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Diffstat (limited to 'sys/sys/runq.h')
| -rw-r--r-- | sys/sys/runq.h | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/sys/sys/runq.h b/sys/sys/runq.h new file mode 100644 index 000000000000..bf1f2837e8a2 --- /dev/null +++ b/sys/sys/runq.h @@ -0,0 +1,80 @@ +/* + * Copyright (c) 2001 Jake Burkholder <jake@FreeBSD.org> + * 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. + * + * 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 _RUNQ_H_ +#define _RUNQ_H_ + +/* + * Run queue parameters. + */ + +#define RQ_NQS (64) /* Number of run queues. */ +#define RQ_PPQ (4) /* Priorities per queue. */ + +#define RQB_LEN (2) /* Number of priority status words. */ +#define RQB_L2BPW (5) /* Log2(sizeof(rqb_word_t) * NBBY)). */ +#define RQB_BPW (1<<RQB_L2BPW) /* Bits in an rqb_word_t. */ + +#define RQB_BIT(pri) (1 << ((pri) & (RQB_BPW - 1))) +#define RQB_WORD(pri) ((pri) >> RQB_L2BPW) +#define RQB_FFS(word) (ffs(word)) + +/* + * Type of run queue status word. + */ +typedef u_int32_t rqb_word_t; + +/* + * Head of run queues. + */ +TAILQ_HEAD(rqhead, proc); + +/* + * Bit array which maintains the status of a run queue. When a queue is + * non-empty the bit corresponding to the queue number will be set. + */ +struct rqbits { + rqb_word_t rqb_bits[RQB_LEN]; +}; + +/* + * Run queue structure. Contains an array of run queues on which processes + * are placed, and a structure to maintain the status of each queue. + */ +struct runq { + struct rqbits rq_status; + struct rqhead rq_queues[RQ_NQS]; +}; + +void runq_add(struct runq *, struct proc *); +int runq_check(struct runq *); +struct proc *runq_choose(struct runq *); +void runq_init(struct runq *); +void runq_remove(struct runq *, struct proc *); + +#endif |