1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright (c) 1994, Henrik Vestergaard Draboel 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 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. 20 * 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 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifndef _SYS_PRIORITY_H_ 35 #define _SYS_PRIORITY_H_ 36 37 /* 38 * Process priority specifications. 39 */ 40 41 /* 42 * Priority classes. 43 */ 44 45 #define PRI_ITHD 1 /* Interrupt thread. */ 46 #define PRI_REALTIME 2 /* Real time process. */ 47 #define PRI_TIMESHARE 3 /* Time sharing process. */ 48 #define PRI_IDLE 4 /* Idle process. */ 49 50 /* 51 * PRI_FIFO is POSIX.1B SCHED_FIFO. 52 */ 53 54 #define PRI_FIFO_BIT 8 55 #define PRI_FIFO (PRI_FIFO_BIT | PRI_REALTIME) 56 57 #define PRI_BASE(P) ((P) & ~PRI_FIFO_BIT) 58 #define PRI_IS_REALTIME(P) (PRI_BASE(P) == PRI_REALTIME) 59 #define PRI_NEED_RR(P) ((P) != PRI_FIFO) 60 61 /* 62 * Priorities. Note that with 64 run queues, differences less than 4 are 63 * insignificant. 64 */ 65 66 /* 67 * Priorities range from 0 to 255. Ranges are as follows: 68 * 69 * Interrupt threads: 0 - 7 70 * Realtime user threads: 8 - 39 71 * Top half kernel threads: 40 - 55 72 * Time sharing user threads: 56 - 223 73 * Idle user threads: 224 - 255 74 * 75 * Priority levels of rtprio(2)'s RTP_PRIO_FIFO and RTP_PRIO_REALTIME and 76 * POSIX's SCHED_FIFO and SCHED_RR are directly mapped to the internal realtime 77 * range mentioned above by a simple translation. This range's length 78 * consequently cannot be changed without impacts on the scheduling priority 79 * code, and in any case must never be smaller than 32 for POSIX compliance and 80 * rtprio(2) backwards compatibility. Similarly, priority levels of rtprio(2)'s 81 * RTP_PRIO_IDLE are directly mapped to the internal idle range above (and, 82 * soon, those of the to-be-introduced SCHED_IDLE policy as well), so changing 83 * that range is subject to the same caveats and restrictions. 84 */ 85 86 #define PRI_MIN (0) /* Highest priority. */ 87 #define PRI_MAX (255) /* Lowest priority. */ 88 89 #define PRI_MIN_ITHD (PRI_MIN) 90 #define PRI_MAX_ITHD (PRI_MIN_REALTIME - 1) 91 92 /* 93 * Most hardware interrupt threads run at the same priority, but can 94 * decay to lower priorities if they run for full time slices. 95 */ 96 #define PI_REALTIME (PRI_MIN_ITHD + 0) 97 #define PI_INTR (PRI_MIN_ITHD + 1) 98 #define PI_AV PI_INTR 99 #define PI_NET PI_INTR 100 #define PI_DISK PI_INTR 101 #define PI_TTY PI_INTR 102 #define PI_DULL PI_INTR 103 #define PI_SOFT (PRI_MIN_ITHD + 2) 104 #define PI_SOFTCLOCK PI_SOFT 105 #define PI_SWI(x) PI_SOFT 106 107 #define PRI_MIN_REALTIME (8) 108 #define PRI_MAX_REALTIME (PRI_MIN_KERN - 1) 109 110 #define PRI_MIN_KERN (40) 111 #define PRI_MAX_KERN (PRI_MIN_TIMESHARE - 1) 112 113 #define PSWP (PRI_MIN_KERN + 0) 114 #define PVM (PRI_MIN_KERN + 1) 115 #define PINOD (PRI_MIN_KERN + 2) 116 #define PRIBIO (PRI_MIN_KERN + 3) 117 #define PVFS (PRI_MIN_KERN + 4) 118 #define PZERO (PRI_MIN_KERN + 5) 119 #define PSOCK (PRI_MIN_KERN + 6) 120 #define PWAIT (PRI_MIN_KERN + 7) 121 #define PLOCK (PRI_MIN_KERN + 8) 122 #define PPAUSE (PRI_MIN_KERN + 9) 123 124 #define PRI_MIN_TIMESHARE (56) 125 #define PRI_MAX_TIMESHARE (PRI_MIN_IDLE - 1) 126 127 #define PUSER (PRI_MIN_TIMESHARE) 128 129 #define PRI_MIN_IDLE (224) 130 #define PRI_MAX_IDLE (PRI_MAX) 131 132 #ifdef _KERNEL 133 /* Other arguments for kern_yield(9). */ 134 #define PRI_USER -2 /* Change to current user priority. */ 135 #define PRI_UNCHANGED -1 /* Do not change priority. */ 136 #endif 137 138 struct priority { 139 u_char pri_class; /* Scheduling class. */ 140 u_char pri_level; /* Normal priority level. */ 141 u_char pri_native; /* Priority before propagation. */ 142 u_char pri_user; /* User priority based on p_cpu and p_nice. */ 143 }; 144 145 #endif /* !_SYS_PRIORITY_H_ */ 146