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NUMA(3) Linux Programmer's Manual NUMA(3)
numa - NUMA policy library
#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(const char *string);
struct bitmask *numa_parse_nodestring_all(const char *string);
struct bitmask *numa_parse_cpustring(const char *string);
struct bitmask *numa_parse_cpustring_all(const 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);
int numa_run_on_node_mask_all(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, ...);
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),
preferred 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(), numa_run_on_node_mask_all(), 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
execute. 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
structure. 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_nodestring_all() is similar to numa_parse_nodestring , but
can parse all possible nodes, not only current nodeset.
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_parse_cpustring_all() is similar to numa_parse_cpustring , but
can parse all possible cpus, not only current cpuset.
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
interleaved 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 allocated using mmap(2) or shmat(2), but has not been
accessed by the current process yet. The memory is page interleaved
to all nodes specified 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 uninitialized. 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_run_on_node_mask_all() runs the current task and its children
only on nodes specified in nodemask like numa_run_on_node_mask but
without any cpuset awareness.
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 kernel 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
bitmask 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_nodemask() , 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 identifying 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.
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
numa_set_bind_policy and numa_exit_on_error are process global. The
other calls are thread safe.
Copyright 2002, 2004, 2007, 2008 Andi Kleen, SuSE Labs. libnuma is
under the GNU Lesser General Public License, v2.1.
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)
This page is part of the numactl (NUMA commands) project.
Information about the project can be found at
⟨http://oss.sgi.com/projects/libnuma/⟩. If you have a bug report for
this manual page, send it to linux-numa@vger.kernel.org. This page
was obtained from the tarball numactl-2.0.11.tar.gz fetched from
⟨ftp://oss.sgi.com/www/projects/libnuma/download⟩ on 2017-07-05. If
you discover any rendering problems in this HTML version of the page,
or you believe there is a better or more up-to-date source for the
page, or you have corrections or improvements to the information in
this COLOPHON (which is not part of the original manual page), send a
mail to man-pages@man7.org
SuSE Labs December 2007 NUMA(3)
Pages that refer to this page: get_mempolicy(2), mbind(2), migrate_pages(2), move_pages(2), set_mempolicy(2), numa_maps(5), numa(7), numastat(8)