Manpage of PTHREAD_ATTR_SETAFFINITY_NP

PTHREAD_ATTR_SETAFFINITY_NP

Section: Linux Programmer's Manual (3)
Updated: 2015-07-23
Index
 

NAME

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

SYNOPSIS

#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(const pthread_attr_t *attr,                   size_t cpusetsize, cpu_set_t *cpuset);Compile and link with -pthread.
 

DESCRIPTION

The pthread_attr_setaffinity_np() function sets the CPU affinity mask attribute of the thread attributes object referred to by attrto 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 attrin the buffer pointed to by cpuset.

The argument cpusetsizeis 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).  

RETURN VALUE

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

ERRORS

EINVAL
(pthread_attr_setaffinity_np()) cpusetspecified a CPU that was outside the set supported by the kernel. (The kernel configuration option CONFIG_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 by attrlies outside the range specified by cpusetsize(i.e., cpuset/cpusetsizeis too small).
ENOMEM
(pthread_attr_setaffinity_np()) Could not allocate memory.
 

VERSIONS

These functions are provided by glibc since version 2.3.4.  

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).
InterfaceAttributeValue
pthread_attr_setaffinity_np(), pthread_attr_getaffinity_np() Thread safetyMT-Safe

 

CONFORMING TO

These functions are nonstandard GNU extensions; hence the suffix "_np" (nonportable) in the names.  

NOTES

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

SEE ALSO

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


 

Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
ERRORS
VERSIONS
ATTRIBUTES
CONFORMING TO
NOTES
SEE ALSO

This document was created by man2html, using the manual pages.
Time: 22:27:57 GMT, June 20, 2016