2 * SPDX-License-Identifier: BSD-4-Clause
4 * Copyright (c) 1994, Henrik Vestergaard Draboel
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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 the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by Henrik Vestergaard Draboel.
18 * 4. The name of the author may not be used to endorse or promote products
19 * derived from this software without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 #ifndef _SYS_PRIORITY_H_
37 #define _SYS_PRIORITY_H_
40 * Process priority specifications.
47 #define PRI_ITHD 1 /* Interrupt thread. */
48 #define PRI_REALTIME 2 /* Real time process. */
49 #define PRI_TIMESHARE 3 /* Time sharing process. */
50 #define PRI_IDLE 4 /* Idle process. */
53 * PRI_FIFO is POSIX.1B SCHED_FIFO.
56 #define PRI_FIFO_BIT 8
57 #define PRI_FIFO (PRI_FIFO_BIT | PRI_REALTIME)
59 #define PRI_BASE(P) ((P) & ~PRI_FIFO_BIT)
60 #define PRI_IS_REALTIME(P) (PRI_BASE(P) == PRI_REALTIME)
61 #define PRI_NEED_RR(P) ((P) != PRI_FIFO)
64 * Priorities. Note that with 64 run queues, differences less than 4 are
69 * Priorities range from 0 to 255, but differences of less then 4 (RQ_PPQ)
70 * are insignificant. Ranges are as follows:
72 * Interrupt threads: 0 - 47
73 * Realtime user threads: 48 - 79
74 * Top half kernel threads: 80 - 119
75 * Time sharing user threads: 120 - 223
76 * Idle user threads: 224 - 255
78 * XXX If/When the specific interrupt thread and top half thread ranges
79 * disappear, a larger range can be used for user processes.
82 #define PRI_MIN (0) /* Highest priority. */
83 #define PRI_MAX (255) /* Lowest priority. */
85 #define PRI_MIN_ITHD (PRI_MIN)
86 #define PRI_MAX_ITHD (PRI_MIN_REALTIME - 1)
88 #define PI_REALTIME (PRI_MIN_ITHD + 0)
89 #define PI_AV (PRI_MIN_ITHD + 4)
90 #define PI_NET (PRI_MIN_ITHD + 8)
91 #define PI_DISK (PRI_MIN_ITHD + 12)
92 #define PI_TTY (PRI_MIN_ITHD + 16)
93 #define PI_DULL (PRI_MIN_ITHD + 20)
94 #define PI_SOFT (PRI_MIN_ITHD + 24)
95 #define PI_SWI(x) (PI_SOFT + (x) * RQ_PPQ)
97 #define PRI_MIN_REALTIME (48)
98 #define PRI_MAX_REALTIME (PRI_MIN_KERN - 1)
100 #define PRI_MIN_KERN (80)
101 #define PRI_MAX_KERN (PRI_MIN_TIMESHARE - 1)
103 #define PSWP (PRI_MIN_KERN + 0)
104 #define PVM (PRI_MIN_KERN + 4)
105 #define PINOD (PRI_MIN_KERN + 8)
106 #define PRIBIO (PRI_MIN_KERN + 12)
107 #define PVFS (PRI_MIN_KERN + 16)
108 #define PZERO (PRI_MIN_KERN + 20)
109 #define PSOCK (PRI_MIN_KERN + 24)
110 #define PWAIT (PRI_MIN_KERN + 28)
111 #define PLOCK (PRI_MIN_KERN + 32)
112 #define PPAUSE (PRI_MIN_KERN + 36)
114 #define PRI_MIN_TIMESHARE (120)
115 #define PRI_MAX_TIMESHARE (PRI_MIN_IDLE - 1)
117 #define PUSER (PRI_MIN_TIMESHARE)
119 #define PRI_MIN_IDLE (224)
120 #define PRI_MAX_IDLE (PRI_MAX)
123 /* Other arguments for kern_yield(9). */
124 #define PRI_USER -2 /* Change to current user priority. */
125 #define PRI_UNCHANGED -1 /* Do not change priority. */
129 u_char pri_class; /* Scheduling class. */
130 u_char pri_level; /* Normal priority level. */
131 u_char pri_native; /* Priority before propagation. */
132 u_char pri_user; /* User priority based on p_cpu and p_nice. */
135 #endif /* !_SYS_PRIORITY_H_ */