[dpdk-stable] patch 'app/testpmd: use clock time in throughput calculation' has been queued to LTS release 18.11.10

[Kevin Traynor]

Hi,

FYI, your patch has been queued to LTS release 18.11.10

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 08/25/20. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable-queue

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable-queue/commit/c6b6392a369508349351c1b9407a80515be14361

Thanks.

Kevin.

---
>From c6b6392a369508349351c1b9407a80515be14361 Mon Sep 17 00:00:00 2001
From: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
Date: Mon, 6 Jul 2020 18:32:29 -0500
Subject: [PATCH] app/testpmd: use clock time in throughput calculation

[ upstream commit aac2b6a78d7728ee39aed8822cba102b3a99a6bf ]

The throughput calculation requires a counter that measures
passing of time. However, the kernel saves and restores the PMU
state when a thread is unscheduled and scheduled. This ensures
that the PMU cycles are not counted towards a thread that is
not scheduled. Hence, when RTE_ARM_EAL_RDTSC_USE_PMU is enabled,
the PMU cycles do not represent the passing of time.
This results in incorrect calculation of throughput numbers.
Use clock_gettime system call to calculate the time passed since
last call.

Bugzilla ID: 450
Fixes: 0e106980301d ("app/testpmd: show throughput in port stats")

Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
Reviewed-by: Phil Yang <phil.yang at arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang at arm.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit at intel.com>
Tested-by: Phil Yang <phil.yang at arm.com>
Tested-by: Ali Alnubani <alialnu at mellanox.com>
---
 app/test-pmd/config.c | 37 +++++++++++++++++++++++++++----------
 1 file changed, 27 insertions(+), 10 deletions(-)

diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
index 0e5d77159d..b51e821a45 100644
--- a/app/test-pmd/config.c
+++ b/app/test-pmd/config.c
@@ -55,4 +55,12 @@
 #include "testpmd.h"
 
+#ifdef CLOCK_MONOTONIC_RAW /* Defined in glibc bits/time.h */
+#define CLOCK_TYPE_ID CLOCK_MONOTONIC_RAW
+#else
+#define CLOCK_TYPE_ID CLOCK_MONOTONIC
+#endif
+
+#define NS_PER_SEC 1E9
+
 static char *flowtype_to_str(uint16_t flow_type);
 
@@ -121,6 +129,7 @@ nic_stats_display(portid_t port_id)
 	static uint64_t prev_pkts_rx[RTE_MAX_ETHPORTS];
 	static uint64_t prev_pkts_tx[RTE_MAX_ETHPORTS];
-	static uint64_t prev_cycles[RTE_MAX_ETHPORTS];
-	uint64_t diff_pkts_rx, diff_pkts_tx, diff_cycles;
+	static uint64_t prev_ns[RTE_MAX_ETHPORTS];
+	struct timespec cur_time;
+	uint64_t diff_pkts_rx, diff_pkts_tx, diff_ns;
 	uint64_t mpps_rx, mpps_tx;
 	struct rte_eth_stats stats;
@@ -179,8 +188,15 @@ nic_stats_display(portid_t port_id)
 	}
 
-	diff_cycles = prev_cycles[port_id];
-	prev_cycles[port_id] = rte_rdtsc();
-	if (diff_cycles > 0)
-		diff_cycles = prev_cycles[port_id] - diff_cycles;
+	diff_ns = 0;
+	if (clock_gettime(CLOCK_TYPE_ID, &cur_time) == 0) {
+		uint64_t ns;
+
+		ns = cur_time.tv_sec * NS_PER_SEC;
+		ns += cur_time.tv_nsec;
+
+		if (prev_ns[port_id] != 0)
+			diff_ns = ns - prev_ns[port_id];
+		prev_ns[port_id] = ns;
+	}
 
 	diff_pkts_rx = (stats.ipackets > prev_pkts_rx[port_id]) ?
@@ -190,8 +206,9 @@ nic_stats_display(portid_t port_id)
 	prev_pkts_rx[port_id] = stats.ipackets;
 	prev_pkts_tx[port_id] = stats.opackets;
-	mpps_rx = diff_cycles > 0 ?
-		diff_pkts_rx * rte_get_tsc_hz() / diff_cycles : 0;
-	mpps_tx = diff_cycles > 0 ?
-		diff_pkts_tx * rte_get_tsc_hz() / diff_cycles : 0;
+	mpps_rx = diff_ns > 0 ?
+		(double)diff_pkts_rx / diff_ns * NS_PER_SEC : 0;
+	mpps_tx = diff_ns > 0 ?
+		(double)diff_pkts_tx / diff_ns * NS_PER_SEC : 0;
+
 	printf("\n  Throughput (since last show)\n");
 	printf("  Rx-pps: %12"PRIu64"\n  Tx-pps: %12"PRIu64"\n",
-- 
2.26.2

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2020-08-20 16:26:16.437389024 +0100
+++ 0015-app-testpmd-use-clock-time-in-throughput-calculation.patch	2020-08-20 16:26:15.799324097 +0100
@@ -1 +1 @@
-From aac2b6a78d7728ee39aed8822cba102b3a99a6bf Mon Sep 17 00:00:00 2001
+From c6b6392a369508349351c1b9407a80515be14361 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit aac2b6a78d7728ee39aed8822cba102b3a99a6bf ]
+
@@ -18 +19,0 @@
-Cc: stable at dpdk.org
@@ -27,2 +28,2 @@
- app/test-pmd/config.c | 44 +++++++++++++++++++++++++++++--------------
- 1 file changed, 30 insertions(+), 14 deletions(-)
+ app/test-pmd/config.c | 37 +++++++++++++++++++++++++++----------
+ 1 file changed, 27 insertions(+), 10 deletions(-)
@@ -31 +32 @@
-index a79019f522..75013100f5 100644
+index 0e5d77159d..b51e821a45 100644
@@ -35 +36 @@
- #define ETHDEV_FWVERS_LEN 32
+ #include "testpmd.h"
@@ -47,3 +48,3 @@
-@@ -140,7 +148,8 @@ nic_stats_display(portid_t port_id)
- 	static uint64_t prev_bytes_rx[RTE_MAX_ETHPORTS];
- 	static uint64_t prev_bytes_tx[RTE_MAX_ETHPORTS];
+@@ -121,6 +129,7 @@ nic_stats_display(portid_t port_id)
+ 	static uint64_t prev_pkts_rx[RTE_MAX_ETHPORTS];
+ 	static uint64_t prev_pkts_tx[RTE_MAX_ETHPORTS];
@@ -50,0 +52 @@
+-	uint64_t diff_pkts_rx, diff_pkts_tx, diff_cycles;
@@ -53,4 +55,2 @@
- 	uint64_t diff_pkts_rx, diff_pkts_tx, diff_bytes_rx, diff_bytes_tx,
--								diff_cycles;
-+								diff_ns;
- 	uint64_t mpps_rx, mpps_tx, mbps_rx, mbps_tx;
++	uint64_t diff_pkts_rx, diff_pkts_tx, diff_ns;
+ 	uint64_t mpps_rx, mpps_tx;
@@ -58 +58 @@
-@@ -199,8 +208,15 @@ nic_stats_display(portid_t port_id)
+@@ -179,8 +188,15 @@ nic_stats_display(portid_t port_id)
@@ -78 +78 @@
-@@ -210,8 +226,8 @@ nic_stats_display(portid_t port_id)
+@@ -190,8 +206,9 @@ nic_stats_display(portid_t port_id)
@@ -89,14 +89 @@
- 
- 	diff_bytes_rx = (stats.ibytes > prev_bytes_rx[port_id]) ?
-@@ -221,8 +237,8 @@ nic_stats_display(portid_t port_id)
- 	prev_bytes_rx[port_id] = stats.ibytes;
- 	prev_bytes_tx[port_id] = stats.obytes;
--	mbps_rx = diff_cycles > 0 ?
--		diff_bytes_rx * rte_get_tsc_hz() / diff_cycles : 0;
--	mbps_tx = diff_cycles > 0 ?
--		diff_bytes_tx * rte_get_tsc_hz() / diff_cycles : 0;
-+	mbps_rx = diff_ns > 0 ?
-+		(double)diff_bytes_rx / diff_ns * NS_PER_SEC : 0;
-+	mbps_tx = diff_ns > 0 ?
-+		(double)diff_bytes_tx / diff_ns * NS_PER_SEC : 0;
- 
++
@@ -103,0 +91 @@
+ 	printf("  Rx-pps: %12"PRIu64"\n  Tx-pps: %12"PRIu64"\n",