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_exit_thread(struct thread *td, struct thread *child);
93 u_int sched_estcpu(struct thread *td);
94 void sched_fork_thread(struct thread *td, struct thread *child);
95 void sched_lend_prio(struct thread *td, u_char prio);
96 void sched_lend_user_prio(struct thread *td, u_char pri);
97 void sched_lend_user_prio_cond(struct thread *td, u_char pri);
98 fixpt_t sched_pctcpu(struct thread *td);
99 void sched_prio(struct thread *td, u_char prio);
100 void sched_sleep(struct thread *td, int prio);
101 void sched_switch(struct thread *td, int flags);
102 void sched_throw(struct thread *td);
103 void sched_unlend_prio(struct thread *td, u_char prio);
104 void sched_user_prio(struct thread *td, u_char prio);
105 void sched_userret_slowpath(struct thread *td);
106 #ifdef RACCT
107 #ifdef SCHED_4BSD
108 fixpt_t sched_pctcpu_delta(struct thread *td);
109 #endif
110 #endif
111
112 static inline void
sched_userret(struct thread * td)113 sched_userret(struct thread *td)
114 {
115
116 /*
117 * XXX we cheat slightly on the locking here to avoid locking in
118 * the usual case. Setting td_priority here is essentially an
119 * incomplete workaround for not setting it properly elsewhere.
120 * Now that some interrupt handlers are threads, not setting it
121 * properly elsewhere can clobber it in the window between setting
122 * it here and returning to user mode, so don't waste time setting
123 * it perfectly here.
124 */
125 KASSERT((td->td_flags & TDF_BORROWING) == 0,
126 ("thread with borrowed priority returning to userland"));
127 if (__predict_false(td->td_priority != td->td_user_pri))
128 sched_userret_slowpath(td);
129 }
130
131 /*
132 * Threads are moved on and off of run queues
133 */
134 void sched_add(struct thread *td, int flags);
135 struct thread *sched_choose(void);
136 void sched_clock(struct thread *td, int cnt);
137 void sched_idletd(void *);
138 void sched_preempt(struct thread *td);
139 void sched_relinquish(struct thread *td);
140 void sched_rem(struct thread *td);
141 void sched_wakeup(struct thread *td, int srqflags);
142
143 /*
144 * Binding makes cpu affinity permanent while pinning is used to temporarily
145 * hold a thread on a particular CPU.
146 */
147 void sched_bind(struct thread *td, int cpu);
148 static __inline void sched_pin(void);
149 void sched_unbind(struct thread *td);
150 static __inline void sched_unpin(void);
151 int sched_is_bound(struct thread *td);
152 void sched_affinity(struct thread *td);
153
154 /*
155 * These procedures tell the process data structure allocation code how
156 * many bytes to actually allocate.
157 */
158 int sched_sizeof_proc(void);
159 int sched_sizeof_thread(void);
160
161 /*
162 * This routine provides a consistent thread name for use with KTR graphing
163 * functions.
164 */
165 char *sched_tdname(struct thread *td);
166 #ifdef KTR
167 void sched_clear_tdname(struct thread *td);
168 #endif
169
170 static __inline void
sched_pin(void)171 sched_pin(void)
172 {
173 curthread->td_pinned++;
174 atomic_interrupt_fence();
175 }
176
177 static __inline void
sched_unpin(void)178 sched_unpin(void)
179 {
180 atomic_interrupt_fence();
181 curthread->td_pinned--;
182 }
183
184 /* sched_add arguments (formerly setrunqueue) */
185 #define SRQ_BORING 0x0000 /* No special circumstances. */
186 #define SRQ_YIELDING 0x0001 /* We are yielding (from mi_switch). */
187 #define SRQ_OURSELF 0x0002 /* It is ourself (from mi_switch). */
188 #define SRQ_INTR 0x0004 /* It is probably urgent. */
189 #define SRQ_PREEMPTED 0x0008 /* has been preempted.. be kind */
190 #define SRQ_BORROWING 0x0010 /* Priority updated due to prio_lend */
191 #define SRQ_HOLD 0x0020 /* Return holding original td lock */
192 #define SRQ_HOLDTD 0x0040 /* Return holding td lock */
193
194 /* Scheduler stats. */
195 #ifdef SCHED_STATS
196 DPCPU_DECLARE(long, sched_switch_stats[SWT_COUNT]);
197
198 #define SCHED_STAT_DEFINE_VAR(name, ptr, descr) \
199 static void name ## _add_proc(void *dummy __unused) \
200 { \
201 \
202 SYSCTL_ADD_PROC(NULL, \
203 SYSCTL_STATIC_CHILDREN(_kern_sched_stats), OID_AUTO, \
204 #name, CTLTYPE_LONG|CTLFLAG_RD|CTLFLAG_MPSAFE, \
205 ptr, 0, sysctl_dpcpu_long, "LU", descr); \
206 } \
207 SYSINIT(name, SI_SUB_LAST, SI_ORDER_MIDDLE, name ## _add_proc, NULL);
208
209 #define SCHED_STAT_DEFINE(name, descr) \
210 DPCPU_DEFINE(unsigned long, name); \
211 SCHED_STAT_DEFINE_VAR(name, &DPCPU_NAME(name), descr)
212 /*
213 * Sched stats are always incremented in critical sections so no atomic
214 * is necesssary to increment them.
215 */
216 #define SCHED_STAT_INC(var) DPCPU_GET(var)++;
217 #else
218 #define SCHED_STAT_DEFINE_VAR(name, descr, ptr)
219 #define SCHED_STAT_DEFINE(name, descr)
220 #define SCHED_STAT_INC(var) (void)0
221 #endif
222
223 /*
224 * Fixup scheduler state for proc0 and thread0
225 */
226 void schedinit(void);
227
228 /*
229 * Fixup scheduler state for secondary APs
230 */
231 void schedinit_ap(void);
232 #endif /* _KERNEL */
233
234 /* POSIX 1003.1b Process Scheduling */
235
236 /*
237 * POSIX scheduling policies
238 */
239 #define SCHED_FIFO 1
240 #define SCHED_OTHER 2
241 #define SCHED_RR 3
242
243 struct sched_param {
244 int sched_priority;
245 };
246
247 /*
248 * POSIX scheduling declarations for userland.
249 */
250 #ifndef _KERNEL
251 #include <sys/cdefs.h>
252 #include <sys/_timespec.h>
253 #include <sys/_types.h>
254
255 #ifndef _PID_T_DECLARED
256 typedef __pid_t pid_t;
257 #define _PID_T_DECLARED
258 #endif
259
260 __BEGIN_DECLS
261 int sched_get_priority_max(int);
262 int sched_get_priority_min(int);
263 int sched_getparam(pid_t, struct sched_param *);
264 int sched_getscheduler(pid_t);
265 int sched_rr_get_interval(pid_t, struct timespec *);
266 int sched_setparam(pid_t, const struct sched_param *);
267 int sched_setscheduler(pid_t, int, const struct sched_param *);
268 int sched_yield(void);
269 __END_DECLS
270
271 #endif
272 #endif /* !_SCHED_H_ */
273