-
Notifications
You must be signed in to change notification settings - Fork 0
/
sched_get_priority_min.html
166 lines (124 loc) · 4.83 KB
/
sched_get_priority_min.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
<!-- Creator : groff version 1.22.4 -->
<!-- CreationDate: Wed Jan 29 11:26:42 2020 -->
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta name="generator" content="groff -Thtml, see www.gnu.org">
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<meta name="Content-Style" content="text/css">
<style type="text/css">
p { margin-top: 0; margin-bottom: 0; vertical-align: top }
pre { margin-top: 0; margin-bottom: 0; vertical-align: top }
table { margin-top: 0; margin-bottom: 0; vertical-align: top }
h1 { text-align: center }
</style>
<title>SCHED_GET_PRIORITY_MAX</title>
</head>
<body>
<h1 align="center">SCHED_GET_PRIORITY_MAX</h1>
<a href="#NAME">NAME</a><br>
<a href="#SYNOPSIS">SYNOPSIS</a><br>
<a href="#DESCRIPTION">DESCRIPTION</a><br>
<a href="#RETURN VALUE">RETURN VALUE</a><br>
<a href="#ERRORS">ERRORS</a><br>
<a href="#CONFORMING TO">CONFORMING TO</a><br>
<a href="#SEE ALSO">SEE ALSO</a><br>
<a href="#COLOPHON">COLOPHON</a><br>
<hr>
<h2>NAME
<a name="NAME"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em">sched_get_priority_max,
sched_get_priority_min - get static priority range</p>
<h2>SYNOPSIS
<a name="SYNOPSIS"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em"><b>#include
<sched.h></b></p>
<p style="margin-left:11%; margin-top: 1em"><b>int
sched_get_priority_max(int</b> <i>policy</i><b>);</b></p>
<p style="margin-left:11%; margin-top: 1em"><b>int
sched_get_priority_min(int</b> <i>policy</i><b>);</b></p>
<h2>DESCRIPTION
<a name="DESCRIPTION"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em"><b>sched_get_priority_max</b>()
returns the maximum priority value that can be used with the
scheduling algorithm identified by <i>policy</i>.
<b>sched_get_priority_min</b>() returns the minimum priority
value that can be used with the scheduling algorithm
identified by <i>policy</i>. Supported <i>policy</i> values
are <b>SCHED_FIFO</b>, <b>SCHED_RR</b>, <b>SCHED_OTHER</b>,
<b>SCHED_BATCH</b>, <b>SCHED_IDLE</b>, and
<b>SCHED_DEADLINE</b>. Further details about these policies
can be found in <b>sched</b>(7).</p>
<p style="margin-left:11%; margin-top: 1em">Processes with
numerically higher priority values are scheduled before
processes with numerically lower priority values. Thus, the
value returned by <b>sched_get_priority_max</b>() will be
greater than the value returned by
<b>sched_get_priority_min</b>().</p>
<p style="margin-left:11%; margin-top: 1em">Linux allows
the static priority range 1 to 99 for the <b>SCHED_FIFO</b>
and <b>SCHED_RR</b> policies, and the priority 0 for the
remaining policies. Scheduling priority ranges for the
various policies are not alterable.</p>
<p style="margin-left:11%; margin-top: 1em">The range of
scheduling priorities may vary on other POSIX systems, thus
it is a good idea for portable applications to use a virtual
priority range and map it to the interval given by
<b>sched_get_priority_max</b>() and
<b>sched_get_priority_min</b> POSIX.1 requires a spread of
at least 32 between the maximum and the minimum values for
<b>SCHED_FIFO</b> and <b>SCHED_RR</b>.</p>
<p style="margin-left:11%; margin-top: 1em">POSIX systems
on which <b>sched_get_priority_max</b>() and
<b>sched_get_priority_min</b>() are available define
<b>_POSIX_PRIORITY_SCHEDULING</b> in
<i><unistd.h></i>.</p>
<h2>RETURN VALUE
<a name="RETURN VALUE"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em">On success,
<b>sched_get_priority_max</b>() and
<b>sched_get_priority_min</b>() return the maximum/minimum
priority value for the named scheduling policy. On error, -1
is returned, and <i>errno</i> is set appropriately.</p>
<h2>ERRORS
<a name="ERRORS"></a>
</h2>
<table width="100%" border="0" rules="none" frame="void"
cellspacing="0" cellpadding="0">
<tr valign="top" align="left">
<td width="11%"></td>
<td width="9%">
<p style="margin-top: 1em"><b>EINVAL</b></p></td>
<td width="2%"></td>
<td width="78%">
<p style="margin-top: 1em">The argument <i>policy</i> does
not identify a defined scheduling policy.</p></td></tr>
</table>
<h2>CONFORMING TO
<a name="CONFORMING TO"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em">POSIX.1-2001,
POSIX.1-2008.</p>
<h2>SEE ALSO
<a name="SEE ALSO"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em"><b>sched_getaffinity</b>(2),
<b>sched_getparam</b>(2), <b>sched_getscheduler</b>(2),
<b>sched_setaffinity</b>(2), <b>sched_setparam</b>(2),
<b>sched_setscheduler</b>(2), <b>sched</b>(7)</p>
<h2>COLOPHON
<a name="COLOPHON"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em">This page is
part of release 5.02 of the Linux <i>man-pages</i> project.
A description of the project, information about reporting
bugs, and the latest version of this page, can be found at
https://www.kernel.org/doc/man-pages/.</p>
<hr>
</body>
</html>