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cpuset(3) [netbsd man page]

CPUSET(3)						   BSD Library Functions Manual 						 CPUSET(3)

NAME
cpuset_create, cpuset_destroy, cpuset_zero, cpuset_set, cpuset_clr, cpuset_isset, cpuset_size -- dynamic CPU sets SYNOPSIS
#include <sched.h> cpuset_t * cpuset_create(void); void cpuset_destroy(cpuset_t *set); void cpuset_zero(cpuset_t *set); int cpuset_set(cpuid_t cpu, cpuset_t *set); int cpuset_clr(cpuid_t cpu, cpuset_t *set); int cpuset_isset(cpuid_t cpu, const cpuset_t *set); size_t cpuset_size(const cpuset_t *set); DESCRIPTION
This section describes the functions used to create, set, use and destroy the dynamic CPU sets. This API can be used with the POSIX threads, see pthread(3) and affinity(3). The ID of the primary CPU in the system is 0. FUNCTIONS
cpuset_create() Allocates and initializes a clean CPU-set. Returns the pointer to the CPU-set, or NULL on failure. cpuset_destroy(set) Destroy the CPU-set specified by set. cpuset_zero(set) Makes the CPU-set specified by set clean, that is, memory is initialized to zero bytes, and none of the CPUs set. cpuset_set(cpu, set) Sets the CPU specified by cpu in set. Returns zero on success, and -1 if cpu is invalid. cpuset_clr(cpu, set) Clears the CPU specified by cpu in the CPU-set set. Returns zero on success, and -1 if cpu is invalid. cpuset_isset(cpu, set) Checks if CPU specified by cpu is set in the CPU-set set. Returns the positive number if set, zero if not set, and -1 if cpu is invalid. cpuset_size(set) Returns the size in bytes of CPU-set specified by set. SEE ALSO
affinity(3), pset(3), sched(3), schedctl(8), kcpuset(9) HISTORY
The dynamic CPU sets appeared in NetBSD 5.0. BSD
November 2, 2011 BSD

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AFFINITY(3)						   BSD Library Functions Manual 					       AFFINITY(3)

NAME
pthread_setaffinity_np, pthread_getaffinity_np -- affinity of threads LIBRARY
POSIX Threads Library (libpthread, -lpthread) SYNOPSIS
#include <pthread.h> #include <sched.h> int pthread_setaffinity_np(pthread_t thread, size_t size, cpuset_t *set); int pthread_getaffinity_np(pthread_t thread, size_t size, cpuset_t *set); DESCRIPTION
Thread affinity allows to run the thread on specified CPU or CPUs only. The pthread_setaffinity_np() function sets the affinity mask set for thread. At least one valid CPU must be set in the mask. The pthread_getaffinity_np() function gets the affinity mask of thread into set. Note that set must be created and initialized using the cpuset(3) functions. IMPLEMENTATION NOTES
Setting CPU pthread_setaffinity_np requires super-user privileges. Ordinary users can be allowed to control CPU affinity of their threads via the security.models.extensions.user_set_cpu_affinity sysctl(7). See secmodel_extensions(9). Portable applications should not use the pthread_setaffinity_np() and pthread_getaffinity_np() functions. RETURN VALUES
The pthread_setaffinity_np() and pthread_getaffinity_np() functions return 0 on success. Otherwise, an error number is returned to indicate the error. EXAMPLES
An example of code fragment, which sets the affinity for the current thread to the CPU whose ID is 0: cpuset_t *cset; pthread_t pth; cpuid_t ci; cset = cpuset_create(); if (cset == NULL) { err(EXIT_FAILURE, "cpuset_create"); } ci = 0; cpuset_set(ci, cset); pth = pthread_self(); error = pthread_setaffinity_np(pth, cpuset_size(cset), cset); if (error) { ... } cpuset_destroy(cset); COMPATIBILITY
Both functions are non-standard extensions. ERRORS
Both functions may fail if: [EINVAL] The specified set was invalid. [EPERM] The calling process lacks the appropriate privileges to perform the operation. [ESRCH] No thread could be found corresponding to the one specified by thread. NOTES
There is an alternative processor sets interface, see pset(3). However, thread affinity and processor sets are mutually exclusive, hence mixing of these interfaces is prohibited. SEE ALSO
cpuset(3), pset(3), pthread_getschedparam(3), pthread_setschedparam(3), sched(3), schedctl(8) BSD
December 4, 2011 BSD

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