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hugeadm

NAME

hugeadm - Configure the system huge page pools

SYNOPSIS

hugeadm [options]

DESCRIPTION

hugeadm displays and configures the systems huge page pools. The size of the pools is set as a minimum and maximum threshold. The minimum value is allocated up front by the kernel and guaranteed to remain as hugepages until the pool is shrunk. If a maximum is set, the system will dynamically allocate pages if applications request more hugepages than the minimum size of the pool. There is no guarantee that more pages than this minimum pool size can be allocated.

The following options create mounts hugetlbfs mount points.

--create-mounts

This creates mount points for each supported huge page size under /var/lib/hugetlbfs. After creation they are mounts and are owned by root:root with permissions set to 770. Each mount point is named pagesize-<size in bytes>.

--create-user-mounts=<user>

This creates mount points for each supported huge page size under /var/lib/hugetlbfs/user/<user>. Mount point naming is the same as --create-mounts. After creation they are mounted and are owned by <user>:root with permissions set to 700.

--create-group-mounts=<group>

This creates mount points for each supported huge page size under /var/lib/hugetlbfs/group/<group>. Mount point naming is the same as --create-mounts. After creation they are mounted and are owned by root:<group> with permissions set to 070.

--create-global-mounts

This creates mount points for each supported huge page size under /var/lib/hugetlbfs/global. Mount point naming is the same as --create-mounts. After creation they are mounted and are owned by root:root with permissions set to 1777.

The following options display information about the pools.

--pool-list

This displays the Minimum, Current and Maximum number of huge pages in the pool for each pagesize supported by the system. The "Minimum" value is the size of the static pool and there will always be at least this number of hugepages in use by the system, either by applications or kept by the kernel in a reserved pool. The "Current" value is the number of hugepages currently in use, either by applications or stored on the kernels free list. The "Maximum" value is the largest number of hugepages that can be in use at any given time.

--page-sizes

This displays every page size supported by the system and has a pool configured.

--page-sizes-all

This displays all page sizes supported by the system, even if no pool is available.

--list-all-mounts

This displays all active mount points for hugetlbfs.

The following options configure the pool.

--pool-pages-min=<size>:[+|-]<count>

This option sets or adjusts the Minimum number of hugepages in the pool for pagesize size. size may be specified in bytes or in kilobytes, megabytes, or gigabytes by appending K, M, or G respectively. The pool is set to count pages if + or - are not specified. If + or - are specified, then the size of the pool will adjust by that amount. Note that there is no guarantee that the system can allocate the hugepages requested for the Minimum pool. The size of the pools should be checked after executing this command to ensure they were successful.

--pool-pages-max=<size>:[+|-]<count>

This option sets or adjusts the Maximum number of hugepages. Note that while the Minimum number of pages are guaranteed to be available to applications, there is not guarantee that the system can allocate the pages on demand when the number of huge pages requested by applications is between the Minimum and Maximum pool sizes.

SEE ALSO

oprofile(1), pagesize(1), libhugetlbfs(7), hugectl(8),

AUTHORS

libhugetlbfs was written by various people on the libhugetlbfs-devel mailing list.