[dpdk-dev] [PATCH v2] app/testpmd: fix CPU cycles per pkt stats on transmit modes

[Phil Yang]

> -----Original Message-----
> From: Honnappa Nagarahalli <Honnappa.Nagarahalli at arm.com>
> Sent: Monday, June 22, 2020 11:40 AM
> To: Phil Yang <Phil.Yang at arm.com>; dev at dpdk.org
> Cc: ferruh.yigit at intel.com; maxime.coquelin at redhat.com; Ruifeng Wang
> <Ruifeng.Wang at arm.com>; nd <nd at arm.com>; stable at dpdk.org;
> david.marchand at redhat.com; Honnappa Nagarahalli
> <Honnappa.Nagarahalli at arm.com>; nd <nd at arm.com>
> Subject: RE: [PATCH v2] app/testpmd: fix CPU cycles per pkt stats on transmit
> modes
> 
> <snip>
> 
> > Subject: [PATCH v2] 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 at arm.com>
> > Reviewed-by: Ruifeng Wang <ruifeng.wang at arm.com>
> > Fixes: 53324971a14e ("app/testpmd: display/clear forwarding stats on
> > demand")
> > Cc: stable at dpdk.org
> > Cc: david.marchand at redhat.com
> > ---
> > v2:
> > Consolidate the output into a single printf. (Honnappa Nagarahalli)
> >
> >  app/test-pmd/testpmd.c | 21 +++++++++++++++------
> >  1 file changed, 15 insertions(+), 6 deletions(-)
> >
> > diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c index
> > 4989d22..826d7dd 100644
> > --- a/app/test-pmd/testpmd.c
> > +++ b/app/test-pmd/testpmd.c
> > @@ -1961,13 +1961,22 @@ 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)
> > +	if (total_recv > 0 || total_xmit > 0) {
> > +		uint8_t ingress;
> > +		if (strcmp(cur_fwd_eng->fwd_mode_name, "txonly") == 0
> ||
> > +		    strcmp(cur_fwd_eng->fwd_mode_name, "flowgen") == 0)
> > +			ingress = 0;
> This can be 'total_pkts = total_recv'
> 
> > +		else
> > +			ingress = 1;
> This can be 'total_pkts = total_xmit'

Agree. Much better.
Updated in V3.

Thanks,
Phil
> 
> > +
> >  		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));
> > +			"%"PRIu64" / total %s packets=%"PRIu64") at %"
> > +			PRIu64" MHz Clock\n", ((double) fwd_cycles /
> > +				(ingress ? total_recv : total_xmit)),
> Can be just 'total_pkts'.
> 
> > +			fwd_cycles, cur_fwd_eng->fwd_mode_name,
> > +			(ingress ? total_recv : total_xmit),
> Can be just 'total_pkts'.
> 
> > +			(uint64_t)(rte_get_tsc_hz() / CYC_PER_MHZ));
> > +	}
> >  #endif
> >  }
> Otherwise,
> Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
> 
> >
> > --
> > 2.7.4