Manpages - slabtop.1

slabtop - display kernel slab cache information in real time

slabtop [/options/]

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.

Normal invocation of slabtop does not require any options. The behavior, however, can be fine-tuned by specifying one or more of the following flags:

-d, *–delay*=/N/

Refresh the display every n in seconds. By default, slabtop refreshes the display every three seconds. To exit the program, hit q.

-s, *–sort*=/S/

Sort by S, where S is one of the sort criteria.

-o, –once

Display the output once and then exit.

-V, –version

Display version information and exit.

-h, –help

Display usage information and exit.

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.

character	description	header
a	number of active objects	ACTIVE
b	objects per slab	OBJ/SLAB
c	cache size	CACHE SIZE
l	number of slabs	SLABS
v	number of active slabs	N/A
n	name	NAME
o	number of objects	OBJS
p	pages per slab	N/A
s	object size	OBJ SIZE
u	cache utilization	USE

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 SORT CRITERIA.

<SPACEBAR>

Refresh the screen.

Q

Quit the program.

/proc/slabinfo

slab information

*free*(1), *ps*(1), *top*(1), *vmstat*(8)

Currently, slabtop requires a 2.4 or later kernel (specifically, a version 1.1 or later /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 is not a measure of physical memory. The 'Slab' field in the /proc/meminfo file is tracking information about used slab physical memory.

Written by Chris Rivera and Robert Love.

slabtop was inspired by Martin Bligh's perl script, vmtop.

Please send bug reports to [email protected]