---
name: "xfsdist-bpfcc"
section: "8"
platform: "linux"
package: "bpfcc-tools"
version: "0.31.0+ds-7"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/xfsdist-bpfcc"
---

# xfsdist-bpfcc(8)

Summarize XFS operation latency. Uses Linux eBPF/bcc.

## NAME

xfsdist - Summarize XFS operation latency. Uses Linux eBPF/bcc.

## SYNOPSIS

**xfsdist \[-h\] \[-T\] \[-m\] \[-p PID\] \[interval\] \[count\]**

## DESCRIPTION

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.

## REQUIREMENTS

CONFIG\_BPF and bcc.

## OPTIONS

- \-h

  Print usage message.

- \-T

  Don't include timestamps on interval output.

- \-m

  Output in milliseconds.

- \-p PID

  Trace this PID only.

## EXAMPLES

- Trace XFS operation time, and print a summary on Ctrl-C:

  \# **xfsdist**

- Trace PID 181 only:

  \# **xfsdist -p 181**

- Print 1 second summaries, 10 times:

  \# **xfsdist 1 10**

- 1 second summaries, printed in milliseconds

  \# **xfsdist -m 1**

## FIELDS

- msecs

  Range of milliseconds for this bucket.

- usecs

  Range of microseconds for this bucket.

- count

  Number of operations in this time range.

- distribution

  ASCII representation of the distribution (the count column).

## OVERHEAD

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.

## SOURCE

This is from bcc.

-

  https://github.com/iovisor/bcc

Also look in the bcc 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

xfssnoop(8)