Movatterモバイル変換

pthread_attr_setaffinity_np(3) — Linux manual page

pthread_...finity_np(3)  Library Functions Manualpthread_...finity_np(3)

NAME        top

       pthread_attr_setaffinity_np, pthread_attr_getaffinity_np - set/get       CPU affinity attribute in thread attributes object

LIBRARY        top

       POSIX threads library (libpthread,-lpthread)

SYNOPSIS        top

#define _GNU_SOURCE/* See feature_test_macros(7) */#include <pthread.h>int pthread_attr_setaffinity_np(pthread_attr_t *attr,size_tcpusetsize, const cpu_set_t *cpuset);int pthread_attr_getaffinity_np(const pthread_attr_t *attr,size_tcpusetsize, cpu_set_t *cpuset);

DESCRIPTION        top

       Thepthread_attr_setaffinity_np() function sets the CPU affinity       mask attribute of the thread attributes object referred to byattr       to the value specified incpuset.  This attribute determines the       CPU affinity mask of a thread created using the thread attributes       objectattr.       Thepthread_attr_getaffinity_np() function returns the CPU       affinity mask attribute of the thread attributes object referred       to byattr in the buffer pointed to bycpuset.       The argumentcpusetsize is the length (in bytes) of the buffer       pointed to bycpuset.  Typically, this argument would be specified       assizeof(cpu_set_t).       For more details on CPU affinity masks, seesched_setaffinity(2).       For a description of a set of macros that can be used to       manipulate and inspect CPU sets, seeCPU_SET(3).

RETURN VALUE        top

       On success, these functions return 0; on error, they return a       nonzero error number.

ERRORS        top

EINVAL(pthread_attr_setaffinity_np())cpuset specified a CPU that              was outside the set supported by the kernel.  (The kernel              configuration optionCONFIG_NR_CPUSdefines the range of              the set supported by the kernel data type used to represent              CPU sets.)EINVAL(pthread_attr_getaffinity_np()) A CPU in the affinity mask              of the thread attributes object referred to byattr lies              outside the range specified bycpusetsize (i.e.,cpuset/cpusetsize is too small).ENOMEM(pthread_attr_setaffinity_np()) Could not allocate memory.

ATTRIBUTES        top

       For an explanation of the terms used in this section, seeattributes(7).       ┌──────────────────────────────────────┬───────────────┬─────────┐       │Interface│Attribute│Value│       ├──────────────────────────────────────┼───────────────┼─────────┤       │pthread_attr_setaffinity_np(),       │ Thread safety │ MT-Safe │       │pthread_attr_getaffinity_np()        │               │         │       └──────────────────────────────────────┴───────────────┴─────────┘

STANDARDS        top

       GNU; hence the suffix "_np" (nonportable) in the names.

HISTORY        top

       glibc 2.3.4.

NOTES        top

       In glibc 2.3.3 only, versions of these functions were provided       that did not have acpusetsize argument.  Instead the CPU set size       given to the underlying system calls was alwayssizeof(cpu_set_t).

SEE ALSO        top

sched_setaffinity(2),pthread_attr_init(3),pthread_setaffinity_np(3),cpuset(7),pthreads(7)

COLOPHON        top

       This page is part of theman-pages (Linux kernel and C library       user-space interface documentation) project.  Information about       the project can be found at        ⟨https://www.kernel.org/doc/man-pages/⟩.  If you have a bug report       for this manual page, see       ⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.       This page was obtained from the tarball man-pages-6.15.tar.gz       fetched from       ⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on       2025-08-11.  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 isnot       part of the original manual page), send a mail to       man-pages@man7.orgLinux man-pages 6.15            2025-05-17pthread_...finity_np(3)

Pages that refer to this page:CPU_SET(3), pthread_attr_init(3), pthread_attr_setscope(3), pthread_getattr_default_np(3), pthread_getattr_np(3), pthread_setaffinity_np(3)

HTML rendering created 2025-09-06 byMichael Kerrisk, author ofThe Linux Programming Interface. For details of in-depthLinux/UNIX system programming training courses that I teach, lookhere. Hosting byjambit GmbH.