We currently poll all available queues based on the max queue count
exchanged with the vhost peer and rely on the vhost library in DPDK to
check the vring status beneath.
This can lead to some overhead when we have a lot of unused queues.
To enhance the situation, we can skip the disabled queues.
On rxq notifications, we make use of the netdev's change_seq number so
that the pmd thread main loop can cache the queue state periodically.
$ ovs-appctl dpif-netdev/pmd-rxq-show
pmd thread numa_id 0 core_id 1:
isolated : true
port: dpdk0 queue-id: 0 pmd usage: 0 %
pmd thread numa_id 0 core_id 2:
isolated : true
port: vhost1 queue-id: 0 pmd usage: 0 %
port: vhost3 queue-id: 0 pmd usage: 0 %
pmd thread numa_id 0 core_id 15:
isolated : true
port: dpdk1 queue-id: 0 pmd usage: 0 %
pmd thread numa_id 0 core_id 16:
isolated : true
port: vhost0 queue-id: 0 pmd usage: 0 %
port: vhost2 queue-id: 0 pmd usage: 0 %
$ while true; do
ovs-appctl dpif-netdev/pmd-rxq-show |awk '
/port: / {
tot++;
if ($NF == "disabled") {
dis++;
}
}
END {
print "total: " tot ", enabled: " (tot - dis)
}'
sleep 1
done
total: 6, enabled: 2
total: 6, enabled: 2
...
# Started vm, virtio devices are bound to kernel driver which enables
# F_MQ + all queue pairs
total: 6, enabled: 2
total: 66, enabled: 66
...
# Unbound vhost0 and vhost1 from the kernel driver
total: 66, enabled: 66
total: 66, enabled: 34
...
# Configured kernel bound devices to use only 1 queue pair
total: 66, enabled: 34
total: 66, enabled: 19
total: 66, enabled: 4
...
# While rebooting the vm
total: 66, enabled: 4
total: 66, enabled: 2
...
total: 66, enabled: 66
...
# After shutting down the vm
total: 66, enabled: 66
total: 66, enabled: 2
Signed-off-by: David Marchand <david.march...@redhat.com>
---
Changes since v1:
- only indicate disabled queues in dpif-netdev/pmd-rxq-show output
- Ilya comments
- no need for a struct as we only need a boolean per rxq
- "rx_q" is generic, while we only care for this in vhost case,
renamed as "vhost_rxq_enabled",
- add missing rte_free on allocation error,
- vhost_rxq_enabled is freed in vhost destruct only,
- rxq0 is enabled at the virtio device activation to accomodate
legacy implementations which would not report per queue states
later,
- do not mix boolean with integer,
- do not use bit operand on boolean,
---
lib/dpif-netdev.c | 27 ++++++++++++++++++++++++
lib/netdev-dpdk.c | 58 +++++++++++++++++++++++++++++++++++++++------------
lib/netdev-provider.h | 5 +++++
lib/netdev.c | 10 +++++++++
lib/netdev.h | 1 +
5 files changed, 88 insertions(+), 13 deletions(-)
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index 4d6d0c3..5bfa6ad 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -591,6 +591,8 @@ struct polled_queue {
struct dp_netdev_rxq *rxq;
odp_port_t port_no;
bool emc_enabled;
+ bool enabled;
+ uint64_t change_seq;
};
/* Contained by struct dp_netdev_pmd_thread's 'poll_list' member. */
@@ -1171,6 +1173,9 @@ pmd_info_show_rxq(struct ds *reply, struct
dp_netdev_pmd_thread *pmd)
} else {
ds_put_format(reply, "%s", "NOT AVAIL");
}
+ if (!netdev_rxq_enabled(list[i].rxq->rx)) {
+ ds_put_cstr(reply, " polling: disabled");
+ }
ds_put_cstr(reply, "\n");
}
ovs_mutex_unlock(&pmd->port_mutex);
@@ -5198,6 +5203,11 @@ dpif_netdev_run(struct dpif *dpif)
}
for (i = 0; i < port->n_rxq; i++) {
+
+ if (!netdev_rxq_enabled(port->rxqs[i].rx)) {
+ continue;
+ }
+
if (dp_netdev_process_rxq_port(non_pmd,
&port->rxqs[i],
port->port_no)) {
@@ -5371,6 +5381,9 @@ pmd_load_queues_and_ports(struct dp_netdev_pmd_thread
*pmd,
poll_list[i].rxq = poll->rxq;
poll_list[i].port_no = poll->rxq->port->port_no;
poll_list[i].emc_enabled = poll->rxq->port->emc_enabled;
+ poll_list[i].enabled = netdev_rxq_enabled(poll->rxq->rx);
+ poll_list[i].change_seq =
+ netdev_get_change_seq(poll->rxq->port->netdev);
i++;
}
@@ -5436,6 +5449,10 @@ reload:
for (i = 0; i < poll_cnt; i++) {
+ if (!poll_list[i].enabled) {
+ continue;
+ }
+
if (poll_list[i].emc_enabled) {
atomic_read_relaxed(&pmd->dp->emc_insert_min,
&pmd->ctx.emc_insert_min);
@@ -5472,6 +5489,16 @@ reload:
if (reload) {
break;
}
+
+ for (i = 0; i < poll_cnt; i++) {
+ uint64_t current_seq =
+ netdev_get_change_seq(poll_list[i].rxq->port->netdev);
+ if (poll_list[i].change_seq != current_seq) {
+ poll_list[i].change_seq = current_seq;
+ poll_list[i].enabled =
+ netdev_rxq_enabled(poll_list[i].rxq->rx);
+ }
+ }
}
pmd_perf_end_iteration(s, rx_packets, tx_packets,
pmd_perf_metrics_enabled(pmd));
diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index 47153dc..9ba8e67 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -424,6 +424,9 @@ struct netdev_dpdk {
OVSRCU_TYPE(struct ingress_policer *) ingress_policer;
uint32_t policer_rate;
uint32_t policer_burst;
+
+ /* Array of vhost rxq states, see vring_state_changed */
+ bool *vhost_rxq_enabled;
);
PADDED_MEMBERS(CACHE_LINE_SIZE,
@@ -1235,8 +1238,14 @@ vhost_common_construct(struct netdev *netdev)
int socket_id = rte_lcore_to_socket_id(rte_get_master_lcore());
struct netdev_dpdk *dev = netdev_dpdk_cast(netdev);
+ dev->vhost_rxq_enabled = dpdk_rte_mzalloc(OVS_VHOST_MAX_QUEUE_NUM *
+ sizeof *dev->vhost_rxq_enabled);
+ if (!dev->vhost_rxq_enabled) {
+ return ENOMEM;
+ }
dev->tx_q = netdev_dpdk_alloc_txq(OVS_VHOST_MAX_QUEUE_NUM);
if (!dev->tx_q) {
+ rte_free(dev->vhost_rxq_enabled);
return ENOMEM;
}
@@ -1448,6 +1457,7 @@ netdev_dpdk_vhost_destruct(struct netdev *netdev)
dev->vhost_id = NULL;
common_destruct(dev);
+ rte_free(dev->vhost_rxq_enabled);
ovs_mutex_unlock(&dpdk_mutex);
@@ -2200,6 +2210,14 @@ netdev_dpdk_vhost_rxq_recv(struct netdev_rxq *rxq,
return 0;
}
+static bool
+netdev_dpdk_vhost_rxq_enabled(struct netdev_rxq *rxq)
+{
+ struct netdev_dpdk *dev = netdev_dpdk_cast(rxq->netdev);
+
+ return dev->vhost_rxq_enabled[rxq->queue_id];
+}
+
static int
netdev_dpdk_rxq_recv(struct netdev_rxq *rxq, struct dp_packet_batch *batch,
int *qfill)
@@ -3563,6 +3581,8 @@ destroy_device(int vid)
ovs_mutex_lock(&dev->mutex);
dev->vhost_reconfigured = false;
ovsrcu_index_set(&dev->vid, -1);
+ memset(dev->vhost_rxq_enabled, 0,
+ OVS_VHOST_MAX_QUEUE_NUM * sizeof *dev->vhost_rxq_enabled);
netdev_dpdk_txq_map_clear(dev);
netdev_change_seq_changed(&dev->up);
@@ -3597,24 +3617,30 @@ vring_state_changed(int vid, uint16_t queue_id, int
enable)
struct netdev_dpdk *dev;
bool exists = false;
int qid = queue_id / VIRTIO_QNUM;
+ bool is_rx = (queue_id % VIRTIO_QNUM) == VIRTIO_TXQ;
char ifname[IF_NAME_SZ];
rte_vhost_get_ifname(vid, ifname, sizeof ifname);
- if (queue_id % VIRTIO_QNUM == VIRTIO_TXQ) {
- return 0;
- }
-
ovs_mutex_lock(&dpdk_mutex);
LIST_FOR_EACH (dev, list_node, &dpdk_list) {
ovs_mutex_lock(&dev->mutex);
if (nullable_string_is_equal(ifname, dev->vhost_id)) {
- if (enable) {
- dev->tx_q[qid].map = qid;
+ if (is_rx) {
+ bool enabled = dev->vhost_rxq_enabled[qid];
+
+ dev->vhost_rxq_enabled[qid] = enable != 0;
+ if (enabled != dev->vhost_rxq_enabled[qid]) {
+ netdev_change_seq_changed(&dev->up);
+ }
} else {
- dev->tx_q[qid].map = OVS_VHOST_QUEUE_DISABLED;
+ if (enable) {
+ dev->tx_q[qid].map = qid;
+ } else {
+ dev->tx_q[qid].map = OVS_VHOST_QUEUE_DISABLED;
+ }
+ netdev_dpdk_remap_txqs(dev);
}
- netdev_dpdk_remap_txqs(dev);
exists = true;
ovs_mutex_unlock(&dev->mutex);
break;
@@ -3624,9 +3650,9 @@ vring_state_changed(int vid, uint16_t queue_id, int
enable)
ovs_mutex_unlock(&dpdk_mutex);
if (exists) {
- VLOG_INFO("State of queue %d ( tx_qid %d ) of vhost device '%s' "
- "changed to \'%s\'", queue_id, qid, ifname,
- (enable == 1) ? "enabled" : "disabled");
+ VLOG_INFO("State of queue %d ( %s_qid %d ) of vhost device '%s' "
+ "changed to \'%s\'", queue_id, is_rx == true ? "rx" : "tx",
+ qid, ifname, (enable == 1) ? "enabled" : "disabled");
} else {
VLOG_INFO("vHost Device '%s' not found", ifname);
return -1;
@@ -4085,6 +4112,10 @@ dpdk_vhost_reconfigure_helper(struct netdev_dpdk *dev)
dev->up.n_rxq = dev->requested_n_rxq;
int err;
+ /* Always keep RX queue 0 enabled for implementations that won't
+ * report vring states. */
+ dev->vhost_rxq_enabled[0] = true;
+
/* Enable TX queue 0 by default if it wasn't disabled. */
if (dev->tx_q[0].map == OVS_VHOST_QUEUE_MAP_UNKNOWN) {
dev->tx_q[0].map = 0;
@@ -4297,7 +4327,8 @@ static const struct netdev_class dpdk_vhost_class = {
.get_stats = netdev_dpdk_vhost_get_stats,
.get_status = netdev_dpdk_vhost_user_get_status,
.reconfigure = netdev_dpdk_vhost_reconfigure,
- .rxq_recv = netdev_dpdk_vhost_rxq_recv
+ .rxq_recv = netdev_dpdk_vhost_rxq_recv,
+ .rxq_enabled = netdev_dpdk_vhost_rxq_enabled,
};
static const struct netdev_class dpdk_vhost_client_class = {
@@ -4311,7 +4342,8 @@ static const struct netdev_class dpdk_vhost_client_class
= {
.get_stats = netdev_dpdk_vhost_get_stats,
.get_status = netdev_dpdk_vhost_user_get_status,
.reconfigure = netdev_dpdk_vhost_client_reconfigure,
- .rxq_recv = netdev_dpdk_vhost_rxq_recv
+ .rxq_recv = netdev_dpdk_vhost_rxq_recv,
+ .rxq_enabled = netdev_dpdk_vhost_rxq_enabled,
};
void
diff --git a/lib/netdev-provider.h b/lib/netdev-provider.h
index fb0c27e..5faae0d 100644
--- a/lib/netdev-provider.h
+++ b/lib/netdev-provider.h
@@ -789,6 +789,11 @@ struct netdev_class {
void (*rxq_destruct)(struct netdev_rxq *);
void (*rxq_dealloc)(struct netdev_rxq *);
+ /* A netdev can report if a queue won't get traffic and should be excluded
+ * from polling (no callback implicitely means that the queue is enabled).
+ */
+ bool (*rxq_enabled)(struct netdev_rxq *);
+
/* Attempts to receive a batch of packets from 'rx'. In 'batch', the
* caller supplies 'packets' as the pointer to the beginning of an array
* of NETDEV_MAX_BURST pointers to dp_packet. If successful, the
diff --git a/lib/netdev.c b/lib/netdev.c
index 7d7ecf6..03a1b24 100644
--- a/lib/netdev.c
+++ b/lib/netdev.c
@@ -682,6 +682,16 @@ netdev_rxq_close(struct netdev_rxq *rx)
}
}
+bool netdev_rxq_enabled(struct netdev_rxq *rx)
+{
+ bool enabled = true;
+
+ if (rx->netdev->netdev_class->rxq_enabled) {
+ enabled = rx->netdev->netdev_class->rxq_enabled(rx);
+ }
+ return enabled;
+}
+
/* Attempts to receive a batch of packets from 'rx'. 'batch' should point to
* the beginning of an array of NETDEV_MAX_BURST pointers to dp_packet. If
* successful, this function stores pointers to up to NETDEV_MAX_BURST
diff --git a/lib/netdev.h b/lib/netdev.h
index d94817f..bfcdf39 100644
--- a/lib/netdev.h
+++ b/lib/netdev.h
@@ -183,6 +183,7 @@ enum netdev_pt_mode netdev_get_pt_mode(const struct netdev
*);
/* Packet reception. */
int netdev_rxq_open(struct netdev *, struct netdev_rxq **, int id);
void netdev_rxq_close(struct netdev_rxq *);
+bool netdev_rxq_enabled(struct netdev_rxq *);
const char *netdev_rxq_get_name(const struct netdev_rxq *);
int netdev_rxq_get_queue_id(const struct netdev_rxq *);
--
1.8.3.1
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