You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
53 lines
1.4 KiB
53 lines
1.4 KiB
.TH bitesize 8 "2016-02-05" "USER COMMANDS"
|
|
.SH NAME
|
|
bitesize \- Summarize block device I/O size as a histogram \- Linux eBPF/bcc.
|
|
.SH SYNOPSIS
|
|
.B bitesize
|
|
.SH DESCRIPTION
|
|
Show I/O distribution for requested block sizes, by process name.
|
|
|
|
This works by tracing block I/O kernel functions using dynamic
|
|
tracing and prints a historgram of I/O size.
|
|
|
|
Since this uses BPF, only the root user can use this tool.
|
|
.SH REQUIREMENTS
|
|
CONFIG_BPF and bcc.
|
|
.SH EXAMPLES
|
|
.TP
|
|
Count I/O size per process until Ctrl-C is hit:
|
|
#
|
|
.B bitesize
|
|
.SH FIELDS
|
|
.TP
|
|
Kbtes
|
|
Size in kilobytes of range
|
|
.TP
|
|
count
|
|
How many I/O fell into this range
|
|
.TP
|
|
distribution
|
|
An ASCII bar chart to visualize the distribution (count column)
|
|
|
|
.SH OVERHEAD
|
|
This traces kernel block I/O functions to update a histgroam, which are
|
|
asynchronously copied to user-space. This method is very efficient, and
|
|
the overhead for most storage I/O rates (< 10k IOPS) should be negligible.
|
|
If you have a higher IOPS storage environment, test and quantify the overhead
|
|
before use.
|
|
|
|
.SH SOURCE
|
|
This is from bcc.
|
|
.IP
|
|
https://github.com/iovisor/bcc
|
|
.PP
|
|
Also look in the bcc distribution for a companion _examples.txt file containing
|
|
example usage, output, and commentary for this tool.
|
|
.SH OS
|
|
Linux
|
|
.SH STABILITY
|
|
Unstable - in development.
|
|
.SH AUTHOR
|
|
Allan McAleavy
|
|
.SH SEE ALSO
|
|
https://github.com/brendangregg/systemtap-lwtools/blob/master/disk/bitesize-nd.stp
|