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 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 173 sched_pin(void) 174 { 175 curthread->td_pinned++; 176 atomic_interrupt_fence(); 177 } 178 179 static __inline void 180 sched_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 199 DPCPU_DECLARE(long, sched_switch_stats[SWT_COUNT]); 200 201 #define SCHED_STAT_DEFINE_VAR(name, ptr, descr) \ 202 static 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 } \ 210 SYSINIT(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 necessary 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 */ 229 void schedinit(void); 230 231 /* 232 * Fixup scheduler state for secondary APs 233 */ 234 void 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 3 245 246 struct 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 259 typedef __pid_t pid_t; 260 #define _PID_T_DECLARED 261 #endif 262 263 __BEGIN_DECLS 264 int sched_get_priority_max(int); 265 int sched_get_priority_min(int); 266 int sched_getparam(pid_t, struct sched_param *); 267 int sched_getscheduler(pid_t); 268 int sched_rr_get_interval(pid_t, struct timespec *); 269 int sched_setparam(pid_t, const struct sched_param *); 270 int sched_setscheduler(pid_t, int, const struct sched_param *); 271 int sched_yield(void); 272 __END_DECLS 273 274 #endif 275 #endif /* !_SCHED_H_ */ 276