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by Colin King
Import upstream version 0.3 |
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Introduction
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The purpose of idlestat is to measure how long we have been in the different |
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idle and operating states. |
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Idlestat uses kernel's FTRACE function to monitor and capture C-state and |
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P-state transitions of CPUs over a time interval. It extracts the following |
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information from trace file: |
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- Times when CPUs entered and exited a certain C-state
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- Times when CPUs entered and exited a certain P-state
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- Raised IRQs
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Following a successful run, idlestat calculates and reports the following |
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information: |
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- Total, average, minimum and maximum time spent in each C-state,
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per-CPU. |
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- Total, average, minimum and maximum time spent in each P-state,
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per-CPU. |
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- Total, average, minimum and maximum time during which all CPUs in
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a cluster were in the same C-state, per-cluster. |
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- Number of times a certain IRQ caused a CPU to exit idle state,
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per-CPU and per-IRQ |
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Requirements
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1. It must be run as root in order to access /sys/kernel/debug.
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2. It requires tracing to be enabled in the kernel
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Help
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----
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./idlestat -h will show all the options |
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Example Usage
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-------------
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Trace mode: |
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sudo ./idlestat --trace -f /tmp/myoutput -t 10 |
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Reporing mode (/tmp/mytrace already contains traces): |
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sudo ./idlestat --import -f /tmp/mytrace |