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Diffstat (limited to 'man3/pthread_attr_setaffinity_np.3')
| -rw-r--r-- | man3/pthread_attr_setaffinity_np.3 | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/man3/pthread_attr_setaffinity_np.3 b/man3/pthread_attr_setaffinity_np.3 new file mode 100644 index 0000000..923ee0b --- /dev/null +++ b/man3/pthread_attr_setaffinity_np.3 @@ -0,0 +1,121 @@ +'\" t +.\" Copyright (c) 2008 Linux Foundation, written by Michael Kerrisk +.\" <mtk.manpages@gmail.com> +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.TH pthread_attr_setaffinity_np 3 2023-07-20 "Linux man-pages 6.05.01" +.SH NAME +pthread_attr_setaffinity_np, pthread_attr_getaffinity_np \- set/get +CPU affinity attribute in thread attributes object +.SH LIBRARY +POSIX threads library +.RI ( libpthread ", " \-lpthread ) +.SH SYNOPSIS +.nf +.BR "#define _GNU_SOURCE" " /* See feature_test_macros(7) */" +.B #include <pthread.h> +.PP +.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(const pthread_attr_t *" attr , +.BI " size_t " cpusetsize ", cpu_set_t *" cpuset ); +.fi +.SH DESCRIPTION +The +.BR pthread_attr_setaffinity_np () +function +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 . +.PP +The +.BR pthread_attr_getaffinity_np () +function +returns the CPU affinity mask attribute of the thread attributes object +referred to by +.I attr +in the buffer pointed to by +.IR cpuset . +.PP +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) . +.PP +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 nonzero error number. +.SH ERRORS +.TP +.B EINVAL +.RB ( pthread_attr_setaffinity_np ()) +.I cpuset +specified a CPU that was outside the set supported by the kernel. +(The kernel configuration option +.B CONFIG_NR_CPUS +defines the range of the set supported 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. +.TP +.B EINVAL +.RB ( pthread_attr_getaffinity_np ()) +A CPU in the affinity mask of the thread attributes object referred to by +.I attr +lies outside the range specified by +.I cpusetsize +(i.e., +.IR cpuset / cpusetsize +is too small). +.TP +.B ENOMEM +.RB ( pthread_attr_setaffinity_np ()) +Could not allocate memory. +.SH ATTRIBUTES +For an explanation of the terms used in this section, see +.BR attributes (7). +.TS +allbox; +lbx lb lb +l l l. +Interface Attribute Value +T{ +.na +.nh +.BR pthread_attr_setaffinity_np (), +.BR pthread_attr_getaffinity_np () +T} Thread safety MT-Safe +.TE +.sp 1 +.SH STANDARDS +GNU; +hence the suffix "_np" (nonportable) in the names. +.SH HISTORY +glibc 2.3.4. +.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 pthread_attr_init (3), +.BR pthread_setaffinity_np (3), +.BR cpuset (7), +.BR pthreads (7) |