thermald - start Linux thermal daemon
is a Linux daemon used to prevent the overheating of platforms.
This daemon monitors temperature and applies compensation using available
By default, it monitors CPU temperature using available CPU digital temperature
sensors and maintains CPU temperature under control, before HW takes
aggressive correction action.
Thermal daemon looks for thermal sensors and thermal cooling drivers in the
Linux thermal sysfs (/sys/class/thermal) and builds a list of sensors and
cooling drivers. Each of the thermal sensors can optionally be binded to a
cooling drivers by the in kernel drivers. In this case the Linux kernel
thermal core can directly take actions based on the temperature trip points,
for each sensor and associated cooling device. For example a trip temperature
X in a sensor can be associates a cooling driver Y. So when the sensor
temperature = X, the cooling driver "Y" is activated.
Thermal daemon allows one to change this relationship or add new one via a
thermal configuration file (thermal-conf.xml). This file is automatically
created and used, if the platform has ACPI thermal relationship table. If not
this needs to be manually configured.
When there is a sensor, which has no associate cooling device, via configuration
file or thermal relationship table, then this sensor is tested for
relationship with CPU load dynamically up to maximum 3 times. If there is no
relationship, then it is added to a black list of unbinded sensors and not
Optionally thermal daemon can act as an exclusive thermal controller by using
thermal sysfs and acting as a user space governor. In this case kernel thermal
core is not active and decision is taken by thermal daemon only.
Dbus Interface: When started with dbus-enable option, dbus interface can be used
to control thermal temperature at which cooling action takes place. This
change is persistent. For example, to start CPU cooling at 80C, dbus-send
command can be used:
# dbus-send --system --dest=org.freedesktop.thermald /org/freedesktop/thermald
org.freedesktop.thermald.SetUserPassiveTemperature string:cpu uint32:80000
- -h, --help
- Show help options.
- Print thermald version and exit.
- Don't become a daemon: Default is daemon mode.
- log severity: info level and up.
- log severity: debug level and up: Max logging.
- Poll interval in seconds: Poll for zone temperature
changes. To disable polling, set to zero. Polling can only be disabled, if
available temperature sensors can notify temperature change
- Enable Dbus.
- Act as exclusive thermal controller. This will use
user-space governor for thermal sysfs and take over control.
- Ignore cpuid check for supported CPU models.
- Specify thermal-conf.xml path and ignore default