Re: [dpdk-dev] [PATCH] eventdev: remove event copy in Rx adapter

["Mattias Rönnblom" <mattias.ronnblom@ericsson.com>]

On 2019-05-21 23:52, Nikhil Rao wrote:
> Remove copy from temporary event array on the stack to the
> enqueue buffer event array entry, instead initialize event in the
> enqueue buffer event array entry.
> 
> Suggested-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
> Signed-off-by: Nikhil Rao <nikhil.rao@intel.com>
> ---
> 
> Hi Mattias,
> 
> This patch eliminates the event copy as you previously mentioned
> (https://patches.dpdk.org/patch/53350/), the enqueue buffer
> array is still retained in the rx_adapter struct, since the Rx adapter
> service function can return with events in the enqueue buffer
> that have not yet been shipped to the event device.
> 
> Let me know your comments.
> 
> Thanks,
> Nikhil

Looks good to me. Sorry about the late reply.

> 
>   lib/librte_eventdev/rte_event_eth_rx_adapter.c | 20 ++++----------------
>   1 file changed, 4 insertions(+), 16 deletions(-)
> 
> diff --git a/lib/librte_eventdev/rte_event_eth_rx_adapter.c b/lib/librte_eventdev/rte_event_eth_rx_adapter.c
> index 8d178be..a201668 100644
> --- a/lib/librte_eventdev/rte_event_eth_rx_adapter.c
> +++ b/lib/librte_eventdev/rte_event_eth_rx_adapter.c
> @@ -715,18 +715,6 @@ static uint16_t rxa_gcd_u16(uint16_t a, uint16_t b)
>   	}
>   }
>   
> -/* Add event to buffer, free space check is done prior to calling
> - * this function
> - */
> -static inline void
> -rxa_buffer_event(struct rte_event_eth_rx_adapter *rx_adapter,
> -		struct rte_event *ev)
> -{
> -	struct rte_eth_event_enqueue_buffer *buf =
> -	    &rx_adapter->event_enqueue_buffer;
> -	rte_memcpy(&buf->events[buf->count++], ev, sizeof(struct rte_event));
> -}
> -
>   /* Enqueue buffered events to event device */
>   static inline uint16_t
>   rxa_flush_event_buffer(struct rte_event_eth_rx_adapter *rx_adapter)
> @@ -769,11 +757,11 @@ static uint16_t rxa_gcd_u16(uint16_t a, uint16_t b)
>   					&dev_info->rx_queue[rx_queue_id];
>   	struct rte_eth_event_enqueue_buffer *buf =
>   					&rx_adapter->event_enqueue_buffer;
> +	struct rte_event *ev = &buf->events[buf->count];
>   	int32_t qid = eth_rx_queue_info->event_queue_id;
>   	uint8_t sched_type = eth_rx_queue_info->sched_type;
>   	uint8_t priority = eth_rx_queue_info->priority;
>   	uint32_t flow_id;
> -	struct rte_event events[BATCH_SIZE];
>   	struct rte_mbuf *m = mbufs[0];
>   	uint32_t rss_mask;
>   	uint32_t rss;
> @@ -811,7 +799,6 @@ static uint16_t rxa_gcd_u16(uint16_t a, uint16_t b)
>   
>   	for (i = 0; i < num; i++) {
>   		m = mbufs[i];
> -		struct rte_event *ev = &events[i];
>   
>   		rss = do_rss ?
>   			rxa_do_softrss(m, rx_adapter->rss_key_be) :
> @@ -828,9 +815,10 @@ static uint16_t rxa_gcd_u16(uint16_t a, uint16_t b)
>   		ev->sub_event_type = 0;
>   		ev->priority = priority;
>   		ev->mbuf = m;
> -
> -		rxa_buffer_event(rx_adapter, ev);
> +		ev++;
>   	}
> +
> +	buf->count += num;
>   }
>   
>   /* Enqueue packets from  <port, q>  to event buffer */
>