sched.h revision 219820 
1/*-
2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2010 iX Systems, Inc.
4 * Copyright (c) 2010 Panasas, Inc.
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 unmodified, this list of conditions, and the following
12 *    disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28#ifndef	_LINUX_SCHED_H_
29#define	_LINUX_SCHED_H_
30
31#include <sys/param.h>
32#include <sys/systm.h>
33#include <sys/proc.h>
34#include <sys/sched.h>
35#include <sys/sleepqueue.h>
36
37#define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
38
39#define	TASK_RUNNING		0
40#define	TASK_INTERRUPTIBLE	1
41#define	TASK_UNINTERRUPTIBLE	2
42#define	TASK_DEAD		64
43#define	TASK_WAKEKILL		128
44#define	TASK_WAKING		256
45
46#define	TASK_SHOULD_STOP	1
47#define	TASK_STOPPED		2
48
49/*
50 * A task_struct is only provided for those tasks created with kthread.
51 * Using these routines with threads not started via kthread will cause
52 * panics because no task_struct is allocated and td_retval[1] is
53 * overwritten by syscalls which kernel threads will not make use of.
54 */
55struct task_struct {
56	struct	thread *task_thread;
57	int	(*task_fn)(void *data);
58	void	*task_data;
59	int	task_ret;
60	int	state;
61	int	should_stop;
62};
63
64#define	current			((struct task_struct *)curthread->td_retval[1])
65#define	task_struct_get(x)	(struct task_struct *)(x)->td_retval[1]
66#define	task_struct_set(x, y)	(x)->td_retval[1] = (register_t)(y)
67
68#define	set_current_state(x)						\
69	atomic_store_rel_int((volatile int *)&current->state, (x))
70#define	__set_current_state(x)	current->state = (x)
71
72
73#define	schedule()							\
74do {									\
75	void *c;							\
76									\
77	if (cold)							\
78		break;							\
79	c = curthread;							\
80	sleepq_lock(c);							\
81	if (current->state == TASK_INTERRUPTIBLE ||			\
82	    current->state == TASK_UNINTERRUPTIBLE) {			\
83		sleepq_add(c, NULL, "task", SLEEPQ_SLEEP, 0);		\
84		sleepq_wait(c, 0);					\
85	} else {							\
86		sleepq_release(c);					\
87		sched_relinquish(curthread);				\
88	}								\
89} while (0)
90
91#define	wake_up_process(x)						\
92do {									\
93	int wakeup_swapper;						\
94	void *c;							\
95									\
96	c = (x)->task_thread;						\
97	sleepq_lock(c);							\
98	(x)->state = TASK_RUNNING;					\
99	wakeup_swapper = sleepq_signal(c, SLEEPQ_SLEEP, 0, 0);		\
100	sleepq_release(c);						\
101	if (wakeup_swapper)						\
102		kick_proc0();						\
103} while (0)
104
105#define	cond_resched()	if (!cold)	sched_relinquish(curthread)
106
107#define	sched_yield()	sched_relinquish(curthread)
108
109#endif	/* _LINUX_SCHED_H_ */
110