memhog.8

'\" t
.TH MEMHOG 8 "2003,2004" "SuSE Labs" "Linux Administrator's Manual"
.SH NAME
memhog \- Allocates memory with policy for testing
.SH SYNOPSIS
.B memhog 
[
.B \-r<NUM>
] [
.B size kmg
] [
.B policy nodeset
] [
.B \-f<filename>
]
.SH DESCRIPTION
.B 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.
.TS
tab(|);
l l.
-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)
.TE

Supported numa-policies:
.TP
.B 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.
.TP
.B membind 
Only  allocate  memory  from  nodes. Allocation will fail 
when there is not enough memory available on these nodes. Multiple 
nodes  may be specified.
.TP
.B 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.
.TP
.B default 
Memory will be allocated on the local node (the node the 
thread is running on)

.SH EXAMPLES
.TP
# 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
.TP
# Allocate a 1G region, interleave across nodes 0,1,2,3, repeat test 4 times
memhog -r4 1G --interleave 0-3
.TP
# Allocate a 1G region, (implicit) default policy, repeat test 8 times
memhog -r8 1G

.SH AUTHORS
Andi Kleen (ak@suse.de)

.SH LICENSE
GPL v2

.SH SEE ALSO
.I mmap(2), memset(3), numactl(8), numastat(8)