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 July 17, 2016 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_ADD_CPU 82add the cpuid specified by 83.Fa data 84to the list of available CPUs for the LWP. 85.It Dv USCHED_DEL_CPU 86remove the cpuid specified by 87.Fa data 88from the list of available CPUs for the LWP. 89.El 90.Sh RETURN VALUES 91.Rv -std 92.Sh ERRORS 93The function will fail if: 94.Bl -tag -width Er 95.It Bq Er EINVAL 96The user scheduler to set is not in the list of available user schedulers. 97The 98.Fa bytes 99argument is not the correct size 100.Vt ( int ) 101for a cpuid. 102The specified cpuid is not set in 103.Va smp_active_mask . 104.Fa Cmd 105contains an unknown value. 106.It Bq Er EFBIG 107The specified cpuid is not a valid cpuid for the system. 108.It Bq Er EPERM 109Deleting the specified cpuid leaves the LWP without a CPU to run on. 110.El 111.Sh SEE ALSO 112.Xr usched 8 113.Sh HISTORY 114The 115.Fn usched_set 116function call was added in 117.Dx 1.9 . 118.Sh AUTHORS 119.An -nosplit 120The 121.Fn usched_set 122system call was written by 123.An Matt Dillon . 124This manual page was written by 125.An Joe Talbott . 126.Sh BUGS 127Only 128.Fa pid 129equals current LWP PID or 0 is implemented. 130The current LWP PID is used for 131.Fa pid 132when 133.Fa pid 134is 0. 135One would normally only use 0 for 136.Fa pid . 137