CPU isolation for NIC: goal is to reduce/prevent packet loss

[Vrolijk]

work in progress:

isolate CPU cores
find your physical and virtual cores
lscpu --all --extended

Isolate the cores (numbers are all virtual cores bound to a physical)
sudo gedit /etc/default/grub
Find and modify : GRUB_CMDLINE_LINUX="isolcpus=1,3 nohz_full=1,3"
save and update Grub:
sudo update-grub

Assign IRQ to CPU. NOTE: need to be done after every reboot.
Find IRQ for enp1s0
grep enp1s0 /proc/interrupts

Bind IRQ to CPU core
echo 2 > /proc/irq/126/smp_affinity
more info about binding to CPU https://support.hpe.com/hpesc/public/docDisplay?docId=c01824714&docLocale=en_US

Stop and start the nic:

sudo ip link set enp1s0 down
sudo ip link set enp1s0 up

Monitor NIC: packetloss and memmory usage
watch -n0 tc -s qdisc show dev enp1s0
Monitor CPU and interupts > search for enp1s0
watch -n0 cat /proc/interrupts

Validate settings:
are the selected cores isolated:
cat /sys/devices/system/cpu/isolated
is the NIC bound to a specific core
cat /proc/irq/126/smp_affinity

research:

Do we need to stop the irqbalance service? stop when needed
sudo service irqbalance status
sudo service irqbalance stop

research values under cat /sys/class/net/enp1s0/queues/tx-0/