| NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | VERSIONS | CONFORMING TO | NOTES | SEE ALSO | COLOPHON | The Linux Programming Interface |
PTHREAD_ATTR_SETAFFINITY_NP(3)Linux Programmer's ManualPTHREAD_ATTR_SETAFFINITY_NP(3)
pthread_attr_setaffinity_np, pthread_attr_getaffinity_np - set/get CPU affin-
ity attribute in thread attributes object
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <pthread.h>
int pthread_attr_setaffinity_np(pthread_attr_t *attr,
size_t cpusetsize, const cpu_set_t *cpuset);
int pthread_attr_getaffinity_np(pthread_attr_t *attr,
size_t cpusetsize, cpu_set_t *cpuset);
Compile and link with -pthread.
The pthread_attr_setaffinity_np() function sets the CPU affinity mask
attribute of the thread attributes object referred to by attr to the value
specified in cpuset. This attribute determines the CPU affinity mask of a
thread created using the thread attributes object attr.
The pthread_attr_getaffinity_np() function returns the CPU affinity mask
attribute of the thread attributes object referred to by attr in the buffer
pointed to by cpuset.
The argument cpusetsize is the length (in bytes) of the buffer pointed to by
cpuset. Typically, this argument would be specified as sizeof(cpu_set_t).
For more details on CPU affinity masks, see sched_setaffinity(2). For a
description of a set of macros that can be used to manipulate and inspect CPU
sets, see CPU_SET(3).
On success, these functions return 0; on error, they return a nonzero error
number.
EINVAL (pthread_attr_setaffinity_np()) cpuset specified a CPU that was outside
the set supported by the kernel. (The kernel configuration option
CONFIG_NR_CPUS defines 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 by attr lies outside the range
specified by cpusetsize (i.e., cpuset/cpusetsize is too small).
ENOMEM (pthread_attr_setaffinity_np()) Could not allocate memory.
These functions are provided by glibc since version 2.3.4.
These functions are nonstandard GNU extensions; hence the suffix "_np"
(nonportable) in the names.
In glibc 2.3.3 only, versions of these functions were provided that did not
have a cpusetsize argument. Instead the CPU set size given to the underlying
system calls was always sizeof(cpu_set_t).
sched_setaffinity(2), pthread_attr_init(3), pthread_setaffinity_np(3),
cpuset(7), pthreads(7)
This page is part of release 3.32 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can be found
at http://www.kernel.org/doc/man-pages/.
Linux 2010-09-10 PTHREAD_ATTR_SETAFFINITY_NP(3)
HTML rendering created 2010-12-03 by Michael Kerrisk, author of The Linux Programming Interface