xfsdist.bt - Summarize XFS operation latency. Uses bpftrace/eBPF.

       Brendan Gregg

       This tool summarizes time (latency) spent in common XFS file operations: reads, writes, opens, and syncs,
       and  presents  it  as  a  power-of-2  histogram. It uses an in-kernel eBPF map to store the histogram for
       efficiency.

       Since this works by tracing the xfs_file_operations interface functions, it will need updating  to  match
       any changes to these functions.

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

       Trace XFS operation time, and print a summary on Ctrl-C:
              # xfsdist.bt

       0th    The operation name (shown in "@[...]") is printed before each I/O histogram.

       1st, 2nd
              This is a range of latency, in microseconds (shown in "[...)" set notation).

       3rd    A column showing the count of operations in this range.

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

       xfsdist.bt - Summarize XFS operation latency. Uses bpftrace/eBPF.

       Linux

       This  adds low-overhead instrumentation to these XFS operations, including reads and writes from the file
       system cache. Such reads and writes can be very frequent (depending on  the  workload;  eg,  1M/sec),  at
       which point the overhead of this tool may become noticeable.  Measure and quantify before use.

       CONFIG_BPF and bpftrace.

biolatency.bt(8)

USER COMMANDS                                      2018-09-08                                      xfsdist.bt(8)

       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.

       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

       Unstable - in development.

xfsdist.bt