Re: [dpdk-dev] [PATCH] eventdev: add event buffer flush in Rx adapter

[Jerin Jacob <jerin.jacob@caviumnetworks.com>]

-----Original Message-----
> Date: Sun, 3 Jun 2018 18:12:25 +0530
> From: Nikhil Rao <nikhil.rao@intel.com>
> To: jerin.jacob@caviumnetworks.com
> CC: dev@dpdk.org, Nikhil Rao <nikhil.rao@intel.com>, stable@dpdk.org
> Subject: [PATCH] eventdev: add event buffer flush in Rx adapter
> X-Mailer: git-send-email 1.8.3.1
> 
> Add an event buffer flush when the current invocation
> of the Rx adapter is completed.
> 
> This patch provides lower latency in case there is a
> BATCH_SIZE of events in the event buffer.
> 
> Suggested-by: Narender Vangati <narender.vangati@intel.com>
> Signed-off-by: Nikhil Rao <nikhil.rao@intel.com>
> Cc: stable@dpdk.org

Acked-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>

Applied to dpdk-next-eventdev/master. Thanks.


> ---
>  lib/librte_eventdev/rte_event_eth_rx_adapter.c | 14 ++++++--------
>  1 file changed, 6 insertions(+), 8 deletions(-)
> 
> diff --git a/lib/librte_eventdev/rte_event_eth_rx_adapter.c b/lib/librte_eventdev/rte_event_eth_rx_adapter.c
> index 53a3788..3a70058 100644
> --- a/lib/librte_eventdev/rte_event_eth_rx_adapter.c
> +++ b/lib/librte_eventdev/rte_event_eth_rx_adapter.c
> @@ -490,7 +490,7 @@ static uint16_t gcd_u16(uint16_t a, uint16_t b)
>   * the hypervisor's switching layer where adjustments can be made to deal with
>   * it.
>   */
> -static inline uint32_t
> +static inline void
>  eth_rx_poll(struct rte_event_eth_rx_adapter *rx_adapter)
>  {
>  	uint32_t num_queue;
> @@ -519,7 +519,7 @@ static uint16_t gcd_u16(uint16_t a, uint16_t b)
>  			flush_event_buffer(rx_adapter);
>  		if (BATCH_SIZE > (ETH_EVENT_BUFFER_SIZE - buf->count)) {
>  			rx_adapter->wrr_pos = wrr_pos;
> -			break;
> +			return;
>  		}
>  
>  		stats->rx_poll_count++;
> @@ -535,7 +535,7 @@ static uint16_t gcd_u16(uint16_t a, uint16_t b)
>  			if (nb_rx > max_nb_rx) {
>  				rx_adapter->wrr_pos =
>  				    (wrr_pos + 1) % rx_adapter->wrr_len;
> -				return nb_rx;
> +				break;
>  			}
>  		}
>  
> @@ -543,20 +543,18 @@ static uint16_t gcd_u16(uint16_t a, uint16_t b)
>  			wrr_pos = 0;
>  	}
>  
> -	return nb_rx;
> +	if (buf->count >= BATCH_SIZE)
> +		flush_event_buffer(rx_adapter);
>  }
>  
>  static int
>  event_eth_rx_adapter_service_func(void *args)
>  {
>  	struct rte_event_eth_rx_adapter *rx_adapter = args;
> -	struct rte_eth_event_enqueue_buffer *buf;
>  
> -	buf = &rx_adapter->event_enqueue_buffer;
>  	if (rte_spinlock_trylock(&rx_adapter->rx_lock) == 0)
>  		return 0;
> -	if (eth_rx_poll(rx_adapter) == 0 && buf->count)
> -		flush_event_buffer(rx_adapter);
> +	eth_rx_poll(rx_adapter);
>  	rte_spinlock_unlock(&rx_adapter->rx_lock);
>  	return 0;
>  }
> -- 
> 1.8.3.1
>