Currently tx_qid is equal to pmd->core_id. This leads to unexpected
behavior if pmd-cpu-mask different from '/(0*)(1|3|7)?(f*)/',
e.g. if core_ids are not sequential, or doesn't start from 0, or both.
Example:
starting 2 pmd threads with 1 port, 2 rxqs per port,
pmd-cpu-mask = 00000014 and let dev->real_n_txq = 2
It that case pmd_1->tx_qid = 2, pmd_2->tx_qid = 4 and
txq_needs_locking = true (if device hasn't ovs_numa_get_n_cores()+1
queues).
In that case, after truncating in netdev_dpdk_send__():
'qid = qid % dev->real_n_txq;'
pmd_1: qid = 2 % 2 = 0
pmd_2: qid = 4 % 2 = 0
So, both threads will call dpdk_queue_pkts() with same qid = 0.
This is unexpected behavior if there is 2 tx queues in device.
Queue #1 will not be used and both threads will lock queue #0
on each send.
Fix that by introducing per pmd thread hash map 'tx_queues', where will
be stored all available tx queues for that pmd thread with
port_no as a key(hash). All tx_qid-s will be unique per port and
sequential to prevent described unexpected mapping after truncating.
Implemented infrastructure can be used in the future to choose
between all tx queues available for that pmd thread.
Signed-off-by: Ilya Maximets <i.maxim...@samsung.com>
---
lib/dpif-netdev.c | 110 ++++++++++++++++++++++++++++++++++++++++++++----------
1 file changed, 91 insertions(+), 19 deletions(-)
diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
index c144352..309994c 100644
--- a/lib/dpif-netdev.c
+++ b/lib/dpif-netdev.c
@@ -365,6 +365,13 @@ struct dp_netdev_pmd_cycles {
atomic_ullong n[PMD_N_CYCLES];
};
+struct dp_netdev_pmd_txq {
+ struct cmap_node node; /* In owning dp_netdev_pmd_thread's */
+ /* 'tx_queues'. */
+ struct dp_netdev_port *port;
+ int tx_qid;
+};
+
/* PMD: Poll modes drivers. PMD accesses devices via polling to eliminate
* the performance overhead of interrupt processing. Therefore netdev can
* not implement rx-wait for these devices. dpif-netdev needs to poll
@@ -420,8 +427,8 @@ struct dp_netdev_pmd_thread {
/* threads on same numa node. */
unsigned core_id; /* CPU core id of this pmd thread. */
int numa_id; /* numa node id of this pmd thread. */
- int tx_qid; /* Queue id used by this pmd thread to
- * send packets on all netdevs */
+ struct cmap tx_queues; /* Queue ids used by this pmd thread to
+ * send packets to ports */
/* Only a pmd thread can write on its own 'cycles' and 'stats'.
* The main thread keeps 'stats_zero' and 'cycles_zero' as base
@@ -2602,6 +2609,46 @@ dpif_netdev_wait(struct dpif *dpif)
seq_wait(tnl_conf_seq, dp->last_tnl_conf_seq);
}
+static void
+pmd_flush_tx_queues(struct dp_netdev_pmd_thread *pmd)
+{
+ struct dp_netdev_pmd_txq *txq;
+
+ CMAP_FOR_EACH (txq, node, &pmd->tx_queues) {
+ cmap_remove(&pmd->tx_queues, &txq->node,
+ hash_port_no(txq->port->port_no));
+ port_unref(txq->port);
+ free(txq);
+ }
+}
+
+static void OVS_UNUSED
+pmd_tx_queues_print(struct dp_netdev_pmd_thread *pmd)
+{
+ struct dp_netdev_pmd_txq *txq;
+
+ CMAP_FOR_EACH (txq, node, &pmd->tx_queues) {
+ VLOG_INFO("Core_id: %d, Port: %s, tx_qid: %d\n",
+ pmd->core_id, netdev_get_name(txq->port->netdev),
+ txq->tx_qid);
+ }
+}
+
+static struct dp_netdev_pmd_txq *
+pmd_lookup_txq(const struct dp_netdev_pmd_thread *pmd,
+ const struct dp_netdev_port *port)
+{
+ struct dp_netdev_pmd_txq *txq;
+
+ CMAP_FOR_EACH_WITH_HASH (txq, node, hash_port_no(port->port_no),
+ &pmd->tx_queues) {
+ if (txq->port == port) {
+ return txq;
+ }
+ }
+ return NULL;
+}
+
struct rxq_poll {
struct dp_netdev_port *port;
struct netdev_rxq *rx;
@@ -2613,16 +2660,20 @@ pmd_load_queues(struct dp_netdev_pmd_thread *pmd,
{
struct rxq_poll *poll_list = *ppoll_list;
struct dp_netdev_port *port;
- int n_pmds_on_numa, index, i;
+ struct dp_netdev_pmd_txq *txq;
+ int n_pmds_on_numa, rx_index, tx_index, i;
/* Simple scheduler for netdev rx polling. */
+ pmd_flush_tx_queues(pmd);
+
for (i = 0; i < poll_cnt; i++) {
port_unref(poll_list[i].port);
}
poll_cnt = 0;
n_pmds_on_numa = get_n_pmd_threads_on_numa(pmd->dp, pmd->numa_id);
- index = 0;
+ rx_index = 0;
+ tx_index = 0;
CMAP_FOR_EACH (port, node, &pmd->dp->ports) {
/* Calls port_try_ref() to prevent the main thread
@@ -2633,7 +2684,7 @@ pmd_load_queues(struct dp_netdev_pmd_thread *pmd,
int i;
for (i = 0; i < netdev_n_rxq(port->netdev); i++) {
- if ((index % n_pmds_on_numa) == pmd->index) {
+ if ((rx_index % n_pmds_on_numa) == pmd->index) {
poll_list = xrealloc(poll_list,
sizeof *poll_list * (poll_cnt + 1));
@@ -2642,7 +2693,20 @@ pmd_load_queues(struct dp_netdev_pmd_thread *pmd,
poll_list[poll_cnt].rx = port->rxq[i];
poll_cnt++;
}
- index++;
+ rx_index++;
+ }
+
+ /* Last queue reserved for non pmd threads */
+ for (i = 0; i < netdev_n_txq(port->netdev) - 1; i++) {
+ if ((tx_index % n_pmds_on_numa) == pmd->index) {
+ txq = xmalloc(sizeof *txq);
+ port_ref(port);
+ txq->port = port;
+ txq->tx_qid = i;
+ cmap_insert(&pmd->tx_queues, &txq->node,
+ hash_port_no(port->port_no));
+ }
+ tx_index++;
}
}
/* Unrefs the port_try_ref(). */
@@ -2712,6 +2776,8 @@ reload:
goto reload;
}
+ pmd_flush_tx_queues(pmd);
+
for (i = 0; i < poll_cnt; i++) {
port_unref(poll_list[i].port);
}
@@ -2825,16 +2891,6 @@ dp_netdev_pmd_get_next(struct dp_netdev *dp, struct
cmap_position *pos)
return next;
}
-static int
-core_id_to_qid(unsigned core_id)
-{
- if (core_id != NON_PMD_CORE_ID) {
- return core_id;
- } else {
- return ovs_numa_get_n_cores();
- }
-}
-
/* Configures the 'pmd' based on the input argument. */
static void
dp_netdev_configure_pmd(struct dp_netdev_pmd_thread *pmd, struct dp_netdev *dp,
@@ -2843,7 +2899,6 @@ dp_netdev_configure_pmd(struct dp_netdev_pmd_thread *pmd,
struct dp_netdev *dp,
pmd->dp = dp;
pmd->index = index;
pmd->core_id = core_id;
- pmd->tx_qid = core_id_to_qid(core_id);
pmd->numa_id = numa_id;
ovs_refcount_init(&pmd->ref_cnt);
@@ -2854,9 +2909,20 @@ dp_netdev_configure_pmd(struct dp_netdev_pmd_thread
*pmd, struct dp_netdev *dp,
ovs_mutex_init(&pmd->flow_mutex);
dpcls_init(&pmd->cls);
cmap_init(&pmd->flow_table);
- /* init the 'flow_cache' since there is no
+ cmap_init(&pmd->tx_queues);
+ /* init the 'flow_cache' and 'tx_queues' since there is no
* actual thread created for NON_PMD_CORE_ID. */
if (core_id == NON_PMD_CORE_ID) {
+ struct dp_netdev_port *port;
+ CMAP_FOR_EACH (port, node, &pmd->dp->ports) {
+ if (port_try_ref(port)) {
+ struct dp_netdev_pmd_txq * txq = xmalloc(sizeof *txq);
+ txq->port = port;
+ txq->tx_qid = ovs_numa_get_n_cores();
+ cmap_insert(&pmd->tx_queues, &txq->node,
+ hash_port_no(port->port_no));
+ }
+ }
emc_cache_init(&pmd->flow_cache);
}
cmap_insert(&dp->poll_threads, CONST_CAST(struct cmap_node *, &pmd->node),
@@ -2869,6 +2935,7 @@ dp_netdev_destroy_pmd(struct dp_netdev_pmd_thread *pmd)
dp_netdev_pmd_flow_flush(pmd);
dpcls_destroy(&pmd->cls);
cmap_destroy(&pmd->flow_table);
+ cmap_destroy(&pmd->tx_queues);
ovs_mutex_destroy(&pmd->flow_mutex);
latch_destroy(&pmd->exit_latch);
xpthread_cond_destroy(&pmd->cond);
@@ -2885,6 +2952,7 @@ dp_netdev_del_pmd(struct dp_netdev_pmd_thread *pmd)
* no actual thread uninit it for NON_PMD_CORE_ID. */
if (pmd->core_id == NON_PMD_CORE_ID) {
emc_cache_uninit(&pmd->flow_cache);
+ pmd_flush_tx_queues(pmd);
} else {
latch_set(&pmd->exit_latch);
dp_netdev_reload_pmd__(pmd);
@@ -3480,13 +3548,17 @@ dp_execute_cb(void *aux_, struct dp_packet **packets,
int cnt,
struct dp_netdev *dp = pmd->dp;
int type = nl_attr_type(a);
struct dp_netdev_port *p;
+ struct dp_netdev_pmd_txq *txq;
int i;
switch ((enum ovs_action_attr)type) {
case OVS_ACTION_ATTR_OUTPUT:
p = dp_netdev_lookup_port(dp, u32_to_odp(nl_attr_get_u32(a)));
if (OVS_LIKELY(p)) {
- netdev_send(p->netdev, pmd->tx_qid, packets, cnt, may_steal);
+ txq = pmd_lookup_txq(pmd, p);
+ if (OVS_UNLIKELY(!txq))
+ break;
+ netdev_send(p->netdev, txq->tx_qid, packets, cnt, may_steal);
return;
}
break;
--
2.1.4
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