mirror of https://github.com/mkerrisk/man-pages
123 lines
3.8 KiB
Groff
123 lines
3.8 KiB
Groff
.\" Copyright (c) 2008 Linux Foundation, written by Michael Kerrisk
|
|
.\" <mtk.manpages@gmail.com>
|
|
.\"
|
|
.\" Permission is granted to make and distribute verbatim copies of this
|
|
.\" manual provided the copyright notice and this permission notice are
|
|
.\" preserved on all copies.
|
|
.\"
|
|
.\" Permission is granted to copy and distribute modified versions of this
|
|
.\" manual under the conditions for verbatim copying, provided that the
|
|
.\" entire resulting derived work is distributed under the terms of a
|
|
.\" permission notice identical to this one.
|
|
.\"
|
|
.\" Since the Linux kernel and libraries are constantly changing, this
|
|
.\" manual page may be incorrect or out-of-date. The author(s) assume no
|
|
.\" responsibility for errors or omissions, or for damages resulting from
|
|
.\" the use of the information contained herein. The author(s) may not
|
|
.\" have taken the same level of care in the production of this manual,
|
|
.\" which is licensed free of charge, as they might when working
|
|
.\" professionally.
|
|
.\"
|
|
.\" Formatted or processed versions of this manual, if unaccompanied by
|
|
.\" the source, must acknowledge the copyright and authors of this work.
|
|
.\"
|
|
.TH PTHREAD_ATTR_SETAFFINITY_NP 3 2008-11-12 "Linux" "Linux Programmer's Manual"
|
|
.SH NAME
|
|
pthread_attr_setaffinity_np, pthread_attr_getaffinity_np \- set/get
|
|
CPU affinity of a thread
|
|
.SH SYNOPSIS
|
|
.nf
|
|
.B #define _GNU_SOURCE
|
|
.B #include <pthread.h>
|
|
|
|
.BI "int pthread_attr_setaffinity_np(pthread_attr_t " attr ,
|
|
.BI " size_t " cpusetsize ", const cpu_set_t *" cpuset );
|
|
.BI "int pthread_attr_getaffinity_np(pthread_attr_t " attr ,
|
|
.BI " size_t " cpusetsize ", cpu_set_t *" cpuset );
|
|
.sp
|
|
Compile and link with \fI\-pthread\fP.
|
|
.SH DESCRIPTION
|
|
The
|
|
.BR pthread_attr_setaffinity_np ()
|
|
sets the CPU affinity mask attribute of the
|
|
thread attributes object referred to by
|
|
.I attr
|
|
to the value specified in
|
|
.IR cpuset .
|
|
This attribute determines the CPU affinity mask
|
|
of a thread created using the thread attributes object
|
|
.IR attr .
|
|
|
|
The
|
|
.BR pthread_attr_getaffinity_np ()
|
|
returns the CPU affinity mask attribute of the thread attributes object
|
|
referred to by
|
|
.IR attr
|
|
in the buffer pointed to by
|
|
.IR cpuset .
|
|
|
|
The argument
|
|
.I cpusetsize
|
|
is the length (in bytes) of the buffer pointed to by
|
|
.IR cpuset .
|
|
Typically, this argument would be specified as
|
|
.IR sizeof(cpu_set_t) .
|
|
|
|
For more details on CPU affinity masks, see
|
|
.BR sched_setaffinity (2).
|
|
For a description of a set of macros
|
|
that can be used to manipulate and inspect CPU sets, see
|
|
.BR CPU_SET (3).
|
|
.SH RETURN VALUE
|
|
On success, these functions return 0;
|
|
on error, they return a non-zero error number.
|
|
.SH ERRORS
|
|
.TP
|
|
.B EINVAL
|
|
.I attr
|
|
or
|
|
.I cpuset
|
|
is invalid.
|
|
.TP
|
|
.BR EINVAL
|
|
.RB ( pthread_attr_setaffinity_np ())
|
|
.I cpuset
|
|
specified a CPU that was outside the range
|
|
permitted by the kernel data type
|
|
.\" cpumask_t
|
|
used to represent CPU sets.
|
|
.\" The raw sched_getaffinity() system call returns the size (in bytes)
|
|
.\" of the cpumask_t type.
|
|
This range is determined by the kernel configuration option
|
|
.BR CONFIG_NR_CPUS .
|
|
.TP
|
|
.B EINVAL
|
|
.RB ( pthread_getaffinity_np ())
|
|
A CPU in the affinity mask of the thread attributes object referred to by
|
|
.I attr
|
|
lies outside the range specified by
|
|
.IR cpusetsize .
|
|
.TP
|
|
.B ENOMEM
|
|
.RB ( pthread_attr_setaffinity_np ())
|
|
Could not allocate memory.
|
|
.SH VERSIONS
|
|
These functions are provided by glibc since version 2.3.4.
|
|
.SH CONFORMING TO
|
|
These functions are non-standard GNU extensions;
|
|
hence the suffix "_np" (non-portable) in the names.
|
|
.SH NOTES
|
|
In glibc 2.3.3 only,
|
|
versions of these functions were provided that did not have a
|
|
.I cpusetsize
|
|
argument.
|
|
Instead the CPU set size given to the underlying system calls was always
|
|
.IR sizeof(cpu_set_t) .
|
|
.SH SEE ALSO
|
|
.BR sched_setaffinity (2),
|
|
.BR sched_setscheduler (2),
|
|
.BR pthread_attr_init (3),
|
|
.BR pthread_setaffinity_np (3),
|
|
.BR cpuset (7),
|
|
.BR pthreads (7)
|