Drop ondemand init script

[Bryan Quigley]

Ondemand init script is not inherited from Debian, it's an Ubuntu specific change.

Some reasons to get rid of it:
On my wily cloud test, systemd blame's 669ms on ondemand on a cloud instance with no ability to change frequency..
In the init script we don't run this for android
Why don't we just always use whatever is that kernel's default?

There are a number of other reported problems with it:
https://launchpad.net/ubuntu/+source/sysvinit/+bugs?field.searchtext=ondemand

[Steve Langasek (vorlon)]

Please see my answer on bug #1497375.

[Bryan Quigley (bryanquigley)]

>which is to ensure that the desired governor is set for the running system.

This is the key part that I don't understand, why don't we just trust the kernel? If the kernel sets the wrong governor on certain hardware isn't that the bug that needs fixing? On one system without this script it defaults to ondemand, on another it goes to performance.. AFAICT our kernel config is set to performance - why not just set it to ondemand?

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Sergio Callegari (callegar)]

@Steve Langasek
A big issue is that the script makes quite arbitrary assumptions on the system, including the fact that there is an ondemand governor at all.

A large number of modern systems use the intel p-state driver that does not have an ondemand governor at all! On this systems, the fallback mechanism in the script causes the system to always run in powersave mode, so hindering system performance for no reason.

[Bryan Quigley (bryanquigley)]

>AFAICT our kernel config is set to performance - why not just set it to ondemand?

So from my understanding, the point of the ondemand script is really so we can have boot set to performance, and then switch later to something that saves more power. The goal is boot performance so If we survey machines and find that's it's harming or negligible to boot performance that makes a compelling argument against it - correct?

[Bryan Quigley (bryanquigley)]

It's been removed in Yakkety due to the merge from Debian. Thanks!

[Bryan Quigley (bryanquigley)]

and by merge I meant sync..

[Bryan Quigley (bryanquigley)]

And it actually got added as a systemd job.. so this is not actually fixed.

[Bryan Quigley (bryanquigley)]

This continues to cause breakage - https://bugs.launchpad.net/charm-sysconfig/+bug/1873028

I'm still looking for a modern justification for it to exist - considering AFAIK no other distro does this.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.