4f89e3ca35
The operation of perf tool can be checked using this sample. Signed-off-by: Mikhail Kushnerov <m.kushnerov@yadro.com>
70 lines
1.5 KiB
ReStructuredText
70 lines
1.5 KiB
ReStructuredText
.. zephyr:code-sample:: profiling-perf
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:name: Perf tool
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Send perf samples to the host with console support
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This application can be used to demonstrate :ref:`profiling-perf` work.
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Requirements
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************
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Perf tool so far implemente only for riscv and x86_64 architectures.
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Usage example
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*************
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Build an image with:
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.. zephyr-app-commands::
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:zephyr-app: samples/subsys/profiling/perf
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:board: qemu_riscv64
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:goals: build
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:compact:
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After the sample starts, enter shell command:
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.. code-block:: console
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uart:~$ perf record <period> <frequency>
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Wait for the completion message ``perf done!`` or ``perf buf override!``
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(if perf buffer size is smaller than required).
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Print made by perf samles in terminal by shell-command:
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.. code-block:: console
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uart:~$ perf printbuf
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Output exaple:
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.. code-block:: console
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Perf buf length 2046
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0000000000000004
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00000000001056b2
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0000000000108192
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000000000010052f
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0000000000000000
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....
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000000000010052f
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0000000000000000
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Copy gotten output in some file, for example *perf_buf*.
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Make graph.svg with :zephyr_file:`scripts/perf/stackcollapse.py` and
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`FlameGraph`_:
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.. _FlameGraph: https://github.com/brendangregg/FlameGraph/
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.. code-block:: shell
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python scripts/perf/stackcollapse.py perf_buf build/zephyr/zephyr.elf | <flamegraph_dir_path>/flamegraph.pl > graph.svg
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Graph example
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=============
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.. image:: images/graph_example.svg
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:align: center
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:alt: graph example
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