runq.h revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2001 Jake Burkholder <jake@FreeBSD.org>
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 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD: stable/11/sys/sys/runq.h 330897 2018-03-14 03:19:51Z eadler $
29 */
30
31#ifndef	_RUNQ_H_
32#define	_RUNQ_H_
33
34#include <machine/runq.h>
35
36struct thread;
37
38/*
39 * Run queue parameters.
40 */
41
42#define	RQ_NQS		(64)		/* Number of run queues. */
43#define	RQ_PPQ		(4)		/* Priorities per queue. */
44
45/*
46 * Head of run queues.
47 */
48TAILQ_HEAD(rqhead, thread);
49
50/*
51 * Bit array which maintains the status of a run queue.  When a queue is
52 * non-empty the bit corresponding to the queue number will be set.
53 */
54struct rqbits {
55	rqb_word_t rqb_bits[RQB_LEN];
56};
57
58/*
59 * Run queue structure.  Contains an array of run queues on which processes
60 * are placed, and a structure to maintain the status of each queue.
61 */
62struct runq {
63	struct	rqbits rq_status;
64	struct	rqhead rq_queues[RQ_NQS];
65};
66
67void	runq_add(struct runq *, struct thread *, int);
68void	runq_add_pri(struct runq *, struct thread *, u_char, int);
69int	runq_check(struct runq *);
70struct	thread *runq_choose(struct runq *);
71struct	thread *runq_choose_from(struct runq *, u_char);
72struct	thread *runq_choose_fuzz(struct runq *, int);
73void	runq_init(struct runq *);
74void	runq_remove(struct runq *, struct thread *);
75void	runq_remove_idx(struct runq *, struct thread *, u_char *);
76
77#endif
78