admin-guide/mm/hugetlbpage.rst

13 256M and ppc64 supports 4K and 16M.  A TLB is a cache of virtual-to-physical
93 Once a number of huge pages have been pre-allocated to the kernel huge page
169 indicates the current number of pre-allocated huge pages of the default size.
180 task that modifies ``nr_hugepages``. The default for the allowed nodes--when the
181 task has default memory policy--is all on-line nodes with memory.  Allowed
206 requested by applications.  Writing any non-zero value into this file
226 of the in-use huge pages to surplus huge pages.  This will occur even if
228 this condition holds--that is, until ``nr_hugepages+nr_overcommit_hugepages`` is
229 increased sufficiently, or the surplus huge pages go out of use and are freed--
232 With support for multiple huge page pools at run-time available, much of
243 	hugepages-${size}kB
280 demote_size) function as described above for the default huge page-sized case.
297     numactl --interleave <node-list> echo 20 \
302     numactl -m <node-list> echo 20 >/proc/sys/vm/nr_hugepages_mempolicy
304 This will allocate or free ``abs(20 - nr_hugepages)`` to or from the nodes
305 specified in <node-list>, depending on whether number of persistent huge pages
307 allocated nor freed on any node not included in the specified <node-list>.
310 memory policy mode--bind, preferred, local or interleave--may be used.  The
314    Documentation/admin-guide/mm/numa_memory_policy.rst],
316    specified in the mempolicy as if "interleave" had been specified.
324 #. One or more nodes may be specified with the bind or interleave policy.
334 #. The nodes allowed mask will be derived from any non-default task mempolicy,
337    shell with non-default policy, that policy will be used.  One can specify a
338    node list of "all" with numactl --interleave or --membind [-m] to achieve
341 #. Any task mempolicy specified--e.g., using numactl--will be constrained by
343    be no way for a task with non-default policy running in a cpuset with a
347 #. Boot-time huge page allocation attempts to distribute the requested number
348    of huge pages over all on-lines nodes with memory.
357 	/sys/devices/system/node/node[0-9]*/hugepages/
366 The free\_' and surplus\_' attribute files are read-only.  They return the number
379 The hugetlb may be migrated between the per-node hugepages pool in the following
384 hugetlb migration, that means these 3 cases can break the per-node hugepages pool.
395   mount -t hugetlbfs \
396 	-o uid=<value>,gid=<value>,mode=<value>,pagesize=<value>,size=<value>,\
471 ``hugepage-shm``
472 	see tools/testing/selftests/mm/hugepage-shm.c
474 ``hugepage-mmap``
475 	see tools/testing/selftests/mm/hugepage-mmap.c