1 /* 2 * Copyright (c) 1996, 1997 3 * HD Associates, Inc. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by HD Associates, Inc 16 * 4. Neither the name of the author nor the names of any co-contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* ksched: Soft real time scheduling based on "rtprio". 34 */ 35 36 #include <sys/cdefs.h> 37 __FBSDID("$FreeBSD$"); 38 39 #include "opt_posix.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/lock.h> 44 #include <sys/mutex.h> 45 #include <sys/proc.h> 46 #include <sys/resource.h> 47 #include <sys/sched.h> 48 49 #include <posix4/posix4.h> 50 51 /* ksched: Real-time extension to support POSIX priority scheduling. 52 */ 53 54 struct ksched { 55 struct timespec rr_interval; 56 }; 57 58 int ksched_attach(struct ksched **p) 59 { 60 struct ksched *ksched= p31b_malloc(sizeof(*ksched)); 61 62 ksched->rr_interval.tv_sec = 0; 63 ksched->rr_interval.tv_nsec = 1000000000L / sched_rr_interval(); 64 65 *p = ksched; 66 return 0; 67 } 68 69 int ksched_detach(struct ksched *ks) 70 { 71 p31b_free(ks); 72 73 return 0; 74 } 75 76 /* 77 * XXX About priorities 78 * 79 * POSIX 1003.1b requires that numerically higher priorities be of 80 * higher priority. It also permits sched_setparam to be 81 * implementation defined for SCHED_OTHER. I don't like 82 * the notion of inverted priorites for normal processes when 83 * you can use "setpriority" for that. 84 * 85 * I'm rejecting sched_setparam for SCHED_OTHER with EINVAL. 86 */ 87 88 /* Macros to convert between the unix (lower numerically is higher priority) 89 * and POSIX 1003.1b (higher numerically is higher priority) 90 */ 91 92 #define p4prio_to_rtpprio(P) (RTP_PRIO_MAX - (P)) 93 #define rtpprio_to_p4prio(P) (RTP_PRIO_MAX - (P)) 94 95 /* These improve readability a bit for me: 96 */ 97 #define P1B_PRIO_MIN rtpprio_to_p4prio(RTP_PRIO_MAX) 98 #define P1B_PRIO_MAX rtpprio_to_p4prio(RTP_PRIO_MIN) 99 100 static __inline int 101 getscheduler(register_t *ret, struct ksched *ksched, struct thread *td) 102 { 103 struct rtprio rtp; 104 int e = 0; 105 106 mtx_lock_spin(&sched_lock); 107 pri_to_rtp(td->td_ksegrp, &rtp); 108 mtx_unlock_spin(&sched_lock); 109 switch (rtp.type) 110 { 111 case RTP_PRIO_FIFO: 112 *ret = SCHED_FIFO; 113 break; 114 115 case RTP_PRIO_REALTIME: 116 *ret = SCHED_RR; 117 break; 118 119 default: 120 *ret = SCHED_OTHER; 121 break; 122 } 123 124 return e; 125 } 126 127 int ksched_setparam(register_t *ret, struct ksched *ksched, 128 struct thread *td, const struct sched_param *param) 129 { 130 register_t policy; 131 int e; 132 133 e = getscheduler(&policy, ksched, td); 134 135 if (e == 0) 136 { 137 if (policy == SCHED_OTHER) 138 e = EINVAL; 139 else 140 e = ksched_setscheduler(ret, ksched, td, policy, param); 141 } 142 143 return e; 144 } 145 146 int ksched_getparam(register_t *ret, struct ksched *ksched, 147 struct thread *td, struct sched_param *param) 148 { 149 struct rtprio rtp; 150 151 mtx_lock_spin(&sched_lock); 152 pri_to_rtp(td->td_ksegrp, &rtp); 153 mtx_unlock_spin(&sched_lock); 154 if (RTP_PRIO_IS_REALTIME(rtp.type)) 155 param->sched_priority = rtpprio_to_p4prio(rtp.prio); 156 157 return 0; 158 } 159 160 /* 161 * XXX The priority and scheduler modifications should 162 * be moved into published interfaces in kern/kern_sync. 163 * 164 * The permissions to modify process p were checked in "p31b_proc()". 165 * 166 */ 167 int ksched_setscheduler(register_t *ret, struct ksched *ksched, 168 struct thread *td, int policy, const struct sched_param *param) 169 { 170 int e = 0; 171 struct rtprio rtp; 172 struct ksegrp *kg = td->td_ksegrp; 173 174 switch(policy) 175 { 176 case SCHED_RR: 177 case SCHED_FIFO: 178 179 if (param->sched_priority >= P1B_PRIO_MIN && 180 param->sched_priority <= P1B_PRIO_MAX) 181 { 182 rtp.prio = p4prio_to_rtpprio(param->sched_priority); 183 rtp.type = (policy == SCHED_FIFO) 184 ? RTP_PRIO_FIFO : RTP_PRIO_REALTIME; 185 186 mtx_lock_spin(&sched_lock); 187 rtp_to_pri(&rtp, kg); 188 FOREACH_THREAD_IN_GROUP(kg, td) { /* XXXKSE */ 189 if (TD_IS_RUNNING(td)) { 190 td->td_flags |= TDF_NEEDRESCHED; 191 } else if (TD_ON_RUNQ(td)) { 192 if (td->td_priority > kg->kg_user_pri) { 193 sched_prio(td, kg->kg_user_pri); 194 } 195 } 196 } 197 mtx_unlock_spin(&sched_lock); 198 } 199 else 200 e = EPERM; 201 202 203 break; 204 205 case SCHED_OTHER: 206 { 207 rtp.type = RTP_PRIO_NORMAL; 208 rtp.prio = p4prio_to_rtpprio(param->sched_priority); 209 mtx_lock_spin(&sched_lock); 210 rtp_to_pri(&rtp, kg); 211 212 /* XXX Simply revert to whatever we had for last 213 * normal scheduler priorities. 214 * This puts a requirement 215 * on the scheduling code: You must leave the 216 * scheduling info alone. 217 */ 218 FOREACH_THREAD_IN_GROUP(kg, td) { 219 if (TD_IS_RUNNING(td)) { 220 td->td_flags |= TDF_NEEDRESCHED; 221 } else if (TD_ON_RUNQ(td)) { 222 if (td->td_priority > kg->kg_user_pri) { 223 sched_prio(td, kg->kg_user_pri); 224 } 225 } 226 227 } 228 mtx_unlock_spin(&sched_lock); 229 } 230 break; 231 } 232 233 return e; 234 } 235 236 int ksched_getscheduler(register_t *ret, struct ksched *ksched, struct thread *td) 237 { 238 return getscheduler(ret, ksched, td); 239 } 240 241 /* ksched_yield: Yield the CPU. 242 */ 243 int ksched_yield(register_t *ret, struct ksched *ksched) 244 { 245 mtx_lock_spin(&sched_lock); 246 curthread->td_flags |= TDF_NEEDRESCHED; 247 mtx_unlock_spin(&sched_lock); 248 return 0; 249 } 250 251 int ksched_get_priority_max(register_t*ret, struct ksched *ksched, int policy) 252 { 253 int e = 0; 254 255 switch (policy) 256 { 257 case SCHED_FIFO: 258 case SCHED_RR: 259 *ret = RTP_PRIO_MAX; 260 break; 261 262 case SCHED_OTHER: 263 *ret = PRIO_MAX; 264 break; 265 266 default: 267 e = EINVAL; 268 } 269 270 return e; 271 } 272 273 int ksched_get_priority_min(register_t *ret, struct ksched *ksched, int policy) 274 { 275 int e = 0; 276 277 switch (policy) 278 { 279 case SCHED_FIFO: 280 case SCHED_RR: 281 *ret = P1B_PRIO_MIN; 282 break; 283 284 case SCHED_OTHER: 285 *ret = PRIO_MIN; 286 break; 287 288 default: 289 e = EINVAL; 290 } 291 292 return e; 293 } 294 295 int ksched_rr_get_interval(register_t *ret, struct ksched *ksched, 296 struct thread *td, struct timespec *timespec) 297 { 298 *timespec = ksched->rr_interval; 299 300 return 0; 301 } 302