From: Petr Machata <petrm@mellanox.com>
Date: Thu, 5 Mar 2020 09:16:44 +0200
Subject: selftests: forwarding: ETS: Use Qdisc counters
Patch-mainline: v5.7-rc1
Git-commit: b9b72999eb86e650489a4321c8e95a4e2e3df20c
References: bsc#1176774

Currently the SW-datapath ETS selftests use "ip link" stats to obtain the
number of packets that went through a given band. mlxsw then uses ethtool
per-priority counters.

Instead, change both to use qdiscs. In SW datapath this is the obvious
choice, and now that mlxsw offloads FIFO, this should work on the offloaded
datapath as well. This has the effect of verifying that the FIFO offload
works.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 tools/testing/selftests/drivers/net/mlxsw/sch_ets.sh    |   14 +++++++++++---
 tools/testing/selftests/net/forwarding/lib.sh           |   10 ++++++++++
 tools/testing/selftests/net/forwarding/sch_ets.sh       |    9 ++++++---
 tools/testing/selftests/net/forwarding/sch_ets_tests.sh |   10 +++-------
 4 files changed, 30 insertions(+), 13 deletions(-)

--- a/tools/testing/selftests/drivers/net/mlxsw/sch_ets.sh
+++ b/tools/testing/selftests/drivers/net/mlxsw/sch_ets.sh
@@ -56,11 +56,19 @@ switch_destroy()
 }
 
 # Callback from sch_ets_tests.sh
-get_stats()
+collect_stats()
 {
-	local band=$1; shift
+	local -a streams=("$@")
+	local stream
 
-	ethtool_stats_get "$h2" rx_octets_prio_$band
+	# Wait for qdisc counter update so that we don't get it mid-way through.
+	busywait_for_counter 1000 +1 \
+		qdisc_parent_stats_get $swp2 10:$((${streams[0]} + 1)) .bytes \
+		> /dev/null
+
+	for stream in ${streams[@]}; do
+		qdisc_parent_stats_get $swp2 10:$((stream + 1)) .bytes
+	done
 }
 
 bail_on_lldpad
--- a/tools/testing/selftests/net/forwarding/lib.sh
+++ b/tools/testing/selftests/net/forwarding/lib.sh
@@ -596,6 +596,16 @@ qdisc_stats_get()
 	    | jq '.[] | select(.handle == "'"$handle"'") | '"$selector"
 }
 
+qdisc_parent_stats_get()
+{
+	local dev=$1; shift
+	local parent=$1; shift
+	local selector=$1; shift
+
+	tc -j -s qdisc show dev "$dev" invisible \
+	    | jq '.[] | select(.parent == "'"$parent"'") | '"$selector"
+}
+
 humanize()
 {
 	local speed=$1; shift
--- a/tools/testing/selftests/net/forwarding/sch_ets.sh
+++ b/tools/testing/selftests/net/forwarding/sch_ets.sh
@@ -34,11 +34,14 @@ switch_destroy()
 }
 
 # Callback from sch_ets_tests.sh
-get_stats()
+collect_stats()
 {
-	local stream=$1; shift
+	local -a streams=("$@")
+	local stream
 
-	link_stats_get $h2.1$stream rx bytes
+	for stream in ${streams[@]}; do
+		qdisc_parent_stats_get $swp2 10:$((stream + 1)) .bytes
+	done
 }
 
 ets_run
--- a/tools/testing/selftests/net/forwarding/sch_ets_tests.sh
+++ b/tools/testing/selftests/net/forwarding/sch_ets_tests.sh
@@ -2,7 +2,7 @@
 
 # Global interface:
 #  $put -- port under test (e.g. $swp2)
-#  get_stats($band) -- A function to collect stats for band
+#  collect_stats($streams...) -- A function to get stats for individual streams
 #  ets_start_traffic($band) -- Start traffic for this band
 #  ets_change_qdisc($op, $dev, $nstrict, $quanta...) -- Add or change qdisc
 
@@ -94,15 +94,11 @@ __ets_dwrr_test()
 
 	sleep 10
 
-	t0=($(for stream in ${streams[@]}; do
-		  get_stats $stream
-	      done))
+	t0=($(collect_stats "${streams[@]}"))
 
 	sleep 10
 
-	t1=($(for stream in ${streams[@]}; do
-		  get_stats $stream
-	      done))
+	t1=($(collect_stats "${streams[@]}"))
 	d=($(for ((i = 0; i < ${#streams[@]}; i++)); do
 		 echo $((${t1[$i]} - ${t0[$i]}))
 	     done))