1.\" Copyright (c) 2007 The DragonFly Project. All rights reserved. 2.\" 3.\" This code is derived from software contributed to The DragonFly Project 4.\" by Matthew Dillon <dillon@backplane.com> 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in 14.\" the documentation and/or other materials provided with the 15.\" distribution. 16.\" 3. Neither the name of The DragonFly Project nor the names of its 17.\" contributors may be used to endorse or promote products derived 18.\" from this software without specific, prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22.\" LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23.\" FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 24.\" COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 25.\" INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 26.\" BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 27.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 28.\" AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 29.\" OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 30.\" OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31.\" SUCH DAMAGE. 32.\" 33.Dd January 9, 2017 34.Dt USCHED_SET 2 35.Os 36.Sh NAME 37.Nm usched_set 38.Nd setting up a proc's usched 39.Sh LIBRARY 40.Lb libc 41.Sh SYNOPSIS 42.In sys/types.h 43.In sys/usched.h 44.Ft int 45.Fn usched_set "pid_t pid" "int cmd" "void *data" "int bytes" 46.Sh DESCRIPTION 47The 48.Fn usched_set 49function is used to perform several user scheduler tasks. 50These tasks include: setting the user scheduler, assigning an LWP to a 51specific CPU, adding a CPU to the available CPUs for an LWP, 52and removing a CPU from the list of available CPUs for an LWP. 53The 54.Fn usched_set 55function requires superuser privileges for all commands except 56.Dv USCHED_GET_CPU 57and 58.Dv USCHED_GET_CPUMASK . 59.Pp 60The 61.Fa cmd 62argument specifies the action for 63.Fn usched_set 64to take: 65.Bl -tag -width ".Dv USCHED_SET_SCHEDULER" 66.It Dv USCHED_SET_SCHEDULER 67set the user scheduler where 68.Fa data 69is a 70.Vt char * 71that contains the name of the user scheduler. 72.It Dv USCHED_SET_CPU 73assign the LWP to the cpuid pointed to by 74.Fa data . 75.It Dv USCHED_GET_CPU 76copy the LWP's CPU ID to the cpuid pointed to by 77.Fa data . 78.It Dv USCHED_GET_CPUMASK 79copy the LWP's CPU mask to the cpumask_t type pointed to by 80.Fa data . 81.It Dv USCHED_SET_CPUMASK 82set the LWP's CPU mask to the cpumask_t type pointed to by 83.Fa data . 84.It Dv USCHED_ADD_CPU 85add the cpuid specified by 86.Fa data 87to the list of available CPUs for the LWP. 88.It Dv USCHED_DEL_CPU 89remove the cpuid specified by 90.Fa data 91from the list of available CPUs for the LWP. 92.El 93.Sh RETURN VALUES 94.Rv -std 95.Sh ERRORS 96The function will fail if: 97.Bl -tag -width Er 98.It Bq Er EINVAL 99The user scheduler to set is not in the list of available user schedulers. 100The 101.Fa bytes 102argument is not the correct size 103.Vt ( int ) 104for a cpuid. 105The specified cpuid is not set in 106.Va smp_active_mask . 107.Fa Cmd 108contains an unknown value. 109.It Bq Er EFBIG 110The specified cpuid is not a valid cpuid for the system. 111.It Bq Er EPERM 112Deleting the specified cpuid leaves the LWP without a CPU to run on. 113.El 114.Sh SEE ALSO 115.Xr usched 8 116.Sh HISTORY 117The 118.Fn usched_set 119function call was added in 120.Dx 1.9 . 121.Sh AUTHORS 122.An -nosplit 123The 124.Fn usched_set 125system call was written by 126.An Matt Dillon . 127This manual page was written by 128.An Joe Talbott . 129.Sh BUGS 130Only 131.Fa pid 132equals current LWP PID or 0 is implemented. 133The current LWP PID is used for 134.Fa pid 135when 136.Fa pid 137is 0. 138One would normally only use 0 for 139.Fa pid . 140