86c5cf18db
The goal of this sample application is to measure the performance loss when a user thread has to go through a system call compared to a supervisor thread that calls the function directly. Signed-off-by: Nicolas Royer <nroyer@baylibre.com>
33 lines
1,001 B
ReStructuredText
33 lines
1,001 B
ReStructuredText
.. _syscall_perf:
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Syscall performances
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====================
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The goal of this sample application is to measure the performance loss when a
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user thread has to go through a system call compared to a supervisor thread that
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calls the function directly.
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Overview
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********
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This application creates a supervisor and a user thread.
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Then both threads call k_current_get() which returns a reference to the
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current thread. The user thread has to go through a system call.
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Both threads are showing the number of core clock cycles and the number of
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instructions executed while calling k_current_get().
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Sample Output
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*************
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.. code-block:: console
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User thread: 18012 cycles 748 instructions
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Supervisor thread: 7 cycles 4 instructions
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User thread: 20136 cycles 748 instructions
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Supervisor thread: 7 cycles 4 instructions
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User thread: 18014 cycles 748 instructions
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Supervisor thread: 7 cycles 4 instructions
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