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 */
75 int sched_load(void);
76 int sched_rr_interval(void);
77 int sched_runnable(void);
78
79 /*
80 * Proc related scheduling hooks.
81 */
82 void sched_exit(struct proc *p, struct thread *childtd);
83 void sched_fork(struct thread *td, struct thread *childtd);
84 void sched_fork_exit(struct thread *td);
85 void sched_class(struct thread *td, int class);
86 void 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 */
92 void sched_ap_entry(void);
93 void sched_exit_thread(struct thread *td, struct thread *child);
94 u_int sched_estcpu(struct thread *td);
95 void sched_fork_thread(struct thread *td, struct thread *child);
96 void sched_ithread_prio(struct thread *td, u_char prio);
97 void sched_lend_prio(struct thread *td, u_char prio);
98 void sched_lend_user_prio(struct thread *td, u_char pri);
99 void sched_lend_user_prio_cond(struct thread *td, u_char pri);
100 fixpt_t sched_pctcpu(struct thread *td);
101 void sched_prio(struct thread *td, u_char prio);
102 void sched_sleep(struct thread *td, int prio);
103 void sched_switch(struct thread *td, int flags);
104 void sched_throw(struct thread *td);
105 void sched_unlend_prio(struct thread *td, u_char prio);
106 void sched_user_prio(struct thread *td, u_char prio);
107 void sched_userret_slowpath(struct thread *td);
108 #ifdef RACCT
109 #ifdef SCHED_4BSD
110 fixpt_t sched_pctcpu_delta(struct thread *td);
111 #endif
112 #endif
113
114 static inline void
sched_userret(struct thread * td)115 sched_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 */
136 void sched_add(struct thread *td, int flags);
137 struct thread *sched_choose(void);
138 void sched_clock(struct thread *td, int cnt);
139 void sched_idletd(void *);
140 void sched_preempt(struct thread *td);
141 void sched_relinquish(struct thread *td);
142 void sched_rem(struct thread *td);
143 void 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 */
149 void sched_bind(struct thread *td, int cpu);
150 static __inline void sched_pin(void);
151 void sched_unbind(struct thread *td);
152 static __inline void sched_unpin(void);
153 int sched_is_bound(struct thread *td);
154 void 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 */
160 int sched_sizeof_proc(void);
161 int sched_sizeof_thread(void);
162
163 /*
164 * This routine provides a consistent thread name for use with KTR graphing
165 * functions.
166 */
167 char *sched_tdname(struct thread *td);
168 #ifdef KTR
169 void sched_clear_tdname(struct thread *td);
170 #endif
171
172 static __inline void
sched_pin(void)173 sched_pin(void)
174 {
175 curthread->td_pinned++;
176 atomic_interrupt_fence();
177 }
178
179 static __inline void
sched_unpin(void)180 sched_unpin(void)
181 {
182 atomic_interrupt_fence();
183 curthread->td_pinned--;
184 }
185
186 /* sched_add arguments (formerly setrunqueue) */
187 #define SRQ_BORING 0x0000 /* No special circumstances. */
188 #define SRQ_YIELDING 0x0001 /* We are yielding (from mi_switch). */
189 #define SRQ_OURSELF 0x0002 /* It is ourself (from mi_switch). */
190 #define SRQ_INTR 0x0004 /* It is probably urgent. */
191 #define SRQ_PREEMPTED 0x0008 /* has been preempted.. be kind */
192 #define SRQ_BORROWING 0x0010 /* Priority updated due to prio_lend */
193 #define SRQ_HOLD 0x0020 /* Return holding original td lock */
194 #define SRQ_HOLDTD 0x0040 /* Return holding td lock */
195
196 /* Scheduler stats. */
197 #ifdef SCHED_STATS
198 DPCPU_DECLARE(long, sched_switch_stats[SWT_COUNT]);
199
200 #define SCHED_STAT_DEFINE_VAR(name, ptr, descr) \
201 static void name ## _add_proc(void *dummy __unused) \
202 { \
203 \
204 SYSCTL_ADD_PROC(NULL, \
205 SYSCTL_STATIC_CHILDREN(_kern_sched_stats), OID_AUTO, \
206 #name, CTLTYPE_LONG|CTLFLAG_RD|CTLFLAG_MPSAFE, \
207 ptr, 0, sysctl_dpcpu_long, "LU", descr); \
208 } \
209 SYSINIT(name, SI_SUB_LAST, SI_ORDER_MIDDLE, name ## _add_proc, NULL);
210
211 #define SCHED_STAT_DEFINE(name, descr) \
212 DPCPU_DEFINE(unsigned long, name); \
213 SCHED_STAT_DEFINE_VAR(name, &DPCPU_NAME(name), descr)
214 /*
215 * Sched stats are always incremented in critical sections so no atomic
216 * is necessary to increment them.
217 */
218 #define SCHED_STAT_INC(var) DPCPU_GET(var)++;
219 #else
220 #define SCHED_STAT_DEFINE_VAR(name, descr, ptr)
221 #define SCHED_STAT_DEFINE(name, descr)
222 #define SCHED_STAT_INC(var) (void)0
223 #endif
224
225 /*
226 * Fixup scheduler state for proc0 and thread0
227 */
228 void schedinit(void);
229
230 /*
231 * Fixup scheduler state for secondary APs
232 */
233 void schedinit_ap(void);
234 #endif /* _KERNEL */
235
236 /* POSIX 1003.1b Process Scheduling */
237
238 /*
239 * POSIX scheduling policies
240 */
241 #define SCHED_FIFO 1
242 #define SCHED_OTHER 2
243 #define SCHED_RR 3
244
245 struct sched_param {
246 int sched_priority;
247 };
248
249 /*
250 * POSIX scheduling declarations for userland.
251 */
252 #ifndef _KERNEL
253 #include <sys/cdefs.h>
254 #include <sys/_timespec.h>
255 #include <sys/_types.h>
256
257 #ifndef _PID_T_DECLARED
258 typedef __pid_t pid_t;
259 #define _PID_T_DECLARED
260 #endif
261
262 __BEGIN_DECLS
263 int sched_get_priority_max(int);
264 int sched_get_priority_min(int);
265 int sched_getparam(pid_t, struct sched_param *);
266 int sched_getscheduler(pid_t);
267 int sched_rr_get_interval(pid_t, struct timespec *);
268 int sched_setparam(pid_t, const struct sched_param *);
269 int sched_setscheduler(pid_t, int, const struct sched_param *);
270 int sched_yield(void);
271 __END_DECLS
272
273 #endif
274 #endif /* !_SCHED_H_ */
275