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NUMA_GETAFFINITY(2)       FreeBSD System Calls Manual      NUMA_GETAFFINITY(2)

NAME
     numa_getaffinity, numa_setaffinity - manage NUMA affinity

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sys/param.h>
     #include <sys/numa.h>

     int
     numa_getaffinity(cpuwhich_t which, id_t id,
         struct vm_domain_policy_entry *policy);

     int
     numa_setaffinity(cpuwhich_t which, id_t id,
         const struct vm_domain_policy_entry *policy);

DESCRIPTION
     numa_getaffinity() and numa_setaffinity() allow the manipulation of NUMA
     policies available to processes and threads.  These functions may
     manipulate NUMA policies that contain many processes or affect only a
     single object.

     Valid values for the which argument are documented in cpuset(2).  These
     arguments specify which object set are used.  Only CPU_WHICH_TID and
     CPU_WHICH_PID can be manipulated.

     The policy entry contains a vm_domain_policy_entry with the following
     fields:

     struct vm_domain_policy_entry {
         vm_domain_policy_type_t policy;   /* VM policy */
         int domain;   /* VM domain, if applicable */
     }
     vm_domain_policy_type_t policy is one these:

     VM_POLICY_NONE  Reset the domain back to none.  Any parent object NUMA
                     domain policy will apply.  The only valid value for
                     domain is -1.

     VM_POLICY_ROUND_ROBIN
                     Select round-robin policy.  Pages will be allocated
                     round-robin from each VM domain in order.  The only valid
                     value for domain is -1.

     VM_POLICY_FIXED_DOMAIN
                     Select fixed-domain only policy.  Pages will be allocated
                     from the given domain which must be set to a valid VM
                     domain.  Pages will not be allocated from another domain
                     if domain is out of free pages.

     VM_POLICY_FIXED_DOMAIN_ROUND_ROBIN
                     Select fixed-domain only policy.  Pages will be allocated
                     from domain which must be set to a valid VM domain.  If
                     page allocation fails, pages will be round-robin
                     allocated from another domain if domain is out of free
                     pages.

     VM_POLICY_FIRST_TOUCH
                     Select first-touch policy.  Pages will be allocated from
                     the NUMA domain which the thread is currently scheduled
                     upon.  Pages will not be allocated from another domain if
                     the current domain is out of free pages.  The only valid
                     value for domain is -1.

     VM_POLICY_FIRST_TOUCH_ROUND_ROBIN
                     Select first-touch policy.  Pages will be allocated from
                     the NUMA domain which the thread is currently scheduled
                     upon.  Pages will be allocated round-robin from another
                     domain if the current domain is out of free pages.  The
                     only valid value for domain is -1.

     Note that the VM might assign some pages from other domains.  For
     example, if an existing page allocation is covered by a superpage
     allocation.

     numa_getaffinity() retrieves the NUMA policy from the object specified by
     which and id and stores it in the space provided by policy.

     numa_setaffinity() attempts to set the NUMA policy for the object
     specified by which and id to the policy in policy.

RETURN VALUES
     Upon successful completion, the value 0 is returned; otherwise the
     value -1 is returned and the global variable errno is set to indicate the
     error.

ERRORS
     errno can contain these error codes:

     [EINVAL]           The level or which argument was not a valid value.

     [EINVAL]           The policy argument specified when calling
                        numa_setaffinity() did not contain a valid policy.

     [EFAULT]           The policy pointer passed was invalid.

     [ESRCH]            The object specified by the id and which arguments
                        could not be found.

     [ERANGE]           The domain in the given policy was out of the range of
                        possible VM domains available.

     [EPERM]            The calling process did not have the credentials
                        required to complete the operation.

SEE ALSO
     cpuset(1), numactl(1), cpuset(2), cpuset_getaffinity(2), cpuset_getid(2),
     cpuset_setaffinity(2), cpuset_setid(2), pthread_affinity_np(3),
     pthread_attr_affinity_np(3), numa(4)

HISTORY
     The numa_getaffinity family of system calls first appeared in
     FreeBSD 11.0.

AUTHORS
     Adrian Chadd <[email protected]>

FreeBSD 11.1-RELEASE-p4           May 7, 2015          FreeBSD 11.1-RELEASE-p4
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