qos_max_descriptors.sh

  1#!/bin/bash
  2# SPDX-License-Identifier: GPL-2.0
  3#
  4# This test sends many small packets (size is less than cell size) through the
  5# switch. A shaper is used in $swp2, so the traffic is limited there. Packets
  6# are queued till they will be sent.
  7#
  8# The idea is to verify that the switch can handle at least 85% of maximum
  9# supported descrpitors by hardware. Then, we verify that the driver configures
 10# firmware to allow infinite size of egress descriptor pool, and does not use a
 11# lower limitation. Increase the size of the relevant pools such that the pool's
 12# size does not limit the traffic.
 13
 14# +-----------------------+
 15# | H1                    |
 16# |   + $h1.111           |
 17# |   | 192.0.2.33/28     |
 18# |   |                   |
 19# |   + $h1               |
 20# +---|-------------------+
 21#     |
 22# +---|-----------------------------+
 23# |   + $swp1                       |
 24# |   | iPOOL1                      |
 25# |   |                             |
 26# | +-|------------------------+    |
 27# | | + $swp1.111              |    |
 28# | |                          |    |
 29# | | BR1                      |    |
 30# | |                          |    |
 31# | | + $swp2.111              |    |
 32# | +-|------------------------+    |
 33# |   |                             |
 34# |   + $swp2                       |
 35# |   | ePOOL6                      |
 36# |   | 1mbit                       |
 37# +---+-----------------------------+
 38#     |
 39# +---|-------------------+
 40# |   + $h2            H2 |
 41# |   |                   |
 42# |   + $h2.111           |
 43# |     192.0.2.34/28     |
 44# +-----------------------+
 45#
 46
 47ALL_TESTS="
 48	ping_ipv4
 49	max_descriptors
 50"
 51
 52lib_dir=$(dirname $0)/../../../net/forwarding
 53
 54NUM_NETIFS=4
 55source $lib_dir/lib.sh
 56source $lib_dir/devlink_lib.sh
 57source mlxsw_lib.sh
 58
 59MAX_POOL_SIZE=$(devlink_pool_size_get)
 60SHAPER_RATE=1mbit
 61
 62# The current TBF qdisc interface does not allow us to configure the shaper to
 63# flat zero. The ASIC shaper is guaranteed to work with a granularity of
 64# 200Mbps. On Spectrum-2, writing a value close to zero instead of zero works
 65# well, but the performance on Spectrum-1 is unpredictable. Thus, do not run the
 66# test on Spectrum-1.
 67mlxsw_only_on_spectrum 2+ || exit
 68
 69h1_create()
 70{
 71	adf_simple_if_init $h1
 72
 73	vlan_create $h1 111 v$h1 192.0.2.33/28
 74	defer vlan_destroy $h1 111
 75	ip link set dev $h1.111 type vlan egress-qos-map 0:1
 76}
 77
 78h2_create()
 79{
 80	adf_simple_if_init $h2
 81
 82	vlan_create $h2 111 v$h2 192.0.2.34/28
 83	defer vlan_destroy $h2 111
 84}
 85
 86switch_create()
 87{
 88	# pools
 89	# -----
 90	# devlink_pool_size_thtype_restore needs to be done first so that we can
 91	# reset the various limits to values that are only valid for the
 92	# original static / dynamic setting.
 93
 94	devlink_pool_size_thtype_save 1
 95	devlink_pool_size_thtype_set 1 dynamic $MAX_POOL_SIZE
 96	defer_prio devlink_pool_size_thtype_restore 1
 97
 98	devlink_pool_size_thtype_save 6
 99	devlink_pool_size_thtype_set 6 static $MAX_POOL_SIZE
100	defer_prio devlink_pool_size_thtype_restore 6
101
102	# $swp1
103	# -----
104
105	ip link set dev $swp1 up
106	defer ip link set dev $swp1 down
107
108	vlan_create $swp1 111
109	defer vlan_destroy $swp1 111
110	ip link set dev $swp1.111 type vlan ingress-qos-map 0:0 1:1
111
112	devlink_port_pool_th_save $swp1 1
113	devlink_port_pool_th_set $swp1 1 16
114	defer devlink_tc_bind_pool_th_restore $swp1 1 ingress
115
116	devlink_tc_bind_pool_th_save $swp1 1 ingress
117	devlink_tc_bind_pool_th_set $swp1 1 ingress 1 16
118	defer devlink_port_pool_th_restore $swp1 1
119
120	tc qdisc replace dev $swp1 root handle 1: \
121	   ets bands 8 strict 8 priomap 7 6
122	defer tc qdisc del dev $swp1 root
123
124	dcb buffer set dev $swp1 prio-buffer all:0 1:1
125	defer dcb buffer set dev $swp1 prio-buffer all:0
126
127	# $swp2
128	# -----
129
130	ip link set dev $swp2 up
131	defer ip link set dev $swp2 down
132
133	vlan_create $swp2 111
134	defer vlan_destroy $swp2 111
135	ip link set dev $swp2.111 type vlan egress-qos-map 0:0 1:1
136
137	devlink_port_pool_th_save $swp2 6
138	devlink_port_pool_th_set $swp2 6 $MAX_POOL_SIZE
139	defer devlink_tc_bind_pool_th_restore $swp2 1 egress
140
141	devlink_tc_bind_pool_th_save $swp2 1 egress
142	devlink_tc_bind_pool_th_set $swp2 1 egress 6 $MAX_POOL_SIZE
143	defer devlink_port_pool_th_restore $swp2 6
144
145	tc qdisc replace dev $swp2 root handle 1: tbf rate $SHAPER_RATE \
146		burst 128K limit 500M
147	defer tc qdisc del dev $swp2 root
148
149	tc qdisc replace dev $swp2 parent 1:1 handle 11: \
150		ets bands 8 strict 8 priomap 7 6
151	defer tc qdisc del dev $swp2 parent 1:1 handle 11:
152
153	# bridge
154	# ------
155
156	ip link add name br1 type bridge vlan_filtering 0
157	defer ip link del dev br1
158
159	ip link set dev $swp1.111 master br1
160	defer ip link set dev $swp1.111 nomaster
161
162	ip link set dev br1 up
163	defer ip link set dev br1 down
164
165	ip link set dev $swp2.111 master br1
166	defer ip link set dev $swp2.111 nomaster
167}
168
169setup_prepare()
170{
171	h1=${NETIFS[p1]}
172	swp1=${NETIFS[p2]}
173
174	swp2=${NETIFS[p3]}
175	h2=${NETIFS[p4]}
176
177	h2mac=$(mac_get $h2)
178
179	adf_vrf_prepare
180
181	h1_create
182	h2_create
183	switch_create
184}
185
186ping_ipv4()
187{
188	ping_test $h1 192.0.2.34 " h1->h2"
189}
190
191percentage_used()
192{
193	local num_packets=$1; shift
194	local max_packets=$1; shift
195
196	bc <<< "
197	    scale=2
198	    100 * $num_packets / $max_packets
199	"
200}
201
202max_descriptors()
203{
204	local cell_size=$(devlink_cell_size_get)
205	local exp_perc_used=85
206	local max_descriptors
207	local pktsize=30
208
209	RET=0
210
211	max_descriptors=$(mlxsw_max_descriptors_get) || exit 1
212
213	local d0=$(ethtool_stats_get $swp2 tc_no_buffer_discard_uc_tc_1)
214
215	log_info "Send many small packets, packet size = $pktsize bytes"
216	start_traffic_pktsize $pktsize $h1.111 192.0.2.33 192.0.2.34 $h2mac
217	defer stop_traffic $!
218
219	# Sleep to wait for congestion.
220	sleep 5
221
222	local d1=$(ethtool_stats_get $swp2 tc_no_buffer_discard_uc_tc_1)
223	((d1 == d0))
224	check_err $? "Drops seen on egress port: $d0 -> $d1 ($((d1 - d0)))"
225
226	# Check how many packets the switch can handle, the limitation is
227	# maximum descriptors.
228	local pkts_bytes=$(ethtool_stats_get $swp2 tc_transmit_queue_tc_1)
229	local pkts_num=$((pkts_bytes / cell_size))
230	local perc_used=$(percentage_used $pkts_num $max_descriptors)
231
232	check_err $(bc <<< "$perc_used < $exp_perc_used") \
233		"Expected > $exp_perc_used% of descriptors, handle $perc_used%"
234
235	log_test "Maximum descriptors usage. The percentage used is $perc_used%"
236}
237
238trap cleanup EXIT
239setup_prepare
240setup_wait
241tests_run
242
243exit $EXIT_STATUS