bcm4908: enable & setup packet steering

Without packet steering NAT masquarade speed on BCM4908 /jumps/ between
two speeds:
1. 826 Mb/s (±3 Mb/s)
2. 909 Mb/s (±8 Mb/s)
and it never reaches ~940 Mb/s.

Proper packet steering can improve it. Below are testing results for
running iperf TCP traffic from LAN to WAN. They were used to pick up
golden values.

┌──────────┬──────────┬───────────┐
│   eth0   │  br-lan  │   speed   │
│ rps_cpus │ rps_cpus │   [Mbps]  │
├──────────┼──────────┼───────────┤
│        0 │        0 │ 743 / 804 │
│        0 │        1 │ 738 / 821 │
│        0 │        2 │     ✓ 940 │
│        0 │        4 │     ✓ 938 │
│        0 │        8 │     ✓ 941 │
├──────────┼──────────┼───────────┤
│        1 │        0 │       829 │
│        1 │        1 │       829 │
│        1 │        2 │     ✓ 942 │
│        1 │        4 │     ✓ 941 │
│        1 │        8 │     ✓ 941 │
├──────────┼──────────┼───────────┤
│        2 │        0 │     ✓ 942 │
│        2 │        1 │       926 │
│        2 │        2 │     ✓ 942 │
│        2 │        4 │     ✓ 942 │
│        2 │        8 │     ✓ 941 │
├──────────┼──────────┼───────────┤
│        4 │        0 │     ✓ 941 │
│        4 │        1 │       925 │
│        4 │        2 │     ✓ 941 │
│        4 │        4 │     ✓ 941 │
│        4 │        8 │     ✓ 941 │
├──────────┼──────────┼───────────┤
│        8 │        0 │     ✓ 942 │
│        8 │        1 │       925 │
│        8 │        2 │     ✓ 941 │
│        8 │        4 │     ✓ 942 │
│        8 │        8 │     ✓ 942 │
└──────────┴──────────┴───────────┘

Ref: fcbd39689e ("bcm53xx: enable & setup packet steering")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
This commit is contained in:
Rafał Miłecki 2022-07-28 17:46:33 +02:00
parent a49212d762
commit 57cad53f4e
2 changed files with 49 additions and 0 deletions

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@ -0,0 +1,46 @@
#!/bin/sh /etc/rc.common
START=25
USE_PROCD=1
start_service() {
reload_service
}
service_triggers() {
procd_add_reload_trigger "network"
procd_add_reload_trigger "firewall"
procd_add_reload_interface_trigger "lan"
}
reload_service() {
local packet_steering="$(uci -q get network.@globals[0].packet_steering)"
local num_cpus="$(grep -c "^processor.*:" /proc/cpuinfo)"
local flow_offloading="$(uci -q get firewall.@defaults[0].flow_offloading)"
local flow_offloading_hw="$(uci -q get firewall.@defaults[0].flow_offloading_hw)"
local rps_eth0=0
local rps_br_lan=0
[ "$num_cpus" -le 1 ] && return
[ "$packet_steering" = 1 ] && {
if [ ${flow_offloading_hw:-0} -gt 0 ]; then
# HW offloading
# Not implemented
:
elif [ ${flow_offloading:-0} -gt 0 ]; then
# SW offloading
# BCM4908 always reaches ~940 Mb/s
:
else
# Default
case "$num_cpus" in
2) rps_eth0=2; rps_br_lan=2;;
4) rps_eth0=e; rps_br_lan=e;;
esac
fi
}
echo $rps_eth0 > /sys/class/net/eth0/queues/rx-0/rps_cpus
echo $rps_br_lan > /sys/class/net/br-lan/queues/rx-0/rps_cpus
}

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# SPDX-License-Identifier: GPL-2.0-only
uci set network.@globals[0].packet_steering="1"