slabtop(1) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | SORT CRITERIA | COMMANDS | FILES | SEE ALSO | NOTES | AUTHORS | REPORTING BUGS | COLOPHON

SLABTOP(1)                    User Commands                   SLABTOP(1)

NAME         top

       slabtop - display kernel slab cache information in real time

SYNOPSIS         top

       slabtop [options]

DESCRIPTION         top

       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         top

       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

       -V, --version
              Display version information and exit.

       -h, --help
              Display usage information and exit.

SORT CRITERIA         top

       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         top

       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         top

       /proc/slabinfo
              slab information

SEE ALSO         top

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

NOTES         top

       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         top

       Written by Chris Rivera and Robert Love.

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

REPORTING BUGS         top

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

COLOPHON         top

       This page is part of the procps-ng (/proc filesystem utilities)
       project.  Information about the project can be found at 
       ⟨https://gitlab.com/procps-ng/procps⟩.  If you have a bug report
       for this manual page, see
       ⟨https://gitlab.com/procps-ng/procps/blob/master/Documentation/bugs.md⟩.
       This page was obtained from the project's upstream Git repository
       ⟨https://gitlab.com/procps-ng/procps.git⟩ on 2023-12-22.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2023-10-16.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to
       man-pages@man7.org

procps-ng                      2023-10-11                     SLABTOP(1)

Pages that refer to this page: free(1)top(1)slabinfo(5)