** Description changed:
- 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.
+ [Impact]
- 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.
+ * Kernel should have sensible default governor set to ondemand for the
+ generic & oem kernel flavours in Focal and Groovy+ for amd64.
- 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:
+ * ondemand.service must not be shipped by systemd package
- - performance
- - balanced performance
- - balanced power
- - power
+ * kvm, cloud-kernels should continue using performance governor.
- It defaults to balanced performance, I think, but I'm not sure.
+ * Users should be given control to rev-up to performance, or rev-down
+ to powersave using other tools, i.e. game-mode and/or similar CLI or GUI
+ tools (these are scheduled to be integrated on Ubuntu platform later).
- 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.
+ [Test Case]
- For a desktop/laptop, the expected behavior is the powersave governor
- with balanced_performance on AC and balanced_power on battery.
+ * Boot ubuntu generic, hwe, or oem kernel
- I don't know about servers or VMs, but the benchmark series seems to
- indicate it does not really matter much performance wise.
+ * Check that default governor is ondemand
- 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.
+ * Check that ondemand.service is not active
+
+ [Regression Potential]
+
+ * ondemand governor is the best kernel default as recently analyzed by
+ colin king, it gives a balance bootspeed and power, giving as responsive
+ machines whilst not wasting power. It is the best experience we can give
+ our users by default.
+
+ [Other Info]
+
+ * It is up to the user to elect/switch to powersave for maximum battery
life, or to the performance for maximum processing power (i.e. gaming /
computation).
** Summary changed:
- Please switch default kernel governor to ondemand, such that advanced
userspace utilities such as game-mode can be later used to rev-up to to
performance, or rev-down to powersave.
+ Please switch default, hwe, oem kernel flavours governor to
CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y , such that advanced userspace utilities
such as game-mode can be later used to rev-up to to performance, or rev-down to
powersave.
** Description changed:
[Impact]
- * Kernel should have sensible default governor set to ondemand for the
- generic & oem kernel flavours in Focal and Groovy+ for amd64.
+ * Kernel should have sensible default governor set to
+ CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y for the generic & oem kernel
+ flavours in Focal and Groovy+ for amd64.
- * ondemand.service must not be shipped by systemd package
+ * ondemand.service must not be shipped by systemd package
- * kvm, cloud-kernels should continue using performance governor.
+ * kvm, cloud-kernels should continue using performance governor.
- * Users should be given control to rev-up to performance, or rev-down
+ * Users should be given control to rev-up to performance, or rev-down
to powersave using other tools, i.e. game-mode and/or similar CLI or GUI
tools (these are scheduled to be integrated on Ubuntu platform later).
[Test Case]
- * Boot ubuntu generic, hwe, or oem kernel
+ * Boot ubuntu generic, hwe, or oem kernel
- * Check that default governor is ondemand
+ * Check that default governor is ondemand
- * Check that ondemand.service is not active
+ * Check that ondemand.service is not active
[Regression Potential]
- * ondemand governor is the best kernel default as recently analyzed by
+ * ondemand governor is the best kernel default as recently analyzed by
colin king, it gives a balance bootspeed and power, giving as responsive
machines whilst not wasting power. It is the best experience we can give
our users by default.
[Other Info]
-
- * It is up to the user to elect/switch to powersave for maximum battery
life, or to the performance for maximum processing power (i.e. gaming /
computation).
+
+ * It is up to the user to elect/switch to powersave for maximum battery
+ life, or to the performa
