vfsstat.bt(8)                                        System Manager's Manual                                        vfsstat.bt(8)

NAME
       vfsstat.bt - Count key VFS calls. Uses bpftrace/eBPF.

SYNOPSIS
       vfsstat.bt

DESCRIPTION
       This  traces  some common VFS calls and prints per-second summaries. This can be useful for general workload characteriza‐
       tion, and looking for patterns in operation usage over time.

       This works by tracing some kernel vfs functions using dynamic tracing, and will need updating  to  match  any  changes  to
       these  functions.  Edit  the  script to customize which functions are traced. Also see vfscount, which is more easily cus‐
       tomized to trace multiple functions.

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

REQUIREMENTS
       CONFIG_BPF and bpftrace.

EXAMPLES
       Count some VFS calls, printing per-second summaries until Ctrl-C is hit:
              # vfsstat.bt

FIELDS
       HH:MM:SS
              Each output summary is prefixed by the time of printing in "HH:MM:SS" format.

       1st    Kernel function name (in @[])

       2nd    Number of calls while tracing

OVERHEAD
       This traces various kernel vfs functions and maintains in-kernel counts, which are asynchronously  copied  to  user-space.
       While the rate of VFS operations can be very high (>1M/sec), this is a relatively efficient way to trace these events, and
       so the overhead is expected to be small for normal workloads.  Measure in a test environment.

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.

       This is a bpftrace version of the bcc tool of the same name. The bcc tool may provide more options and customizations.

              https://github.com/iovisor/bcc

OS
       Linux

STABILITY
       Unstable - in development.

AUTHOR
       Brendan Gregg

SEE ALSO
       vfscount.bt(8)

USER COMMANDS                                               2018-09-06                                              vfsstat.bt(8)