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

  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
---
 lib/librte_eventdev/rte_event_eth_rx_adapter.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)
  

-----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
>