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numa(3) [sunos man page]

NUMA(3) 						     Linux Programmer's Manual							   NUMA(3)

NAME
       numa - NUMA policy library

SYNOPSIS
       #include <numa.h>

       cc ... -lnuma

       int numa_available(void);

       int numa_max_possible_node(void);
       int numa_num_possible_nodes();

       int numa_max_node(void);
       int numa_num_configured_nodes();
       struct bitmask *numa_get_mems_allowed(void);

       int numa_num_configured_cpus(void);
       struct bitmask *numa_all_nodes_ptr;
       struct bitmask *numa_no_nodes_ptr;
       struct bitmask *numa_all_cpus_ptr;

       int numa_num_task_cpus();
       int numa_num_task_nodes();

       int numa_parse_bitmap(char *line , struct bitmask *mask);
       struct bitmask *numa_parse_nodestring(char *string);
       struct bitmask *numa_parse_cpustring(char *string);

       long numa_node_size(int node, long *freep);
       long long numa_node_size64(int node, long long *freep);

       int numa_preferred(void);
       void numa_set_preferred(int node);
       int numa_get_interleave_node(void);
       struct bitmask *numa_get_interleave_mask(void);
       void numa_set_interleave_mask(struct bitmask *nodemask);
       void numa_interleave_memory(void *start, size_t size, struct bitmask *nodemask);
       void numa_bind(struct bitmask *nodemask);
       void numa_set_localalloc(void);
       void numa_set_membind(struct bitmask *nodemask);
       struct bitmask *numa_get_membind(void);

       void *numa_alloc_onnode(size_t size, int node);
       void *numa_alloc_local(size_t size);
       void *numa_alloc_interleaved(size_t size);
       void *numa_alloc_interleaved_subset(size_t size,  struct bitmask *nodemask); void *numa_alloc(size_t size);
       void *numa_realloc(void *old_addr, size_t old_size, size_t new_size);
       void numa_free(void *start, size_t size);

       int numa_run_on_node(int node);
       int numa_run_on_node_mask(struct bitmask *nodemask);
       struct bitmask *numa_get_run_node_mask(void);

       void numa_tonode_memory(void *start, size_t size, int node);
       void numa_tonodemask_memory(void *start, size_t size, struct bitmask *nodemask);
       void numa_setlocal_memory(void *start, size_t size);
       void numa_police_memory(void *start, size_t size);
       void numa_set_bind_policy(int strict);
       void numa_set_strict(int strict);

       int numa_distance(int node1, int node2);

       int numa_sched_getaffinity(pid_t pid, struct bitmask *mask);
       int numa_sched_setaffinity(pid_t pid, struct bitmask *mask);
       int numa_node_to_cpus(int node, struct bitmask *mask);
       int numa_node_of_cpu(int cpu);

       struct bitmask *numa_allocate_cpumask();

       void numa_free_cpumask();
       struct bitmask *numa_allocate_nodemask();

       void numa_free_nodemask();
       struct bitmask *numa_bitmask_alloc(unsigned int n);
       struct bitmask *numa_bitmask_clearall(struct bitmask *bmp);
       struct bitmask *numa_bitmask_clearbit(struct bitmask *bmp, unsigned int n);
       int numa_bitmask_equal(const struct bitmask *bmp1, const struct bitmask *bmp2);
       void numa_bitmask_free(struct bitmask *bmp);
       int numa_bitmask_isbitset(const struct bitmask *bmp, unsigned int n);
       unsigned int numa_bitmask_nbytes(struct bitmask *bmp);
       struct bitmask *numa_bitmask_setall(struct bitmask *bmp);
       struct bitmask *numa_bitmask_setbit(struct bitmask *bmp, unsigned int n);
       void copy_bitmask_to_nodemask(struct bitmask *bmp, nodemask_t *nodemask)
       void copy_nodemask_to_bitmask(nodemask_t *nodemask, struct bitmask *bmp)
       void copy_bitmask_to_bitmask(struct bitmask *bmpfrom, struct bitmask *bmpto)
       unsigned int numa_bitmask_weight(const struct bitmask *bmp )

       int numa_move_pages(int pid, unsigned long count, void **pages, const int *nodes, int *status, int flags);
       int numa_migrate_pages(int pid, struct bitmask *fromnodes, struct bitmask *tonodes);

       void numa_error(char *where);

       extern int numa_exit_on_error;
       extern int numa_exit_on_warn;
       void numa_warn(int number, char *where, ...);

DESCRIPTION
       The  libnuma library offers a simple programming interface to the NUMA (Non Uniform Memory Access) policy supported by the Linux kernel. On
       a NUMA architecture some memory areas have different latency or bandwidth than others.

       Available policies are page interleaving (i.e., allocate in a round-robin fashion from all, or a subset, of the nodes on the system),  pre-
       ferred  node allocation (i.e., preferably allocate on a particular node), local allocation (i.e., allocate on the node on which the task is
       currently executing), or allocation only on specific nodes (i.e., allocate on some subset of the available nodes).  It is also possible	to
       bind tasks to specific nodes.

       Numa  memory  allocation  policy  may  be  specified  as  a per-task attribute, that is inherited by children tasks and processes, or as an
       attribute of a range of process virtual address space.  Numa memory policies specified for a range of virtual address space are	shared	by
       all  tasks  in the process.  Further more, memory policies specified for a range of a shared memory attached using shmat(2) or mmap(2) from
       shmfs/hugetlbfs are shared by all processes that attach to that region.	Memory policies for shared disk backed file mappings are currently
       ignored.

       The  default  memory  allocation  policy for tasks and all memory range is local allocation.  This assumes that no ancestor has installed a
       non-default policy.

       For setting a specific policy globally for all memory allocations in a process and its  children  it  is  easiest  to  start  it  with  the
       numactl(8) utility. For more finegrained policy inside an application this library can be used.

       All  numa  memory  allocation policy only takes effect when a page is actually faulted into the address space of a process by accessing it.
       The numa_alloc_* functions take care of this automatically.

       A node is defined as an area where all memory has the same speed as seen from a particular CPU.	A node can contain multiple CPUs.   Caches
       are ignored for this definition.

       Most  functions	in  this  library  are only concerned about numa nodes and their memory.  The exceptions to this are: numa_node_to_cpus(),
       numa_node_of_cpu(), numa_bind(), numa_run_on_node(), numa_run_on_node_mask() and numa_get_run_node_mask().  These functions deal  with  the
       CPUs associated with numa nodes.  See the descriptions below for more information.

       Some of these functions accept or return a pointer to struct bitmask.  A struct bitmask controls a bit map of arbitrary length containing a
       bit representation of nodes.  The predefined variable  numa_all_nodes_ptr  points  to  a  bit  mask  that  has  all  available  nodes  set;
       numa_no_nodes_ptr points to the empty set.

       Before  any  other calls in this library can be used numa_available() must be called. If it returns -1, all other functions in this library
       are undefined.

       numa_max_possible_node() returns the number of the highest possible node in a system.  In other words, the size of a kernel type nodemask_t
       (in bits) minus 1.  This number can be gotten by calling numa_num_possible_nodes() and subtracting 1.

       numa_num_possible_nodes()  returns  the size of kernel's node mask (kernel type nodemask_t).  In other words, large enough to represent the
       maximum number of nodes that the kernel can handle. This  will  match  the  kernel's  MAX_NUMNODES  value.   This  count  is  derived  from
       /proc/self/status, field Mems_allowed.

       numa_max_node()	returns  the  highest  node number available on the current system.  (See the node numbers in /sys/devices/system/node/ ).
       Also see numa_num_configured_nodes().

       numa_num_configured_nodes() returns the number of memory nodes in the system. This count includes any nodes that  are  currently  disabled.
       This count is derived from the node numbers in /sys/devices/system/node. (Depends on the kernel being configured with /sys (CONFIG_SYSFS)).

       numa_get_mems_allowed() returns the mask of nodes from which the process is allowed to allocate memory in it's current cpuset context.  Any
       nodes that are not included in the returned bitmask will be ignored in any of the following libnuma memory policy calls.

       numa_num_configured_cpus() returns the number of cpus in the system.  This count includes any cpus that are currently disabled. This  count
       is derived from the cpu numbers in /sys/devices/system/cpu. If the kernel is configured without /sys (CONFIG_SYSFS=n) then it falls back to
       using the number of online cpus.

       numa_all_nodes_ptr points to a bitmask that is allocated by the library with bits representing all nodes on  which  the	calling  task  may
       allocate  memory.   This set may be up to all nodes on the system, or up to the nodes in the current cpuset.  The bitmask is allocated by a
       call to numa_allocate_nodemask() using size numa_max_possible_node().  The set of nodes to record is derived from /proc/self/status,  field
       "Mems_allowed".	The user should not alter this bitmask.

       numa_no_nodes_ptr  points  to  a  bitmask  that	is  allocated  by  the library and left all zeroes.  The bitmask is allocated by a call to
       numa_allocate_nodemask() using size numa_max_possible_node().  The user should not alter this bitmask.

       numa_all_cpus_ptr points to a bitmask that is allocated by the library with bits representing all cpus on which the calling task  may  exe-
       cute.   This  set  may  be  up  to  all cpus on the system, or up to the cpus in the current cpuset.  The bitmask is allocated by a call to
       numa_allocate_cpumask() using size numa_num_possible_cpus().   The  set	of  cpus  to  record  is  derived  from  /proc/self/status,  field
       "Cpus_allowed".	The user should not alter this bitmask.

       numa_num_task_cpus()  returns  the  number  of  cpus  that  the	calling  task  is  allowed  to	use.   This  count is derived from the map
       /proc/self/status, field "Cpus_allowed". Also see the bitmask numa_all_cpus_ptr.

       numa_num_task_nodes() returns the number of nodes on which the calling task is allowed to allocate memory.  This count is derived from  the
       map /proc/self/status, field "Mems_allowed".  Also see the bitmask numa_all_nodes_ptr.

       numa_parse_bitmap()  parses line , which is a character string such as found in /sys/devices/system/node/nodeN/cpumap into a bitmask struc-
       ture.  The string contains the hexadecimal representation of a bit  map.   The  bitmask	may  be  allocated  with  numa_allocate_cpumask().
       Returns	 0  on	success.  Returns -1 on failure.  This function is probably of little use to a user application, but it is used by libnuma
       internally.

       numa_parse_nodestring() parses a character string list of nodes into a bit mask.  The bit mask is  allocated  by  numa_allocate_nodemask().
       The  string is a comma-separated list of node numbers or node ranges.  A leading ! can be used to indicate "not" this list (in other words,
       all nodes except this list), and a leading + can be used to indicate that the node numbers in the list are relative to the  task's  cpuset.
       The  string  can  be  "all"  to	specify  all  ( numa_num_task_nodes() ) nodes.	Node numbers are limited by the number in the system.  See
       numa_max_node() and numa_num_configured_nodes().
       Examples:  1-5,7,10   !4-5   +0-3
       If the string is of 0 length, bitmask numa_no_nodes_ptr is returned.  Returns 0 if the string is invalid.

       numa_parse_cpustring() parses a character string list of cpus into a bit mask.  The bit mask is allocated by numa_allocate_cpumask().   The
       string  is  a  comma-separated list of cpu numbers or cpu ranges.  A leading ! can be used to indicate "not" this list (in other words, all
       cpus except this list), and a leading + can be used to indicate that the cpu numbers in the list are relative to the  task's  cpuset.   The
       string  can  be	"all"  to  specify  all  (  numa_num_task_cpus()  )  cpus.   Cpu  numbers  are	limited  by the number in the system.  See
       numa_num_task_cpus() and numa_num_configured_cpus().
       Examples:  1-5,7,10   !4-5   +0-3
       Returns 0 if the string is invalid.

       numa_node_size() returns the memory size of a node. If the argument freep is not NULL, it used to return the amount of free memory  on  the
       node.  On error it returns -1.

       numa_node_size64() works the same as numa_node_size() except that it returns values as long long instead of long.  This is useful on 32-bit
       architectures with large nodes.

       numa_preferred() returns the preferred node of the current task.  This is the node on which the kernel preferably allocates memory,  unless
       some other policy overrides this.

       numa_set_preferred()  sets  the preferred node for the current task to node.  The system will attempt to allocate memory from the preferred
       node, but will fall back to other nodes if no memory is available on the the preferred node.  Passing a node of -1 argument specifies local
       allocation and is equivalent to calling numa_set_localalloc().

       numa_get_interleave_mask() returns the current interleave mask if the task's memory allocation policy is page interleaved.  Otherwise, this
       function returns an empty mask.

       numa_set_interleave_mask() sets the memory interleave mask for the current task to nodemask.  All new memory allocations  are  page  inter-
       leaved  over  all  nodes  in  the interleave mask. Interleaving can be turned off again by passing an empty mask (numa_no_nodes).  The page
       interleaving only occurs on the actual page fault that puts a new page into the current address space. It is also only a hint:  the  kernel
       will fall back to other nodes if no memory is available on the interleave target.

       numa_interleave_memory()  interleaves  size bytes of memory page by page from start on nodes specified in nodemask.  The size argument will
       be rounded up to a multiple of the system page size.  If nodemask contains nodes that are externally denied to this process, this call will
       fail.   This  is a lower level function to interleave allocated but not yet faulted in memory. Not yet faulted in means the memory is allo-
       cated using mmap(2) or shmat(2), but has not been accessed by the current process yet. The memory is page interleaved to all  nodes  speci-
       fied  in  nodemask.   Normally  numa_alloc_interleaved()  should  be used for private memory instead, but this function is useful to handle
       shared memory areas. To be useful the memory area should be several megabytes at least (or tens of megabytes of hugetlbfs mappings) If  the
       numa_set_strict() flag is true then the operation will cause a numa_error if there were already pages in the mapping that do not follow the
       policy.

       numa_bind() binds the current task and its children to the nodes specified in nodemask.	They will only run on the CPUs	of  the  specified
       nodes  and  only  be able to allocate memory from them.	This function is equivalent to calling numa_run_on_node_mask(nodemask) followed by
       numa_set_membind(nodemask).  If tasks  should  be  bound  to  individual  CPUs  inside  nodes  consider	using  numa_node_to_cpus  and  the
       sched_setaffinity(2) syscall.

       numa_set_localalloc()  sets  the  memory  allocation policy for the calling task to local allocation.  In this mode, the preferred node for
       memory allocation is effectively the node where the task is executing at the time of a page allocation.

       numa_set_membind() sets the memory allocation mask.  The task will only allocate memory from the nodes set in nodemask.	Passing  an  empty
       nodemask or a nodemask that contains nodes other than those in the mask returned by numa_get_mems_allowed() will result in an error.

       numa_get_membind()  returns  the  mask  of  nodes  from	which  memory  can  currently  be  allocated.	If  the  returned mask is equal to
       numa_all_nodes, then memory allocation is allowed from all nodes.

       numa_alloc_onnode() allocates memory on a specific node.  The size argument will be rounded up to a multiple of the system page	size.	if
       the  specified node is externally denied to this process, this call will fail.  This function is relatively slow compared to the malloc(3),
       family of functions.  The memory must be freed with numa_free().  On errors NULL is returned.

       numa_alloc_local() allocates size bytes of memory on the local node.  The size argument will be rounded up to a multiple of the system page
       size.   This  function  is  relatively  slow compared to the malloc(3) family of functions.  The memory must be freed with numa_free().	On
       errors NULL is returned.

       numa_alloc_interleaved() allocates size bytes of memory page interleaved on all nodes. This function is relatively slow and should only	be
       used  for  large  areas	consisting  of	multiple pages. The interleaving works at page level and will only show an effect when the area is
       large.  The allocated memory must be freed with numa_free().  On error, NULL is returned.

       numa_alloc_interleaved_subset() attempts to allocate size bytes of memory page interleaved on all nodes.  The size argument will be rounded
       up  to  a  multiple of the system page size.  The nodes on which a process is allowed to allocate memory may be constrained externally.	If
       this is the case, this function may fail.  This function is relatively slow compare to malloc(3), family of functions and  should  only	be
       used  for  large  areas	consisting  of multiple pages.	The interleaving works at page level and will only show an effect when the area is
       large.  The allocated memory must be freed with numa_free().  On error, NULL is returned.

       numa_alloc() allocates size bytes of memory with the current NUMA policy.  The size argument will be rounded up to a multiple of the system
       page  size.  This function is relatively slow compare to the malloc(3) family of functions.  The memory must be freed with numa_free().	On
       errors NULL is returned.

       numa_realloc() changes the size of the memory area pointed to by old_addr from old_size	to  new_size.	The  memory  area  pointed  to	by
       old_addr  must have been allocated with one of the numa_alloc* functions.  The new_size will be rounded up to a multiple of the system page
       size. The contents of the memory area will be unchanged to the minimum of the old and new sizes; newly allocated memory will be	uninitial-
       ized. The memory policy (and node bindings) associated with the original memory area will be preserved in the resized area. For example, if
       the initial area was allocated with a call to numa_alloc_onnode(), then the new pages (if the area is enlarged) will be	allocated  on  the
       same  node.   However,  if  no memory policy was set for the original area, then numa_realloc() cannot guarantee that the new pages will be
       allocated on the same node. On success, the address of the resized area is returned (which might be different  from  that  of  the  initial
       area), otherwise NULL is returned and errno is set to indicate the error. The pointer returned by numa_realloc() is suitable for passing to
       numa_free().

       numa_free() frees size bytes of memory starting at start, allocated by the numa_alloc_* functions above.  The size argument will be rounded
       up to a multiple of the system page size.

       numa_run_on_node()  runs  the current task and its children on a specific node. They will not migrate to CPUs of other nodes until the node
       affinity is reset with a new call to numa_run_on_node_mask().  Passing -1 permits the kernel to schedule on all nodes again.  On success, 0
       is returned; on error -1 is returned, and errno is set to indicate the error.

       numa_run_on_node_mask() runs the current task and its children only on nodes specified in nodemask.  They will not migrate to CPUs of other
       nodes until the node affinity is reset with a new call to numa_run_on_node_mask() or numa_run_on_node().   Passing  numa_all_nodes  permits
       the kernel to schedule on all nodes again.  On success, 0 is returned; on error -1 is returned, and errno is set to indicate the error.

       numa_get_run_node_mask() returns a mask of CPUs on which the current task is allowed to run.

       numa_tonode_memory() put memory on a specific node. The constraints described for numa_interleave_memory() apply here too.

       numa_tonodemask_memory() put memory on a specific set of nodes. The constraints described for numa_interleave_memory() apply here too.

       numa_setlocal_memory() locates memory on the current node. The constraints described for numa_interleave_memory() apply here too.

       numa_police_memory() locates memory with the current NUMA policy. The constraints described for numa_interleave_memory() apply here too.

       numa_distance()	reports  the  distance in the machine topology between two nodes.  The factors are a multiple of 10. It returns 0 when the
       distance cannot be determined. A node has distance 10 to itself.  Reporting the distance requires a  Linux  kernel  version  of	2.6.10	or
       newer.

       numa_set_bind_policy() specifies whether calls that bind memory to a specific node should use the preferred policy or a strict policy.  The
       preferred policy allows the kernel to allocate memory on other nodes when there isn't enough free on the target node. strict will fail  the
       allocation  in  that  case.  Setting the argument to specifies strict, 0 preferred.  Note that specifying more than one node non strict may
       only use the first node in some kernel versions.

       numa_set_strict() sets a flag that says whether the functions allocating on specific nodes should use use a strict policy. Strict means the
       allocation will fail if the memory cannot be allocated on the target node.  Default operation is to fall back to other nodes.  This doesn't
       apply to interleave and default.

       numa_get_interleave_node() is used by libnuma internally. It is probably not useful for user applications.  It uses the MPOL_F_NODE flag of
       the  get_mempolicy system call, which is not intended for application use (its operation may change or be removed altogether in future ker-
       nel versions). See get_mempolicy(2).

       numa_pagesize() returns the number of bytes in page. This function is simply a fast alternative to repeated calls to the getpagesize system
       call.  See getpagesize(2).

       numa_sched_getaffinity()  retrieves a bitmask of the cpus on which a task may run.  The task is specified by pid.  Returns the return value
       of the sched_getaffinity system call.  See sched_getaffinity(2).  The bitmask must be at least the size of the kernel's cpu mask structure.
       Use numa_allocate_cpumask() to allocate it.  Test the bits in the mask by calling numa_bitmask_isbitset().

       numa_sched_setaffinity()  sets  a task's allowed cpu's to those cpu's specified in mask.  The task is specified by pid.	Returns the return
       value of the sched_setaffinity system call.  See sched_setaffinity(2).  You may allocate the bitmask with numa_allocate_cpumask().  Or  the
       bitmask	may  be  smaller  than the kernel's cpu mask structure. For example, call numa_bitmask_alloc() using a maximum number of cpus from
       numa_num_configured_cpus().  Set the bits in the mask by calling numa_bitmask_setbit().

       numa_node_to_cpus() converts a node number to a bitmask of CPUs. The user must pass a bitmask structure with a mask buffer long	enough	to
       represent all possible cpu's.  Use numa_allocate_cpumask() to create it.  If the bitmask is not long enough errno will be set to ERANGE and
       -1 returned. On success 0 is returned.

       numa_node_of_cpu() returns the node that a cpu belongs to. If the user supplies an invalid cpu errno will be set to EINVAL and -1  will	be
       returned.

       numa_allocate_cpumask  () returns a bitmask of a size equal to the kernel's cpu mask (kernel type cpumask_t).  In other words, large enough
       to represent NR_CPUS cpus.  This number of cpus can be gotten by calling numa_num_possible_cpus().  The bitmask is zero-filled.

       numa_free_cpumask frees a cpumask previously allocate by numa_allocate_cpumask.

       numa_allocate_nodemask() returns a bitmask of a size equal to the kernel's node mask (kernel  type  nodemask_t).   In  other  words,  large
       enough  to  represent  MAX_NUMNODES  nodes.  This number of nodes can be gotten by calling numa_num_possible_nodes().  The bitmask is zero-
       filled.

       numa_free_nodemask() frees a nodemask previous allocated by numa_allocate_nodemask().

       numa_bitmask_alloc() allocates a bitmask structure and its associated bit mask.	The memory allocated for  the  bit  mask  contains  enough
       words  (type unsigned long) to contain n bits.  The bit mask is zero-filled.  The bitmask structure points to the bit mask and contains the
       n value.

       numa_bitmask_clearall() sets all bits in the bit mask to 0.  The bitmask structure points to the bit mask  and  contains  its  size  (  bmp
       ->size).  The value of bmp is always returned.  Note that numa_bitmask_alloc() creates a zero-filled bit mask.

       numa_bitmask_clearbit()	sets  a  specified bit in a bit mask to 0.  Nothing is done if the n value is greater than the size of the bitmask
       (and no error is returned). The value of bmp is always returned.

       numa_bitmask_equal() returns 1 if two bitmasks are equal.  It returns 0 if they are not equal.  If the bitmask structures control bit masks
       of different sizes, the "missing" trailing bits of the smaller bit mask are considered to be 0.

       numa_bitmask_free()  deallocates the memory of both the bitmask structure pointed to by bmp and the bit mask.  It is an error to attempt to
       free this bitmask twice.

       numa_bitmask_isbitset() returns the value of a specified bit in a bit mask.  If the n value is greater than the size of the bit map,  0	is
       returned.

       numa_bitmask_nbytes()  returns  the  size (in bytes) of the bit mask controlled by bmp.	The bit masks are always full words (type unsigned
       long), and the returned size is the actual size of all those words.

       numa_bitmask_setall() sets all bits in the bit mask to 1.  The bitmask structure points to the  bit  mask  and  contains  its  size  (  bmp
       ->size).  The value of bmp is always returned.

       numa_bitmask_setbit()  sets a specified bit in a bit mask to 1.	Nothing is done if n is greater than the size of the bitmask (and no error
       is returned). The value of bmp is always returned.

       copy_bitmask_to_nodemask() copies the body (the bit map itself) of the bitmask structure pointed to by  bmp  to	the  nodemask_t  structure
       pointed	to  by	the  nodemask  pointer. If the two areas differ in size, the copy is truncated to the size of the receiving field or zero-
       filled.

       copy_nodemask_to_bitmask() copies the nodemask_t structure pointed to by the nodemask pointer to the body (the bit map itself) of the  bit-
       mask  structure pointed to by the bmp pointer. If the two areas differ in size, the copy is truncated to the size of the receiving field or
       zero-filled.

       copy_bitmask_to_bitmask() copies the body (the bit map itself) of the bitmask structure pointed to by the bmpfrom pointer to  the  body	of
       the  bitmask structure pointed to by the bmpto pointer. If the two areas differ in size, the copy is truncated to the size of the receiving
       field or zero-filled.

       numa_bitmask_weight() returns a count of the bits that are set in the body of the bitmask pointed to by the bmp argument.

       numa_move_pages() moves a list of pages in the address space of the currently executing or current process.  It simply uses the	move_pages
       system call.
       pid - ID of task.  If not valid, use the current task.
       count - Number of pages.
       pages - List of pages to move.
       nodes - List of nodes to which pages can be moved.
       status - Field to which status is to be returned.
       flags - MPOL_MF_MOVE or MPOL_MF_MOVE_ALL
       See move_pages(2).

       numa_migrate_pages()  simply  uses the migrate_pages system call to cause the pages of the calling task, or a specified task, to be migated
       from one set of nodes to another.  See migrate_pages(2).  The bit masks representing the nodes should be allocated with numa_allocate_node-
       mask() , or with numa_bitmask_alloc() using an n value returned from numa_num_possible_nodes().	A task's current node set can be gotten by
       calling numa_get_membind().  Bits in the tonodes mask can be set by calls to numa_bitmask_setbit().

       numa_error() is a libnuma internal function that can be overridden by the user program.	This function is called with  a  char  *  argument
       when a libnuma function fails.  Overriding the library internal definition makes it possible to specify a different error handling strategy
       when a libnuma function fails. It does not affect numa_available().  The numa_error() function defined in libnuma prints an error on stderr
       and terminates the program if numa_exit_on_error is set to a non-zero value.  The default value of numa_exit_on_error is zero.

       numa_warn()  is	a libnuma internal function that can be also overridden by the user program.  It is called to warn the user when a libnuma
       function encounters a non-fatal error.  The default implementation prints a warning to stderr.  The first argument is a unique number iden-
       tifying	each warning. After that there is a printf(3)-style format string and a variable number of arguments.  numa_warn exits the program
       when numa_exit_on_warn is set to a non-zero value.  The default value of numa_exit_on_warn is zero.

Compatibility with libnuma version 1
       Binaries that were compiled for libnuma version 1 need not be re-compiled to run with libnuma version 2.
       Source codes written for libnuma version 1 may be re-compiled without change with version 2 installed. To do so, in the code's Makefile add
       this option to CFLAGS:  -DNUMA_VERSION1_COMPATIBILITY

THREAD SAFETY
       numa_set_bind_policy and numa_exit_on_error are process global. The other calls are thread safe.

COPYRIGHT
       Copyright 2002, 2004, 2007, 2008 Andi Kleen, SuSE Labs.	libnuma is under the GNU Lesser General Public License, v2.1.

SEE ALSO
       get_mempolicy(2),  set_mempolicy(2),  getpagesize(2),  mbind(2),  mmap(2),  shmat(2), numactl(8), sched_getaffinity(2) sched_setaffinity(2)
       move_pages(2) migrate_pages(2)

SuSE Labs							   December 2007							   NUMA(3)
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