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

[Phil Yang <Phil.Yang@arm.com>]

> -----Original Message-----
> From: Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>
> Sent: Friday, June 19, 2020 3:29 AM
> To: Phil Yang <Phil.Yang@arm.com>; dev@dpdk.org
> Cc: ferruh.yigit@intel.com; maxime.coquelin@redhat.com; Ruifeng Wang
> <Ruifeng.Wang@arm.com>; nd <nd@arm.com>; stable@dpdk.org;
> david.marchand@redhat.com; Honnappa Nagarahalli
> <Honnappa.Nagarahalli@arm.com>; nd <nd@arm.com>
> Subject: RE: [PATCH] app/testpmd: fix CPU cycles per pkt stats on transmit
> modes
> 
> <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.

OK. I can use a local flag and a ternary operator to print the ingress and the egress packets respectively.

I will update it in V2.

Thanks,
Phil

> 
> >  #endif
> >  }
> >
> > --
> > 2.7.4