f68a086005
Add documentation for CPU load module. Signed-off-by: Krzysztof Chruściński <krzysztof.chruscinski@nordicsemi.no>
27 lines
972 B
ReStructuredText
27 lines
972 B
ReStructuredText
.. _cpu_load:
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CPU load
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########
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Module can be used to track how much time is spent in idle. It is using tracing hooks
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which are called before and after CPU goes to idle. Compared to :ref:`thread_analyzer`
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it is more accurate since it takes into account time spent in the interrupt context as well.
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Function :c:func:`cpu_load_get` is used to get the latest value. It is also used to reset
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the measurement. By default, module is using :c:func:`k_cycle_get_32` but in cases when higher
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precision is needed a :ref:`counter_api` device can be used.
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Load can also be reported periodically using a logging message. Period is configured using :kconfig:option:`CONFIG_CPU_LOAD_LOG_PERIODICALLY`.
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Using counter device
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********************
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In order to use :ref:`counter_api` device :kconfig:option:`CONFIG_CPU_LOAD_USE_COUNTER` must be
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enabled and chosen in devicetree must be set.
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.. code-block:: devicetree
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chosen {
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zephyr,cpu-load-counter = &counter_device;
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};
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