xref: /dragonfly/lib/libc/sys/usched_set.2 (revision dadd6466)
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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.Bl -tag -width ".Dv USCHED_SET_SCHEDULER"
64.It Dv USCHED_SET_SCHEDULER
65set the user scheduler where
66.Fa data
67is a
68.Vt char *
69that contains the name of the user scheduler.
70.It Dv USCHED_SET_CPU
71assign the LWP to the cpuid pointed to by
72.Fa data .
73.It Dv USCHED_GET_CPU
74copy the LWP's CPU ID to the cpuid pointed to by
75.Fa data .
76.It Dv USCHED_ADD_CPU
77add the cpuid specified by
78.Fa data
79to the list of available CPUs for the LWP.
80.It Dv USCHED_DEL_CPU
81remove the cpuid specified by
82.Fa data
83from the list of available CPUs for the LWP.
84.El
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.Xr usched 8
108.Sh HISTORY
109The
110.Fn usched_set
111function call was added in
112.Dx 1.9 .
113.Sh AUTHORS
114.An -nosplit
115.Fn Usched_set
116was written by
117.An Matt Dillon .
118This manual page was written by
119.An Joe Talbott .
120.Sh BUGS
121Only
122.Fa pid
123equals current LWP PID is implemented.
124