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.
77 lines
1.8 KiB
77 lines
1.8 KiB
.TH slabratetop 8 "2016-10-17" "USER COMMANDS"
|
|
.SH NAME
|
|
slabratetop \- Kernel SLAB/SLUB memory cache allocation rate top.
|
|
Uses Linux BPF/bcc.
|
|
.SH SYNOPSIS
|
|
.B slabratetop [\-h] [\-C] [\-r MAXROWS] [interval] [count]
|
|
.SH DESCRIPTION
|
|
This is top for the the rate of kernel SLAB/SLUB memory allocations.
|
|
It works by tracing kmem_cache_alloc() calls, a commonly used interface for
|
|
kernel memory allocation (SLAB or SLUB). It summarizes the rate and total bytes
|
|
allocated of these calls per interval: the activity. Compare this to
|
|
slabtop(1), which shows the current static volume of the caches.
|
|
|
|
This tool uses kernel dynamic tracing of the kmem_cache_alloc() function.
|
|
|
|
Since this uses BPF, only the root user can use this tool.
|
|
.SH REQUIREMENTS
|
|
CONFIG_BPF and bcc.
|
|
.SH OPTIONS
|
|
.TP
|
|
\-C
|
|
Don't clear the screen.
|
|
.TP
|
|
\-r MAXROWS
|
|
Maximum number of rows to print. Default is 20.
|
|
.TP
|
|
interval
|
|
Interval between updates, seconds.
|
|
.TP
|
|
count
|
|
Number of interval summaries.
|
|
.SH EXAMPLES
|
|
.TP
|
|
Summarize active kernel SLAB/SLUB calls (kmem_cache_alloc()), showing the top 20 caches every second:
|
|
#
|
|
.B slabratetop
|
|
.TP
|
|
Don't clear the screen, and top 8 rows only:
|
|
#
|
|
.B slabratetop -Cr 8
|
|
.TP
|
|
5 second summaries, 10 times only:
|
|
#
|
|
.B slabratetop 5 10
|
|
.SH FIELDS
|
|
.TP
|
|
loadavg:
|
|
The contents of /proc/loadavg
|
|
.TP
|
|
CACHE
|
|
Kernel cache name.
|
|
.TP
|
|
ALLOCS
|
|
Allocations (number of calls).
|
|
.TP
|
|
BYTES
|
|
Total bytes allocated.
|
|
.SH OVERHEAD
|
|
If kmem_cache_alloc() is called at a high rate (eg, >100k/second) the overhead
|
|
of this tool might begin to be measurable. The rate can be seen in the ALLOCS
|
|
column of the output.
|
|
.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
|
|
Brendan Gregg
|
|
.SH SEE ALSO
|
|
slabtop(1)
|