procps/slabtop.1

.\" slabtop.1 - manpage for the slabtop(1) utility, part of procps-ng
.\"
.\" Copyright (C) 2003 Chris Rivera
.\" Licensed under the terms of the GNU Library General Public License, v2
.TH SLABTOP 1 "13 Sep 2003" "Linux" "Linux User's Manual"
.SH NAME
slabtop \- display kernel slab cache information in real time

.SH SYNOPSIS
.B slabtop
.RI [ options ]

.SH DESCRIPTION
.B slabtop
displays detailed kernel slab cache information in real time.  It displays a
listing of the top caches sorted by one of the listed sort criteria.  It also
displays a statistics header filled with slab layer information.

.SH OPTIONS
Normal invocation of 
.B slabtop
does not require any options.  The behavior, however, can be fine-tuned by
specifying one or more of the following flags:
.TP
.B \-\-delay=\fIn\fR, \fB\-d \fIn
Refresh the display every
.I n
in seconds.  By default,
.B slabtop
refreshes the display every three seconds.  To exit the program, hit
.BR q.
.TP
.B \-\-sort=\fIS\fR, \fB\-s\fR \fIS
Sort by \fIS\fR, where \fIS\fR is one of the sort criteria.
.TP
.B \-\-once\fR, \fB\-o
Display the output once and then exit.
.TP
.B \-\-version\fR, \fB\-V
Display version information and exit.
.TP
.B \-\-help
Display usage information and exit.

.SH SORT CRITERIA
The following are valid sort criteria used to sort the individual slab caches
and thereby determine what are the "top" slab caches to display.  The default
sort criteria is to sort by the number of objects ("o").

The sort criteria can also be changed while slabtop is running by pressing
the associated character.
.TP
.BR a: 
sort by number of active objects
.TP
.BR b: 
sort by objects per slab
.TP
.BR c: 
sort by cache size
.TP
.BR l: 
sort by number of slabs
.TP
.BR v
sort by number of active slabs
.TP
.BR n: 
sort by name
.TP
.BR o: 
sort by number of objects
.TP
.BR p: 
sort by pages per slab
.TP
.BR s: 
sort by object size
.TP
.BR u: 
sort by cache utilization

.SH COMMANDS
.B slabtop
accepts keyboard commands from the user during use.  The following are
supported.  In the case of letters, both cases are accepted.

Each of the valid sort characters are also accepted, to change the sort
routine. See the section
.IR "SORT CRITERIA" .

.TP
.BR <SPACEBAR>
Refresh the screen.
.TP
.BR Q
Quit the program.

.SH FILES
.TP
.I /proc/slabinfo
slab information

.SH "SEE ALSO"
.BR free (1),
.BR ps (1),
.BR top (1),
.BR vmstat (8)

.SH NOTES
Currently,
.B slabtop
requires a 2.4 or later kernel (specifically, a version 1.1 or later
.IR /proc/slabinfo ).
Kernel 2.2 should be supported in the future.

The slabtop statistic header is tracking how many bytes of slabs are being used
and it not a measure of physical memory. The 'Slab' field in the /proc/meminfo
file is tracking information about used slab physical memory.

.SH AUTHORS
Written by Chris Rivera and Robert Love.

.B slabtop
was inspired by Martin Bligh's perl script,
.BR vmtop .
Please send bug reports to <procps@freelists.org>.