memhog - Man Page

Allocates memory with policy for testing


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


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
-HDisable transparent hugepages
-sizeAllocation size in bytes, may have case-insensitive order
suffix (G=gigabyte, M=megabyte, K=kilobyte)

Supported numa-policies:


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.


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


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.


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


# 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


Andi Kleen (


GPL v2

See Also

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


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