memhog(8) — Linux manual page

MEMHOG(8)              Linux Administrator's Manual             MEMHOG(8)

NAME         top

       memhog - Allocates memory with policy for testing

SYNOPSIS         top

       memhog [ -r<NUM> ] [ size kmg ] [ policy nodeset ] [ -f<filename>
       ]

DESCRIPTION         top

       memhog mmaps a memory region for a given size and sets the numa
       policy (if specified).  It then updates the memory region for the
       given number of iterations using memset.
       -r<num>    Repeat memset NUM times
       -f<file>   Open file for mmap backing
       -H         Disable transparent hugepages
       -size      Allocation size in bytes, may have case-insensitive order
                  suffix (G=gigabyte, M=megabyte, K=kilobyte)

       Supported numa-policies:

       interleave
              Memory will be allocated using round robin on nodes. When
              memory cannot be allocated on the current interleave,
              target fall back to other nodes.  Multiple nodes may be
              specified.

       membind
              Only  allocate  memory  from  nodes. Allocation will fail
              when there is not enough memory available on these nodes.
              Multiple nodes  may be specified.

       preferred
              Preferably allocate memory on node, but if memory cannot be
              allocated  there  fall  back  to other nodes.  This option
              takes only a single node number.

       default
              Memory will be allocated on the local node (the node the
              thread is running on)

EXAMPLES         top

       # Allocate a 1G region, mmap backed by memhog.mmap file, membind
       to node 0, repeat test 6 times
              memhog -r6 1G --membind 0 -fmemhog.mmap

       # Allocate a 1G region, interleave across nodes 0,1,2,3, repeat
       test 4 times
              memhog -r4 1G --interleave 0-3

       # Allocate a 1G region, (implicit) default policy, repeat test 8
       times
              memhog -r8 1G

AUTHORS         top

       Andi Kleen ([email protected])

LICENSE         top

       GPL v2

SEE ALSO         top

       mmap(2), memset(3), numactl(8), numastat(8)

COLOPHON         top

       This page is part of the numactl (NUMA commands) project.
       Information about the project can be found at 
       ⟨http://oss.sgi.com/projects/libnuma/⟩.  If you have a bug report
       for this manual page, send it to [email protected].  This
       page was obtained from the project's upstream Git repository
       ⟨https://github.com/numactl/numactl.git⟩ on 2025-08-11.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2025-08-04.)  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
       [email protected]

SuSE Labs                       2003,2004                       MEMHOG(8)

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