Debugging Linux Kernel using ftrace Part14 - Measuring scheduling latency

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ftrace provides "wakeup" tracer to find the scheduling latency. This tracer only records the latency for the highest priority to get scheduled after it woken up.

Scheduling latency: Time from the wakeup event until the task actually gets the CPU and begins to run.


You can see from the above screenshot, i wrote a simple program which calls "sleep" to voluntarily leave the CPU from the 'wakeup' process and to give it to another process for us to find out the scheduling latency. It took '30us' for scheduling the next highest priority task.



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