1.\" Copyright (c) 2008 Christian Brueffer
2.\" Copyright (c) 2008 Jeffrey Roberson
3.\" All rights reserved.
4.\"
5.\" Redistribution and use in source and binary forms, with or without
6.\" modification, are permitted provided that the following conditions
7.\" are met:
8.\" 1. Redistributions of source code must retain the above copyright
9.\"    notice, this list of conditions and the following disclaimer.
10.\" 2. Redistributions in binary form must reproduce the above copyright
11.\"    notice, this list of conditions and the following disclaimer in the
12.\"    documentation and/or other materials provided with the distribution.
13.\"
14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24.\" SUCH DAMAGE.
25.\"
26.\" $FreeBSD$
27.\"
28.Dd May 23, 2017
29.Dt CPUSET_GETAFFINITY 2
30.Os
31.Sh NAME
32.Nm cpuset_getaffinity ,
33.Nm cpuset_setaffinity
34.Nd manage CPU affinity
35.Sh LIBRARY
36.Lb libc
37.Sh SYNOPSIS
38.In sys/param.h
39.In sys/cpuset.h
40.Ft int
41.Fn cpuset_getaffinity "cpulevel_t level" "cpuwhich_t which" "id_t id" "size_t setsize" "cpuset_t *mask"
42.Ft int
43.Fn cpuset_setaffinity "cpulevel_t level" "cpuwhich_t which" "id_t id" "size_t setsize" "const cpuset_t *mask"
44.Sh DESCRIPTION
45.Fn cpuset_getaffinity
46and
47.Fn cpuset_setaffinity
48allow the manipulation of sets of CPUs available to processes, threads,
49interrupts, jails and other resources.
50These functions may manipulate sets of CPUs that contain many processes
51or per-object anonymous masks that effect only a single object.
52.Pp
53The valid values for the
54.Fa level
55and
56.Fa which
57arguments are documented in
58.Xr cpuset 2 .
59These arguments specify which object and which set of the object we are
60referring to.
61Not all possible combinations are valid.
62For example, only processes may belong to a numbered set accessed by a
63.Fa level
64argument of
65.Dv CPU_LEVEL_CPUSET .
66All resources, however, have a mask which may be manipulated with
67.Dv CPU_LEVEL_WHICH .
68.Pp
69Masks of type
70.Ft cpuset_t
71are composed using the
72.Dv CPU_SET
73macros.
74The kernel tolerates large sets as long as all CPUs specified
75in the set exist.
76Sets smaller than the kernel uses generate an error on calls to
77.Fn cpuset_getaffinity
78even if the result set would fit within the user supplied set.
79Calls to
80.Fn cpuset_setaffinity
81tolerate small sets with no restrictions.
82.Pp
83The supplied mask should have a size of
84.Fa setsize
85bytes.
86This size is usually provided by calling
87.Li sizeof(mask)
88which is ultimately determined by the value of
89.Dv CPU_SETSIZE
90as defined in
91.In sys/cpuset.h .
92.Pp
93.Fn cpuset_getaffinity
94retrieves the
95mask from the object specified by
96.Fa level ,
97.Fa which
98and
99.Fa id
100and stores it in the space provided by
101.Fa mask .
102.Pp
103.Fn cpuset_setaffinity
104attempts to set the mask for the object specified by
105.Fa level ,
106.Fa which
107and
108.Fa id
109to the value in
110.Fa mask .
111.Sh RETURN VALUES
112.Rv -std
113.Sh ERRORS
114The following error codes may be set in
115.Va errno :
116.Bl -tag -width Er
117.\" When changing this list, consider updating share/man/man3/pthread_create.3,
118.\" since that function can return any of these errors.
119.It Bq Er EINVAL
120The
121.Fa level
122or
123.Fa which
124argument was not a valid value.
125.It Bq Er EINVAL
126The
127.Fa mask
128argument specified when calling
129.Fn cpuset_setaffinity
130was not a valid value.
131.It Bq Er EDEADLK
132The
133.Fn cpuset_setaffinity
134call would leave a thread without a valid CPU to run on because the set
135does not overlap with the thread's anonymous mask.
136.It Bq Er EFAULT
137The mask pointer passed was invalid.
138.It Bq Er ESRCH
139The object specified by the
140.Fa id
141and
142.Fa which
143arguments could not be found.
144.It Bq Er ERANGE
145The
146.Fa cpusetsize
147was either preposterously large or smaller than the kernel set size.
148.It Bq Er EPERM
149The calling process did not have the credentials required to complete the
150operation.
151.It Bq Er ECAPMODE
152The calling process attempted to act on a process other than itself, while
153in capability mode.
154See
155.Xr capsicum 4 .
156.El
157.Sh SEE ALSO
158.Xr cpuset 1 ,
159.Xr cpuset 2 ,
160.Xr cpuset_getdomain 2 ,
161.Xr cpuset_getid 2 ,
162.Xr cpuset_setdomain 2 ,
163.Xr cpuset_setid 2 ,
164.Xr pthread_affinity_np 3 ,
165.Xr pthread_attr_affinity_np 3 ,
166.Xr capsicum 4 ,
167.Xr cpuset 9
168.Sh HISTORY
169The
170.Nm
171family of system calls first appeared in
172.Fx 7.1 .
173.Sh AUTHORS
174.An Jeffrey Roberson Aq Mt [email protected]
175