The commit message removing ondemand.service has several bug references, too: https://git.launchpad.net/~ubuntu-core-dev/ubuntu/+source/systemd/commit/?id=65f46a7d14b335e5743350dbbc5b5ef1e72826f7
remove Ubuntu-specific ondemand.service New processors handle scaling/throttling in internal firmware (e.g. intel_pstate), and do not require OS config. Additionally, nobody else does this, not even Debian. And finally, this has caused problems for years, e.g.: https://bugs.launchpad.net/ubuntu/+source/sysvinit/+bug/1497375 https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1503773 https://bugs.launchpad.net/ubuntu/+source/sysvinit/+bug/1480320 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1579278 https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1806012 https://bugs.launchpad.net/charm-sysconfig/+bug/1873028 IMO the kernel is a better place for setting the default governor properly and can even set different governors in cloud-specific kernels. If the decision is to control the governor in user space in Ubuntu I'd prefer a solution shipped in an other package because systemd does too many things already. -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1885730 Title: Bring back ondemand.service or switch kernel default governor for pstate - pstate now defaults to performance governor Status in linux package in Ubuntu: Incomplete Status in systemd package in Ubuntu: New Bug description: In a recent merge from Debian we lost ondemand.service, meaning all CPUs now run in Turbo all the time when idle, which is clearly suboptimal. The discussion in bug 1806012 seems misleading, focusing on p-state vs other drivers, when in fact, the script actually set the default governor for the pstate driver on platforms that use pstate. Everything below only looks at systems that use pstate. pstate has two governors: performance and powerstate. performance runs CPU at maximum frequency constantly, and powersave can be configured using various energy profiles energy profiles: - performance - balanced performance - balanced power - power It defaults to balanced performance, I think, but I'm not sure. Whether performance governor is faster than powersave governor is not even clear. https://www.phoronix.com/scan.php?page=article&item=linux50-pstate- cpufreq&num=5 benchmarked them, but did not benchmark the individual energy profiles. For a desktop/laptop, the expected behavior is the powersave governor with balanced_performance on AC and balanced_power on battery. I don't know about servers or VMs, but the benchmark series seems to indicate it does not really matter much performance wise. I think most other distributions configure their kernels to use the powersave governor by default, whereas we configure it to use the performance governor and then switch it later in the boot to get the maximum performance during bootup. It's not clear to me that's actually useful. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1885730/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
