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 September 10, 2010 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.It Bq Er EINVAL 118The 119.Fa level 120or 121.Fa which 122argument was not a valid value. 123.It Bq Er EINVAL 124The 125.Fa mask 126argument specified when calling 127.Fn cpuset_setaffinity 128was not a valid value. 129.It Bq Er EDEADLK 130The 131.Fn cpuset_setaffinity 132call would leave a thread without a valid CPU to run on because the set 133does not overlap with the thread's anonymous mask. 134.It Bq Er EFAULT 135The mask pointer passed was invalid. 136.It Bq Er ESRCH 137The object specified by the 138.Fa id 139and 140.Fa which 141arguments could not be found. 142.It Bq Er ERANGE 143The 144.Fa cpusetsize 145was either preposterously large or smaller than the kernel set size. 146.It Bq Er EPERM 147The calling process did not have the credentials required to complete the 148operation. 149.El 150.Sh SEE ALSO 151.Xr cpuset 1 , 152.Xr cpuset 2 , 153.Xr cpuset_getid 2 , 154.Xr cpuset_setid 2 , 155.Xr pthread_affinity_np 3 , 156.Xr pthread_attr_affinity_np 3 157.Sh HISTORY 158The 159.Nm 160family of system calls first appeared in 161.Fx 7.1 . 162.Sh AUTHOR 163.An Jeffrey Roberson Aq jeff@FreeBSD.org 164