[ovs-dev] [branch-2.6] netdev-dpdk: leverage the mempool offload support

[Kevin Traynor]

On 03/20/2017 11:38 AM, Hemant Agrawal wrote:
> DPDK 16.07 introduced the support for mempool offload support.
> rte_pktmbuf_pool_create is the recommended method for creating pktmbuf
> pools. Buffer pools created with rte_mempool_create may not get offloaded
> to the underlying offloaded mempools.
> 
> This patch, changes the rte_mempool_create to use helper wrapper
> "rte_pktmbuf_pool_create" provided by dpdk, so that it can leverage
> offloaded mempools.

This is changing OVS code to enable new functionality in some cases, I'm
not sure that it's really appropriate as a backport.

> 
> Signed-off-by: Hemant Agrawal <hemant.agrawal at nxp.com>
> ---
>  lib/netdev-dpdk.c | 20 +++++++++-----------
>  1 file changed, 9 insertions(+), 11 deletions(-)
> 
> diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c
> index 9203de0..8d658ff 100644
> --- a/lib/netdev-dpdk.c
> +++ b/lib/netdev-dpdk.c
> @@ -468,7 +468,6 @@ dpdk_mp_get(int socket_id, int mtu) OVS_REQUIRES(dpdk_mutex)
>      struct dpdk_mp *dmp = NULL;
>      char mp_name[RTE_MEMPOOL_NAMESIZE];
>      unsigned mp_size;
> -    struct rte_pktmbuf_pool_private mbp_priv;
>  
>      LIST_FOR_EACH (dmp, list_node, &dpdk_mp_list) {
>          if (dmp->socket_id == socket_id && dmp->mtu == mtu) {
> @@ -481,9 +480,6 @@ dpdk_mp_get(int socket_id, int mtu) OVS_REQUIRES(dpdk_mutex)
>      dmp->socket_id = socket_id;
>      dmp->mtu = mtu;
>      dmp->refcount = 1;
> -    mbp_priv.mbuf_data_room_size = MBUF_SIZE(mtu) - sizeof(struct dp_packet);
> -    mbp_priv.mbuf_priv_size = sizeof (struct dp_packet)
> -                              - sizeof (struct rte_mbuf);
>      /* XXX: this is a really rough method of provisioning memory.
>       * It's impossible to determine what the exact memory requirements are when
>       * the number of ports and rxqs that utilize a particular mempool can change
> @@ -500,13 +496,13 @@ dpdk_mp_get(int socket_id, int mtu) OVS_REQUIRES(dpdk_mutex)
>                       dmp->mtu, dmp->socket_id, mp_size) < 0) {
>              goto fail;
>          }
> -
> -        dmp->mp = rte_mempool_create(mp_name, mp_size, MBUF_SIZE(mtu),
> -                                     MP_CACHE_SZ,
> -                                     sizeof(struct rte_pktmbuf_pool_private),
> -                                     rte_pktmbuf_pool_init, &mbp_priv,
> -                                     ovs_rte_pktmbuf_init, NULL,
> -                                     socket_id, 0);
> +	dmp->mp = rte_pktmbuf_pool_create(mp_name, mp_size,
> +                                          MP_CACHE_SZ,
> +                                          sizeof (struct dp_packet)
> +                                                 - sizeof (struct rte_mbuf),
> +                                          MBUF_SIZE(mtu)
> +                                                 - sizeof(struct dp_packet),
> +                                          socket_id);
>      } while (!dmp->mp && rte_errno == ENOMEM && (mp_size /= 2) >= MIN_NB_MBUF);
>  
>      if (dmp->mp == NULL) {
> @@ -514,6 +510,8 @@ dpdk_mp_get(int socket_id, int mtu) OVS_REQUIRES(dpdk_mutex)
>      } else {
>          VLOG_DBG("Allocated \"%s\" mempool with %u mbufs", mp_name, mp_size );
>      }
> +    /* pktmbuf only prepare the rte_mbuf, prepare the ovs bufs */
> +    rte_mempool_obj_iter(dmp->mp, ovs_rte_pktmbuf_init, NULL);
>  
>      ovs_list_push_back(&dpdk_mp_list, &dmp->list_node);
>      return dmp;
>