Files
linux/tools/testing/selftests/net/busy_poll_test.sh
Joe Damato 347fcdc414 selftests: net: Add busy_poll_test
Add an epoll busy poll test using netdevsim.

This test is comprised of:
  - busy_poller (via busy_poller.c)
  - busy_poll_test.sh which loads netdevsim, sets up network namespaces,
    and runs busy_poller to receive data and socat to send data.

The selftest tests two different scenarios:
  - busy poll (the pre-existing version in the kernel)
  - busy poll with suspend enabled (what this series adds)

The data transmit is a 1MiB temporary file generated from /dev/urandom
and the test is considered passing if the md5sum of the input file to
socat matches the md5sum of the output file from busy_poller.

netdevsim was chosen instead of veth due to netdevsim's support for
netdev-genl.

For now, this test uses the functionality that netdevsim provides. In the
future, perhaps netdevsim can be extended to emulate device IRQs to more
thoroughly test all pre-existing kernel options (like defer_hard_irqs)
and suspend.

Signed-off-by: Joe Damato <jdamato@fastly.com>
Co-developed-by: Martin Karsten <mkarsten@uwaterloo.ca>
Signed-off-by: Martin Karsten <mkarsten@uwaterloo.ca>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20241109050245.191288-6-jdamato@fastly.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-11-11 18:45:06 -08:00

166 lines
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Executable File

#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
source net_helper.sh
NSIM_SV_ID=$((256 + RANDOM % 256))
NSIM_SV_SYS=/sys/bus/netdevsim/devices/netdevsim$NSIM_SV_ID
NSIM_CL_ID=$((512 + RANDOM % 256))
NSIM_CL_SYS=/sys/bus/netdevsim/devices/netdevsim$NSIM_CL_ID
NSIM_DEV_SYS_NEW=/sys/bus/netdevsim/new_device
NSIM_DEV_SYS_DEL=/sys/bus/netdevsim/del_device
NSIM_DEV_SYS_LINK=/sys/bus/netdevsim/link_device
NSIM_DEV_SYS_UNLINK=/sys/bus/netdevsim/unlink_device
SERVER_IP=192.168.1.1
CLIENT_IP=192.168.1.2
SERVER_PORT=48675
# busy poll config
MAX_EVENTS=8
BUSY_POLL_USECS=0
BUSY_POLL_BUDGET=16
PREFER_BUSY_POLL=1
# IRQ deferral config
NAPI_DEFER_HARD_IRQS=100
GRO_FLUSH_TIMEOUT=50000
SUSPEND_TIMEOUT=20000000
setup_ns()
{
set -e
ip netns add nssv
ip netns add nscl
NSIM_SV_NAME=$(find $NSIM_SV_SYS/net -maxdepth 1 -type d ! \
-path $NSIM_SV_SYS/net -exec basename {} \;)
NSIM_CL_NAME=$(find $NSIM_CL_SYS/net -maxdepth 1 -type d ! \
-path $NSIM_CL_SYS/net -exec basename {} \;)
# ensure the server has 1 queue
ethtool -L $NSIM_SV_NAME combined 1 2>/dev/null
ip link set $NSIM_SV_NAME netns nssv
ip link set $NSIM_CL_NAME netns nscl
ip netns exec nssv ip addr add "${SERVER_IP}/24" dev $NSIM_SV_NAME
ip netns exec nscl ip addr add "${CLIENT_IP}/24" dev $NSIM_CL_NAME
ip netns exec nssv ip link set dev $NSIM_SV_NAME up
ip netns exec nscl ip link set dev $NSIM_CL_NAME up
set +e
}
cleanup_ns()
{
ip netns del nscl
ip netns del nssv
}
test_busypoll()
{
suspend_value=${1:-0}
tmp_file=$(mktemp)
out_file=$(mktemp)
# fill a test file with random data
dd if=/dev/urandom of=${tmp_file} bs=1M count=1 2> /dev/null
timeout -k 1s 30s ip netns exec nssv ./busy_poller \
-p${SERVER_PORT} \
-b${SERVER_IP} \
-m${MAX_EVENTS} \
-u${BUSY_POLL_USECS} \
-P${PREFER_BUSY_POLL} \
-g${BUSY_POLL_BUDGET} \
-i${NSIM_SV_IFIDX} \
-s${suspend_value} \
-o${out_file}&
wait_local_port_listen nssv ${SERVER_PORT} tcp
ip netns exec nscl socat -u $tmp_file TCP:${SERVER_IP}:${SERVER_PORT}
wait
tmp_file_md5sum=$(md5sum $tmp_file | cut -f1 -d' ')
out_file_md5sum=$(md5sum $out_file | cut -f1 -d' ')
if [ "$tmp_file_md5sum" = "$out_file_md5sum" ]; then
res=0
else
echo "md5sum mismatch"
echo "input file md5sum: ${tmp_file_md5sum}";
echo "output file md5sum: ${out_file_md5sum}";
res=1
fi
rm $out_file $tmp_file
return $res
}
test_busypoll_with_suspend()
{
test_busypoll ${SUSPEND_TIMEOUT}
return $?
}
###
### Code start
###
modprobe netdevsim
# linking
echo $NSIM_SV_ID > $NSIM_DEV_SYS_NEW
echo $NSIM_CL_ID > $NSIM_DEV_SYS_NEW
udevadm settle
setup_ns
NSIM_SV_FD=$((256 + RANDOM % 256))
exec {NSIM_SV_FD}</var/run/netns/nssv
NSIM_SV_IFIDX=$(ip netns exec nssv cat /sys/class/net/$NSIM_SV_NAME/ifindex)
NSIM_CL_FD=$((256 + RANDOM % 256))
exec {NSIM_CL_FD}</var/run/netns/nscl
NSIM_CL_IFIDX=$(ip netns exec nscl cat /sys/class/net/$NSIM_CL_NAME/ifindex)
echo "$NSIM_SV_FD:$NSIM_SV_IFIDX $NSIM_CL_FD:$NSIM_CL_IFIDX" > \
$NSIM_DEV_SYS_LINK
if [ $? -ne 0 ]; then
echo "linking netdevsim1 with netdevsim2 should succeed"
cleanup_ns
exit 1
fi
test_busypoll
if [ $? -ne 0 ]; then
echo "test_busypoll failed"
cleanup_ns
exit 1
fi
test_busypoll_with_suspend
if [ $? -ne 0 ]; then
echo "test_busypoll_with_suspend failed"
cleanup_ns
exit 1
fi
echo "$NSIM_SV_FD:$NSIM_SV_IFIDX" > $NSIM_DEV_SYS_UNLINK
echo $NSIM_CL_ID > $NSIM_DEV_SYS_DEL
cleanup_ns
modprobe -r netdevsim
exit 0