Provided by: bpfcc-tools_0.29.1+ds-1ubuntu7_all
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)