add: ultramarine-system-configs

[korewaChino]

Adds a new system-configs package which contains all the major system tweaks, also moves the networking tweaks from ultramarine-release to this package.

The configs do the following:

• Compress systemd journal and limit size to 200M
• systemd-tmpfiles config to automatically clean up /tmp and /var/tmp
• logrotate config to rotate log files and compress them daily, with weekly backlog rotation
• Enable the tcp_bbr kernel module by Google and enable BBR congestion control as a sysctl knob
• Enables TCP Fast Open to reduce networking latency
• MTU Probing moved from ultramarine-release

[lleyton]

hm, looks good so far, but I'd love to see benchmarks/QA

additionally, we shouldn't land these for 40, but 41

also, maybe we should break this into both core and desktop defaults packages

[korewaChino]

hm, looks good so far, but I'd love to see benchmarks/QA

For BBR, this should be enough I think https://medium.com/google-cloud/tcp-bbr-magic-dust-for-network-performance-57a5f1ccf437, Hopefully BBRv2 or v3 has improved network quality in cases of flaky networking conditions though, According to APNIC BBRv1 may not be beneficial over the standard Cubic implementation when you have lots of packet loss in a flaky networking environment since BBR considers that congestion instead of just the network itself being lossy

Actually, for TFO I'm starting to reconsider it now that it allows for tracking users (since it uses cookies)...

More testing and data needed.

The FS cleanup configs should good to go though, I have moved them to the desktop subpackage specifically so we can simply just add them to the comps list and have the networking/core perf configs optional

[korewaChino]

Should I make subpackages by type of tweaks or should I go with a core and a desktop subpackage?

[korewaChino]

And for MTU probing, it has already been added since UM40, and this fixes some applications that transmit really big packets (i.e modded Minecraft clients/servers, Ubisoft Connect authentication). Fixes basically all Ubisoft Connect games, I tested with UNO specifically but should apply for other games that use it too.

[korewaChino]

Here's networking benchmark results for the sysctl flags

[korewaChino]

Going for BBR + Cake here since it's the most balanced one out of all of them, leads to slightly better QoS

Desktop apps are very noisy so it makes sense to keep less of them