Merge branch 'mlxsw-Enable-minimum-shaper-on-MC-TCs'

Ido Schimmel says:

====================
mlxsw: Enable minimum shaper on MC TCs

Petr says:

An MC-aware mode was introduced in commit 7b8195306694 ("mlxsw:
spectrum: Configure MC-aware mode on mlxsw ports"). In MC-aware mode,
BUM traffic gets a special treatment by being assigned to a separate set
of traffic classes 8..15. Pairs of TCs 0 and 8, 1 and 9, etc., are then
configured to strictly prioritize the lower-numbered ones. The intention
is to prevent BUM traffic from flooding the switch and push out all UC
traffic, which would otherwise happen, and instead give UC traffic
precedence.

However strictly prioritizing UC traffic has the effect that UC overload
pushes out all BUM traffic, such as legitimate ARP queries. These
packets are kept in queues for a while, but under sustained UC overload,
their lifetime eventually expires and these packets are dropped. That is
detrimental to network performance as well.

In this patchset, MC TCs (8..15) are configured with minimum shaper of
200Mbps (a minimum permitted value) to allow a trickle of necessary
control traffic to get through.

First in patch #1, the QEEC register is extended with fields necessary
to configure the minimum shaper.

In patch #2, minimum shaper is enabled on TCs 8..15.

In patches #3 and #4, first the MC-awareness test is tweaked to support
the minimum shaper, and then a new test is introduced to test that MC
traffic behaves well under UC overload.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 71 insertions, 24 deletions

diff --git a/tools/testing/selftests/drivers/net/mlxsw/qos_mc_aware.sh b/tools/testing/selftests/drivers/net/mlxsw/qos_mc_aware.sh
index 0150bb2741eb..117f6f35d72f 100755
--- a/tools/testing/selftests/drivers/net/mlxsw/qos_mc_aware.sh
+++ b/tools/testing/selftests/drivers/net/mlxsw/qos_mc_aware.sh
@@ -25,24 +25,24 @@
 # Thus we set MTU to 10K on all involved interfaces. Then both unicast and
 # multicast traffic uses 8K frames.
 #
-# +-----------------------+                +----------------------------------+
-# | H1                    |                |                               H2 |
-# |                       |                |  unicast --> + $h2.111           |
-# |                       |                |  traffic     | 192.0.2.129/28    |
-# |          multicast    |                |              | e-qos-map 0:1     |
-# |          traffic      |                |              |                   |
-# | $h1 + <-----          |                |              + $h2               |
-# +-----|-----------------+                +--------------|-------------------+
-#       |                                                 |
-# +-----|-------------------------------------------------|-------------------+
-# |     + $swp1                                           + $swp2             |
-# |     | >1Gbps                                          | >1Gbps            |
-# | +---|----------------+                     +----------|----------------+  |
-# | |   + $swp1.1        |                     |          + $swp2.111      |  |
+# +---------------------------+            +----------------------------------+
+# | H1                        |            |                               H2 |
+# |                           |            |  unicast --> + $h2.111           |
+# |                 multicast |            |  traffic     | 192.0.2.129/28    |
+# |                 traffic   |            |              | e-qos-map 0:1     |
+# |           $h1 + <-----    |            |              |                   |
+# | 192.0.2.65/28 |           |            |              + $h2               |
+# +---------------|-----------+            +--------------|-------------------+
+#                 |                                       |
+# +---------------|---------------------------------------|-------------------+
+# |         $swp1 +                                       + $swp2             |
+# |        >1Gbps |                                       | >1Gbps            |
+# | +-------------|------+                     +----------|----------------+  |
+# | |     $swp1.1 +      |                     |          + $swp2.111      |  |
 # | |                BR1 |             SW      | BR111                     |  |
-# | |   + $swp3.1        |                     |          + $swp3.111      |  |
-# | +---|----------------+                     +----------|----------------+  |
-# |     \_________________________________________________/                   |
+# | |     $swp3.1 +      |                     |          + $swp3.111      |  |
+# | +-------------|------+                     +----------|----------------+  |
+# |               \_______________________________________/                   |
 # |                                    |                                      |
 # |                                    + $swp3                                |
 # |                                    | 1Gbps bottleneck                     |
@@ -51,6 +51,7 @@
 #                                      |
 #                                   +--|-----------------+
 #                                   |  + $h3          H3 |
+#                                   |  | 192.0.2.66/28   |
 #                                   |  |                 |
 #                                   |  + $h3.111         |
 #                                   |    192.0.2.130/28  |
@@ -59,6 +60,7 @@
 ALL_TESTS="
 	ping_ipv4
 	test_mc_aware
+	test_uc_aware
 "
 
 lib_dir=$(dirname $0)/../../../net/forwarding
@@ -68,14 +70,14 @@ source $lib_dir/lib.sh
 
 h1_create()
 {
-	simple_if_init $h1
+	simple_if_init $h1 192.0.2.65/28
 	mtu_set $h1 10000
 }
 
 h1_destroy()
 {
 	mtu_restore $h1
-	simple_if_fini $h1
+	simple_if_fini $h1 192.0.2.65/28
 }
 
 h2_create()
@@ -97,7 +99,7 @@ h2_destroy()
 
 h3_create()
 {
-	simple_if_init $h3
+	simple_if_init $h3 192.0.2.66/28
 	mtu_set $h3 10000
 
 	vlan_create $h3 111 v$h3 192.0.2.130/28
@@ -108,7 +110,7 @@ h3_destroy()
 	vlan_destroy $h3 111
 
 	mtu_restore $h3
-	simple_if_fini $h3
+	simple_if_fini $h3 192.0.2.66/28
 }
 
 switch_create()
@@ -251,7 +253,7 @@ measure_uc_rate()
 	# average ingress rate to somewhat mitigate this.
 	local min_ingress=2147483648
 
-	mausezahn $h2.111 -p 8000 -A 192.0.2.129 -B 192.0.2.130 -c 0 \
+	$MZ $h2.111 -p 8000 -A 192.0.2.129 -B 192.0.2.130 -c 0 \
 		-a own -b $h3mac -t udp -q &
 	sleep 1
 
@@ -291,7 +293,7 @@ test_mc_aware()
 	check_err $? "Could not get high enough UC-only ingress rate"
 	local ucth1=${uc_rate[1]}
 
-	mausezahn $h1 -p 8000 -c 0 -a own -b bc -t udp -q &
+	$MZ $h1 -p 8000 -c 0 -a own -b bc -t udp -q &
 
 	local d0=$(date +%s)
 	local t0=$(ethtool_stats_get $h3 rx_octets_prio_0)
@@ -311,7 +313,7 @@ test_mc_aware()
 			ret = 100 * ($ucth1 - $ucth2) / $ucth1
 			if (ret > 0) { ret } else { 0 }
 		    ")
-	check_err $(bc <<< "$deg > 10")
+	check_err $(bc <<< "$deg > 25")
 
 	local interval=$((d1 - d0))
 	local mc_ir=$(rate $u0 $u1 $interval)
@@ -335,6 +337,51 @@ test_mc_aware()
 	echo "    egress UC throughput  $(humanize ${uc_rate_2[1]})"
 	echo "    ingress MC throughput $(humanize $mc_ir)"
 	echo "    egress MC throughput  $(humanize $mc_er)"
+	echo
+}
+
+test_uc_aware()
+{
+	RET=0
+
+	$MZ $h2.111 -p 8000 -A 192.0.2.129 -B 192.0.2.130 -c 0 \
+		-a own -b $h3mac -t udp -q &
+
+	local d0=$(date +%s)
+	local t0=$(ethtool_stats_get $h3 rx_octets_prio_1)
+	local u0=$(ethtool_stats_get $swp2 rx_octets_prio_1)
+	sleep 1
+
+	local attempts=50
+	local passes=0
+	local i
+
+	for ((i = 0; i < attempts; ++i)); do
+		if $ARPING -c 1 -I $h1 -b 192.0.2.66 -q -w 0.1; then
+			((passes++))
+		fi
+
+		sleep 0.1
+	done
+
+	local d1=$(date +%s)
+	local t1=$(ethtool_stats_get $h3 rx_octets_prio_1)
+	local u1=$(ethtool_stats_get $swp2 rx_octets_prio_1)
+
+	local interval=$((d1 - d0))
+	local uc_ir=$(rate $u0 $u1 $interval)
+	local uc_er=$(rate $t0 $t1 $interval)
+
+	((attempts == passes))
+	check_err $?
+
+	# Suppress noise from killing mausezahn.
+	{ kill %% && wait; } 2>/dev/null
+
+	log_test "MC performace under UC overload"
+	echo "    ingress UC throughput $(humanize ${uc_ir})"
+	echo "    egress UC throughput  $(humanize ${uc_er})"
+	echo "    sent $attempts BC ARPs, got $passes responses"
 }
 
 trap cleanup EXIT