Lines Matching +full:kernel +full:- +full:policy
11 the Linux kernel. This support is built on top of multiple page size support
15 256M and ppc64 supports 4K and 16M. A TLB is a cache of virtual-to-physical
21 Users can use the huge page support in Linux kernel by either using the mmap
24 First the Linux kernel needs to be built with the CONFIG_HUGETLBFS
30 persistent hugetlb pages in the kernel's huge page pool. It also displays
71 ``/sys/kernel/mm/hugepages`` (described below).
75 configured in the kernel.
78 pages in the kernel's huge page pool. "Persistent" huge pages will be
83 Pages that are used as huge pages are reserved inside the kernel and cannot
87 Once a number of huge pages have been pre-allocated to the kernel huge page
92 The administrator can allocate persistent huge pages on the kernel boot
150 indicates the current number of pre-allocated huge pages of the default size.
159 On a NUMA platform, the kernel will attempt to distribute the huge page pool
160 over all the set of allowed nodes specified by the NUMA memory policy of the
161 task that modifies ``nr_hugepages``. The default for the allowed nodes--when the
162 task has default memory policy--is all on-line nodes with memory. Allowed
166 of the interaction of task memory policy, cpusets and per node attributes
171 allocation attempt. If the kernel is unable to allocate huge pages from
177 init files. This will enable the kernel to allocate huge pages early in
187 requested by applications. Writing any non-zero value into this file
189 number of "surplus" huge pages from the kernel's normal page pool, when the
191 unused, they are freed back to the kernel's normal page pool.
200 smaller value. The kernel will attempt to balance the freeing of huge pages
201 across all nodes in the memory policy of the task modifying ``nr_hugepages``.
202 Any free huge pages on the selected nodes will be freed back to the kernel's
207 of the in-use huge pages to surplus huge pages. This will occur even if
209 this condition holds--that is, until ``nr_hugepages+nr_overcommit_hugepages`` is
210 increased sufficiently, or the surplus huge pages go out of use and are freed--
213 With support for multiple huge page pools at run-time available, much of
219 /sys/kernel/mm/hugepages
221 For each huge page size supported by the running kernel, a subdirectory
224 hugepages-${size}kB
235 which function as described above for the default huge page-sized case.
239 Interaction of Task Memory Policy with Huge Page Allocation/Freeing
245 NUMA memory policy of the task that modifies the ``nr_hugepages_mempolicy``
249 The recommended method to allocate or free huge pages to/from the kernel
252 numactl --interleave <node-list> echo 20 \
257 numactl -m <node-list> echo 20 >/proc/sys/vm/nr_hugepages_mempolicy
259 This will allocate or free ``abs(20 - nr_hugepages)`` to or from the nodes
260 specified in <node-list>, depending on whether number of persistent huge pages
262 allocated nor freed on any node not included in the specified <node-list>.
265 memory policy mode--bind, preferred, local or interleave--may be used. The
269 :ref:`Documentation/admin-guide/mm/numa_memory_policy.rst <numa_memory_policy>`],
272 However, if a node in the policy does not contain sufficient contiguous
277 the task's memory policy.
279 #. One or more nodes may be specified with the bind or interleave policy.
280 If more than one node is specified with the preferred policy, only the
281 lowest numeric id will be used. Local policy will select the node where
283 For local policy to be deterministic, the task must be bound to a cpu or
286 indeterminate. Thus, local policy is not very useful for this purpose.
289 #. The nodes allowed mask will be derived from any non-default task mempolicy,
290 whether this policy was set explicitly by the task itself or one of its
292 shell with non-default policy, that policy will be used. One can specify a
293 node list of "all" with numactl --interleave or --membind [-m] to achieve
296 #. Any task mempolicy specified--e.g., using numactl--will be constrained by
298 be no way for a task with non-default policy running in a cpuset with a
302 #. Boot-time huge page allocation attempts to distribute the requested number
303 of huge pages over all on-lines nodes with memory.
312 /sys/devices/system/node/node[0-9]*/hugepages/
321 The free\_' and surplus\_' attribute files are read-only. They return the number
343 mount -t hugetlbfs \
344 -o uid=<value>,gid=<value>,mode=<value>,pagesize=<value>,size=<value>,\
419 ``hugepage-shm``
420 see tools/testing/selftests/vm/hugepage-shm.c
422 ``hugepage-mmap``
423 see tools/testing/selftests/vm/hugepage-mmap.c