/*- * SPDX-License-Identifier: BSD-4-Clause * * Copyright (c) 1994, Henrik Vestergaard Draboel * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Henrik Vestergaard Draboel. * 4. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef _SYS_PRIORITY_H_ #define _SYS_PRIORITY_H_ /* * Process priority specifications. */ /* * Priority classes. */ #define PRI_ITHD 1 /* Interrupt thread. */ #define PRI_REALTIME 2 /* Real time process. */ #define PRI_TIMESHARE 3 /* Time sharing process. */ #define PRI_IDLE 4 /* Idle process. */ /* * PRI_FIFO is POSIX.1B SCHED_FIFO. */ #define PRI_FIFO_BIT 8 #define PRI_FIFO (PRI_FIFO_BIT | PRI_REALTIME) #define PRI_BASE(P) ((P) & ~PRI_FIFO_BIT) #define PRI_IS_REALTIME(P) (PRI_BASE(P) == PRI_REALTIME) #define PRI_NEED_RR(P) ((P) != PRI_FIFO) /* * Priorities. Note that with 64 run queues, differences less than 4 are * insignificant. */ /* * Priorities range from 0 to 255. Ranges are as follows: * * Interrupt threads: 0 - 7 * Realtime user threads: 8 - 39 * Top half kernel threads: 40 - 55 * Time sharing user threads: 56 - 223 * Idle user threads: 224 - 255 * * Priority levels of rtprio(2)'s RTP_PRIO_FIFO and RTP_PRIO_REALTIME and * POSIX's SCHED_FIFO and SCHED_RR are directly mapped to the internal realtime * range mentioned above by a simple translation. This range's length * consequently cannot be changed without impacts on the scheduling priority * code, and in any case must never be smaller than 32 for POSIX compliance and * rtprio(2) backwards compatibility. Similarly, priority levels of rtprio(2)'s * RTP_PRIO_IDLE are directly mapped to the internal idle range above (and, * soon, those of the to-be-introduced SCHED_IDLE policy as well), so changing * that range is subject to the same caveats and restrictions. */ #define PRI_MIN (0) /* Highest priority. */ #define PRI_MAX (255) /* Lowest priority. */ #define PRI_MIN_ITHD (PRI_MIN) #define PRI_MAX_ITHD (PRI_MIN_REALTIME - 1) /* * Most hardware interrupt threads run at the same priority, but can * decay to lower priorities if they run for full time slices. */ #define PI_REALTIME (PRI_MIN_ITHD + 0) #define PI_INTR (PRI_MIN_ITHD + 1) #define PI_AV PI_INTR #define PI_NET PI_INTR #define PI_DISK PI_INTR #define PI_TTY PI_INTR #define PI_DULL PI_INTR #define PI_SOFT (PRI_MIN_ITHD + 2) #define PI_SOFTCLOCK PI_SOFT #define PI_SWI(x) PI_SOFT #define PRI_MIN_REALTIME (8) #define PRI_MAX_REALTIME (PRI_MIN_KERN - 1) #define PRI_MIN_KERN (40) #define PRI_MAX_KERN (PRI_MIN_TIMESHARE - 1) #define PSWP (PRI_MIN_KERN + 0) #define PVM (PRI_MIN_KERN + 1) #define PINOD (PRI_MIN_KERN + 2) #define PRIBIO (PRI_MIN_KERN + 3) #define PVFS (PRI_MIN_KERN + 4) #define PZERO (PRI_MIN_KERN + 5) #define PSOCK (PRI_MIN_KERN + 6) #define PWAIT (PRI_MIN_KERN + 7) #define PLOCK (PRI_MIN_KERN + 8) #define PPAUSE (PRI_MIN_KERN + 9) #define PRI_MIN_TIMESHARE (56) #define PRI_MAX_TIMESHARE (PRI_MIN_IDLE - 1) #define PUSER (PRI_MIN_TIMESHARE) #define PRI_MIN_IDLE (224) #define PRI_MAX_IDLE (PRI_MAX) #ifdef _KERNEL /* Other arguments for kern_yield(9). */ #define PRI_USER -2 /* Change to current user priority. */ #define PRI_UNCHANGED -1 /* Do not change priority. */ #endif struct priority { u_char pri_class; /* Scheduling class. */ u_char pri_level; /* Normal priority level. */ u_char pri_native; /* Priority before propagation. */ u_char pri_user; /* User priority based on p_cpu and p_nice. */ }; #endif /* !_SYS_PRIORITY_H_ */
