---
name: "slabtop"
section: "1"
platform: "linux"
package: "procps-ng"
version: "4.0.7-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/slabtop"
---

# slabtop(1)

display kernel slab cache information in real time

## NAME

slabtop - display kernel slab cache information in real time

## SYNOPSIS

**slabtop** \[*option* ...\]

## 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.

## 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.

- **--human**

  Show slab sizes automatically scaled to shortest three digit unit and display the units of print out.  Following units are used.

  ```
    B = bytes
    Ki = kibibyte
    Mi = mebibyte
    Gi = gibibyte
    Ti = tebibyte
    Pi = pebibyte
  ```

- If this flag is not used, the slab sizes will be shown in KiB.

  - **-V**, **--version**

  Display version information and exit.

- **-h**, **--help**

  Display usage information and exit.

## 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.

| | | |
| --- | --- | --- |
| **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 |

## 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 **SORT CRITERIA**.

- **\<SPACEBAR\>**

  Refresh the screen.

- **Q**

  Quit the program.

## FILES

- */proc/slabinfo*

  slab information

## SEE ALSO

[**free**(1)](/free/1.md), [**ps**(1)](/ps/1.md), [**top**(1)](/top/1.md), [**vmstat**(8)](/vmstat/8.md)

## 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 **CACHE SIZE** 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.

## AUTHORS

Written by Chris Rivera and Robert Love.

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

## REPORTING BUGS

Please send bug reports to ⟨procps@freelists.org⟩.