[dpdk-stable] patch 'app/testpmd: use clock time in throughput calculation' has been queued to stable release 19.11.4

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 19.11.4

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 07/26/20. 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.

Thanks.

Luca Boccassi

---
>From e3481fb27c70b9d5fb50f95c9545e99e31dcc40c 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 | 44 +++++++++++++++++++++++++++++--------------
 1 file changed, 30 insertions(+), 14 deletions(-)

diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
index e345cea6d..726a26342 100644
--- a/app/test-pmd/config.c
+++ b/app/test-pmd/config.c
@@ -53,6 +53,14 @@
 
 #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);
 
 static const struct {
@@ -125,9 +133,10 @@ nic_stats_display(portid_t port_id)
 	static uint64_t prev_pkts_tx[RTE_MAX_ETHPORTS];
 	static uint64_t prev_bytes_rx[RTE_MAX_ETHPORTS];
 	static uint64_t prev_bytes_tx[RTE_MAX_ETHPORTS];
-	static uint64_t prev_cycles[RTE_MAX_ETHPORTS];
+	static uint64_t prev_ns[RTE_MAX_ETHPORTS];
+	struct timespec cur_time;
 	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;
 	struct rte_eth_stats stats;
 	struct rte_port *port = &ports[port_id];
@@ -184,10 +193,17 @@ 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]) ?
 		(stats.ipackets - prev_pkts_rx[port_id]) : 0;
@@ -195,10 +211,10 @@ nic_stats_display(portid_t port_id)
 		(stats.opackets - prev_pkts_tx[port_id]) : 0;
 	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;
 
 	diff_bytes_rx = (stats.ibytes > prev_bytes_rx[port_id]) ?
 		(stats.ibytes - prev_bytes_rx[port_id]) : 0;
@@ -206,10 +222,10 @@ nic_stats_display(portid_t port_id)
 		(stats.obytes - prev_bytes_tx[port_id]) : 0;
 	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;
 
 	printf("\n  Throughput (since last show)\n");
 	printf("  Rx-pps: %12"PRIu64"          Rx-bps: %12"PRIu64"\n  Tx-pps: %12"
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2020-07-24 12:53:53.167374596 +0100
+++ 0120-app-testpmd-use-clock-time-in-throughput-calculation.patch	2020-07-24 12:53:48.407008695 +0100
@@ -1,8 +1,10 @@
-From aac2b6a78d7728ee39aed8822cba102b3a99a6bf Mon Sep 17 00:00:00 2001
+From e3481fb27c70b9d5fb50f95c9545e99e31dcc40c 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
@@ -15,7 +17,6 @@
 
 Bugzilla ID: 450
 Fixes: 0e106980301d ("app/testpmd: show throughput in port stats")
-Cc: stable at dpdk.org
 
 Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
 Reviewed-by: Phil Yang <phil.yang at arm.com>
@@ -28,12 +29,12 @@
  1 file changed, 30 insertions(+), 14 deletions(-)
 
 diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
-index a79019f52..75013100f 100644
+index e345cea6d..726a26342 100644
 --- a/app/test-pmd/config.c
 +++ b/app/test-pmd/config.c
-@@ -54,6 +54,14 @@
+@@ -53,6 +53,14 @@
  
- #define ETHDEV_FWVERS_LEN 32
+ #include "testpmd.h"
  
 +#ifdef CLOCK_MONOTONIC_RAW /* Defined in glibc bits/time.h */
 +#define CLOCK_TYPE_ID CLOCK_MONOTONIC_RAW
@@ -46,7 +47,7 @@
  static char *flowtype_to_str(uint16_t flow_type);
  
  static const struct {
-@@ -139,9 +147,10 @@ nic_stats_display(portid_t port_id)
+@@ -125,9 +133,10 @@ nic_stats_display(portid_t port_id)
  	static uint64_t prev_pkts_tx[RTE_MAX_ETHPORTS];
  	static uint64_t prev_bytes_rx[RTE_MAX_ETHPORTS];
  	static uint64_t prev_bytes_tx[RTE_MAX_ETHPORTS];
@@ -59,7 +60,7 @@
  	uint64_t mpps_rx, mpps_tx, mbps_rx, mbps_tx;
  	struct rte_eth_stats stats;
  	struct rte_port *port = &ports[port_id];
-@@ -198,10 +207,17 @@ nic_stats_display(portid_t port_id)
+@@ -184,10 +193,17 @@ nic_stats_display(portid_t port_id)
  		}
  	}
  
@@ -81,7 +82,7 @@
  
  	diff_pkts_rx = (stats.ipackets > prev_pkts_rx[port_id]) ?
  		(stats.ipackets - prev_pkts_rx[port_id]) : 0;
-@@ -209,10 +225,10 @@ nic_stats_display(portid_t port_id)
+@@ -195,10 +211,10 @@ nic_stats_display(portid_t port_id)
  		(stats.opackets - prev_pkts_tx[port_id]) : 0;
  	prev_pkts_rx[port_id] = stats.ipackets;
  	prev_pkts_tx[port_id] = stats.opackets;
@@ -96,7 +97,7 @@
  
  	diff_bytes_rx = (stats.ibytes > prev_bytes_rx[port_id]) ?
  		(stats.ibytes - prev_bytes_rx[port_id]) : 0;
-@@ -220,10 +236,10 @@ nic_stats_display(portid_t port_id)
+@@ -206,10 +222,10 @@ nic_stats_display(portid_t port_id)
  		(stats.obytes - prev_bytes_tx[port_id]) : 0;
  	prev_bytes_rx[port_id] = stats.ibytes;
  	prev_bytes_tx[port_id] = stats.obytes;