chore: better knowledge in the quest for power efficiency

.vscode/settings.json

@@ -41,7 +41,9 @@
         "configmap",
         "containerd",
         "cowsay",
+        "cpufreq",
         "cpulimit",
+        "cpupower",
         "cryptsetup",
         "csma",
         "datagram",
@@ -109,6 +111,7 @@
         "nvme",
         "ocsp",
         "odhcpd",
+        "ondemand",
         "openpgp",
         "opkg",
         "pacman",
@@ -122,6 +125,8 @@
         "portsnap",
         "posix",
         "poweroff",
+        "powersave",
+        "pstate",
         "pulumi",
         "pvresize",
         "radeon",
@@ -136,6 +141,7 @@
         "runtimes",
         "sata",
         "schedulable",
+        "schedutil",
         "scrollback",
         "setfacl",
         "setfattr",
@@ -168,7 +174,6 @@
         "xkcd",
         "zstd"
     ],
-
     "markdown.extension.toc.levels": "2..6",
     "markdown.extension.toc.orderedList": true
 }

knowledge base/check or set the cpu frequency or governor.md

@@ -0,0 +1,73 @@
+# Check or set the CPU frequency or governor
+
+1. [TL;DR](#tldr)
+1. [Further readings](#further-readings)
+1. [Sources](#sources)
+
+## TL;DR
+
+```sh
+# Check what governors are available.
+cat '/sys/devices/system/cpu/cpufreq/'*'/scaling_available_governors'
+
+# Get the current active governor.
+cat '/sys/devices/system/cpu/cpufreq/policy0/scaling_governor'
+cat '/sys/devices/system/cpu/cpufreq/'*'/scaling_governor'
+
+# List the active CPUs affected by the current governor.
+cat '/sys/devices/system/cpu/cpufreq/'*'/affected_cpus'
+
+# Enable new governors.
+echo 'schedutil' | sudo tee '/sys/devices/system/cpu/cpufreq/policy0/scaling_governor'
+echo 'powersave' | sudo tee '/sys/devices/system/cpu/cpufreq/policy1/scaling_governor'
+
+# Get the current frequency of CPUs.
+cat '/sys/devices/system/cpu/cpufreq/policy0/scaling_cur_freq'
+cat '/sys/devices/system/cpu/cpufreq/'*'/scaling_cur_freq'
+
+# Do not boost the CPU frequency for niced loads.
+# The governor must support it - check if the file exists.
+echo 1 | sudo tee '/sys/devices/system/cpu/cpufreq/ondemand/ignore_nice_load'
+
+# Disable (1) or enable (0) turbo boost for Intel CPUs.
+echo 1 | sudo tee '/sys/devices/system/cpu/intel_pstate/no_turbo'
+
+# Check what energy vs performance hint are available for CPUs.
+cat '/sys/devices/system/cpu/cpu0/cpufreq/energy_performance_available_preferences'
+
+# Get the current energy vs performance hint used by CPUs.
+cat '/sys/devices/system/cpu/cpu0/cpufreq/energy_performance_preference'
+cat '/sys/devices/system/cpu/cpu'*'/cpufreq/energy_performance_preference'
+
+# Set energy vs performance hints.
+echo 'balance_performance' | sudo tee '/sys/devices/system/cpu/cpu0/cpufreq/energy_performance_preference'
+echo 'power' | sudo tee '/sys/devices/system/cpu/cpu'*'/cpufreq/energy_performance_preference'
+```
+
+## Further readings
+
+- [`cpupower`][cpupower]
+- [Set the _ondemand_ CPU governor to not rise the frequencies for niced loads][set the ondemand cpu governor to not rise the frequencies for niced loads]
+
+## Sources
+
+All the references in the [further readings] section, plus the following:
+
+- [CPU performance scaling]
+- The [*intel_pstate* CPU performance scaling driver][intel_pstate cpu performance scaling driver]
+
+<!--
+  References
+  -->
+
+<!-- In-article sections -->
+[further readings]: #further-readings
+
+<!-- Knowledge base -->
+[cpupower]: cpupower.md
+[set the ondemand cpu governor to not rise the frequencies for niced loads]: set%20the%20ondemand%20cpu%20governor%20to%20not%20rise%20the%20frequencies%20for%20niced%20loads.md
+[tlp]: tlp.md
+
+<!-- Upstream -->
+[cpu performance scaling]: https://www.kernel.org/doc/html/latest/admin-guide/pm/cpufreq.html
+[intel_pstate cpu performance scaling driver]: https://www.kernel.org/doc/html/next/admin-guide/pm/intel_pstate.html

knowledge base/check or set the cpu frequency or governor.placeholder

@@ -1,17 +0,0 @@
-# Check or set the CPU frequency or governor
-
-```sh
-cat '/sys/devices/system/cpu/cpufreq/'*'/affected_cpus'
-cat '/sys/devices/system/cpu/cpufreq/'*'/scaling_available_governors'
-
-# Get the current active governor.
-cat '/sys/devices/system/cpu/cpufreq/policy0/scaling_governor'
-cat '/sys/devices/system/cpu/cpufreq/'*'/scaling_governor'
-
-# Enable a new governor.
-echo 'schedutil' | sudo tee '/sys/devices/system/cpu/cpufreq/policy0/scaling_governor'
-echo 'powersave' | sudo tee '/sys/devices/system/cpu/cpufreq/policy1/scaling_governor'
-
-# Do not boost the CPU frequency for nice loads.
-echo 1 | sudo tee '/sys/devices/system/cpu/cpufreq/ondemand/ignore_nice_load'
-```

knowledge base/cpupower.md

@@ -6,19 +6,29 @@ Default governor is _ondemand_ for older CPUs and kernels and _schedutil_ for ne
 
 ```sh
 # Install.
-sudo apt install 'linux-cpupower'
+apt install 'linux-cpupower'
-sudo dnf install 'kernel-tools'
+dnf install 'kernel-tools'
+zypper install 'cpupower'
 
 # List the available governors.
 cpupower frequency-info --governors
+cpupower -c "3-6" frequency-info --governors
+cpupower --cpu "0-$(( $(nproc) - 1 ))" frequency-info --governors
 
 # Get the current active governor.
 cpupower frequency-info --policy
+cpupower -c '4' frequency-info --policy
+cpupower --cpu '4,5' frequency-info --policy
 
-# Set a new governor until reboot.
+# Set new governors until reboot.
 sudo cpupower frequency-set -g 'performance'
-sudo cpupower frequency-set --governor 'powersave'
+sudo cpupower -c '1' frequency-set --governor 'powersave'
-sudo cpupower frequency-set --governor 'schedutil'
+sudo cpupower --cpu '2,4,7' frequency-set --governor 'schedutil'
+
+# Get the current frequency of CPUs.
+cpupower frequency-info -f
+cpupower -c '4-7' frequency-info -fm
+cpupower --cpu '2,5' frequency-info --freq --human
 ```
 
 ## Further readings

knowledge base/set the ondemand cpu governor to not rise the frequencies for niced loads.md

@@ -8,16 +8,16 @@
 ## TL;DR
 
 ```sh
-sudo cpupower frequency-set --governor ondemand
+sudo cpupower frequency-set --governor 'ondemand'
-echo 1 | sudo tee /sys/devices/system/cpu/cpufreq/ondemand/ignore_nice_load
+echo 1 | sudo tee '/sys/devices/system/cpu/cpufreq/ondemand/ignore_nice_load'
 
 # set this on boot
-echo "w /sys/devices/system/cpu/cpufreq/ondemand/ignore_nice_load - - - - 1" | sudo tee /etc/tmpfiles.d/ondemand-ignore-nice.conf
+echo "w /sys/devices/system/cpu/cpufreq/ondemand/ignore_nice_load - - - - 1" | sudo tee '/etc/tmpfiles.d/ondemand-ignore-nice.conf'
 ```
 
 ## Further readings
 
-- [Cpufreq]
+- [`cpupower`][cpupower]
 - [Laptop overheating and battery duration reduction]
 
 <!--

knowledge base/tlp.md

@@ -0,0 +1,88 @@
+# tlp
+
+1. [TL;DR](#tldr)
+1. [Further readings](#further-readings)
+1. [Sources](#sources)
+
+## TL;DR
+
+Manual mode: changes to the power source will be ignored until the next reboot, or until the `tlp start` command is issued to resume automatic mode.
+
+Changes through commands are valid until next reboot.
+
+```sh
+# Install it.
+zypper install 'tlp' 'tlp-rdw'
+
+# Start the service.
+sudo tlp start
+sudo systemctl start 'tlp.service'
+
+# Show information about the system.
+sudo tlp-stat
+
+# Show information about the CPU only.
+# Includes the active scaling driver and available governors.
+sudo tlp-stat -p
+sudo tlp-stat --processor -v
+
+# Show information about the battery only.
+sudo tlp-stat -b
+sudo tlp-stat --battery
+
+# Show the service's status.
+tlp-stat -s
+tlp-stat --system
+
+# Show the active configuration.
+tlp-stat -c
+tlp-stat --config
+
+# Show differences between the defaults and the user configuration.
+# From version 1.4.
+tlp-stat --cdiff
+
+# Apply profiles.
+# Doing this enters manual mode.
+sudo tlp bat
+sudo tlp ac
+
+# Change battery charge thresholds.
+sudo tlp setcharge '70' '90' 'BAT0'
+
+# Restore battery charge thresholds.
+sudo tlp setcharge
+
+# Check, enable, or disable automatic, event based actions on radio devices.
+# Leverages the Radio Device Wizard.
+tlp-rdw
+tlp-rdw enable
+tlp-rdw disable
+```
+
+## Further readings
+
+- [Documentation]
+- [`cpupower`][cpupower]
+
+## Sources
+
+All the references in the [further readings] section, plus the following:
+
+- [Battery care vendor specifics]
+
+<!--
+  References
+  -->
+
+<!-- In-article sections -->
+[further readings]: #further-readings
+
+<!-- Knowledge base -->
+[cpupower]: cpupower.md
+
+<!-- Upstream -->
+[battery care vendor specifics]: https://linrunner.de/tlp/settings/bc-vendors.html
+[documentation]: https://linrunner.de/tlp/index.html
+
+<!-- Others -->