugtool/ovs-bugtool-get-port-stats

diff --git a/include/openvswitch/netdev.h b/include/openvswitch/netdev.h
index 0c10f7b48..c17e6a97d 100644
--- a/include/openvswitch/netdev.h
+++ b/include/openvswitch/netdev.h
@@ -89,6 +89,20 @@ struct netdev_stats {
     uint64_t rx_jabber_errors;
 };
 
+/* Custom software stats for dpdk ports */ struct netdev_dpdk_sw_stats 
+{
+    /* No. of retries when unable to transmit. */
+    uint64_t tx_retries;
+    /* Pkt drops when unable to transmit; Probably Tx queue is full */
+    uint64_t tx_failure_drops;
+    /* Pkt len greater than max dev MTU */
+    uint64_t tx_mtu_exceeded_drops;
+    /* Pkt drops in egress policier processing */
+    uint64_t tx_qos_drops;
+    /* Pkt drops in ingress policier processing */
+    uint64_t rx_qos_drops;
+};
+
 /* Structure representation of custom statistics counter */  struct
netdev_custom_counter {
     uint64_t value;
diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c index
bc20d6843..39aab4672 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -413,11 +413,10 @@ struct netdev_dpdk {
 
     PADDED_MEMBERS(CACHE_LINE_SIZE,
         struct netdev_stats stats;
-        /* Custom stat for retries when unable to transmit. */
-        uint64_t tx_retries;
+        struct netdev_dpdk_sw_stats *sw_stats;
         /* Protects stats */
         rte_spinlock_t stats_lock;
-        /* 4 pad bytes here. */
+        /* 36 pad bytes here. */
     );
 
     PADDED_MEMBERS(CACHE_LINE_SIZE,
@@ -1171,7 +1170,8 @@ common_construct(struct netdev *netdev, dpdk_port_t
port_no,
     dev->rte_xstats_ids = NULL;
     dev->rte_xstats_ids_size = 0;
 
-    dev->tx_retries = 0;
+    dev->sw_stats = (struct netdev_dpdk_sw_stats *)
+                        xcalloc(1,sizeof(struct netdev_dpdk_sw_stats));
 
     return 0;
 }
@@ -1357,6 +1357,7 @@ common_destruct(struct netdev_dpdk *dev)
     ovs_list_remove(&dev->list_node);
     free(ovsrcu_get_protected(struct ingress_policer *,
                               &dev->ingress_policer));
+    free(dev->sw_stats);
     ovs_mutex_destroy(&dev->mutex);
 }
 
@@ -2171,6 +2172,7 @@ netdev_dpdk_vhost_rxq_recv(struct netdev_rxq *rxq,
     struct ingress_policer *policer = netdev_dpdk_get_ingress_policer(dev);
     uint16_t nb_rx = 0;
     uint16_t dropped = 0;
+    uint16_t qos_drops = 0;
     int qid = rxq->queue_id * VIRTIO_QNUM + VIRTIO_TXQ;
     int vid = netdev_dpdk_get_vid(dev);
 
@@ -2202,11 +2204,13 @@ netdev_dpdk_vhost_rxq_recv(struct netdev_rxq *rxq,
                                     (struct rte_mbuf **) batch->packets,
                                     nb_rx, true);
         dropped -= nb_rx;
+        qos_drops = dropped;
     }
 
     rte_spinlock_lock(&dev->stats_lock);
     netdev_dpdk_vhost_update_rx_counters(&dev->stats, batch->packets,
                                          nb_rx, dropped);
+    dev->sw_stats->rx_qos_drops += qos_drops;
     rte_spinlock_unlock(&dev->stats_lock);
 
     batch->count = nb_rx;
@@ -2232,6 +2236,7 @@ netdev_dpdk_rxq_recv(struct netdev_rxq *rxq, struct
dp_packet_batch *batch,
     struct ingress_policer *policer = netdev_dpdk_get_ingress_policer(dev);
     int nb_rx;
     int dropped = 0;
+    int qos_drops = 0;
 
     if (OVS_UNLIKELY(!(dev->flags & NETDEV_UP))) {
         return EAGAIN;
@@ -2250,12 +2255,14 @@ netdev_dpdk_rxq_recv(struct netdev_rxq *rxq, struct
dp_packet_batch *batch,
                                     (struct rte_mbuf **) batch->packets,
                                     nb_rx, true);
         dropped -= nb_rx;
+        qos_drops = dropped;
     }
 
     /* Update stats to reflect dropped packets */
     if (OVS_UNLIKELY(dropped)) {
         rte_spinlock_lock(&dev->stats_lock);
         dev->stats.rx_dropped += dropped;
+        dev->sw_stats->rx_qos_drops += qos_drops;
         rte_spinlock_unlock(&dev->stats_lock);
     }
 
@@ -2339,6 +2346,10 @@ __netdev_dpdk_vhost_send(struct netdev *netdev, int
qid,
     struct rte_mbuf **cur_pkts = (struct rte_mbuf **) pkts;
     unsigned int total_pkts = cnt;
     unsigned int dropped = 0;
+    unsigned int tx_failure;
+    unsigned int mtu_drops;
+    unsigned int qos_drops;
+    struct netdev_dpdk_sw_stats *sw_stats = dev->sw_stats;
     int i, retries = 0;
     int max_retries = VHOST_ENQ_RETRY_MIN;
     int vid = netdev_dpdk_get_vid(dev); @@ -2356,9 +2367,12 @@
__netdev_dpdk_vhost_send(struct netdev *netdev, int qid,
     rte_spinlock_lock(&dev->tx_q[qid].tx_lock);
 
     cnt = netdev_dpdk_filter_packet_len(dev, cur_pkts, cnt);
+    mtu_drops = total_pkts - cnt;
+    qos_drops = cnt;
     /* Check has QoS has been configured for the netdev */
     cnt = netdev_dpdk_qos_run(dev, cur_pkts, cnt, true);
-    dropped = total_pkts - cnt;
+    qos_drops -= cnt;
+    dropped = qos_drops + mtu_drops;
 
     do {
         int vhost_qid = qid * VIRTIO_QNUM + VIRTIO_RXQ; @@ -2383,12
+2397,16 @@ __netdev_dpdk_vhost_send(struct netdev *netdev, int qid,
         }
     } while (cnt && (retries++ < max_retries));
 
+    tx_failure = cnt;
     rte_spinlock_unlock(&dev->tx_q[qid].tx_lock);
 
     rte_spinlock_lock(&dev->stats_lock);
     netdev_dpdk_vhost_update_tx_counters(&dev->stats, pkts, total_pkts,
                                          cnt + dropped);
-    dev->tx_retries += MIN(retries, max_retries);
+    sw_stats->tx_retries += MIN(retries, max_retries);
+    sw_stats->tx_failure_drops += tx_failure;
+    sw_stats->tx_mtu_exceeded_drops += mtu_drops;
+    sw_stats->tx_qos_drops += qos_drops;
     rte_spinlock_unlock(&dev->stats_lock);
 
 out:
@@ -2413,12 +2431,16 @@ dpdk_do_tx_copy(struct netdev *netdev, int qid,
struct dp_packet_batch *batch)
     struct rte_mbuf *pkts[PKT_ARRAY_SIZE];
     uint32_t cnt = batch_cnt;
     uint32_t dropped = 0;
+    uint32_t tx_failure = 0;
+    uint32_t mtu_drops = 0;
+    uint32_t qos_drops = 0;
+    struct netdev_dpdk_sw_stats *sw_stats = dev->sw_stats;
 
     if (dev->type != DPDK_DEV_VHOST) {
         /* Check if QoS has been configured for this netdev. */
         cnt = netdev_dpdk_qos_run(dev, (struct rte_mbuf **) batch->packets,
                                   batch_cnt, false);
-        dropped += batch_cnt - cnt;
+        qos_drops = batch_cnt - cnt;
     }
 
     uint32_t txcnt = 0;
@@ -2431,7 +2453,7 @@ dpdk_do_tx_copy(struct netdev *netdev, int qid, struct
dp_packet_batch *batch)
             VLOG_WARN_RL(&rl, "Too big size %u max_packet_len %d",
                          size, dev->max_packet_len);
 
-            dropped++;
+            mtu_drops++;
             continue;
         }
 
@@ -2454,13 +2476,17 @@ dpdk_do_tx_copy(struct netdev *netdev, int qid,
struct dp_packet_batch *batch)
             __netdev_dpdk_vhost_send(netdev, qid, (struct dp_packet **)
pkts,
                                      txcnt);
         } else {
-            dropped += netdev_dpdk_eth_tx_burst(dev, qid, pkts, txcnt);
+            tx_failure = netdev_dpdk_eth_tx_burst(dev, qid, pkts, 
+ txcnt);
         }
     }
 
+    dropped += qos_drops + mtu_drops + tx_failure;
     if (OVS_UNLIKELY(dropped)) {
         rte_spinlock_lock(&dev->stats_lock);
         dev->stats.tx_dropped += dropped;
+        sw_stats->tx_failure_drops += tx_failure;
+        sw_stats->tx_mtu_exceeded_drops += mtu_drops;
+        sw_stats->tx_qos_drops += qos_drops;
         rte_spinlock_unlock(&dev->stats_lock);
     }
 }
@@ -2485,6 +2511,8 @@ netdev_dpdk_send__(struct netdev_dpdk *dev, int qid,
                    struct dp_packet_batch *batch,
                    bool concurrent_txq)  {
+    struct netdev_dpdk_sw_stats *sw_stats = dev->sw_stats;
+
     if (OVS_UNLIKELY(!(dev->flags & NETDEV_UP))) {
         dp_packet_delete_batch(batch, true);
         return;
@@ -2502,18 +2530,25 @@ netdev_dpdk_send__(struct netdev_dpdk *dev, int qid,
         dp_packet_delete_batch(batch, true);
     } else {
         int tx_cnt, dropped;
+        int tx_failure, mtu_drops, qos_drops;
         int batch_cnt = dp_packet_batch_size(batch);
         struct rte_mbuf **pkts = (struct rte_mbuf **) batch->packets;
 
         tx_cnt = netdev_dpdk_filter_packet_len(dev, pkts, batch_cnt);
+        mtu_drops = batch_cnt - tx_cnt;
+        qos_drops = tx_cnt;
         tx_cnt = netdev_dpdk_qos_run(dev, pkts, tx_cnt, true);
-        dropped = batch_cnt - tx_cnt;
+        qos_drops -= tx_cnt;
 
-        dropped += netdev_dpdk_eth_tx_burst(dev, qid, pkts, tx_cnt);
+        tx_failure = netdev_dpdk_eth_tx_burst(dev, qid, pkts, tx_cnt);
 
+        dropped = tx_failure + mtu_drops + qos_drops;
         if (OVS_UNLIKELY(dropped)) {
             rte_spinlock_lock(&dev->stats_lock);
             dev->stats.tx_dropped += dropped;
+            sw_stats->tx_failure_drops += tx_failure;
+            sw_stats->tx_mtu_exceeded_drops += mtu_drops;
+            sw_stats->tx_qos_drops += qos_drops;
             rte_spinlock_unlock(&dev->stats_lock);
         }
     }
@@ -2772,6 +2807,17 @@ netdev_dpdk_get_custom_stats(const struct netdev
*netdev,
     uint32_t i;
     struct netdev_dpdk *dev = netdev_dpdk_cast(netdev);
     int rte_xstats_ret;
+    uint16_t index = 0;
+
+#define DPDK_CSTATS                         \
+    DPDK_CSTAT(tx_failure_drops)            \
+    DPDK_CSTAT(tx_mtu_exceeded_drops)       \
+    DPDK_CSTAT(tx_qos_drops)                \
+    DPDK_CSTAT(rx_qos_drops)
+
+#define DPDK_CSTAT(NAME) +1
+    custom_stats->size = DPDK_CSTATS;
+#undef DPDK_CSTAT
 
     ovs_mutex_lock(&dev->mutex);
 
@@ -2786,9 +2832,10 @@ netdev_dpdk_get_custom_stats(const struct netdev
*netdev,
         if (rte_xstats_ret > 0 &&
             rte_xstats_ret <= dev->rte_xstats_ids_size) {
 
-            custom_stats->size = rte_xstats_ret;
+            index = rte_xstats_ret;
+            custom_stats->size += rte_xstats_ret;
             custom_stats->counters =
-                    (struct netdev_custom_counter *)
xcalloc(rte_xstats_ret,
+                   (struct netdev_custom_counter *) 
+ xcalloc(custom_stats->size,
                             sizeof(struct netdev_custom_counter));
 
             for (i = 0; i < rte_xstats_ret; i++) { @@ -2802,7 +2849,6 @@
netdev_dpdk_get_custom_stats(const struct netdev *netdev,
             VLOG_WARN("Cannot get XSTATS values for port:
"DPDK_PORT_ID_FMT,
                       dev->port_id);
             custom_stats->counters = NULL;
-            custom_stats->size = 0;
             /* Let's clear statistics cache, so it will be
              * reconfigured */
             netdev_dpdk_clear_xstats(dev); @@ -2811,6 +2857,27 @@
netdev_dpdk_get_custom_stats(const struct netdev *netdev,
         free(values);
     }
 
+    if (custom_stats->counters == NULL) {
+        custom_stats->counters =
+            (struct netdev_custom_counter *) xcalloc(custom_stats->size,
+                                  sizeof(struct netdev_custom_counter));
+    }
+
+    rte_spinlock_lock(&dev->stats_lock);
+    i = index;
+#define DPDK_CSTAT(NAME)                                                \
+    ovs_strlcpy(custom_stats->counters[i++].name, "netdev_dpdk_"#NAME,  \
+                NETDEV_CUSTOM_STATS_NAME_SIZE);
+    DPDK_CSTATS;
+#undef DPDK_CSTAT
+
+    i = index;
+#define DPDK_CSTAT(NAME)                                     \
+    custom_stats->counters[i++].value = dev->sw_stats->NAME;
+    DPDK_CSTATS;
+#undef DPDK_CSTAT
+    rte_spinlock_unlock(&dev->stats_lock);
+
     ovs_mutex_unlock(&dev->mutex);
 
     return 0;
@@ -2823,8 +2890,12 @@ netdev_dpdk_vhost_get_custom_stats(const struct
netdev *netdev,
     struct netdev_dpdk *dev = netdev_dpdk_cast(netdev);
     int i;
 
-#define VHOST_CSTATS \
-    VHOST_CSTAT(tx_retries)
+#define VHOST_CSTATS                        \
+    VHOST_CSTAT(tx_retries)                 \
+    VHOST_CSTAT(tx_failure_drops)           \
+    VHOST_CSTAT(tx_mtu_exceeded_drops)      \
+    VHOST_CSTAT(tx_qos_drops)               \
+    VHOST_CSTAT(rx_qos_drops)
 
 #define VHOST_CSTAT(NAME) + 1
     custom_stats->size = VHOST_CSTATS;
@@ -2832,8 +2903,8 @@ netdev_dpdk_vhost_get_custom_stats(const struct netdev
*netdev,
     custom_stats->counters = xcalloc(custom_stats->size,
                                      sizeof *custom_stats->counters);
     i = 0;
-#define VHOST_CSTAT(NAME) \
-    ovs_strlcpy(custom_stats->counters[i++].name, #NAME, \
+#define VHOST_CSTAT(NAME)                                                \
+    ovs_strlcpy(custom_stats->counters[i++].name, "netdev_dpdk_"#NAME,   \
                 NETDEV_CUSTOM_STATS_NAME_SIZE);
     VHOST_CSTATS;
 #undef VHOST_CSTAT
@@ -2843,7 +2914,7 @@ netdev_dpdk_vhost_get_custom_stats(const struct netdev
*netdev,
     rte_spinlock_lock(&dev->stats_lock);
     i = 0;
 #define VHOST_CSTAT(NAME) \
-    custom_stats->counters[i++].value = dev->NAME;
+    custom_stats->counters[i++].value = dev->sw_stats->NAME;
     VHOST_CSTATS;
 #undef VHOST_CSTAT
     rte_spinlock_unlock(&dev->stats_lock);
diff --git a/utilities/bugtool/automake.mk b/utilities/bugtool/automake.mk
index 40980b367..dda58e0a1 100644
--- a/utilities/bugtool/automake.mk
+++ b/utilities/bugtool/automake.mk
@@ -22,7 +22,8 @@ bugtool_scripts = \
 	utilities/bugtool/ovs-bugtool-ovs-bridge-datapath-type \
 	utilities/bugtool/ovs-bugtool-ovs-vswitchd-threads-affinity \
 	utilities/bugtool/ovs-bugtool-qos-configs \
-	utilities/bugtool/ovs-bugtool-get-dpdk-nic-numa
+	utilities/bugtool/ovs-bugtool-get-dpdk-nic-numa \
+	utilities/bugtool/ovs-bugtool-get-port-stats
 
 scripts_SCRIPTS += $(bugtool_scripts)
 
diff --git a/utilities/bugtool/ovs-bugtool-get-port-stats
b/utilities/bugtool/ovs-bugtool-get-port-stats
new file mode 100755
index 000000000..0fe175e6b
--- /dev/null
+++ b/utilities/bugtool/ovs-bugtool-get-port-stats
@@ -0,0 +1,25 @@
+#! /bin/bash
+
+# This library is free software; you can redistribute it and/or # 
+modify it under the terms of version 2.1 of the GNU Lesser General # 
+Public License as published by the Free Software Foundation.
+#
+# This library is distributed in the hope that it will be useful, # but 
+WITHOUT ANY WARRANTY; without even the implied warranty of # 
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU # 
+Lesser General Public License for more details.
+#
+# Copyright (C) 2019 Ericsson AB
+
+for bridge in `ovs-vsctl -- --real list-br` do
+    echo -e "\nBridge : ${bridge}\n"
+    for iface in `ovs-vsctl list-ifaces ${bridge}`
+    do
+        echo -e "iface : ${iface}"
+        ovs-vsctl get interface ${iface} statistics
+        echo -e "\n"
+    done
+    echo -e "iface : ${bridge}"
+    ovs-vsctl get interface ${bridge} statistics done
diff --git a/utilities/bugtool/plugins/network-status/openvswitch.xml
b/utilities/bugtool/plugins/network-status/openvswitch.xml
index d39867c6e..8c1ec643e 100644
--- a/utilities/bugtool/plugins/network-status/openvswitch.xml
+++ b/utilities/bugtool/plugins/network-status/openvswitch.xml
@@ -40,4 +40,5 @@
     <command label="ovs-ofctl-dump-groups"
filters="ovs">/usr/share/openvswitch/scripts/ovs-bugtool-ovs-ofctl-loop-over
-bridges "dump-groups"</command>
     <command label="ovs-ofctl-dump-group-stats" filters="ovs"
repeat="2">/usr/share/openvswitch/scripts/ovs-bugtool-ovs-ofctl-loop-over-br
idges "dump-group-stats"</command>
     <command label="get_dpdk_nic_numa"
filters="ovs">/usr/share/openvswitch/scripts/ovs-bugtool-get-dpdk-nic-numa</
command>
+    <command label="get_port_statistics" 
+ filters="ovs">/usr/share/openvswitch/scripts/ovs-bugtool-get-port-stat
+ s</command>
 </collect>
diff --git a/vswitchd/vswitch.xml b/vswitchd/vswitch.xml index
9a743c05b..402f3c8ec 100644
--- a/vswitchd/vswitch.xml
+++ b/vswitchd/vswitch.xml
@@ -3486,6 +3486,30 @@ ovs-vsctl add-port br0 p0 -- set Interface p0
type=patch options:peer=p1 \
           the above.
         </column>
       </group>
+      <group title="Statistics: Custom Software stats for dpdk ports">
+        <column name="statistics" key="tx_retries">
+          Total number of transmit retries on a vhost-user or
vhost-user-client
+          interface.
+        </column>
+        <column name="statistics" key="tx_failure_drops">
+          Total number of packets dropped because DPDP transmit API for
+          physical/vhost ports fails to transmit the packets. This happens
+          most likely because the transmit queue is full or has been filled
+          up. There are other reasons as well which are unlikely to happen.
+        </column>
+        <column name="statistics" key="tx_mtu_exceeded_drops">
+          Number of packets dropped due to packet length exceeding the max
+          device MTU.
+        </column>
+        <column name="statistics" key="tx_qos_drops">
+          Total number of packets dropped due to transmission rate
exceeding
+          the configured egress policer rate.
+        </column>
+        <column name="statistics" key="rx_qos_drops">
+          Total number of packets dropped due to reception rate exceeding
+          the configured ingress policer rate.
+        </column>
+      </group>
     </group>
 
     <group title="Ingress Policing">
--
2.20.1


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