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/*
* 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
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