priority.h

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/*-
 * 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.
 *
 * $FreeBSD$
 */
 
#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. */
 
/*
 * Priorities range from 0 to 255, but differences of less then 4 (RQ_PPQ)
 * are insignificant.  Ranges are as follows:
 *
 * Interrupt threads:           0 - 47
 * Realtime user threads:       48 - 79
 * Top half kernel threads:     80 - 119
 * Time sharing user threads:   120 - 223
 * Idle user threads:           224 - 255
 *
 * XXX If/When the specific interrupt thread and top half thread ranges
 * disappear, a larger range can be used for user processes.
 */
 
#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)
 
#define PI_REALTIME             (PRI_MIN_ITHD + 0)
#define PI_AV                   (PRI_MIN_ITHD + 4)
#define PI_NET                  (PRI_MIN_ITHD + 8)
#define PI_DISK                 (PRI_MIN_ITHD + 12)
#define PI_TTY                  (PRI_MIN_ITHD + 16)
#define PI_DULL                 (PRI_MIN_ITHD + 20)
#define PI_SOFT                 (PRI_MIN_ITHD + 24)
#define PI_SWI(x)               (PI_SOFT + (x) * RQ_PPQ)
 
#define PRI_MIN_REALTIME        (48)
#define PRI_MAX_REALTIME        (PRI_MIN_KERN - 1)
 
#define PRI_MIN_KERN            (80)
#define PRI_MAX_KERN            (PRI_MIN_TIMESHARE - 1)
 
#define PSWP                    (PRI_MIN_KERN + 0)
#define PVM                     (PRI_MIN_KERN + 4)
#define PINOD                   (PRI_MIN_KERN + 8)
#define PRIBIO                  (PRI_MIN_KERN + 12)
#define PVFS                    (PRI_MIN_KERN + 16)
#define PZERO                   (PRI_MIN_KERN + 20)
#define PSOCK                   (PRI_MIN_KERN + 24)
#define PWAIT                   (PRI_MIN_KERN + 28)
#define PLOCK                   (PRI_MIN_KERN + 32)
#define PPAUSE                  (PRI_MIN_KERN + 36)
 
#define PRI_MIN_TIMESHARE       (120)
#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
 
#endif  /* !_SYS_PRIORITY_H_ */