xref: /dragonfly/lib/libc/sys/usched_set.2 (revision 19380330)
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33.Dd October 16, 2012
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 .
57.Pp
58The
59.Fa cmd
60argument specifies the action for
61.Fn usched_set
62to take.
63.Dv USCHED_SET_SCHEDULER
64sets the user scheduler where
65.Fa data
66is a
67.Vt char *
68that contains the name of the user scheduler.
69.Dv USCHED_SET_CPU
70assigns the LWP to the cpuid pointed to by
71.Fa data .
72.Dv USCHED_GET_CPU
73copies the LWP's CPU ID to the cpuid pointed to by
74.Fa data .
75.Dv USCHED_ADD_CPU
76adds the cpuid specified by
77.Fa data
78to the list of available CPUs for the LWP.
79.Dv USCHED_DEL_CPU
80removes the cpuid specified by
81.Fa data
82from the list of available CPUs for the LWP.
83.Sh RETURN VALUES
84.Rv -std
85.Sh ERRORS
86The function will fail if:
87.Bl -tag -width Er
88.It Bq Er EINVAL
89The user scheduler to set is not in the list of available user schedulers.
90The
91.Fa bytes
92argument is not the correct size
93.Vt ( int )
94for a cpuid.
95The specified cpuid is not set in
96.Va smp_active_mask .
97.Fa Cmd
98contains an unknown value.
99.It Bq Er EFBIG
100The specified cpuid is not a valid cpuid for the system.
101.It Bq Er EPERM
102Deleting the specified cpuid leaves the LWP without a CPU to run on.
103.El
104.Sh SEE ALSO
105.Xr usched 8
106.Sh HISTORY
107The
108.Fn usched_set
109function call was added in
110.Dx 1.9 .
111.Sh AUTHORS
112.An -nosplit
113.Fn Usched_set
114was written by
115.An Matt Dillon .
116This manual page was written by
117.An Joe Talbott .
118