Another speed-up... NUMA Balancing

First, record what your current boot looks like:
sudo systemd-analyze critical-chain # Boot Chain Analysis

sudo echo 1 > /proc/sys/kernel/numa_balancing

In /etc/default/grub, enter:

Reboot, then:
sudo systemd-analyze critical-chain # Boot Chain Analysis

It shaved 3 seconds off my boot time to run level 5 (the desktop), and the desktop comes up quicker with less of a dark-screen lag between the console boot logging and the desktop. I'm now down to 19.621 seconds.

This is Non-Uniform Memory Access balancing... moving code to the node where it's got fastest access to a CPU. Each core of my CPU is a node and the memory is a node, it shuffles things about to get the shortest distance between core and code.

grep NUMA=y /boot/config-'uname -r'

The forum auto-formatting messes that up... don't use the single quote ('), use the slanted single quote (`).


lscpu | grep -i numa
NUMA node(s): 1
NUMA node0 CPU(s): 0-11

Where this really shines is if you've got several servers (such as IBM 3950s) connected together to act as a single server, or a multi-processor server. But even with a single processor (which can enumerate each core as a NUMA node), it helps.