[dpdk-stable] [PATCH v3] app/testpmd: fix CPU cycles per pkt stats on transmit modes

[Phil Yang]

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>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
Fixes: 53324971a14e ("app/testpmd: display/clear forwarding stats on demand")
Cc: stable at dpdk.org
Cc: david.marchand at redhat.com
---
v3:
replace ingress flag with total_pkts. (Honnappa Nagarahalli)

v2:
Consolidate the output into a single printf. (Honnappa Nagarahalli)

 app/test-pmd/testpmd.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index 4989d22..be47a7d 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -1961,13 +1961,21 @@ 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) {
+		uint64_t total_pkts = 0;
+		if (strcmp(cur_fwd_eng->fwd_mode_name, "txonly") == 0 ||
+		    strcmp(cur_fwd_eng->fwd_mode_name, "flowgen") == 0)
+			total_pkts = total_xmit;
+		else
+			total_pkts = total_recv;
+
 		printf("\n  CPU cycles/packet=%.2F (total cycles="
-		       "%"PRIu64" / total RX packets=%"PRIu64") at %"PRIu64
+		       "%"PRIu64" / total %s packets=%"PRIu64") at %"PRIu64
 		       " MHz Clock\n",
-		       (double) fwd_cycles / total_recv,
-		       fwd_cycles, total_recv,
+		       (double) fwd_cycles / total_pkts,
+		       fwd_cycles, cur_fwd_eng->fwd_mode_name, total_pkts,
 		       (uint64_t)(rte_get_tsc_hz() / CYC_PER_MHZ));
+	}
 #endif
 }
 
-- 
2.7.4