2 * Copyright (c) 2001 Jake Burkholder <jake@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * Run queue parameters.
38 #define RQ_NQS (64) /* Number of run queues. */
39 #define RQ_PPQ (4) /* Priorities per queue. */
41 #define RQB_LEN (2) /* Number of priority status words. */
42 #define RQB_L2BPW (5) /* Log2(sizeof(rqb_word_t) * NBBY)). */
43 #define RQB_BPW (1<<RQB_L2BPW) /* Bits in an rqb_word_t. */
45 #define RQB_BIT(pri) (1 << ((pri) & (RQB_BPW - 1)))
46 #define RQB_WORD(pri) ((pri) >> RQB_L2BPW)
47 #define RQB_FFS(word) (ffs(word))
50 * Type of run queue status word.
52 typedef u_int32_t rqb_word_t;
57 TAILQ_HEAD(rqhead, kse);
60 * Bit array which maintains the status of a run queue. When a queue is
61 * non-empty the bit corresponding to the queue number will be set.
64 rqb_word_t rqb_bits[RQB_LEN];
68 * Run queue structure. Contains an array of run queues on which processes
69 * are placed, and a structure to maintain the status of each queue.
72 struct rqbits rq_status;
73 struct rqhead rq_queues[RQ_NQS];
76 void runq_add(struct runq *, struct kse *);
77 int runq_check(struct runq *);
78 struct kse *runq_choose(struct runq *);
79 void runq_init(struct runq *);
80 void runq_remove(struct runq *, struct kse *);