sched.h revision 270710 
1/*-
2 * Copyright (c) 2010 Isilon Systems, Inc.
3 * Copyright (c) 2010 iX Systems, Inc.
4 * Copyright (c) 2010 Panasas, Inc.
5 * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice unmodified, this list of conditions, and the following
13 *    disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29#ifndef	_LINUX_SCHED_H_
30#define	_LINUX_SCHED_H_
31
32#include <sys/param.h>
33#include <sys/systm.h>
34#include <sys/proc.h>
35#include <sys/sched.h>
36#include <sys/sleepqueue.h>
37
38#define	MAX_SCHEDULE_TIMEOUT	LONG_MAX
39
40#define	TASK_RUNNING		0
41#define	TASK_INTERRUPTIBLE	1
42#define	TASK_UNINTERRUPTIBLE	2
43#define	TASK_DEAD		64
44#define	TASK_WAKEKILL		128
45#define	TASK_WAKING		256
46
47#define	TASK_SHOULD_STOP	1
48#define	TASK_STOPPED		2
49
50/*
51 * A task_struct is only provided for those tasks created with kthread.
52 * Using these routines with threads not started via kthread will cause
53 * panics because no task_struct is allocated and td_retval[1] is
54 * overwritten by syscalls which kernel threads will not make use of.
55 */
56struct task_struct {
57	struct	thread *task_thread;
58	int	(*task_fn)(void *data);
59	void	*task_data;
60	int	task_ret;
61	int	state;
62	int	should_stop;
63};
64
65#define	current			((struct task_struct *)curthread->td_retval[1])
66#define	task_struct_get(x)	(struct task_struct *)(x)->td_retval[1]
67#define	task_struct_set(x, y)	(x)->td_retval[1] = (register_t)(y)
68
69#define	set_current_state(x)						\
70	atomic_store_rel_int((volatile int *)&current->state, (x))
71#define	__set_current_state(x)	current->state = (x)
72
73
74#define	schedule()							\
75do {									\
76	void *c;							\
77									\
78	if (cold)							\
79		break;							\
80	c = curthread;							\
81	sleepq_lock(c);							\
82	if (current->state == TASK_INTERRUPTIBLE ||			\
83	    current->state == TASK_UNINTERRUPTIBLE) {			\
84		sleepq_add(c, NULL, "task", SLEEPQ_SLEEP, 0);		\
85		sleepq_wait(c, 0);					\
86	} else {							\
87		sleepq_release(c);					\
88		sched_relinquish(curthread);				\
89	}								\
90} while (0)
91
92#define	wake_up_process(x)						\
93do {									\
94	int wakeup_swapper;						\
95	void *c;							\
96									\
97	c = (x)->task_thread;						\
98	sleepq_lock(c);							\
99	(x)->state = TASK_RUNNING;					\
100	wakeup_swapper = sleepq_signal(c, SLEEPQ_SLEEP, 0, 0);		\
101	sleepq_release(c);						\
102	if (wakeup_swapper)						\
103		kick_proc0();						\
104} while (0)
105
106#define	cond_resched()	if (!cold)	sched_relinquish(curthread)
107
108#define	sched_yield()	sched_relinquish(curthread)
109
110#endif	/* _LINUX_SCHED_H_ */
111