xref: /dragonfly/lib/libc/sys/usched_set.2 (revision 63ab6604)
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33.\" $DragonFly: src/lib/libc/sys/usched_set.2,v 1.4 2007/12/23 15:31:28 swildner Exp $
34.\"
35.Dd February 26, 2009
36.Dt USCHED_SET 2
37.Os
38.Sh NAME
39.Nm usched_set
40.Nd setting up a proc's usched
41.Sh LIBRARY
42.Lb libc
43.Sh SYNOPSIS
44.In sys/types.h
45.In sys/usched.h
46.Ft int
47.Fn usched_set "pid_t pid" "int cmd" "void *data" "int bytes"
48.Sh DESCRIPTION
49The
50.Fn usched_set
51function is used to perform several user scheduler tasks.
52These tasks include: setting the user scheduler, assigning an LWP to a
53specific CPU, adding a CPU to the available CPUs for an LWP,
54and removing a CPU from the list of available CPUs for an LWP.
55The
56.Fn usched_set
57function requires superuser privileges for all commands except
58.Dv USCHED_GET_CPU .
59.Pp
60The
61.Fa cmd
62argument specifies the action for
63.Fn usched_set
64to take.
65.Dv USCHED_SET_SCHEDULER
66sets the user scheduler where
67.Fa data
68is a
69.Vt char *
70that contains the name of the user scheduler.
71.Dv USCHED_SET_CPU
72assigns the LWP to the cpuid pointed to by
73.Fa data .
74.Dv USCHED_GET_CPU
75copies the LWP's CPU ID to the cpuid pointed to by
76.Fa data .
77.Dv USCHED_ADD_CPU
78adds the cpuid specified by
79.Fa data
80to the list of available CPUs for the LWP.
81.Dv USCHED_DEL_CPU
82removes the cpuid specified by
83.Fa data
84from the list of available CPUs for the LWP.
85.Sh RETURN VALUES
86.Rv -std
87.Sh ERRORS
88The function will fail if:
89.Bl -tag -width Er
90.It Bq Er EINVAL
91The user scheduler to set is not in the list of available user schedulers.
92The
93.Fa bytes
94argument is not the correct size
95.Vt ( int )
96for a cpuid.
97The specified cpuid is not set in
98.Va smp_active_mask .
99.Fa Cmd
100contains an unknown value.
101.It Bq Er EFBIG
102The specified cpuid is not a valid cpuid for the system.
103.It Bq Er EPERM
104Deleting the specified cpuid leaves the LWP without a CPU to run on.
105.El
106.\".Sh SEE ALSO
107.Sh HISTORY
108The
109.Fn usched_set
110function call was added in
111.Dx 1.9 .
112.Sh AUTHORS
113.An -nosplit
114.Fn Usched_set
115was written by
116.An Matt Dillon .
117This manual page was written by
118.An Joe Talbott .
119