Re: [dpdk-dev] [PATCH] app/testpmd: fix CPU cycles per pkt stats on transmit modes

[Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>]

<snip>

> Subject: [PATCH] app/testpmd: fix CPU cycles per pkt stats on transmit modes
> 
> In txonly and flowgen forwarding mode, calculating CPU per packets with total
> received packets is not accurate. Use total transmitted packets for these cases.
> 
> The error output under txonly mode:
> testpmd> show fwd stats all
> 
> ---------------------- Forward statistics for port 0  -------------------
> RX-packets: 0              RX-dropped: 0             RX-total: 0
> TX-packets: 3582891927     TX-dropped: 401965824     TX-total: 3984857751
> TX-bursts : 86381636 [0% of 0 pkts + 85% of 64 pkts + 15% of 32 pkts]
> -------------------------------------------------------------------------
> 
> ---------------------- Forward statistics for port 1  -------------------
> RX-packets: 1              RX-dropped: 394351696     RX-total: 394351697
> TX-packets: 3582890632     TX-dropped: 401965568     TX-total: 3984856200
> TX-bursts : 86381679 [0% of 0 pkts + 85% of 64 pkts + 15% of 32 pkts]
> -------------------------------------------------------------------------
> 
> +++++++++++++++ Accumulated forward statistics for all
> +++++++++++++++ ports+++++++++++++
> RX-packets: 1              RX-dropped: 394351696     RX-total: 394351697
> TX-packets: 7165782559     TX-dropped: 803931392     TX-total: 7969713951
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> ++++++++
> 
> CPU cycles/packet=54984156291.00 \
> (total cycles=54984156291 / total RX packets=1) at 200 MHz Clock
> 
> Signed-off-by: Phil Yang <phil.yang@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> Fixes: 53324971a14e ("app/testpmd: display/clear forwarding stats on
> demand")
> Cc: stable@dpdk.org
> Cc: david.marchand@redhat.com
> ---
>  app/test-pmd/testpmd.c | 24 +++++++++++++++++-------
>  1 file changed, 17 insertions(+), 7 deletions(-)
> 
> diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c index
> 4989d22..798b8e0 100644
> --- a/app/test-pmd/testpmd.c
> +++ b/app/test-pmd/testpmd.c
> @@ -1961,13 +1961,23 @@ fwd_stats_display(void)
>  	       acc_stats_border, acc_stats_border);  #ifdef
> RTE_TEST_PMD_RECORD_CORE_CYCLES  #define CYC_PER_MHZ 1E6
> -	if (total_recv > 0)
> -		printf("\n  CPU cycles/packet=%.2F (total cycles="
> -		       "%"PRIu64" / total RX packets=%"PRIu64") at %"PRIu64
> -		       " MHz Clock\n",
> -		       (double) fwd_cycles / total_recv,
> -		       fwd_cycles, total_recv,
> -		       (uint64_t)(rte_get_tsc_hz() / CYC_PER_MHZ));
> +	if (total_recv > 0 || total_xmit > 0) {
> +		if (strcmp(cur_fwd_eng->fwd_mode_name, "txonly") == 0 ||
> +		    strcmp(cur_fwd_eng->fwd_mode_name, "flowgen") == 0)
> +			printf("\n  CPU cycles/packet=%.2F (total cycles="
> +			     "%"PRIu64" / total %s packets=%"PRIu64") at %"
> +			     PRIu64" MHz Clock\n",
> +			     (double) fwd_cycles / total_xmit,
> +			     fwd_cycles, cur_fwd_eng->fwd_mode_name,
> total_xmit,
> +			     (uint64_t)(rte_get_tsc_hz() / CYC_PER_MHZ));
> +		else
> +			printf("\n  CPU cycles/packet=%.2F (total cycles="
> +			    "%"PRIu64" / total %s packets=%"PRIu64") at %"
> +			    PRIu64" MHz Clock\n",
> +			    (double) fwd_cycles / total_recv,
> +			    fwd_cycles, cur_fwd_eng->fwd_mode_name,
> total_recv,
> +			    (uint64_t)(rte_get_tsc_hz() / CYC_PER_MHZ));
> +	}
nit. Only difference between the two 'printf' calls are total_recv vs total_xmit. Can be consolidated into a single printf.

>  #endif
>  }
> 
> --
> 2.7.4