Section: Linux Programmer's Manual (3)Updated: 2010-09-10Local indexUp
pthread_attr_setaffinity_np, pthread_attr_getaffinity_np - set/get
CPU affinity 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.
sets the CPU affinity mask attribute of the
thread attributes object referred to by
to the value specified in
This attribute determines the CPU affinity mask
of a thread created using the thread attributes object
returns the CPU affinity mask attribute of the thread attributes object
referred to by
in the buffer pointed to by
is the length (in bytes) of the buffer pointed to by
Typically, this argument would be specified as
For more details on CPU affinity masks, see
For a description of a set of macros
that can be used to manipulate and inspect CPU sets, see
On success, these functions return 0;
on error, they return a nonzero error number.
specified a CPU that was outside the set supported by the kernel.
(The kernel configuration option
defines the range of the set supported by the kernel data type
used to represent CPU sets.)
A CPU in the affinity mask of the thread attributes object referred to by
lies outside the range specified by
is too small).
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
Instead the CPU set size given to the underlying system calls was always