If CPU number in pmd-cpu-mask is not divisible by the number of queues and
in a few more complex situations there may be unfair distribution of TX
queue-ids between PMD threads.
For example, if we have 2 ports with 4 queues and 6 CPUs in pmd-cpu-mask
such distribution is possible:
<------------------------------------------------------------------------>
pmd thread numa_id 0 core_id 13:
port: vhost-user1 queue-id: 1
port: dpdk0 queue-id: 3
pmd thread numa_id 0 core_id 14:
port: vhost-user1 queue-id: 2
pmd thread numa_id 0 core_id 16:
port: dpdk0 queue-id: 0
pmd thread numa_id 0 core_id 17:
port: dpdk0 queue-id: 1
pmd thread numa_id 0 core_id 12:
port: vhost-user1 queue-id: 0
port: dpdk0 queue-id: 2
pmd thread numa_id 0 core_id 15:
port: vhost-user1 queue-id: 3
<------------------------------------------------------------------------>
As we can see above dpdk0 port polled by threads on cores:
12, 13, 16 and 17.
By design of dpif-netdev, there is only one TX queue-id assigned to each
pmd thread. This queue-id's are sequential similar to core-id's. And
thread will send packets to queue with exact this queue-id regardless
of port.
In previous example:
pmd thread on core 12 will send packets to tx queue 0
pmd thread on core 13 will send packets to tx queue 1
...
pmd thread on core 17 will send packets to tx queue 5
So, for dpdk0 port after truncating in netdev-dpdk:
core 12 --> TX queue-id 0 % 4 == 0
core 13 --> TX queue-id 1 % 4 == 1
core 16 --> TX queue-id 4 % 4 == 0
core 17 --> TX queue-id 5 % 4 == 1
As a result only 2 of 4 queues used.
To fix this issue some kind of XPS implemented in following way:
* TX queue-ids are allocated dynamically.
* When PMD thread first time tries to send packets to new port
it allocates less used TX queue for this port.
* PMD threads periodically performes revalidation of
allocated TX queue-ids. If queue wasn't used in last
XPS_TIMEOUT_MS milliseconds it will be freed while revalidation.
* XPS is not working if we have enough TX queues.
Reported-by: Zhihong Wang <zhihong.w...@intel.com>
Signed-off-by: Ilya Maximets <i.maxim...@samsung.com>
---
lib/dpif-netdev.c | 204 ++++++++++++++++++++++++++++++++++++++++----------
lib/netdev-bsd.c | 3 +-
lib/netdev-dpdk.c | 32 +++-----
lib/netdev-dummy.c | 3 +-
lib/netdev-linux.c | 3 +-
lib/netdev-provider.h | 11 +--
lib/netdev.c | 13 ++--
lib/netdev.h | 2 +-
8 files changed, 198 insertions(+), 73 deletions(-)
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index f05ca4e..d1ba6f3 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -248,6 +248,8 @@ enum pmd_cycles_counter_type {
PMD_N_CYCLES
};
+#define XPS_TIMEOUT_MS 500LL
+
/* A port in a netdev-based datapath. */
struct dp_netdev_port {
odp_port_t port_no;
@@ -256,6 +258,9 @@ struct dp_netdev_port {
struct netdev_saved_flags *sf;
unsigned n_rxq; /* Number of elements in 'rxq' */
struct netdev_rxq **rxq;
+ atomic_bool dynamic_txqs; /* If true XPS will be used. */
+ unsigned *txq_used; /* Number of threads that uses each tx queue.
*/
+ struct ovs_mutex txq_used_mutex;
char *type; /* Port type as requested by user. */
};
@@ -384,8 +389,9 @@ struct rxq_poll {
/* Contained by struct dp_netdev_pmd_thread's 'port_cache' or 'tx_ports'. */
struct tx_port {
- odp_port_t port_no;
- struct netdev *netdev;
+ struct dp_netdev_port *port;
+ int qid;
+ long long last_used;
struct hmap_node node;
};
@@ -443,9 +449,10 @@ struct dp_netdev_pmd_thread {
unsigned core_id; /* CPU core id of this pmd thread. */
int numa_id; /* numa node id of this pmd thread. */
- /* Queue id used by this pmd thread to send packets on all netdevs.
- * All tx_qid's are unique and less than 'ovs_numa_get_n_cores() + 1'. */
- atomic_int tx_qid;
+ /* Queue id used by this pmd thread to send packets on all netdevs if
+ * XPS disabled for this netdev. All static_tx_qid's are unique and less
+ * than 'ovs_numa_get_n_cores() + 1'. */
+ atomic_int static_tx_qid;
struct ovs_mutex port_mutex; /* Mutex for 'poll_list' and 'tx_ports'. */
/* List of rx queues to poll. */
@@ -498,7 +505,8 @@ static void dp_netdev_execute_actions(struct
dp_netdev_pmd_thread *pmd,
struct dp_packet_batch *,
bool may_steal,
const struct nlattr *actions,
- size_t actions_len);
+ size_t actions_len,
+ long long now);
static void dp_netdev_input(struct dp_netdev_pmd_thread *,
struct dp_packet_batch *, odp_port_t port_no);
static void dp_netdev_recirculate(struct dp_netdev_pmd_thread *,
@@ -541,6 +549,12 @@ static void dp_netdev_pmd_flow_flush(struct
dp_netdev_pmd_thread *pmd);
static void pmd_load_cached_ports(struct dp_netdev_pmd_thread *pmd)
OVS_REQUIRES(pmd->port_mutex);
+static void
+dpif_netdev_xps_revalidate_pmd(const struct dp_netdev_pmd_thread *pmd,
+ long long now, bool purge);
+static int dpif_netdev_xps_get_tx_qid(const struct dp_netdev_pmd_thread *pmd,
+ struct tx_port *tx, long long now);
+
static inline bool emc_entry_alive(struct emc_entry *ce);
static void emc_clear_entry(struct emc_entry *ce);
@@ -1138,6 +1152,7 @@ port_create(const char *devname, const char *open_type,
const char *type,
struct netdev *netdev;
int n_open_rxqs = 0;
int i, error;
+ bool dynamic_txqs = false;
*portp = NULL;
@@ -1171,6 +1186,9 @@ port_create(const char *devname, const char *open_type,
const char *type,
VLOG_ERR("%s, cannot set multiq", devname);
goto out;
}
+ if (netdev_n_txq(netdev) < n_cores + 1) {
+ dynamic_txqs = true;
+ }
}
if (netdev_is_reconf_required(netdev)) {
@@ -1185,7 +1203,10 @@ port_create(const char *devname, const char *open_type,
const char *type,
port->netdev = netdev;
port->n_rxq = netdev_n_rxq(netdev);
port->rxq = xcalloc(port->n_rxq, sizeof *port->rxq);
+ port->txq_used = xcalloc(netdev_n_txq(netdev), sizeof *port->txq_used);
port->type = xstrdup(type);
+ ovs_mutex_init(&port->txq_used_mutex);
+ atomic_init(&port->dynamic_txqs, dynamic_txqs);
for (i = 0; i < port->n_rxq; i++) {
error = netdev_rxq_open(netdev, &port->rxq[i], i);
@@ -1211,7 +1232,9 @@ out_rxq_close:
for (i = 0; i < n_open_rxqs; i++) {
netdev_rxq_close(port->rxq[i]);
}
+ ovs_mutex_destroy(&port->txq_used_mutex);
free(port->type);
+ free(port->txq_used);
free(port->rxq);
free(port);
@@ -1351,7 +1374,8 @@ port_destroy(struct dp_netdev_port *port)
for (unsigned i = 0; i < port->n_rxq; i++) {
netdev_rxq_close(port->rxq[i]);
}
-
+ ovs_mutex_destroy(&port->txq_used_mutex);
+ free(port->txq_used);
free(port->rxq);
free(port->type);
free(port);
@@ -2476,7 +2500,7 @@ dpif_netdev_execute(struct dpif *dpif, struct
dpif_execute *execute)
packet_batch_init_packet(&pp, execute->packet);
dp_netdev_execute_actions(pmd, &pp, false, execute->actions,
- execute->actions_len);
+ execute->actions_len, time_msec());
if (pmd->core_id == NON_PMD_CORE_ID) {
ovs_mutex_unlock(&dp->non_pmd_mutex);
@@ -2650,6 +2674,10 @@ port_reconfigure(struct dp_netdev_port *port)
}
/* If the netdev_reconfigure() above succeeds, reopens the 'rxq's. */
port->rxq = xrealloc(port->rxq, sizeof *port->rxq * netdev_n_rxq(netdev));
+ /* Realloc 'used' counters for tx queues. */
+ free(port->txq_used);
+ port->txq_used = xcalloc(netdev_n_txq(netdev), sizeof *port->txq_used);
+
for (i = 0; i < netdev_n_rxq(netdev); i++) {
err = netdev_rxq_open(netdev, &port->rxq[i], i);
if (err) {
@@ -2666,9 +2694,21 @@ reconfigure_pmd_threads(struct dp_netdev *dp)
OVS_REQUIRES(dp->port_mutex)
{
struct dp_netdev_port *port, *next;
+ int n_cores;
dp_netdev_destroy_all_pmds(dp);
+ /* Reconfigures the cpu mask. */
+ ovs_numa_set_cpu_mask(dp->requested_pmd_cmask);
+ free(dp->pmd_cmask);
+ dp->pmd_cmask = nullable_xstrdup(dp->requested_pmd_cmask);
+
+ n_cores = ovs_numa_get_n_cores();
+ if (n_cores == OVS_CORE_UNSPEC) {
+ VLOG_ERR("Cannot get cpu core info");
+ return;
+ }
+
HMAP_FOR_EACH_SAFE (port, next, node, &dp->ports) {
int err;
@@ -2677,13 +2717,11 @@ reconfigure_pmd_threads(struct dp_netdev *dp)
hmap_remove(&dp->ports, &port->node);
seq_change(dp->port_seq);
port_destroy(port);
+ } else {
+ atomic_init(&port->dynamic_txqs,
+ netdev_n_txq(port->netdev) < n_cores + 1);
}
}
- /* Reconfigures the cpu mask. */
- ovs_numa_set_cpu_mask(dp->requested_pmd_cmask);
- free(dp->pmd_cmask);
- dp->pmd_cmask = nullable_xstrdup(dp->requested_pmd_cmask);
-
/* Restores the non-pmd. */
dp_netdev_set_nonpmd(dp);
/* Restores all pmd threads. */
@@ -2727,6 +2765,7 @@ dpif_netdev_run(struct dpif *dpif)
}
}
}
+ dpif_netdev_xps_revalidate_pmd(non_pmd, time_msec(), false);
ovs_mutex_unlock(&dp->non_pmd_mutex);
dp_netdev_pmd_unref(non_pmd);
@@ -2776,6 +2815,9 @@ pmd_free_cached_ports(struct dp_netdev_pmd_thread *pmd)
{
struct tx_port *tx_port_cached;
+ /* Free all used tx queue ids. */
+ dpif_netdev_xps_revalidate_pmd(pmd, 0, true);
+
HMAP_FOR_EACH_POP (tx_port_cached, node, &pmd->port_cache) {
free(tx_port_cached);
}
@@ -2795,7 +2837,7 @@ pmd_load_cached_ports(struct dp_netdev_pmd_thread *pmd)
HMAP_FOR_EACH (tx_port, node, &pmd->tx_ports) {
tx_port_cached = xmemdup(tx_port, sizeof *tx_port_cached);
hmap_insert(&pmd->port_cache, &tx_port_cached->node,
- hash_port_no(tx_port_cached->port_no));
+ hash_port_no(tx_port_cached->port->port_no));
}
}
@@ -3011,7 +3053,7 @@ dp_netdev_configure_pmd(struct dp_netdev_pmd_thread *pmd,
struct dp_netdev *dp,
pmd->numa_id = numa_id;
pmd->poll_cnt = 0;
- atomic_init(&pmd->tx_qid,
+ atomic_init(&pmd->static_tx_qid,
(core_id == NON_PMD_CORE_ID)
? ovs_numa_get_n_cores()
: get_n_pmd_threads(dp));
@@ -3107,7 +3149,7 @@ dp_netdev_destroy_all_pmds(struct dp_netdev *dp)
}
/* Deletes all pmd threads on numa node 'numa_id' and
- * fixes tx_qids of other threads to keep them sequential. */
+ * fixes static_tx_qids of other threads to keep them sequential. */
static void
dp_netdev_del_pmds_on_numa(struct dp_netdev *dp, int numa_id)
{
@@ -3125,7 +3167,7 @@ dp_netdev_del_pmds_on_numa(struct dp_netdev *dp, int
numa_id)
* 'dp->poll_threads' (while we're iterating it) and it
* might quiesce. */
if (pmd->numa_id == numa_id) {
- atomic_read_relaxed(&pmd->tx_qid, &free_idx[k]);
+ atomic_read_relaxed(&pmd->static_tx_qid, &free_idx[k]);
pmd_list[k] = pmd;
ovs_assert(k < n_pmds_on_numa);
k++;
@@ -3140,12 +3182,12 @@ dp_netdev_del_pmds_on_numa(struct dp_netdev *dp, int
numa_id)
CMAP_FOR_EACH (pmd, node, &dp->poll_threads) {
int old_tx_qid;
- atomic_read_relaxed(&pmd->tx_qid, &old_tx_qid);
+ atomic_read_relaxed(&pmd->static_tx_qid, &old_tx_qid);
if (old_tx_qid >= n_pmds) {
int new_tx_qid = free_idx[--k];
- atomic_store_relaxed(&pmd->tx_qid, new_tx_qid);
+ atomic_store_relaxed(&pmd->static_tx_qid, new_tx_qid);
}
}
@@ -3178,7 +3220,7 @@ tx_port_lookup(const struct hmap *hmap, odp_port_t
port_no)
struct tx_port *tx;
HMAP_FOR_EACH_IN_BUCKET (tx, node, hash_port_no(port_no), hmap) {
- if (tx->port_no == port_no) {
+ if (tx->port->port_no == port_no) {
return tx;
}
}
@@ -3303,11 +3345,11 @@ dp_netdev_add_port_tx_to_pmd(struct
dp_netdev_pmd_thread *pmd,
{
struct tx_port *tx = xzalloc(sizeof *tx);
- tx->netdev = port->netdev;
- tx->port_no = port->port_no;
+ tx->port = port;
+ tx->qid = -1;
ovs_mutex_lock(&pmd->port_mutex);
- hmap_insert(&pmd->tx_ports, &tx->node, hash_port_no(tx->port_no));
+ hmap_insert(&pmd->tx_ports, &tx->node, hash_port_no(tx->port->port_no));
ovs_mutex_unlock(&pmd->port_mutex);
}
@@ -3648,7 +3690,7 @@ packet_batch_per_flow_execute(struct
packet_batch_per_flow *batch,
actions = dp_netdev_flow_get_actions(flow);
dp_netdev_execute_actions(pmd, &batch->array, true,
- actions->actions, actions->size);
+ actions->actions, actions->size, now);
}
static inline void
@@ -3736,7 +3778,7 @@ static inline void
handle_packet_upcall(struct dp_netdev_pmd_thread *pmd, struct dp_packet
*packet,
const struct netdev_flow_key *key,
struct ofpbuf *actions, struct ofpbuf *put_actions,
- int *lost_cnt)
+ int *lost_cnt, long long now)
{
struct ofpbuf *add_actions;
struct dp_packet_batch b;
@@ -3775,7 +3817,7 @@ handle_packet_upcall(struct dp_netdev_pmd_thread *pmd,
struct dp_packet *packet,
* we'll send the packet up twice. */
packet_batch_init_packet(&b, packet);
dp_netdev_execute_actions(pmd, &b, true,
- actions->data, actions->size);
+ actions->data, actions->size, now);
add_actions = put_actions->size ? put_actions : actions;
if (OVS_LIKELY(error != ENOSPC)) {
@@ -3804,7 +3846,8 @@ static inline void
fast_path_processing(struct dp_netdev_pmd_thread *pmd,
struct dp_packet_batch *packets_,
struct netdev_flow_key *keys,
- struct packet_batch_per_flow batches[], size_t *n_batches)
+ struct packet_batch_per_flow batches[], size_t *n_batches,
+ long long now)
{
int cnt = packets_->count;
#if !defined(__CHECKER__) && !defined(_WIN32)
@@ -3850,8 +3893,8 @@ fast_path_processing(struct dp_netdev_pmd_thread *pmd,
}
miss_cnt++;
- handle_packet_upcall(pmd, packets[i], &keys[i], &actions,
&put_actions,
- &lost_cnt);
+ handle_packet_upcall(pmd, packets[i], &keys[i], &actions,
+ &put_actions, &lost_cnt, now);
}
ofpbuf_uninit(&actions);
@@ -3915,7 +3958,7 @@ dp_netdev_input__(struct dp_netdev_pmd_thread *pmd,
md_is_valid, port_no);
if (OVS_UNLIKELY(newcnt)) {
packets->count = newcnt;
- fast_path_processing(pmd, packets, keys, batches, &n_batches);
+ fast_path_processing(pmd, packets, keys, batches, &n_batches, now);
}
for (i = 0; i < n_batches; i++) {
@@ -3944,6 +3987,7 @@ dp_netdev_recirculate(struct dp_netdev_pmd_thread *pmd,
struct dp_netdev_execute_aux {
struct dp_netdev_pmd_thread *pmd;
+ long long now;
};
static void
@@ -3964,6 +4008,79 @@ dpif_netdev_register_upcall_cb(struct dpif *dpif,
upcall_callback *cb,
dp->upcall_cb = cb;
}
+static void
+dpif_netdev_xps_revalidate_pmd(const struct dp_netdev_pmd_thread *pmd,
+ long long now, bool purge)
+{
+ struct tx_port *tx;
+ struct dp_netdev_port *port;
+ long long interval;
+ bool dynamic_txqs;
+
+ HMAP_FOR_EACH (tx, node, &pmd->port_cache) {
+ atomic_read_relaxed(&tx->port->dynamic_txqs, &dynamic_txqs);
+ if (dynamic_txqs) {
+ continue;
+ }
+ interval = now - tx->last_used;
+ if (tx->qid >= 0 && (purge || interval >= XPS_TIMEOUT_MS)) {
+ port = tx->port;
+ ovs_mutex_lock(&port->txq_used_mutex);
+ port->txq_used[tx->qid]--;
+ ovs_mutex_unlock(&port->txq_used_mutex);
+ tx->qid = -1;
+ }
+ }
+}
+
+static int
+dpif_netdev_xps_get_tx_qid(const struct dp_netdev_pmd_thread *pmd,
+ struct tx_port *tx, long long now)
+{
+ struct dp_netdev_port *port;
+ long long interval;
+ int i, min_cnt, min_qid;
+
+ if (OVS_UNLIKELY(!now)) {
+ now = time_msec();
+ }
+
+ interval = now - tx->last_used;
+ tx->last_used = now;
+
+ if (OVS_LIKELY(tx->qid >= 0 && interval < XPS_TIMEOUT_MS)) {
+ return tx->qid;
+ }
+
+ port = tx->port;
+
+ ovs_mutex_lock(&port->txq_used_mutex);
+ if (tx->qid >= 0) {
+ port->txq_used[tx->qid]--;
+ tx->qid = -1;
+ }
+
+ min_cnt = -1;
+ min_qid = 0;
+ for (i = 0; i < netdev_n_txq(port->netdev); i++) {
+ if (port->txq_used[i] < min_cnt || min_cnt == -1) {
+ min_cnt = port->txq_used[i];
+ min_qid = i;
+ }
+ }
+
+ port->txq_used[min_qid]++;
+ tx->qid = min_qid;
+
+ ovs_mutex_unlock(&port->txq_used_mutex);
+
+ dpif_netdev_xps_revalidate_pmd(pmd, now, false);
+
+ VLOG_DBG("Core %d: New TX queue ID %d for port \'%s\'.",
+ pmd->core_id, tx->qid, netdev_get_name(tx->port->netdev));
+ return min_qid;
+}
+
static struct tx_port *
pmd_tx_port_cache_lookup(const struct dp_netdev_pmd_thread *pmd,
odp_port_t port_no)
@@ -3987,7 +4104,7 @@ push_tnl_action(const struct dp_netdev_pmd_thread *pmd,
err = -EINVAL;
goto error;
}
- err = netdev_push_header(tun_port->netdev, batch, data);
+ err = netdev_push_header(tun_port->port->netdev, batch, data);
if (!err) {
return 0;
}
@@ -4001,7 +4118,7 @@ dp_execute_userspace_action(struct dp_netdev_pmd_thread
*pmd,
struct dp_packet *packet, bool may_steal,
struct flow *flow, ovs_u128 *ufid,
struct ofpbuf *actions,
- const struct nlattr *userdata)
+ const struct nlattr *userdata, long long now)
{
struct dp_packet_batch b;
int error;
@@ -4014,7 +4131,7 @@ dp_execute_userspace_action(struct dp_netdev_pmd_thread
*pmd,
if (!error || error == ENOSPC) {
packet_batch_init_packet(&b, packet);
dp_netdev_execute_actions(pmd, &b, may_steal,
- actions->data, actions->size);
+ actions->data, actions->size, now);
} else if (may_steal) {
dp_packet_delete(packet);
}
@@ -4029,6 +4146,7 @@ dp_execute_cb(void *aux_, struct dp_packet_batch
*packets_,
struct dp_netdev_pmd_thread *pmd = aux->pmd;
struct dp_netdev *dp = pmd->dp;
int type = nl_attr_type(a);
+ long long now = aux->now;
struct tx_port *p;
switch ((enum ovs_action_attr)type) {
@@ -4036,10 +4154,17 @@ dp_execute_cb(void *aux_, struct dp_packet_batch
*packets_,
p = pmd_tx_port_cache_lookup(pmd, u32_to_odp(nl_attr_get_u32(a)));
if (OVS_LIKELY(p)) {
int tx_qid;
+ bool dynamic_txqs;
- atomic_read_relaxed(&pmd->tx_qid, &tx_qid);
+ atomic_read_relaxed(&p->port->dynamic_txqs, &dynamic_txqs);
+ if (dynamic_txqs) {
+ tx_qid = dpif_netdev_xps_get_tx_qid(pmd, p, now);
+ } else {
+ atomic_read_relaxed(&pmd->static_tx_qid, &tx_qid);
+ }
- netdev_send(p->netdev, tx_qid, packets_, may_steal);
+ netdev_send(p->port->netdev, tx_qid, packets_, may_steal,
+ dynamic_txqs);
return;
}
break;
@@ -4086,7 +4211,7 @@ dp_execute_cb(void *aux_, struct dp_packet_batch
*packets_,
dp_packet_batch_apply_cutlen(packets_);
- netdev_pop_header(p->netdev, packets_);
+ netdev_pop_header(p->port->netdev, packets_);
if (!packets_->count) {
return;
}
@@ -4134,7 +4259,7 @@ dp_execute_cb(void *aux_, struct dp_packet_batch
*packets_,
flow_extract(packets[i], &flow);
dpif_flow_hash(dp->dpif, &flow, sizeof flow, &ufid);
dp_execute_userspace_action(pmd, packets[i], may_steal, &flow,
- &ufid, &actions, userdata);
+ &ufid, &actions, userdata, now);
}
if (clone) {
@@ -4200,9 +4325,10 @@ static void
dp_netdev_execute_actions(struct dp_netdev_pmd_thread *pmd,
struct dp_packet_batch *packets,
bool may_steal,
- const struct nlattr *actions, size_t actions_len)
+ const struct nlattr *actions, size_t actions_len,
+ long long now)
{
- struct dp_netdev_execute_aux aux = { pmd };
+ struct dp_netdev_execute_aux aux = { pmd, now };
odp_execute_actions(&aux, packets, may_steal, actions,
actions_len, dp_execute_cb);
diff --git a/lib/netdev-bsd.c b/lib/netdev-bsd.c
index f963c6e..2f57c1a 100644
--- a/lib/netdev-bsd.c
+++ b/lib/netdev-bsd.c
@@ -680,7 +680,8 @@ netdev_bsd_rxq_drain(struct netdev_rxq *rxq_)
*/
static int
netdev_bsd_send(struct netdev *netdev_, int qid OVS_UNUSED,
- struct dp_packet_batch *batch, bool may_steal)
+ struct dp_packet_batch *batch, bool may_steal,
+ bool concurrent_txq OVS_UNUSED)
{
struct netdev_bsd *dev = netdev_bsd_cast(netdev_);
const char *name = netdev_get_name(netdev_);
diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
index af87f18..c208f32 100644
--- a/lib/netdev-dpdk.c
+++ b/lib/netdev-dpdk.c
@@ -298,7 +298,7 @@ struct dpdk_tx_queue {
rte_spinlock_t tx_lock; /* Protects the members and the NIC queue
* from concurrent access. It is used only
* if the queue is shared among different
- * pmd threads (see 'txq_needs_locking'). */
+ * pmd threads (see 'concurrent_txq'). */
int map; /* Mapping of configured vhost-user queues
* to enabled by guest. */
};
@@ -349,13 +349,6 @@ struct netdev_dpdk {
struct rte_eth_link link;
int link_reset_cnt;
- /* Caller of netdev_send() might want to use more txqs than the device has.
- * For physical NICs, if the 'requested_n_txq' less or equal to 'up.n_txq',
- * 'txq_needs_locking' is false, otherwise it is true and we will take a
- * spinlock on transmission. For vhost devices, 'requested_n_txq' is
- * always true. */
- bool txq_needs_locking;
-
/* virtio-net structure for vhost device */
OVSRCU_TYPE(struct virtio_net *) virtio_dev;
@@ -778,10 +771,8 @@ netdev_dpdk_init(struct netdev *netdev, unsigned int
port_no,
goto unlock;
}
netdev_dpdk_alloc_txq(dev, netdev->n_txq);
- dev->txq_needs_locking = netdev->n_txq < dev->requested_n_txq;
} else {
netdev_dpdk_alloc_txq(dev, OVS_VHOST_MAX_QUEUE_NUM);
- dev->txq_needs_locking = true;
/* Enable DPDK_DEV_VHOST device and set promiscuous mode flag. */
dev->flags = NETDEV_UP | NETDEV_PROMISC;
}
@@ -1468,7 +1459,7 @@ dpdk_do_tx_copy(struct netdev *netdev, int qid, struct
dp_packet_batch *batch)
static int
netdev_dpdk_vhost_send(struct netdev *netdev, int qid,
struct dp_packet_batch *batch,
- bool may_steal)
+ bool may_steal, bool concurrent_txq OVS_UNUSED)
{
if (OVS_UNLIKELY(batch->packets[0]->source != DPBUF_DPDK)) {
@@ -1484,9 +1475,10 @@ netdev_dpdk_vhost_send(struct netdev *netdev, int qid,
static inline void
netdev_dpdk_send__(struct netdev_dpdk *dev, int qid,
- struct dp_packet_batch *batch, bool may_steal)
+ struct dp_packet_batch *batch, bool may_steal,
+ bool concurrent_txq)
{
- if (OVS_UNLIKELY(dev->txq_needs_locking)) {
+ if (OVS_UNLIKELY(concurrent_txq)) {
qid = qid % dev->up.n_txq;
rte_spinlock_lock(&dev->tx_q[qid].tx_lock);
}
@@ -1551,18 +1543,19 @@ netdev_dpdk_send__(struct netdev_dpdk *dev, int qid,
}
}
- if (OVS_UNLIKELY(dev->txq_needs_locking)) {
+ if (OVS_UNLIKELY(concurrent_txq)) {
rte_spinlock_unlock(&dev->tx_q[qid].tx_lock);
}
}
static int
netdev_dpdk_eth_send(struct netdev *netdev, int qid,
- struct dp_packet_batch *batch, bool may_steal)
+ struct dp_packet_batch *batch, bool may_steal,
+ bool concurrent_txq)
{
struct netdev_dpdk *dev = netdev_dpdk_cast(netdev);
- netdev_dpdk_send__(dev, qid, batch, may_steal);
+ netdev_dpdk_send__(dev, qid, batch, may_steal, concurrent_txq);
return 0;
}
@@ -2533,7 +2526,8 @@ dpdk_ring_open(const char dev_name[], unsigned int
*eth_port_id)
static int
netdev_dpdk_ring_send(struct netdev *netdev, int qid,
- struct dp_packet_batch *batch, bool may_steal)
+ struct dp_packet_batch *batch, bool may_steal,
+ bool concurrent_txq)
{
struct netdev_dpdk *dev = netdev_dpdk_cast(netdev);
unsigned i;
@@ -2546,7 +2540,7 @@ netdev_dpdk_ring_send(struct netdev *netdev, int qid,
dp_packet_rss_invalidate(batch->packets[i]);
}
- netdev_dpdk_send__(dev, qid, batch, may_steal);
+ netdev_dpdk_send__(dev, qid, batch, may_steal, concurrent_txq);
return 0;
}
@@ -2823,8 +2817,6 @@ netdev_dpdk_reconfigure(struct netdev *netdev)
err = dpdk_eth_dev_init(dev);
netdev_dpdk_alloc_txq(dev, netdev->n_txq);
- dev->txq_needs_locking = netdev->n_txq < dev->requested_n_txq;
-
out:
ovs_mutex_unlock(&dev->mutex);
diff --git a/lib/netdev-dummy.c b/lib/netdev-dummy.c
index a95f7bb..813ce69 100644
--- a/lib/netdev-dummy.c
+++ b/lib/netdev-dummy.c
@@ -1034,7 +1034,8 @@ netdev_dummy_rxq_drain(struct netdev_rxq *rxq_)
static int
netdev_dummy_send(struct netdev *netdev, int qid OVS_UNUSED,
- struct dp_packet_batch *batch, bool may_steal)
+ struct dp_packet_batch *batch, bool may_steal,
+ bool concurrent_txq OVS_UNUSED)
{
struct netdev_dummy *dev = netdev_dummy_cast(netdev);
int error = 0;
diff --git a/lib/netdev-linux.c b/lib/netdev-linux.c
index c71a3df..2da8c18 100644
--- a/lib/netdev-linux.c
+++ b/lib/netdev-linux.c
@@ -1161,7 +1161,8 @@ netdev_linux_rxq_drain(struct netdev_rxq *rxq_)
* expected to do additional queuing of packets. */
static int
netdev_linux_send(struct netdev *netdev_, int qid OVS_UNUSED,
- struct dp_packet_batch *batch, bool may_steal)
+ struct dp_packet_batch *batch, bool may_steal,
+ bool concurrent_txq OVS_UNUSED)
{
int i;
int error = 0;
diff --git a/lib/netdev-provider.h b/lib/netdev-provider.h
index 915a5a5..41fa9e7 100644
--- a/lib/netdev-provider.h
+++ b/lib/netdev-provider.h
@@ -303,10 +303,6 @@ struct netdev_class {
* otherwise a positive errno value.
*
* 'n_txq' specifies the exact number of transmission queues to create.
- * The caller will call netdev_send() concurrently from 'n_txq' different
- * threads (with different qid). The netdev provider is responsible for
- * making sure that these concurrent calls do not create a race condition
- * by using multiple hw queues or locking.
*
* The caller will call netdev_reconfigure() (if necessary) before using
* netdev_send() on any of the newly configured queues, giving the provider
@@ -328,6 +324,11 @@ struct netdev_class {
* packets. If 'may_steal' is true, the caller transfers ownership of all
* the packets to the network device, regardless of success.
*
+ * If 'concurrent_txq' is true, the caller may perform concurrent calls
+ * to netdev_send() with the same 'qid'. The netdev provider is responsible
+ * for making sure that these concurrent calls do not create a race
+ * condition by using locking or other synchronization if required.
+ *
* The network device is expected to maintain one or more packet
* transmission queues, so that the caller does not ordinarily have to
* do additional queuing of packets. 'qid' specifies the queue to use
@@ -341,7 +342,7 @@ struct netdev_class {
* datapath". It will also prevent the OVS implementation of bonding from
* working properly over 'netdev'.) */
int (*send)(struct netdev *netdev, int qid, struct dp_packet_batch *batch,
- bool may_steal);
+ bool may_steal, bool concurrent_txq);
/* Registers with the poll loop to wake up from the next call to
* poll_block() when the packet transmission queue for 'netdev' has
diff --git a/lib/netdev.c b/lib/netdev.c
index 31a6a46..a792eb6 100644
--- a/lib/netdev.c
+++ b/lib/netdev.c
@@ -655,9 +655,6 @@ netdev_rxq_drain(struct netdev_rxq *rx)
* otherwise a positive errno value.
*
* 'n_txq' specifies the exact number of transmission queues to create.
- * If this function returns successfully, the caller can make 'n_txq'
- * concurrent calls to netdev_send() (each one with a different 'qid' in the
- * range [0..'n_txq'-1]).
*
* The change might not effective immediately. The caller must check if a
* reconfiguration is required with netdev_is_reconf_required() and eventually
@@ -694,6 +691,11 @@ netdev_set_tx_multiq(struct netdev *netdev, unsigned int
n_txq)
* If 'may_steal' is true, the caller transfers ownership of all the packets
* to the network device, regardless of success.
*
+ * If 'concurrent_txq' is true, the caller may perform concurrent calls
+ * to netdev_send() with the same 'qid'. The netdev provider is responsible
+ * for making sure that these concurrent calls do not create a race condition
+ * by using locking or other synchronization if required.
+ *
* The network device is expected to maintain one or more packet
* transmission queues, so that the caller does not ordinarily have to
* do additional queuing of packets. 'qid' specifies the queue to use
@@ -704,14 +706,15 @@ netdev_set_tx_multiq(struct netdev *netdev, unsigned int
n_txq)
* cases this function will always return EOPNOTSUPP. */
int
netdev_send(struct netdev *netdev, int qid, struct dp_packet_batch *batch,
- bool may_steal)
+ bool may_steal, bool concurrent_txq)
{
if (!netdev->netdev_class->send) {
dp_packet_delete_batch(batch, may_steal);
return EOPNOTSUPP;
}
- int error = netdev->netdev_class->send(netdev, qid, batch, may_steal);
+ int error = netdev->netdev_class->send(netdev, qid, batch, may_steal,
+ concurrent_txq);
if (!error) {
COVERAGE_INC(netdev_sent);
if (!may_steal) {
diff --git a/lib/netdev.h b/lib/netdev.h
index 591d861..dc7ede8 100644
--- a/lib/netdev.h
+++ b/lib/netdev.h
@@ -149,7 +149,7 @@ int netdev_rxq_drain(struct netdev_rxq *);
/* Packet transmission. */
int netdev_send(struct netdev *, int qid, struct dp_packet_batch *,
- bool may_steal);
+ bool may_steal, bool concurrent_txq);
void netdev_send_wait(struct netdev *, int qid);
/* native tunnel APIs */
--
2.7.4
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