26 lines
980 B
Plaintext
26 lines
980 B
Plaintext
Demonstrations of runqlen, the Linux BPF/bpftrace version.
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This tool samples the length of the CPU scheduler run queues, showing these
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sampled lengths as a histogram. This can be used to characterize demand for
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CPU resources. For example:
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# ./runqlen.bt
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Attaching 2 probes...
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Sampling run queue length at 99 Hertz... Hit Ctrl-C to end.
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^C
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@runqlen:
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[0, 1) 1967 |@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@|
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[1, 2) 0 | |
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[2, 3) 0 | |
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[3, 4) 306 |@@@@@@@@ |
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This output shows that the run queue length was usually zero, except for some
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samples where it was 3. This was caused by binding 4 CPU bound threads to a
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single CPUs.
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There is another version of this tool in bcc: https://github.com/iovisor/bcc
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The bcc version provides options to customize the output.
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