NAME

       memhog - Allocates memory with policy for testing

SYNOPSIS

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

DESCRIPTION

       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

       # 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, iterleave 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

       Andi Kleen (ak@suse.de)

LICENSE

       GPL v2

SEE ALSO

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