Hi Ilya,
Sorry for the delay,
One question inline
On 11/09/2015 12:38, "Ilya Maximets" <i.maxim...@samsung.com> wrote:
>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>
>---
>version 5:
> * txqs 0 from ports of non-pmd netdevs added to all pmd threads
>
>version 4:
> * fixed distribution of tx queues if multiqueue is not supported
>
>version 3:
> * fixed failing of unit tests by adding tx queues of non
> pmd devices to non pmd thread. (they haven't been used by any thread)
> * pmd_flush_tx_queues --> dp_netdev_pmd_detach_tx_queues
> * function names changed to dp_netdev_*
> * dp_netdev_pmd_lookup_txq now looks by port_no.
> * removed unnecessary dp_netdev_lookup_port in dp_execute_cb
> for OVS_ACTION_ATTR_OUTPUT.
> * refactoring
>
> lib/dpif-netdev.c | 173
>++++++++++++++++++++++++++++++++++++++++++++++--------
> 1 file changed, 147 insertions(+), 26 deletions(-)
>
>diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
>index db76290..65cd533 100644
>--- a/lib/dpif-netdev.c
>+++ b/lib/dpif-netdev.c
>@@ -372,6 +372,13 @@ 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
>@@ -427,8 +434,8 @@ 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
>@@ -470,6 +477,15 @@ static void dp_netdev_input(struct
>dp_netdev_pmd_thread *,
>
> static void dp_netdev_disable_upcall(struct dp_netdev *);
> void dp_netdev_pmd_reload_done(struct dp_netdev_pmd_thread *pmd);
>+static void dp_netdev_configure_non_pmd_txqs(struct dp_netdev_pmd_thread
>*pmd);
>+static void dp_netdev_pmd_add_txq(struct dp_netdev_pmd_thread *pmd,
>+ struct dp_netdev_port *port, int
>queue_id);
>+static void dp_netdev_pmd_del_txq(struct dp_netdev_pmd_thread *pmd,
>+ struct dp_netdev_pmd_txq *txq);
>+static void dp_netdev_pmd_detach_tx_queues(struct dp_netdev_pmd_thread
>*pmd);
>+static struct dp_netdev_pmd_txq *
>+dp_netdev_pmd_lookup_txq(const struct dp_netdev_pmd_thread *pmd,
>+ odp_port_t port_no);
> static void dp_netdev_configure_pmd(struct dp_netdev_pmd_thread *pmd,
> struct dp_netdev *dp, int index,
> unsigned core_id, int numa_id);
>@@ -1051,6 +1067,7 @@ do_add_port(struct dp_netdev *dp, const char
>*devname, const char *type,
> struct netdev_saved_flags *sf;
> struct dp_netdev_port *port;
> struct netdev *netdev;
>+ struct dp_netdev_pmd_thread *non_pmd;
> enum netdev_flags flags;
> const char *open_type;
> int error;
>@@ -1127,10 +1144,15 @@ do_add_port(struct dp_netdev *dp, const char
>*devname, const char *type,
> ovs_refcount_init(&port->ref_cnt);
> cmap_insert(&dp->ports, &port->node, hash_port_no(port_no));
>
>- if (netdev_is_pmd(netdev)) {
>- dp_netdev_set_pmds_on_numa(dp, netdev_get_numa_id(netdev));
>- dp_netdev_reload_pmds(dp);
>+ non_pmd = dp_netdev_get_pmd(dp, NON_PMD_CORE_ID);
>+ if (non_pmd) {
>+ dp_netdev_pmd_add_txq(non_pmd, port, ovs_numa_get_n_cores());
>+ dp_netdev_pmd_unref(non_pmd);
> }
>+ if (netdev_is_pmd(netdev))
>+ dp_netdev_set_pmds_on_numa(dp, netdev_get_numa_id(netdev));
>+ dp_netdev_reload_pmds(dp);
>+
> seq_change(dp->port_seq);
>
> return 0;
>@@ -1308,18 +1330,32 @@ static void
> do_del_port(struct dp_netdev *dp, struct dp_netdev_port *port)
> OVS_REQUIRES(dp->port_mutex)
> {
>+ struct dp_netdev_pmd_thread *non_pmd;
>+
> cmap_remove(&dp->ports, &port->node, hash_odp_port(port->port_no));
> seq_change(dp->port_seq);
>+
>+ non_pmd = dp_netdev_get_pmd(dp, NON_PMD_CORE_ID);
>+ if (non_pmd) {
>+ /* There is only one txq for each port for non pmd thread */
>+ struct dp_netdev_pmd_txq *txq;
>+ txq = dp_netdev_pmd_lookup_txq(non_pmd, port->port_no);
>+ if (OVS_LIKELY(txq))
>+ dp_netdev_pmd_del_txq(non_pmd, txq);
>+ dp_netdev_pmd_unref(non_pmd);
>+ }
>+
> if (netdev_is_pmd(port->netdev)) {
> int numa_id = netdev_get_numa_id(port->netdev);
>
> /* If there is no netdev on the numa node, deletes the pmd
>threads
>- * for that numa. Else, just reloads the queues. */
>+ * for that numa. */
> if (!has_pmd_port_for_numa(dp, numa_id)) {
> dp_netdev_del_pmds_on_numa(dp, numa_id);
> }
>- dp_netdev_reload_pmds(dp);
> }
>+ /* Reload queues of pmd threads. */
>+ dp_netdev_reload_pmds(dp);
>
> port_unref(port);
> }
>@@ -2580,6 +2616,80 @@ dpif_netdev_wait(struct dpif *dpif)
> seq_wait(tnl_conf_seq, dp->last_tnl_conf_seq);
> }
>
>+static void
>+dp_netdev_pmd_add_txq(struct dp_netdev_pmd_thread *pmd,
>+ struct dp_netdev_port *port, int queue_id)
>+{
>+ if (port_try_ref(port)) {
>+ struct dp_netdev_pmd_txq * txq = xmalloc(sizeof *txq);
>+ txq->port = port;
>+ txq->tx_qid = queue_id;
>+ cmap_insert(&pmd->tx_queues, &txq->node,
>+ hash_port_no(port->port_no));
>+ }
>+}
>+
>+/* Configures tx_queues for non pmd thread. */
>+static void
>+dp_netdev_configure_non_pmd_txqs(struct dp_netdev_pmd_thread *pmd)
>+{
>+ if (!cmap_is_empty(&pmd->tx_queues))
>+ dp_netdev_pmd_detach_tx_queues(pmd);
>+
>+ struct dp_netdev_port *port;
>+ CMAP_FOR_EACH (port, node, &pmd->dp->ports) {
>+ dp_netdev_pmd_add_txq(pmd, port, ovs_numa_get_n_cores());
>+ }
>+}
>+
>+static void
>+dp_netdev_pmd_del_txq(struct dp_netdev_pmd_thread *pmd,
>+ struct dp_netdev_pmd_txq *txq)
>+{
>+ cmap_remove(&pmd->tx_queues, &txq->node,
>+ hash_port_no(txq->port->port_no));
>+ port_unref(txq->port);
>+ free(txq);
>+}
>+
>+/* Removes all queues from 'tx_queues' of pmd thread. */
>+static void
>+dp_netdev_pmd_detach_tx_queues(struct dp_netdev_pmd_thread *pmd)
>+{
>+ struct dp_netdev_pmd_txq *txq;
>+
>+ CMAP_FOR_EACH (txq, node, &pmd->tx_queues) {
>+ dp_netdev_pmd_del_txq(pmd, txq);
>+ }
>+}
>+
>+static void OVS_UNUSED
>+dp_netdev_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 *
>+dp_netdev_pmd_lookup_txq(const struct dp_netdev_pmd_thread *pmd,
>+ odp_port_t port_no)
>+{
>+ struct dp_netdev_pmd_txq *txq;
>+
>+ CMAP_FOR_EACH_WITH_HASH (txq, node, hash_port_no(port_no),
>+ &pmd->tx_queues) {
>+ if (txq->port->port_no == port_no) {
>+ return txq;
>+ }
>+ }
>+ return NULL;
>+}
>+
> struct rxq_poll {
> struct dp_netdev_port *port;
> struct netdev_rxq *rx;
>@@ -2591,16 +2701,19 @@ 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;
>+ int n_pmds_on_numa, rx_index, tx_index, i, n_txq;
>
> /* Simple scheduler for netdev rx polling. */
>+ dp_netdev_pmd_detach_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
>@@ -2611,7 +2724,7 @@ 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));
>
>@@ -2620,9 +2733,20 @@ pmd_load_queues(struct dp_netdev_pmd_thread *pmd,
> poll_list[poll_cnt].rx = port->rxq[i];
> poll_cnt++;
> }
>- index++;
>+ rx_index++;
> }
>+
>+ }
>+
>+ n_txq = netdev_n_txq(port->netdev);
>+ /* Last queue reserved for non pmd threads */
>+ n_txq = n_txq == 1 ? 1 : n_txq - 1;
>+ for (i = 0; i < n_txq; i++) {
>+ if ((tx_index % n_pmds_on_numa) == pmd->index || n_txq
>== 1)
>+ dp_netdev_pmd_add_txq(pmd, port, i);
>+ tx_index++;
> }
>+
This code assigns more than one txq for each NIC to a pmd thread.
Is this a wanted effect?
Also, the same txq can be assigned to multiple pmd threads on different
NUMA sockets.
The logic should be different from rxq assignment:
* rxq: each rxq should be assigned to one thread
* txq: each thread should have its own txq for each netdev.
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