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/iovisor/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)