[ovs-dev] [PATCH] netdev-dpdk: Do not flush tx queue which is shared among CPUs since it is always flushed

[Gray, Mark D]

> 
> When tx queue is shared among CPUS,the pkts always be flush in
> 'netdev_dpdk_eth_send'
> So it is unnecessarily for flushing in netdev_dpdk_rxq_recv Otherwise tx will
> be accessed without locking

Are you seeing a specific bug or is this just to account for a device with
less queues than pmds?

> 
> Signed-off-by: Wei li <liw at dtdream.com>
> ---
>  lib/netdev-dpdk.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c index 63243d8..25e3a73
> 100644
> --- a/lib/netdev-dpdk.c
> +++ b/lib/netdev-dpdk.c
> @@ -892,8 +892,11 @@ netdev_dpdk_rxq_recv(struct netdev_rxq *rxq_,
> struct dp_packet **packets,
>      int nb_rx;
> 
>      /* There is only one tx queue for this core.  Do not flush other
> -     * queueus. */
> -    if (rxq_->queue_id == rte_lcore_id()) {
> +     * queueus.

s/queueus/queues

> +     * Do not flush tx queue which is shared among CPUs
> +     * since it is always flushed */
> +    if (rxq_->queue_id == rte_lcore_id() &&
> +		OVS_LIKELY(!dev->txq_needs_locking)) {
>          dpdk_queue_flush(dev, rxq_->queue_id);

Do you see any drop in performance in a simple phy-phy case before
and after this patch?

>      }
> 
> --
> 1.9.5.msysgit.1
> 
> 
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