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tuned/doc/guide/modules/performance/ref_available-tuned-plug-ins.adoc
Jaroslav Škarvada 7efac3bcb3
doc: renamed tuned-documentation to guide
Signed-off-by: Jaroslav Škarvada <jskarvad@redhat.com>
2019-03-12 19:02:22 +01:00

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[id="available-tuned-plug-ins_{context}"]
= Available Tuned plug-ins
This section lists all monitoring and tuning plug-ins currently available in *Tuned*.
[discrete]
== Monitoring plug-ins
Currently, the following monitoring plug-ins are implemented:
`disk`::
Gets disk load (number of IO operations) per device and measurement interval.
`net`::
Gets network load (number of transferred packets) per network card and measurement interval.
`load`::
Gets CPU load per CPU and measurement interval.
[discrete]
== Tuning plug-ins
Currently, the following tuning plug-ins are implemented. Only some of these plug-ins implement dynamic tuning. Options supported by plug-ins are also listed:
`cpu`::
Sets the CPU governor to the value specified by the [option]`governor` option and dynamically changes the Power Management Quality of Service (PM QoS) CPU Direct Memory Access (DMA) latency according to the CPU load.
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If the CPU load is lower than the value specified by the [option]`load_threshold` option, the latency is set to the value specified by the [option]`latency_high` option, otherwise it is set to the value specified by [option]`latency_low`.
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You can also force the latency to a specific value and prevent it from dynamically changing further. To do so, set the [option]`force_latency` option to the required latency value.
`eeepc_she`::
Dynamically sets the front-side bus (FSB) speed according to the CPU load.
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This feature can be found on some netbooks and is also known as the ASUS Super Hybrid Engine (SHE).
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If the CPU load is lower or equal to the value specified by the [option]`load_threshold_powersave` option, the plug-in sets the FSB speed to the value specified by the [option]`she_powersave` option. If the CPU load is higher or equal to the value specified by the [option]`load_threshold_normal` option, it sets the FSB speed to the value specified by the [option]`she_normal` option.
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Static tuning is not supported and the plug-in is transparently disabled if *Tuned* does not detect the hardware support for this feature.
`net`::
Configures the Wake-on-LAN functionality to the values specified by the [option]`wake_on_lan` option. It uses the same syntax as the `ethtool` utility. It also dynamically changes the interface speed according to the interface utilization.
`sysctl`::
Sets various `sysctl` settings specified by the plug-in options.
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The syntax is ``[replaceable]__name__=[replaceable]__value__``, where [replaceable]_name_ is the same as the name provided by the `sysctl` utility.
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Use the `sysctl` plug-in if you need to change system settings that are not covered by other plug-ins available in *Tuned*. If the settings are covered by some specific plug-ins, prefer these plug-ins.
`usb`::
Sets autosuspend timeout of USB devices to the value specified by the [option]`autosuspend` parameter.
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The value `0` means that autosuspend is disabled.
`vm`::
Enables or disables transparent huge pages depending on the Boolean value of the [option]`transparent_hugepages` option.
`audio`::
Sets the autosuspend timeout for audio codecs to the value specified by the [option]`timeout` option.
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Currently, the `snd_hda_intel` and `snd_ac97_codec` codecs are supported. The value `0` means that the autosuspend is disabled. You can also enforce the controller reset by setting the Boolean option [option]`reset_controller` to `true`.
`disk`::
Sets the disk elevator to the value specified by the [option]`elevator` option.
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It also sets:
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--
* APM to the value specified by the [option]`apm` option
* Scheduler quantum to the value specified by the [option]`scheduler_quantum` option
* Disk spindown timeout to the value specified by the [option]`spindown` option
* Disk readahead to the value specified by the [option]`readahead` parameter
* The current disk readahead to a value multiplied by the constant specified by the [option]`readahead_multiply` option
--
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In addition, this plug-in dynamically changes the advanced power management and spindown timeout setting for the drive according to the current drive utilization. The dynamic tuning can be controlled by the Boolean option [option]`dynamic` and is enabled by default.
`scsi_host`::
Tunes options for SCSI hosts.
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It sets Aggressive Link Power Management (ALPM) to the value specified by the [option]`alpm` option.
`mounts`::
Enables or disables barriers for mounts according to the Boolean value of the [option]`disable_barriers` option.
`script`::
Can be used for the execution of an external script that is run when the profile is loaded or unloaded.
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The script is called by one argument which can be `start` or `stop`, depending on whether the script is called during the profile load or unload. The script file name can be specified by the `script` parameter.
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You need to correctly implement the stop action in your script and revert all settings that you changed during the start action. Otherwise, the roll-back step after changing your *Tuned* profile will not work.
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The `functions` Bash helper script is installed by default and enables you to import and use various functions defined in it.
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Note that this plug-in is provided mainly for backwards compatibility, and it is recommended that you use it as the last resort and prefer other plug-ins if they cover the required settings.
`sysfs`::
Sets various `sysfs` settings specified by the plug-in options.
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The syntax is ``[replaceable]__name__=[replaceable]__value__``, where [replaceable]_name_ is the `sysfs` path to use.
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Use this plugin in case you need to change some settings that are not covered by other plug-ins. Prefer specific plug-ins if they cover the required settings.
`video`::
Sets various powersave levels on video cards. Currently, only the Radeon cards are supported.
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The powersave level can be specified by using the [option]`radeon_powersave` option. Supported values are:
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--
* `default`
* `auto`
* `low`
* `mid`
* `high`
* `dynpm`
* `dpm-battery`
* `dpm-balanced`
* `dpm-perfomance`
--
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For details, see link:http://www.x.org/wiki/RadeonFeature#KMS_Power_Management_Options[www.x.org]. Note that this plug-in is experimental and the option might change in future releases.
`bootloader`::
Adds options to the kernel command line. This plug-in supports only the GRUB 2 boot loader.
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Customized non-standard location of the GRUB 2 configuration file can be specified by the [option]`grub2_cfg_file` option.
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The kernel options are added to the current GRUB configuration and its templates. The system needs to be rebooted for the kernel options to take effect.
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Switching to another profile or manually stopping the `tuned` service removes the additional options. If you shut down or reboot the system, the kernel options persist in the [filename]`grub.cfg` file.
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The kernel options can be specified by the following syntax:
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[subs=+quotes]
----
cmdline=[replaceable]_arg1_ [replaceable]_arg2_ ... [replaceable]_argN_
----
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--
.Modifying the kernel command line
====
For example, to add the [option]`quiet` kernel option to a *Tuned* profile, include the following lines in the [filename]`tuned.conf` file:
----
[bootloader]
cmdline=quiet
----
The following is an example of a custom profile that adds the [option]`isolcpus=2` option to the kernel command line:
----
[bootloader]
cmdline=isolcpus=2
----
====
--