master
1/*-
2 * SPDX-License-Identifier: (BSD-4-Clause AND BSD-2-Clause)
3 *
4 * Copyright (c) 1996, 1997
5 * HD Associates, Inc. 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, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by HD Associates, Inc
18 * and Jukka Antero Ukkonen.
19 * 4. Neither the name of the author nor the names of any co-contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36/*-
37 * Copyright (c) 2002-2008, Jeffrey Roberson <jeff@freebsd.org>
38 * All rights reserved.
39 *
40 * Redistribution and use in source and binary forms, with or without
41 * modification, are permitted provided that the following conditions
42 * are met:
43 * 1. Redistributions of source code must retain the above copyright
44 * notice unmodified, this list of conditions, and the following
45 * disclaimer.
46 * 2. Redistributions in binary form must reproduce the above copyright
47 * notice, this list of conditions and the following disclaimer in the
48 * documentation and/or other materials provided with the distribution.
49 *
50 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
51 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
52 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
53 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
54 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
55 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
56 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
57 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
58 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
59 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
60 */
61
62#ifndef _SCHED_H_
63#define _SCHED_H_
64
65#ifdef _KERNEL
66/*
67 * General scheduling info.
68 *
69 * sched_load:
70 * Total runnable non-ithread threads in the system.
71 *
72 * sched_runnable:
73 * Runnable threads for this processor.
74 */
75int sched_load(void);
76int sched_rr_interval(void);
77int sched_runnable(void);
78
79/*
80 * Proc related scheduling hooks.
81 */
82void sched_exit(struct proc *p, struct thread *childtd);
83void sched_fork(struct thread *td, struct thread *childtd);
84void sched_fork_exit(struct thread *td);
85void sched_class(struct thread *td, int class);
86void sched_nice(struct proc *p, int nice);
87
88/*
89 * Threads are switched in and out, block on resources, have temporary
90 * priorities inherited from their procs, and use up cpu time.
91 */
92void sched_ap_entry(void);
93void sched_exit_thread(struct thread *td, struct thread *child);
94u_int sched_estcpu(struct thread *td);
95void sched_fork_thread(struct thread *td, struct thread *child);
96void sched_ithread_prio(struct thread *td, u_char prio);
97void sched_lend_prio(struct thread *td, u_char prio);
98void sched_lend_user_prio(struct thread *td, u_char pri);
99void sched_lend_user_prio_cond(struct thread *td, u_char pri);
100fixpt_t sched_pctcpu(struct thread *td);
101void sched_prio(struct thread *td, u_char prio);
102void sched_sleep(struct thread *td, int prio);
103void sched_switch(struct thread *td, int flags);
104void sched_throw(struct thread *td);
105void sched_unlend_prio(struct thread *td, u_char prio);
106void sched_user_prio(struct thread *td, u_char prio);
107void sched_userret_slowpath(struct thread *td);
108#ifdef RACCT
109#ifdef SCHED_4BSD
110fixpt_t sched_pctcpu_delta(struct thread *td);
111#endif
112#endif
113
114static inline void
115sched_userret(struct thread *td)
116{
117
118 /*
119 * XXX we cheat slightly on the locking here to avoid locking in
120 * the usual case. Setting td_priority here is essentially an
121 * incomplete workaround for not setting it properly elsewhere.
122 * Now that some interrupt handlers are threads, not setting it
123 * properly elsewhere can clobber it in the window between setting
124 * it here and returning to user mode, so don't waste time setting
125 * it perfectly here.
126 */
127 KASSERT((td->td_flags & TDF_BORROWING) == 0,
128 ("thread with borrowed priority returning to userland"));
129 if (__predict_false(td->td_priority != td->td_user_pri))
130 sched_userret_slowpath(td);
131}
132
133/*
134 * Threads are moved on and off of run queues
135 */
136void sched_add(struct thread *td, int flags);
137struct thread *sched_choose(void);
138void sched_clock(struct thread *td, int cnt);
139void sched_idletd(void *);
140void sched_preempt(struct thread *td);
141void sched_relinquish(struct thread *td);
142void sched_rem(struct thread *td);
143void sched_wakeup(struct thread *td, int srqflags);
144
145/*
146 * Binding makes cpu affinity permanent while pinning is used to temporarily
147 * hold a thread on a particular CPU.
148 */
149void sched_bind(struct thread *td, int cpu);
150static __inline void sched_pin(void);
151void sched_unbind(struct thread *td);
152static __inline void sched_unpin(void);
153int sched_is_bound(struct thread *td);
154void sched_affinity(struct thread *td);
155
156/*
157 * These procedures tell the process data structure allocation code how
158 * many bytes to actually allocate.
159 */
160int sched_sizeof_proc(void);
161int sched_sizeof_thread(void);
162
163/*
164 * This routine provides a consistent thread name for use with KTR graphing
165 * functions.
166 */
167char *sched_tdname(struct thread *td);
168#ifdef KTR
169void sched_clear_tdname(struct thread *td);
170#endif
171
172static __inline void
173sched_pin(void)
174{
175 curthread->td_pinned++;
176 atomic_interrupt_fence();
177}
178
179static __inline void
180sched_unpin(void)
181{
182 atomic_interrupt_fence();
183 MPASS(curthread->td_pinned > 0);
184 curthread->td_pinned--;
185}
186
187/* sched_add arguments (formerly setrunqueue) */
188#define SRQ_BORING 0x0000 /* No special circumstances. */
189#define SRQ_YIELDING 0x0001 /* We are yielding (from mi_switch). */
190#define SRQ_OURSELF 0x0002 /* It is ourself (from mi_switch). */
191#define SRQ_INTR 0x0004 /* It is probably urgent. */
192#define SRQ_PREEMPTED 0x0008 /* has been preempted.. be kind */
193#define SRQ_BORROWING 0x0010 /* Priority updated due to prio_lend */
194#define SRQ_HOLD 0x0020 /* Return holding original td lock */
195#define SRQ_HOLDTD 0x0040 /* Return holding td lock */
196
197/* Scheduler stats. */
198#ifdef SCHED_STATS
199DPCPU_DECLARE(long, sched_switch_stats[SWT_COUNT]);
200
201#define SCHED_STAT_DEFINE_VAR(name, ptr, descr) \
202static void name ## _add_proc(void *dummy __unused) \
203{ \
204 \
205 SYSCTL_ADD_PROC(NULL, \
206 SYSCTL_STATIC_CHILDREN(_kern_sched_stats), OID_AUTO, \
207 #name, CTLTYPE_LONG|CTLFLAG_RD|CTLFLAG_MPSAFE, \
208 ptr, 0, sysctl_dpcpu_long, "LU", descr); \
209} \
210SYSINIT(name, SI_SUB_LAST, SI_ORDER_MIDDLE, name ## _add_proc, NULL);
211
212#define SCHED_STAT_DEFINE(name, descr) \
213 DPCPU_DEFINE(unsigned long, name); \
214 SCHED_STAT_DEFINE_VAR(name, &DPCPU_NAME(name), descr)
215/*
216 * Sched stats are always incremented in critical sections so no atomic
217 * is necesssary to increment them.
218 */
219#define SCHED_STAT_INC(var) DPCPU_GET(var)++;
220#else
221#define SCHED_STAT_DEFINE_VAR(name, descr, ptr)
222#define SCHED_STAT_DEFINE(name, descr)
223#define SCHED_STAT_INC(var) (void)0
224#endif
225
226/*
227 * Fixup scheduler state for proc0 and thread0
228 */
229void schedinit(void);
230
231/*
232 * Fixup scheduler state for secondary APs
233 */
234void schedinit_ap(void);
235#endif /* _KERNEL */
236
237/* POSIX 1003.1b Process Scheduling */
238
239/*
240 * POSIX scheduling policies
241 */
242#define SCHED_FIFO 1
243#define SCHED_OTHER 2
244#define SCHED_RR 3
245
246struct sched_param {
247 int sched_priority;
248};
249
250/*
251 * POSIX scheduling declarations for userland.
252 */
253#ifndef _KERNEL
254#include <sys/cdefs.h>
255#include <sys/_timespec.h>
256#include <sys/_types.h>
257
258#ifndef _PID_T_DECLARED
259typedef __pid_t pid_t;
260#define _PID_T_DECLARED
261#endif
262
263__BEGIN_DECLS
264int sched_get_priority_max(int);
265int sched_get_priority_min(int);
266int sched_getparam(pid_t, struct sched_param *);
267int sched_getscheduler(pid_t);
268int sched_rr_get_interval(pid_t, struct timespec *);
269int sched_setparam(pid_t, const struct sched_param *);
270int sched_setscheduler(pid_t, int, const struct sched_param *);
271int sched_yield(void);
272__END_DECLS
273
274#endif
275#endif /* !_SCHED_H_ */