cpuwalk(8)

1cpuwalk(8)                  System Manager's Manual                 cpuwalk(8)
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NAME

6       cpuwalk.bt  -  Sample  which  CPUs  are executing processes.. Uses bpf‐
7       trace/eBPF.
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SYNOPSIS

10       cpuwalk.bt
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DESCRIPTION

13       This tool samples CPUs at 99 Hertz, then  prints  a  histogram  showing
14       which  CPUs  were  active.  99 Hertz is used to avoid lockstep sampling
15       that would skew results. This tool can help identify if  your  applica‐
16       tion's  workload  is evenly using the CPUs, or if there is an imbalance
17       problem.
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19       Since this uses BPF, only the root user can use this tool.
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REQUIREMENTS

22       CONFIG_BPF and bpftrace.
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EXAMPLES

25       Sample CPUs and print a summary on Ctrl-C:
26              # cpuwalk.bt
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FIELDS

29       1st, 2nd
30              The CPU is shown in the first field, after  the  "[".  Disregard
31              the second field.
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33       3rd    A column showing the number of samples for this CPU.
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35       4th    This is an ASCII histogram representing the count column.
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OVERHEAD

38       This should be negligible.
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SOURCE

41       This is from bpftrace.
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43              https://github.com/iovisor/bpftrace
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45       Also  look  in  the bpftrace distribution for a companion _examples.txt
46       file containing example usage, output, and commentary for this tool.
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OS

49       Linux
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STABILITY

52       Unstable - in development.
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AUTHOR

55       Brendan Gregg
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