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Diffstat (limited to 'man2/set_mempolicy.2')
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diff --git a/man2/set_mempolicy.2 b/man2/set_mempolicy.2 deleted file mode 100644 index 58e3959..0000000 --- a/man2/set_mempolicy.2 +++ /dev/null @@ -1,325 +0,0 @@ -.\" SPDX-License-Identifier: Linux-man-pages-copyleft-var -.\" -.\" Copyright 2003,2004 Andi Kleen, SuSE Labs. -.\" and Copyright 2007 Lee Schermerhorn, Hewlett Packard -.\" -.\" 2006-02-03, mtk, substantial wording changes and other improvements -.\" 2007-08-27, Lee Schermerhorn <Lee.Schermerhorn@hp.com> -.\" more precise specification of behavior. -.\" -.TH set_mempolicy 2 2023-10-31 "Linux man-pages 6.7" -.SH NAME -set_mempolicy \- set default NUMA memory policy for a thread and its children -.SH LIBRARY -NUMA (Non-Uniform Memory Access) policy library -.RI ( libnuma ", " \-lnuma ) -.SH SYNOPSIS -.nf -.B "#include <numaif.h>" -.P -.BI "long set_mempolicy(int " mode ", const unsigned long *" nodemask , -.BI " unsigned long " maxnode ); -.fi -.SH DESCRIPTION -.BR set_mempolicy () -sets the NUMA memory policy of the calling thread, -which consists of a policy mode and zero or more nodes, -to the values specified by the -.IR mode , -.IR nodemask , -and -.I maxnode -arguments. -.P -A NUMA machine has different -memory controllers with different distances to specific CPUs. -The memory policy defines from which node memory is allocated for -the thread. -.P -This system call defines the default policy for the thread. -The thread policy governs allocation of pages in the process's -address space outside of memory ranges -controlled by a more specific policy set by -.BR mbind (2). -The thread default policy also controls allocation of any pages for -memory-mapped files mapped using the -.BR mmap (2) -call with the -.B MAP_PRIVATE -flag and that are only read (loaded) from by the thread -and of memory-mapped files mapped using the -.BR mmap (2) -call with the -.B MAP_SHARED -flag, regardless of the access type. -The policy is applied only when a new page is allocated -for the thread. -For anonymous memory this is when the page is first -touched by the thread. -.P -The -.I mode -argument must specify one of -.BR MPOL_DEFAULT , -.BR MPOL_BIND , -.BR MPOL_INTERLEAVE , -.BR MPOL_PREFERRED , -or -.B MPOL_LOCAL -(which are described in detail below). -All modes except -.B MPOL_DEFAULT -require the caller to specify the node or nodes to which the mode applies, -via the -.I nodemask -argument. -.P -The -.I mode -argument may also include an optional -.IR "mode flag" . -The supported -.I "mode flags" -are: -.TP -.BR MPOL_F_NUMA_BALANCING " (since Linux 5.12)" -.\" commit bda420b985054a3badafef23807c4b4fa38a3dff -When -.I mode -is -.BR MPOL_BIND , -enable the kernel NUMA balancing for the task if it is supported by the kernel. -If the flag isn't supported by the kernel, or is used with -.I mode -other than -.BR MPOL_BIND , -\-1 is returned and -.I errno -is set to -.BR EINVAL . -.TP -.BR MPOL_F_RELATIVE_NODES " (since Linux 2.6.26)" -A nonempty -.I nodemask -specifies node IDs that are relative to the -set of node IDs allowed by the process's current cpuset. -.TP -.BR MPOL_F_STATIC_NODES " (since Linux 2.6.26)" -A nonempty -.I nodemask -specifies physical node IDs. -Linux will not remap the -.I nodemask -when the process moves to a different cpuset context, -nor when the set of nodes allowed by the process's -current cpuset context changes. -.P -.I nodemask -points to a bit mask of node IDs that contains up to -.I maxnode -bits. -The bit mask size is rounded to the next multiple of -.IR "sizeof(unsigned long)" , -but the kernel will use bits only up to -.IR maxnode . -A NULL value of -.I nodemask -or a -.I maxnode -value of zero specifies the empty set of nodes. -If the value of -.I maxnode -is zero, -the -.I nodemask -argument is ignored. -.P -Where a -.I nodemask -is required, it must contain at least one node that is on-line, -allowed by the process's current cpuset context, -(unless the -.B MPOL_F_STATIC_NODES -mode flag is specified), -and contains memory. -If the -.B MPOL_F_STATIC_NODES -is set in -.I mode -and a required -.I nodemask -contains no nodes that are allowed by the process's current cpuset context, -the memory policy reverts to -.IR "local allocation" . -This effectively overrides the specified policy until the process's -cpuset context includes one or more of the nodes specified by -.IR nodemask . -.P -The -.I mode -argument must include one of the following values: -.TP -.B MPOL_DEFAULT -This mode specifies that any nondefault thread memory policy be removed, -so that the memory policy "falls back" to the system default policy. -The system default policy is "local allocation"\[em]that is, -allocate memory on the node of the CPU that triggered the allocation. -.I nodemask -must be specified as NULL. -If the "local node" contains no free memory, the system will -attempt to allocate memory from a "near by" node. -.TP -.B MPOL_BIND -This mode defines a strict policy that restricts memory allocation to the -nodes specified in -.IR nodemask . -If -.I nodemask -specifies more than one node, page allocations will come from -the node with the lowest numeric node ID first, until that node -contains no free memory. -Allocations will then come from the node with the next highest -node ID specified in -.I nodemask -and so forth, until none of the specified nodes contain free memory. -Pages will not be allocated from any node not specified in the -.IR nodemask . -.TP -.B MPOL_INTERLEAVE -This mode interleaves page allocations across the nodes specified in -.I nodemask -in numeric node ID order. -This optimizes for bandwidth instead of latency -by spreading out pages and memory accesses to those pages across -multiple nodes. -However, accesses to a single page will still be limited to -the memory bandwidth of a single node. -.\" NOTE: the following sentence doesn't make sense in the context -.\" of set_mempolicy() -- no memory area specified. -.\" To be effective the memory area should be fairly large, -.\" at least 1 MB or bigger. -.TP -.B MPOL_PREFERRED -This mode sets the preferred node for allocation. -The kernel will try to allocate pages from this node first -and fall back to "near by" nodes if the preferred node is low on free -memory. -If -.I nodemask -specifies more than one node ID, the first node in the -mask will be selected as the preferred node. -If the -.I nodemask -and -.I maxnode -arguments specify the empty set, then the policy -specifies "local allocation" -(like the system default policy discussed above). -.TP -.BR MPOL_LOCAL " (since Linux 3.8)" -.\" commit 479e2802d09f1e18a97262c4c6f8f17ae5884bd8 -.\" commit f2a07f40dbc603c15f8b06e6ec7f768af67b424f -This mode specifies "local allocation"; the memory is allocated on -the node of the CPU that triggered the allocation (the "local node"). -The -.I nodemask -and -.I maxnode -arguments must specify the empty set. -If the "local node" is low on free memory, -the kernel will try to allocate memory from other nodes. -The kernel will allocate memory from the "local node" -whenever memory for this node is available. -If the "local node" is not allowed by the process's current cpuset context, -the kernel will try to allocate memory from other nodes. -The kernel will allocate memory from the "local node" whenever -it becomes allowed by the process's current cpuset context. -.P -The thread memory policy is preserved across an -.BR execve (2), -and is inherited by child threads created using -.BR fork (2) -or -.BR clone (2). -.SH RETURN VALUE -On success, -.BR set_mempolicy () -returns 0; -on error, \-1 is returned and -.I errno -is set to indicate the error. -.SH ERRORS -.TP -.B EFAULT -Part of all of the memory range specified by -.I nodemask -and -.I maxnode -points outside your accessible address space. -.TP -.B EINVAL -.I mode -is invalid. -Or, -.I mode -is -.B MPOL_DEFAULT -and -.I nodemask -is nonempty, -or -.I mode -is -.B MPOL_BIND -or -.B MPOL_INTERLEAVE -and -.I nodemask -is empty. -Or, -.I maxnode -specifies more than a page worth of bits. -Or, -.I nodemask -specifies one or more node IDs that are -greater than the maximum supported node ID. -Or, none of the node IDs specified by -.I nodemask -are on-line and allowed by the process's current cpuset context, -or none of the specified nodes contain memory. -Or, the -.I mode -argument specified both -.B MPOL_F_STATIC_NODES -and -.BR MPOL_F_RELATIVE_NODES . -Or, the -.B MPOL_F_NUMA_BALANCING -isn't supported by the kernel, or is used with -.I mode -other than -.BR MPOL_BIND . -.TP -.B ENOMEM -Insufficient kernel memory was available. -.SH STANDARDS -Linux. -.SH HISTORY -Linux 2.6.7. -.SH NOTES -Memory policy is not remembered if the page is swapped out. -When such a page is paged back in, it will use the policy of -the thread or memory range that is in effect at the time the -page is allocated. -.P -For information on library support, see -.BR numa (7). -.SH SEE ALSO -.BR get_mempolicy (2), -.BR getcpu (2), -.BR mbind (2), -.BR mmap (2), -.BR numa (3), -.BR cpuset (7), -.BR numa (7), -.BR numactl (8) |