examples/l3fwd: fib skip tx queue drain on first iteration

The commit a8f8b672d575 ("examples/l3fwd: skip Tx queue drain on first
iteration") implemented a change to the em and lpm lookup methods to
prevent the TX queue drain running in the first iteration of their
packet processing loops. This patch introduces this change into the
fib lookup method, this was done to keep the fib code aligned with
the em and lpm code.

Signed-off-by: Conor Walsh <conor.walsh@intel.com>
---
 examples/l3fwd/l3fwd_fib.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)
  

> The commit a8f8b672d575 ("examples/l3fwd: skip Tx queue drain on first
> iteration") implemented a change to the em and lpm lookup methods to
> prevent the TX queue drain running in the first iteration of their
> packet processing loops. This patch introduces this change into the
> fib lookup method, this was done to keep the fib code aligned with
> the em and lpm code.
> 
> Signed-off-by: Conor Walsh <conor.walsh@intel.com>
> ---
>  examples/l3fwd/l3fwd_fib.c | 9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/examples/l3fwd/l3fwd_fib.c b/examples/l3fwd/l3fwd_fib.c
> index c7d7689a94..1787229942 100644
> --- a/examples/l3fwd/l3fwd_fib.c
> +++ b/examples/l3fwd/l3fwd_fib.c
> @@ -179,8 +179,6 @@ fib_main_loop(__rte_unused void *dummy)
>  	const uint64_t drain_tsc = (rte_get_tsc_hz() + US_PER_S - 1) /
>  			US_PER_S * BURST_TX_DRAIN_US;
> 
> -	prev_tsc = 0;
> -
>  	lcore_id = rte_lcore_id();
>  	qconf = &lcore_conf[lcore_id];
> 
> @@ -200,9 +198,10 @@ fib_main_loop(__rte_unused void *dummy)
>  				lcore_id, portid, queueid);
>  	}
> 
> -	while (!force_quit) {
> +	cur_tsc = rte_rdtsc();
> +	prev_tsc = cur_tsc;
> 
> -		cur_tsc = rte_rdtsc();
> +	while (!force_quit) {
> 
>  		/* TX burst queue drain. */
>  		diff_tsc = cur_tsc - prev_tsc;
> @@ -233,6 +232,8 @@ fib_main_loop(__rte_unused void *dummy)
>  			/* Use fib to lookup port IDs and transmit them. */
>  			fib_send_packets(nb_rx, pkts_burst,	portid, qconf);
>  		}
> +
> +		cur_tsc = rte_rdtsc();
>  	}
> 
>  	return 0;
> --

Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>

> 2.25.1
  

On 21/04/2021 15:48, Conor Walsh wrote:
> The commit a8f8b672d575 ("examples/l3fwd: skip Tx queue drain on first
> iteration") implemented a change to the em and lpm lookup methods to
> prevent the TX queue drain running in the first iteration of their
> packet processing loops. This patch introduces this change into the
> fib lookup method, this was done to keep the fib code aligned with
> the em and lpm code.
> 
> Signed-off-by: Conor Walsh <conor.walsh@intel.com>
> ---
>   examples/l3fwd/l3fwd_fib.c | 9 +++++----
>   1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/examples/l3fwd/l3fwd_fib.c b/examples/l3fwd/l3fwd_fib.c
> index c7d7689a94..1787229942 100644
> --- a/examples/l3fwd/l3fwd_fib.c
> +++ b/examples/l3fwd/l3fwd_fib.c
> @@ -179,8 +179,6 @@ fib_main_loop(__rte_unused void *dummy)
>   	const uint64_t drain_tsc = (rte_get_tsc_hz() + US_PER_S - 1) /
>   			US_PER_S * BURST_TX_DRAIN_US;
>   
> -	prev_tsc = 0;
> -
>   	lcore_id = rte_lcore_id();
>   	qconf = &lcore_conf[lcore_id];
>   
> @@ -200,9 +198,10 @@ fib_main_loop(__rte_unused void *dummy)
>   				lcore_id, portid, queueid);
>   	}
>   
> -	while (!force_quit) {
> +	cur_tsc = rte_rdtsc();
> +	prev_tsc = cur_tsc;
>   
> -		cur_tsc = rte_rdtsc();
> +	while (!force_quit) {
>   
>   		/* TX burst queue drain. */
>   		diff_tsc = cur_tsc - prev_tsc;
> @@ -233,6 +232,8 @@ fib_main_loop(__rte_unused void *dummy)
>   			/* Use fib to lookup port IDs and transmit them. */
>   			fib_send_packets(nb_rx, pkts_burst,	portid, qconf);
>   		}
> +
> +		cur_tsc = rte_rdtsc();
>   	}
>   
>   	return 0;
> 

Acked-by: Vladimir Medvedkin <vladimir.medvedkin@intel.com>
  

> > The commit a8f8b672d575 ("examples/l3fwd: skip Tx queue drain on first
> > iteration") implemented a change to the em and lpm lookup methods to
> > prevent the TX queue drain running in the first iteration of their
> > packet processing loops. This patch introduces this change into the
> > fib lookup method, this was done to keep the fib code aligned with
> > the em and lpm code.
> > 
> > Signed-off-by: Conor Walsh <conor.walsh@intel.com>
> 
> Acked-by: Vladimir Medvedkin <vladimir.medvedkin@intel.com>

Applied, thanks