[ovs-dev] [PATCH v2 11/11] netdev-dpdk: Use ->reconfigure() call to change rx/tx queues.

Daniele Di Proietto diproiettod at vmware.com
Tue Mar 15 22:28:12 UTC 2016


Hi Ilya,

thanks for your comments, replies inline

I'll post a v3 soon

On 15/03/2016 06:43, "Ilya Maximets" <i.maximets at samsung.com> wrote:

>Few comments inline.
>
>Best regards, Ilya Maximets.
>
>On 03.03.2016 04:33, Daniele Di Proietto wrote:
>> This introduces in dpif-netdev and netdev-dpdk the first use for the
>> newly introduce reconfigure netdev call.
>> 
>> When a request to change the number of queues comes, netdev-dpdk will
>> remember this and notify the upper layer via
>> netdev_request_reconfigure().
>> 
>> The datapath, instead of periodically calling netdev_set_multiq(), can
>> detect this and call reconfigure().
>> 
>> This mechanism can also be used to:
>> * Automatically match the number of rxq with the one provided by qemu
>>   via the new_device callback.
>> * Provide a way to change the MTU of dpdk devices at runtime.
>> 
>> Signed-off-by: Daniele Di Proietto <diproiettod at vmware.com>
>> ---
>>  lib/dpif-netdev.c     |  70 +++++++++----------
>>  lib/netdev-dpdk.c     | 181
>>+++++++++++++++++++++++++-------------------------
>>  lib/netdev-provider.h |  19 ++----
>>  lib/netdev.c          |  30 ++-------
>>  lib/netdev.h          |   3 +-
>>  5 files changed, 136 insertions(+), 167 deletions(-)
>> 
>> diff --git a/lib/dpif-netdev.c b/lib/dpif-netdev.c
>> index 0c3673b..8e9181c 100644
>> --- a/lib/dpif-netdev.c
>> +++ b/lib/dpif-netdev.c
>> @@ -256,8 +256,6 @@ struct dp_netdev_port {
>>      unsigned n_rxq;             /* Number of elements in 'rxq' */
>>      struct netdev_rxq **rxq;
>>      char *type;                 /* Port type as requested by user. */
>> -    int latest_requested_n_rxq; /* Latest requested from netdev number
>> -                                   of rx queues. */
>>  };
>>  
>>  /* Contained by struct dp_netdev_flow's 'stats' member.  */
>> @@ -1161,20 +1159,26 @@ do_add_port(struct dp_netdev *dp, const char
>>*devname, const char *type,
>>          /* There can only be ovs_numa_get_n_cores() pmd threads,
>>           * so creates a txq for each, and one extra for the non
>>           * pmd threads. */
>> -        error = netdev_set_multiq(netdev, n_cores + 1,
>> -                                  netdev_requested_n_rxq(netdev));
>> +        error = netdev_set_multiq(netdev, n_cores + 1);
>>          if (error && (error != EOPNOTSUPP)) {
>>              VLOG_ERR("%s, cannot set multiq", devname);
>>              goto out_close;
>>          }
>>      }
>> +
>> +    if (netdev_is_reconf_required(netdev)) {
>> +        error = netdev_reconfigure(netdev);
>> +        if (error) {
>> +            goto out_close;
>> +        }
>> +    }
>> +
>>      port = xzalloc(sizeof *port);
>>      port->port_no = port_no;
>>      port->netdev = netdev;
>>      port->n_rxq = netdev_n_rxq(netdev);
>>      port->rxq = xmalloc(sizeof *port->rxq * port->n_rxq);
>>      port->type = xstrdup(type);
>> -    port->latest_requested_n_rxq = netdev_requested_n_rxq(netdev);
>>  
>>      for (i = 0; i < port->n_rxq; i++) {
>>          error = netdev_rxq_open(netdev, &port->rxq[i], i);
>> @@ -2450,24 +2454,6 @@ dpif_netdev_operate(struct dpif *dpif, struct
>>dpif_op **ops, size_t n_ops)
>>      }
>>  }
>>  
>> -/* Returns true if the configuration for rx queues is changed. */
>> -static bool
>> -pmd_n_rxq_changed(const struct dp_netdev *dp)
>> -{
>> -    struct dp_netdev_port *port;
>> -
>> -    CMAP_FOR_EACH (port, node, &dp->ports) {
>> -        int requested_n_rxq = netdev_requested_n_rxq(port->netdev);
>> -
>> -        if (netdev_is_pmd(port->netdev)
>> -            && port->latest_requested_n_rxq != requested_n_rxq) {
>> -            return true;
>> -        }
>> -    }
>> -
>> -    return false;
>> -}
>> -
>>  static bool
>>  cmask_equals(const char *a, const char *b)
>>  {
>> @@ -2600,14 +2586,12 @@ reconfigure_pmd_threads(struct dp_netdev *dp)
>>      dp_netdev_destroy_all_pmds(dp);
>>  
>>      CMAP_FOR_EACH (port, node, &dp->ports) {
>> -        struct netdev *netdev = port->netdev;
>> -        int requested_n_rxq = netdev_requested_n_rxq(netdev);
>> -        if (netdev_is_pmd(port->netdev)
>> -            && port->latest_requested_n_rxq != requested_n_rxq) {
>> +        if (netdev_is_reconf_required(port->netdev)) {
>>              cmap_remove(&dp->ports, &port->node,
>>hash_odp_port(port->port_no));
>>              hmapx_add(&to_reconfigure, port);
>>          }
>>      }
>> +
>>      ovs_mutex_unlock(&dp->port_mutex);
>>  
>>      /* Waits for the other threads to see the ports removed from the
>>cmap,
>> @@ -2616,11 +2600,9 @@ reconfigure_pmd_threads(struct dp_netdev *dp)
>>  
>>      ovs_mutex_lock(&dp->port_mutex);
>>      HMAPX_FOR_EACH (node, &to_reconfigure) {
>> -        int requested_n_rxq = netdev_requested_n_rxq(port->netdev);
>>          int i, err;
>>  
>>          port = node->data;
>> -        requested_n_rxq = netdev_requested_n_rxq(port->netdev);
>>          /* Closes the existing 'rxq's. */
>>          for (i = 0; i < port->n_rxq; i++) {
>>              netdev_rxq_close(port->rxq[i]);
>> @@ -2628,18 +2610,15 @@ reconfigure_pmd_threads(struct dp_netdev *dp)
>>          }
>>          port->n_rxq = 0;
>>  
>> -        /* Sets the new rx queue config. */
>> -        err = netdev_set_multiq(port->netdev, ovs_numa_get_n_cores() +
>>1,
>> -                                requested_n_rxq);
>> +        /* Allows the netdev to apply the pending configuration
>>changes. */
>> +        err = netdev_reconfigure(port->netdev);
>>          if (err && (err != EOPNOTSUPP)) {
>> -            VLOG_ERR("Failed to set dpdk interface %s rx_queue to: %u",
>> -                     netdev_get_name(port->netdev),
>> -                     requested_n_rxq);
>> +            VLOG_ERR("Failed to set interface %s new configuration",
>> +                     netdev_get_name(port->netdev));
>>              do_destroy_port(port);
>>              failed_config = true;
>>              continue;
>>          }
>> -        port->latest_requested_n_rxq = requested_n_rxq;
>>          /* If the netdev_reconfigure() above succeeds, reopens the
>>'rxq's and
>>           * inserts the port back in the cmap, to allow transmitting
>>packets. */
>>          port->n_rxq = netdev_n_rxq(port->netdev);
>> @@ -2670,6 +2649,21 @@ reconfigure_pmd_threads(struct dp_netdev *dp)
>>      dp_netdev_reset_pmd_threads(dp);
>>  }
>>  
>> +/* Returns true if one of the netdevs in 'dp' requires a
>>reconfiguration */
>> +static bool
>> +ports_require_restart(const struct dp_netdev *dp)
>> +{
>> +    struct dp_netdev_port *port;
>> +
>> +    CMAP_FOR_EACH (port, node, &dp->ports) {
>> +        if (netdev_is_reconf_required(port->netdev)) {
>> +            return true;
>> +        }
>> +    }
>> +
>> +    return false;
>> +}
>> +
>>  /* Return true if needs to revalidate datapath flows. */
>>  static bool
>>  dpif_netdev_run(struct dpif *dpif)
>> @@ -2695,7 +2689,7 @@ dpif_netdev_run(struct dpif *dpif)
>>      ovs_mutex_unlock(&dp->non_pmd_mutex);
>>  
>>      if (!cmask_equals(dp->pmd_cmask, dp->requested_pmd_cmask)
>> -        || pmd_n_rxq_changed(dp)) {
>> +        || ports_require_restart(dp)) {
>>          reconfigure_pmd_threads(dp);
>>      }
>>  
>> @@ -2718,6 +2712,8 @@ dpif_netdev_wait(struct dpif *dpif)
>>  
>>      ovs_mutex_lock(&dp_netdev_mutex);
>>      CMAP_FOR_EACH (port, node, &dp->ports) {
>> +        netdev_wait_reconf_required(port->netdev);
>> +
>>          if (!netdev_is_pmd(port->netdev)) {
>>              int i;
>>  
>> diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
>> index a48ca71..ce35427 100644
>> --- a/lib/netdev-dpdk.c
>> +++ b/lib/netdev-dpdk.c
>> @@ -237,6 +237,12 @@ struct netdev_dpdk {
>>  
>>      /* In dpdk_list. */
>>      struct ovs_list list_node OVS_GUARDED_BY(dpdk_mutex);
>> +
>> +    /* The following properties cannot be changed when a device is
>>running,
>> +     * so we remember the request and update them next time
>> +     * netdev_dpdk*_reconfigure() is called */
>> +    int requested_n_txq;
>> +    int requested_n_rxq;
>>  };
>>  
>>  struct netdev_rxq_dpdk {
>> @@ -614,7 +620,8 @@ netdev_dpdk_init(struct netdev *netdev_, unsigned
>>int port_no,
>>  
>>      netdev_->n_txq = NR_QUEUE;
>>      netdev_->n_rxq = NR_QUEUE;
>> -    netdev_->requested_n_rxq = NR_QUEUE;
>> +    netdev->requested_n_rxq = NR_QUEUE;
>> +    netdev->requested_n_txq = NR_QUEUE;
>>      netdev->real_n_txq = NR_QUEUE;
>>  
>>      if (type == DPDK_DEV_ETH) {
>> @@ -796,7 +803,7 @@ netdev_dpdk_get_config(const struct netdev *netdev,
>>struct smap *args)
>>  
>>      ovs_mutex_lock(&dev->mutex);
>>  
>> -    smap_add_format(args, "requested_rx_queues", "%d",
>>netdev->requested_n_rxq);
>> +    smap_add_format(args, "requested_rx_queues", "%d",
>>dev->requested_n_rxq);
>>      smap_add_format(args, "configured_rx_queues", "%d", netdev->n_rxq);
>>      smap_add_format(args, "requested_tx_queues", "%d", netdev->n_txq);
>>      smap_add_format(args, "configured_tx_queues", "%d",
>>dev->real_n_txq);
>> @@ -809,11 +816,14 @@ static int
>>  netdev_dpdk_set_config(struct netdev *netdev, const struct smap *args)
>>  {
>>      struct netdev_dpdk *dev = netdev_dpdk_cast(netdev);
>> +    int new_n_rxq;
>>  
>>      ovs_mutex_lock(&dev->mutex);
>> -    netdev->requested_n_rxq = MAX(smap_get_int(args, "n_rxq",
>> -               
>>netdev->requested_n_rxq), 1);
>> -    netdev_change_seq_changed(netdev);
>> +    new_n_rxq = MAX(smap_get_int(args, "n_rxq", dev->requested_n_rxq),
>>1);
>> +    if (new_n_rxq != dev->requested_n_rxq) {
>> +        dev->requested_n_rxq = new_n_rxq;
>> +        netdev_request_reconfigure(netdev);
>> +    }
>>      ovs_mutex_unlock(&dev->mutex);
>>  
>>      return 0;
>> @@ -827,95 +837,26 @@ netdev_dpdk_get_numa_id(const struct netdev
>>*netdev_)
>>      return netdev->socket_id;
>>  }
>>  
>> -/* Sets the number of tx queues and rx queues for the dpdk interface.
>> - * If the configuration fails, do not try restoring its old
>>configuration
>> - * and just returns the error. */
>> +/* Sets the number of tx queues for the dpdk interface. */
>>  static int
>> -netdev_dpdk_set_multiq(struct netdev *netdev_, unsigned int n_txq,
>> -                       unsigned int n_rxq)
>> +netdev_dpdk_set_multiq(struct netdev *netdev_, unsigned int n_txq)
>>  {
>>      struct netdev_dpdk *netdev = netdev_dpdk_cast(netdev_);
>>      int err = 0;
>
>'err' unused here.

You're right, removed

>
>> -    int old_rxq, old_txq;
>>  
>> -    if (netdev->up.n_txq == n_txq && netdev->up.n_rxq == n_rxq) {
>> -        return err;
>> -    }
>> -
>> -    ovs_mutex_lock(&dpdk_mutex);
>>      ovs_mutex_lock(&netdev->mutex);
>>  
>> -    rte_eth_dev_stop(netdev->port_id);
>> -
>> -    old_txq = netdev->up.n_txq;
>> -    old_rxq = netdev->up.n_rxq;
>> -    netdev->up.n_txq = n_txq;
>> -    netdev->up.n_rxq = n_rxq;
>> -
>> -    rte_free(netdev->tx_q);
>> -    err = dpdk_eth_dev_init(netdev);
>> -    netdev_dpdk_alloc_txq(netdev, netdev->real_n_txq);
>> -    if (err) {
>> -        /* If there has been an error, it means that the requested
>>queues
>> -         * have not been created.  Restore the old numbers. */
>> -        netdev->up.n_txq = old_txq;
>> -        netdev->up.n_rxq = old_rxq;
>> -    }
>> -
>> -    netdev->txq_needs_locking = netdev->real_n_txq != netdev->up.n_txq;
>> -
>> -    ovs_mutex_unlock(&netdev->mutex);
>> -    ovs_mutex_unlock(&dpdk_mutex);
>> -
>> -    return err;
>> -}
>> -
>> -static int
>> -netdev_dpdk_vhost_cuse_set_multiq(struct netdev *netdev_, unsigned int
>>n_txq,
>> -                             unsigned int n_rxq)
>> -{
>> -    struct netdev_dpdk *netdev = netdev_dpdk_cast(netdev_);
>> -    int err = 0;
>> -
>> -    if (netdev->up.n_txq == n_txq && netdev->up.n_rxq == n_rxq) {
>> -        return err;
>> +    if (netdev->up.n_txq == n_txq) {
>> +        goto out;
>>      }
>
>May be we should compare 'netdev->requested_n_txq' and 'n_txq' here?

With the current code it doesn't change much, but I agree that it
looks cleaner

>
>>  
>> -    ovs_mutex_lock(&dpdk_mutex);
>> -    ovs_mutex_lock(&netdev->mutex);
>> -
>> -    netdev->up.n_txq = n_txq;
>> -    netdev->real_n_txq = 1;
>> -    netdev->up.n_rxq = 1;
>> -    netdev->txq_needs_locking = netdev->real_n_txq != netdev->up.n_txq;
>> +    netdev->requested_n_txq = n_txq;
>> +    netdev_request_reconfigure(netdev_);
>>  
>> +out:
>>      ovs_mutex_unlock(&netdev->mutex);
>> -    ovs_mutex_unlock(&dpdk_mutex);
>> -
>>      return err;
>
>respectively, 'return 0;'

ok

> 
>
>> -}
>> -
>> -static int
>> -netdev_dpdk_vhost_set_multiq(struct netdev *netdev_, unsigned int
>>n_txq,
>> -                             unsigned int n_rxq)
>> -{
>> -    struct netdev_dpdk *netdev = netdev_dpdk_cast(netdev_);
>> -    int err = 0;
>> -
>> -    if (netdev->up.n_txq == n_txq && netdev->up.n_rxq == n_rxq) {
>> -        return err;
>> -    }
>> -
>> -    ovs_mutex_lock(&dpdk_mutex);
>> -    ovs_mutex_lock(&netdev->mutex);
>> -
>> -    netdev->up.n_txq = n_txq;
>> -    netdev->up.n_rxq = n_rxq;
>> -
>> -    ovs_mutex_unlock(&netdev->mutex);
>> -    ovs_mutex_unlock(&dpdk_mutex);
>>  
>> -    return err;
>>  }
>>  
>>  static struct netdev_rxq *
>> @@ -2239,8 +2180,70 @@ unlock_dpdk:
>>      return err;
>>  }
>>  
>> -#define NETDEV_DPDK_CLASS(NAME, INIT, CONSTRUCT, DESTRUCT, MULTIQ,
>>SEND, \
>> -    GET_CARRIER, GET_STATS, GET_FEATURES, GET_STATUS, RXQ_RECV)
>>  \
>> +static int
>> +netdev_dpdk_reconfigure(struct netdev *netdev_)
>> +{
>> +    struct netdev_dpdk *netdev = netdev_dpdk_cast(netdev_);
>> +    int err = 0;
>> +
>> +    ovs_mutex_lock(&dpdk_mutex);
>> +    ovs_mutex_lock(&netdev->mutex);
>
>May be useful to check if (netdev_->n_txq == netdev->requested_n_txq &&
>netdev_->n_rxq = netdev->requested_n_rxq) and return immediately.

Agreed

>
>> +    rte_eth_dev_stop(netdev->port_id);
>> +
>> +    netdev_->n_txq = netdev->requested_n_txq;
>> +    netdev_->n_rxq = netdev->requested_n_rxq;
>> +
>> +    rte_free(netdev->tx_q);
>> +    err = dpdk_eth_dev_init(netdev);
>
>Why restoring of old values on error was removed here? Was it useful?

On current master, I don't think restoring of old values is useful: if
netdev_set_multiq() fails we return prematurely from dpif_netdev_pmd_set().

With this patch we remove the port from the datapath, until a correct
configuration is applied.

>
>> +    netdev_dpdk_alloc_txq(netdev, netdev->real_n_txq);
>> +
>> +    netdev->txq_needs_locking = netdev->real_n_txq != netdev->up.n_txq;
>> +
>> +    ovs_mutex_unlock(&netdev->mutex);
>> +    ovs_mutex_unlock(&dpdk_mutex);
>> +
>> +    return err;
>> +}
>> +
>> +static int
>> +netdev_dpdk_vhost_user_reconfigure(struct netdev *netdev_)
>> +{
>> +    struct netdev_dpdk *netdev = netdev_dpdk_cast(netdev_);
>> +
>> +    ovs_mutex_lock(&dpdk_mutex);
>> +    ovs_mutex_lock(&netdev->mutex);
>> +
>> +    netdev->up.n_txq = netdev->requested_n_txq;
>> +    netdev->up.n_rxq = netdev->requested_n_rxq;
>> +
>> +    ovs_mutex_unlock(&netdev->mutex);
>> +    ovs_mutex_unlock(&dpdk_mutex);
>> +
>> +    return 0;
>> +}
>> +
>> +static int
>> +netdev_dpdk_vhost_cuse_reconfigure(struct netdev *netdev_)
>> +{
>> +    struct netdev_dpdk *netdev = netdev_dpdk_cast(netdev_);
>> +
>> +    ovs_mutex_lock(&dpdk_mutex);
>> +    ovs_mutex_lock(&netdev->mutex);
>> +
>> +    netdev->up.n_txq = netdev->requested_n_txq;
>> +    netdev->real_n_txq = 1;
>> +    netdev->up.n_rxq = 1;
>> +    netdev->txq_needs_locking = netdev->real_n_txq != netdev->up.n_txq;
>> +
>> +    ovs_mutex_unlock(&netdev->mutex);
>> +    ovs_mutex_unlock(&dpdk_mutex);
>> +
>> +    return 0;
>> +}
>> +
>> +#define NETDEV_DPDK_CLASS(NAME, INIT, CONSTRUCT, DESTRUCT, SEND, \
>> +                          GET_CARRIER, GET_STATS, GET_FEATURES,  \
>> +                          GET_STATUS, RECONFIGURE, RXQ_RECV)     \
>>  {                                                             \
>>      NAME,                                                     \
>>      INIT,                       /* init */                    \
>> @@ -2258,7 +2261,7 @@ unlock_dpdk:
>>      NULL,                       /* push header */             \
>>      NULL,                       /* pop header */              \
>>      netdev_dpdk_get_numa_id,    /* get_numa_id */             \
>> -    MULTIQ,                     /* set_multiq */              \
>> +    netdev_dpdk_set_multiq,                                   \
>>                                                                \
>>      SEND,                       /* send */                    \
>>      NULL,                       /* send_wait */               \
>> @@ -2298,7 +2301,7 @@ unlock_dpdk:
>>      NULL,                       /* arp_lookup */              \
>>                                                                \
>>      netdev_dpdk_update_flags,                                 \
>> -    NULL,                       /* reconfigure */             \
>> +    RECONFIGURE,                                              \
>>                                                                \
>>      netdev_dpdk_rxq_alloc,                                    \
>>      netdev_dpdk_rxq_construct,                                \
>> @@ -2413,12 +2416,12 @@ static const struct netdev_class dpdk_class =
>>          NULL,
>>          netdev_dpdk_construct,
>>          netdev_dpdk_destruct,
>> -        netdev_dpdk_set_multiq,
>>          netdev_dpdk_eth_send,
>>          netdev_dpdk_get_carrier,
>>          netdev_dpdk_get_stats,
>>          netdev_dpdk_get_features,
>>          netdev_dpdk_get_status,
>> +        netdev_dpdk_reconfigure,
>>          netdev_dpdk_rxq_recv);
>>  
>>  static const struct netdev_class dpdk_ring_class =
>> @@ -2427,12 +2430,12 @@ static const struct netdev_class
>>dpdk_ring_class =
>>          NULL,
>>          netdev_dpdk_ring_construct,
>>          netdev_dpdk_destruct,
>> -        netdev_dpdk_set_multiq,
>>          netdev_dpdk_ring_send,
>>          netdev_dpdk_get_carrier,
>>          netdev_dpdk_get_stats,
>>          netdev_dpdk_get_features,
>>          netdev_dpdk_get_status,
>> +        netdev_dpdk_reconfigure,
>>          netdev_dpdk_rxq_recv);
>>  
>>  static const struct netdev_class OVS_UNUSED dpdk_vhost_cuse_class =
>> @@ -2441,12 +2444,12 @@ static const struct netdev_class OVS_UNUSED
>>dpdk_vhost_cuse_class =
>>          dpdk_vhost_cuse_class_init,
>>          netdev_dpdk_vhost_cuse_construct,
>>          netdev_dpdk_vhost_destruct,
>> -        netdev_dpdk_vhost_cuse_set_multiq,
>>          netdev_dpdk_vhost_send,
>>          netdev_dpdk_vhost_get_carrier,
>>          netdev_dpdk_vhost_get_stats,
>>          NULL,
>>          NULL,
>> +        netdev_dpdk_vhost_cuse_reconfigure,
>>          netdev_dpdk_vhost_rxq_recv);
>>  
>>  static const struct netdev_class OVS_UNUSED dpdk_vhost_user_class =
>> @@ -2455,12 +2458,12 @@ static const struct netdev_class OVS_UNUSED
>>dpdk_vhost_user_class =
>>          dpdk_vhost_user_class_init,
>>          netdev_dpdk_vhost_user_construct,
>>          netdev_dpdk_vhost_destruct,
>> -        netdev_dpdk_vhost_set_multiq,
>>          netdev_dpdk_vhost_send,
>>          netdev_dpdk_vhost_get_carrier,
>>          netdev_dpdk_vhost_get_stats,
>>          NULL,
>>          NULL,
>> +        netdev_dpdk_vhost_user_reconfigure,
>>          netdev_dpdk_vhost_rxq_recv);
>>  
>>  void
>> diff --git a/lib/netdev-provider.h b/lib/netdev-provider.h
>> index 9646cca..b405c4b 100644
>> --- a/lib/netdev-provider.h
>> +++ b/lib/netdev-provider.h
>> @@ -67,8 +67,6 @@ struct netdev {
>>       * modify them. */
>>      int n_txq;
>>      int n_rxq;
>> -    /* Number of rx queues requested by user. */
>> -    int requested_n_rxq;
>>      int ref_cnt;                        /* Times this devices was
>>opened. */
>>      struct shash_node *node;            /* Pointer to element in
>>global map. */
>>      struct ovs_list saved_flags_list; /* Contains "struct
>>netdev_saved_flags". */
>> @@ -295,13 +293,8 @@ struct netdev_class {
>>       * such info, returns NETDEV_NUMA_UNSPEC. */
>>      int (*get_numa_id)(const struct netdev *netdev);
>>  
>> -    /* Configures the number of tx queues and rx queues of 'netdev'.
>> -     * Return 0 if successful, otherwise a positive errno value.
>> -     *
>> -     * 'n_rxq' specifies the maximum number of receive queues to
>>create.
>> -     * The netdev provider might choose to create less (e.g. if the
>>hardware
>> -     * supports only a smaller number).  The actual number of queues
>>created
>> -     * is stored in the 'netdev->n_rxq' field.
>> +    /* Configures the number of tx queues of 'netdev'. Returns 0 if
>>successful,
>> +     * 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
>> @@ -309,12 +302,8 @@ struct netdev_class {
>>       * making sure that these concurrent calls do not create a race
>>condition
>>       * by using multiple hw queues or locking.
>>       *
>> -     * On error, the tx queue and rx queue configuration is
>>indeterminant.
>> -     * Caller should make decision on whether to restore the previous
>>or
>> -     * the default configuration.  Also, caller must make sure there
>>is no
>> -     * other thread accessing the queues at the same time. */
>> -    int (*set_multiq)(struct netdev *netdev, unsigned int n_txq,
>> -                      unsigned int n_rxq);
>> +     * On error, the tx queue configuration is unchanged. */
>> +    int (*set_multiq)(struct netdev *netdev, unsigned int n_txq);
>>  
>>      /* Sends buffers on 'netdev'.
>>       * Returns 0 if successful (for every buffer), otherwise a
>>positive errno
>> diff --git a/lib/netdev.c b/lib/netdev.c
>> index 2c0918b..49c5534 100644
>> --- a/lib/netdev.c
>> +++ b/lib/netdev.c
>> @@ -106,12 +106,6 @@ netdev_n_rxq(const struct netdev *netdev)
>>      return netdev->n_rxq;
>>  }
>>  
>> -int
>> -netdev_requested_n_rxq(const struct netdev *netdev)
>> -{
>> -    return netdev->requested_n_rxq;
>> -}
>> -
>>  bool
>>  netdev_is_pmd(const struct netdev *netdev)
>>  {
>> @@ -384,7 +378,6 @@ netdev_open(const char *name, const char *type,
>>struct netdev **netdevp)
>>                  /* By default enable one tx and rx queue per netdev. */
>>                  netdev->n_txq = netdev->netdev_class->send ? 1 : 0;
>>                  netdev->n_rxq = netdev->netdev_class->rxq_alloc ? 1 :
>>0;
>> -                netdev->requested_n_rxq = netdev->n_rxq;
>>  
>>                  list_init(&netdev->saved_flags_list);
>>  
>> @@ -685,37 +678,26 @@ netdev_rxq_drain(struct netdev_rxq *rx)
>>              : 0);
>>  }
>>  
>> -/* Configures the number of tx queues and rx queues of 'netdev'.
>> - * Return 0 if successful, otherwise a positive errno value.
>> - *
>> - * 'n_rxq' specifies the maximum number of receive queues to create.
>> - * The netdev provider might choose to create less (e.g. if the
>>hardware
>> - * supports only a smaller number).  The caller can check how many
>>have been
>> - * actually created by calling 'netdev_n_rxq()'
>> +/* Configures the number of tx queues of 'netdev'. Returns 0 if
>>successful,
>> + * 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]).
>>   *
>> - * On error, the tx queue and rx queue configuration is indeterminant.
>> - * Caller should make decision on whether to restore the previous or
>> - * the default configuration.  Also, caller must make sure there is no
>> - * other thread accessing the queues at the same time. */
>> + * On error, the tx queue and rx queue configuration is unchanged */
>>  int
>> -netdev_set_multiq(struct netdev *netdev, unsigned int n_txq,
>> -                  unsigned int n_rxq)
>> +netdev_set_multiq(struct netdev *netdev, unsigned int n_txq)
>>  {
>>      int error;
>>  
>>      error = (netdev->netdev_class->set_multiq
>> -             ? netdev->netdev_class->set_multiq(netdev,
>> -                                                MAX(n_txq, 1),
>> -                                                MAX(n_rxq, 1))
>> +             ? netdev->netdev_class->set_multiq(netdev, MAX(n_txq, 1))
>>               : EOPNOTSUPP);
>>  
>>      if (error && error != EOPNOTSUPP) {
>> -        VLOG_DBG_RL(&rl, "failed to set tx/rx queue for network device
>>%s:"
>> +        VLOG_DBG_RL(&rl, "failed to set tx queue for network device
>>%s:"
>>                      "%s", netdev_get_name(netdev),
>>ovs_strerror(error));
>>      }
>>  
>> diff --git a/lib/netdev.h b/lib/netdev.h
>> index c2a1d6c..bb3d297 100644
>> --- a/lib/netdev.h
>> +++ b/lib/netdev.h
>> @@ -142,7 +142,6 @@ bool netdev_is_reserved_name(const char *name);
>>  
>>  int netdev_n_txq(const struct netdev *netdev);
>>  int netdev_n_rxq(const struct netdev *netdev);
>> -int netdev_requested_n_rxq(const struct netdev *netdev);
>>  bool netdev_is_pmd(const struct netdev *netdev);
>>  
>>  /* Open and close. */
>> @@ -168,7 +167,7 @@ const char *netdev_get_type_from_name(const char *);
>>  int netdev_get_mtu(const struct netdev *, int *mtup);
>>  int netdev_set_mtu(const struct netdev *, int mtu);
>>  int netdev_get_ifindex(const struct netdev *);
>> -int netdev_set_multiq(struct netdev *, unsigned int n_txq, unsigned
>>int n_rxq);
>> +int netdev_set_multiq(struct netdev *, unsigned int n_txq);
>>  
>>  /* Packet reception. */
>>  int netdev_rxq_open(struct netdev *, struct netdev_rxq **, int id);
>> 




More information about the dev mailing list