slabtop - display kernel slab cache information in real time
Contents
Commands
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 SORTCRITERIA.
<SPACEBAR>
Refresh the screen.
Q Quit the program.
Description
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.
Files
/proc/slabinfo
slab information
Name
slabtop - display kernel slab cache information in real time
Notes
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.
The CACHESIZE column is not accurate, it's the upper limit of memory used by specific slab. When system
using slub (most common case) is under high memory pressure, there are slab order fallbacks, which means
"pages per slab" is not constant and may decrease.
Options
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. This cannot be combined with the -o option.
-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.
Reporting Bugs
Please send bug reports to procps@freelists.org
procps-ng 2021-03-11 SLABTOP(1)
See Also
free(1), ps(1), top(1), vmstat(8)
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.
characterdescriptionheader
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
Synopsis
slabtop [options]
