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. 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.
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]