cpuwalk.bt(8)

NAME
cpuwalk.bt - Sample which CPUs are executing processes.. Uses bpftrace/eBPF.

SYNOPSIS
cpuwalk.bt

DESCRIPTION
This tool samples CPUs at 99 Hertz, then prints a histogram showing which CPUs were active. 99 Hertz is used to avoid lockstep sampling that would skew results. This tool can help identify if your application's workload is evenly using the CPUs, or if there is an imbalance problem.

Since this uses BPF, only the root user can use this tool.

REQUIREMENTS
CONFIG_BPF and bpftrace.

EXAMPLES

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

FIELDS

1st, 2nd
    The CPU is shown in the first field, after the "[". Disregard the second field.

3rd A column showing the number of samples for this CPU.

4th This is an ASCII histogram representing the count column.

OVERHEAD
This should be negligible.

SOURCE
This is from bpftrace.

    https://github.com/bpftrace/bpftrace

Also look in the bpftrace distribution for a companion _examples.txt file containing example usage, output, and commentary for this tool.

OS
Linux

STABILITY
Unstable - in development.

AUTHOR
Brendan Gregg

SEE ALSO
mpstat(1)