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 #include <sys/types.h>
68 #ifdef SCHED_STATS
69 #include <sys/pcpu.h>
70 #endif
71
72 struct proc;
73 struct thread;
74
75 /*
76 * General scheduling info.
77 *
78 * sched_load:
79 * Total runnable non-ithread threads in the system.
80 *
81 * sched_runnable:
82 * Runnable threads for this processor.
83 */
84 int sched_load(void);
85 int sched_rr_interval(void);
86 bool sched_runnable(void);
87
88 /*
89 * Proc related scheduling hooks.
90 */
91 void sched_exit(struct proc *p, struct thread *childtd);
92 void sched_fork(struct thread *td, struct thread *childtd);
93 void sched_fork_exit(struct thread *td);
94 void sched_class(struct thread *td, int class);
95 void sched_nice(struct proc *p, int nice);
96
97 /*
98 * Threads are switched in and out, block on resources, have temporary
99 * priorities inherited from their procs, and use up cpu time.
100 */
101 void sched_ap_entry(void);
102 void sched_exit_thread(struct thread *td, struct thread *child);
103 u_int sched_estcpu(struct thread *td);
104 void sched_fork_thread(struct thread *td, struct thread *child);
105 void sched_ithread_prio(struct thread *td, u_char prio);
106 void sched_lend_prio(struct thread *td, u_char prio);
107 void sched_lend_user_prio(struct thread *td, u_char pri);
108 void sched_lend_user_prio_cond(struct thread *td, u_char pri);
109 fixpt_t sched_pctcpu(struct thread *td);
110 void sched_prio(struct thread *td, u_char prio);
111 void sched_sleep(struct thread *td, int prio);
112 void sched_switch(struct thread *td, int flags);
113 void sched_throw(struct thread *td);
114 void sched_unlend_prio(struct thread *td, u_char prio);
115 void sched_user_prio(struct thread *td, u_char prio);
116 void sched_userret_slowpath(struct thread *td);
117 #ifdef RACCT
118 #ifdef SCHED_4BSD
119 fixpt_t sched_pctcpu_delta(struct thread *td);
120 #endif
121 #endif
122
123 static inline void
sched_userret(struct thread * td)124 sched_userret(struct thread *td)
125 {
126
127 /*
128 * XXX we cheat slightly on the locking here to avoid locking in
129 * the usual case. Setting td_priority here is essentially an
130 * incomplete workaround for not setting it properly elsewhere.
131 * Now that some interrupt handlers are threads, not setting it
132 * properly elsewhere can clobber it in the window between setting
133 * it here and returning to user mode, so don't waste time setting
134 * it perfectly here.
135 */
136 KASSERT((td->td_flags & TDF_BORROWING) == 0,
137 ("thread with borrowed priority returning to userland"));
138 if (__predict_false(td->td_priority != td->td_user_pri))
139 sched_userret_slowpath(td);
140 }
141
142 /*
143 * Threads are moved on and off of run queues
144 */
145 void sched_add(struct thread *td, int flags);
146 struct thread *sched_choose(void);
147 void sched_clock(struct thread *td, int cnt);
148 void sched_idletd(void *);
149 void sched_preempt(struct thread *td);
150 void sched_relinquish(struct thread *td);
151 void sched_rem(struct thread *td);
152 void sched_wakeup(struct thread *td, int srqflags);
153
154 /*
155 * Binding makes cpu affinity permanent while pinning is used to temporarily
156 * hold a thread on a particular CPU.
157 */
158 void sched_bind(struct thread *td, int cpu);
159 static __inline void sched_pin(void);
160 void sched_unbind(struct thread *td);
161 static __inline void sched_unpin(void);
162 int sched_is_bound(struct thread *td);
163 void sched_affinity(struct thread *td);
164
165 /*
166 * These procedures tell the process data structure allocation code how
167 * many bytes to actually allocate.
168 */
169 int sched_sizeof_proc(void);
170 int sched_sizeof_thread(void);
171
172 /*
173 * This routine provides a consistent thread name for use with KTR graphing
174 * functions.
175 */
176 char *sched_tdname(struct thread *td);
177 #ifdef KTR
178 void sched_clear_tdname(struct thread *td);
179 #endif
180
181 static __inline void
sched_pin(void)182 sched_pin(void)
183 {
184 curthread->td_pinned++;
185 atomic_interrupt_fence();
186 }
187
188 static __inline void
sched_unpin(void)189 sched_unpin(void)
190 {
191 atomic_interrupt_fence();
192 MPASS(curthread->td_pinned > 0);
193 curthread->td_pinned--;
194 }
195
196 /* sched_add arguments (formerly setrunqueue) */
197 #define SRQ_BORING 0x0000 /* No special circumstances. */
198 #define SRQ_YIELDING 0x0001 /* We are yielding (from mi_switch). */
199 #define SRQ_OURSELF 0x0002 /* It is ourself (from mi_switch). */
200 #define SRQ_INTR 0x0004 /* It is probably urgent. */
201 #define SRQ_PREEMPTED 0x0008 /* has been preempted.. be kind */
202 #define SRQ_BORROWING 0x0010 /* Priority updated due to prio_lend */
203 #define SRQ_HOLD 0x0020 /* Return holding original td lock */
204 #define SRQ_HOLDTD 0x0040 /* Return holding td lock */
205
206 /* Scheduler stats. */
207 #ifdef SCHED_STATS
208 DPCPU_DECLARE(long, sched_switch_stats[SWT_COUNT]);
209
210 #define SCHED_STAT_DEFINE_VAR(name, ptr, descr) \
211 static void name ## _add_proc(void *dummy __unused) \
212 { \
213 \
214 SYSCTL_ADD_PROC(NULL, \
215 SYSCTL_STATIC_CHILDREN(_kern_sched_stats), OID_AUTO, \
216 #name, CTLTYPE_LONG|CTLFLAG_RD|CTLFLAG_MPSAFE, \
217 ptr, 0, sysctl_dpcpu_long, "LU", descr); \
218 } \
219 SYSINIT(name, SI_SUB_LAST, SI_ORDER_MIDDLE, name ## _add_proc, NULL);
220
221 #define SCHED_STAT_DEFINE(name, descr) \
222 DPCPU_DEFINE(unsigned long, name); \
223 SCHED_STAT_DEFINE_VAR(name, &DPCPU_NAME(name), descr)
224 /*
225 * Sched stats are always incremented in critical sections so no atomic
226 * is necessary to increment them.
227 */
228 #define SCHED_STAT_INC(var) DPCPU_GET(var)++;
229 #else
230 #define SCHED_STAT_DEFINE_VAR(name, descr, ptr)
231 #define SCHED_STAT_DEFINE(name, descr)
232 #define SCHED_STAT_INC(var) (void)0
233 #endif
234
235 /*
236 * Fixup scheduler state for proc0 and thread0
237 */
238 void schedinit(void);
239
240 /*
241 * Fixup scheduler state for secondary APs
242 */
243 void schedinit_ap(void);
244 #endif /* _KERNEL */
245
246 /* POSIX 1003.1b Process Scheduling */
247
248 /*
249 * POSIX scheduling policies
250 */
251 #define SCHED_FIFO 1
252 #define SCHED_OTHER 2
253 #define SCHED_RR 3
254
255 struct sched_param {
256 int sched_priority;
257 };
258
259 /*
260 * POSIX scheduling declarations for userland.
261 */
262 #ifndef _KERNEL
263 #include <sys/cdefs.h>
264 #include <sys/_timespec.h>
265 #include <sys/_types.h>
266
267 #ifndef _PID_T_DECLARED
268 typedef __pid_t pid_t;
269 #define _PID_T_DECLARED
270 #endif
271
272 __BEGIN_DECLS
273 int sched_get_priority_max(int);
274 int sched_get_priority_min(int);
275 int sched_getparam(pid_t, struct sched_param *);
276 int sched_getscheduler(pid_t);
277 int sched_rr_get_interval(pid_t, struct timespec *);
278 int sched_setparam(pid_t, const struct sched_param *);
279 int sched_setscheduler(pid_t, int, const struct sched_param *);
280 int sched_yield(void);
281 __END_DECLS
282
283 #endif
284 #endif /* !_SCHED_H_ */
285