1 files changed, 79 insertions, 0 deletions
diff --git a/tools/testing/selftests/net/rps_default_mask.sh b/tools/testing/selftests/net/rps_default_mask.sh
new file mode 100755
index 000000000000..4287a8529890
--- /dev/null
+++ b/tools/testing/selftests/net/rps_default_mask.sh
@@ -0,0 +1,79 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+readonly ksft_skip=4
+readonly cpus=$(nproc)
+ret=0
+
+[ $cpus -gt 2 ] || exit $ksft_skip
+
+readonly INITIAL_RPS_DEFAULT_MASK=$(cat /proc/sys/net/core/rps_default_mask)
+readonly TAG="$(mktemp -u XXXXXX)"
+readonly VETH="veth${TAG}"
+readonly NETNS="ns-${TAG}"
+
+setup() {
+	ip netns add "${NETNS}"
+	ip -netns "${NETNS}" link set lo up
+}
+
+cleanup() {
+	echo $INITIAL_RPS_DEFAULT_MASK > /proc/sys/net/core/rps_default_mask
+	ip netns del $NETNS
+}
+
+chk_rps() {
+	local rps_mask expected_rps_mask=$4
+	local dev_name=$3
+	local netns=$2
+	local cmd="cat"
+	local msg=$1
+
+	[ -n "$netns" ] && cmd="ip netns exec $netns $cmd"
+
+	rps_mask=$($cmd /sys/class/net/$dev_name/queues/rx-0/rps_cpus)
+	printf "%-60s" "$msg"
+
+	# In case there is more than 32 CPUs we need to remove commas from masks
+	rps_mask=${rps_mask//,}
+	expected_rps_mask=${expected_rps_mask//,}
+	if [ $rps_mask -eq $expected_rps_mask ]; then
+		echo "[ ok ]"
+	else
+		echo "[fail] expected $expected_rps_mask found $rps_mask"
+		ret=1
+	fi
+}
+
+trap cleanup EXIT
+
+echo 0 > /proc/sys/net/core/rps_default_mask
+setup
+chk_rps "empty rps_default_mask" $NETNS lo 0
+cleanup
+
+echo 1 > /proc/sys/net/core/rps_default_mask
+setup
+chk_rps "changing rps_default_mask dont affect existing devices" "" lo $INITIAL_RPS_DEFAULT_MASK
+
+echo 3 > /proc/sys/net/core/rps_default_mask
+chk_rps "changing rps_default_mask dont affect existing netns" $NETNS lo 0
+
+ip link add name $VETH type veth peer netns $NETNS name $VETH
+ip link set dev $VETH up
+ip -n $NETNS link set dev $VETH up
+chk_rps "changing rps_default_mask affect newly created devices" "" $VETH 3
+chk_rps "changing rps_default_mask don't affect newly child netns[II]" $NETNS $VETH 0
+ip link del dev $VETH
+ip netns del $NETNS
+
+setup
+chk_rps "rps_default_mask is 0 by default in child netns" "$NETNS" lo 0
+
+ip netns exec $NETNS sysctl -qw net.core.rps_default_mask=1
+ip link add name $VETH type veth peer netns $NETNS name $VETH
+chk_rps "changing rps_default_mask in child ns don't affect the main one" "" lo $INITIAL_RPS_DEFAULT_MASK
+chk_rps "changing rps_default_mask in child ns affects new childns devices" $NETNS $VETH 1
+chk_rps "changing rps_default_mask in child ns don't affect existing devices" $NETNS lo 0
+
+exit $ret