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/posix4.h> 47 #include <sys/resource.h> 48 #include <sys/sched.h> 49 50 /* ksched: Real-time extension to support POSIX priority scheduling. 51 */ 52 53 struct ksched { 54 struct timespec rr_interval; 55 }; 56 57 int 58 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 70 ksched_detach(struct ksched *ks) 71 { 72 p31b_free(ks); 73 74 return 0; 75 } 76 77 /* 78 * XXX About priorities 79 * 80 * POSIX 1003.1b requires that numerically higher priorities be of 81 * higher priority. It also permits sched_setparam to be 82 * implementation defined for SCHED_OTHER. I don't like 83 * the notion of inverted priorites for normal processes when 84 * you can use "setpriority" for that. 85 * 86 * I'm rejecting sched_setparam for SCHED_OTHER with EINVAL. 87 */ 88 89 /* Macros to convert between the unix (lower numerically is higher priority) 90 * and POSIX 1003.1b (higher numerically is higher priority) 91 */ 92 93 #define p4prio_to_rtpprio(P) (RTP_PRIO_MAX - (P)) 94 #define rtpprio_to_p4prio(P) (RTP_PRIO_MAX - (P)) 95 96 /* These improve readability a bit for me: 97 */ 98 #define P1B_PRIO_MIN rtpprio_to_p4prio(RTP_PRIO_MAX) 99 #define P1B_PRIO_MAX rtpprio_to_p4prio(RTP_PRIO_MIN) 100 101 static __inline int 102 getscheduler(struct ksched *ksched, struct thread *td, int *policy) 103 { 104 struct rtprio rtp; 105 int e = 0; 106 107 mtx_lock_spin(&sched_lock); 108 pri_to_rtp(td, &rtp); 109 mtx_unlock_spin(&sched_lock); 110 switch (rtp.type) 111 { 112 case RTP_PRIO_FIFO: 113 *policy = SCHED_FIFO; 114 break; 115 116 case RTP_PRIO_REALTIME: 117 *policy = SCHED_RR; 118 break; 119 120 default: 121 *policy = SCHED_OTHER; 122 break; 123 } 124 125 return e; 126 } 127 128 int 129 ksched_setparam(struct ksched *ksched, 130 struct thread *td, const struct sched_param *param) 131 { 132 int policy; 133 int e; 134 135 e = getscheduler(ksched, td, &policy); 136 137 if (e == 0) 138 { 139 if (policy == SCHED_OTHER) 140 e = EINVAL; 141 else 142 e = ksched_setscheduler(ksched, td, policy, param); 143 } 144 145 return e; 146 } 147 148 int 149 ksched_getparam(struct ksched *ksched, 150 struct thread *td, struct sched_param *param) 151 { 152 struct rtprio rtp; 153 154 mtx_lock_spin(&sched_lock); 155 pri_to_rtp(td, &rtp); 156 mtx_unlock_spin(&sched_lock); 157 if (RTP_PRIO_IS_REALTIME(rtp.type)) 158 param->sched_priority = rtpprio_to_p4prio(rtp.prio); 159 160 return 0; 161 } 162 163 /* 164 * XXX The priority and scheduler modifications should 165 * be moved into published interfaces in kern/kern_sync. 166 * 167 * The permissions to modify process p were checked in "p31b_proc()". 168 * 169 */ 170 int 171 ksched_setscheduler(struct ksched *ksched, 172 struct thread *td, int policy, const struct sched_param *param) 173 { 174 int e = 0; 175 struct rtprio rtp; 176 177 switch(policy) 178 { 179 case SCHED_RR: 180 case SCHED_FIFO: 181 182 if (param->sched_priority >= P1B_PRIO_MIN && 183 param->sched_priority <= P1B_PRIO_MAX) 184 { 185 rtp.prio = p4prio_to_rtpprio(param->sched_priority); 186 rtp.type = (policy == SCHED_FIFO) 187 ? RTP_PRIO_FIFO : RTP_PRIO_REALTIME; 188 189 mtx_lock_spin(&sched_lock); 190 rtp_to_pri(&rtp, td); 191 mtx_unlock_spin(&sched_lock); 192 } 193 else 194 e = EPERM; 195 196 197 break; 198 199 case SCHED_OTHER: 200 { 201 rtp.type = RTP_PRIO_NORMAL; 202 rtp.prio = p4prio_to_rtpprio(param->sched_priority); 203 mtx_lock_spin(&sched_lock); 204 rtp_to_pri(&rtp, td); 205 mtx_unlock_spin(&sched_lock); 206 } 207 break; 208 209 default: 210 e = EINVAL; 211 break; 212 } 213 214 return e; 215 } 216 217 int 218 ksched_getscheduler(struct ksched *ksched, struct thread *td, int *policy) 219 { 220 return getscheduler(ksched, td, policy); 221 } 222 223 /* ksched_yield: Yield the CPU. 224 */ 225 int 226 ksched_yield(struct ksched *ksched) 227 { 228 sched_relinquish(curthread); 229 return 0; 230 } 231 232 int 233 ksched_get_priority_max(struct ksched *ksched, int policy, int *prio) 234 { 235 int e = 0; 236 237 switch (policy) 238 { 239 case SCHED_FIFO: 240 case SCHED_RR: 241 *prio = RTP_PRIO_MAX; 242 break; 243 244 case SCHED_OTHER: 245 *prio = PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE; 246 break; 247 248 default: 249 e = EINVAL; 250 } 251 252 return e; 253 } 254 255 int 256 ksched_get_priority_min(struct ksched *ksched, int policy, int *prio) 257 { 258 int e = 0; 259 260 switch (policy) 261 { 262 case SCHED_FIFO: 263 case SCHED_RR: 264 *prio = P1B_PRIO_MIN; 265 break; 266 267 case SCHED_OTHER: 268 *prio = 0; 269 break; 270 271 default: 272 e = EINVAL; 273 } 274 275 return e; 276 } 277 278 int 279 ksched_rr_get_interval(struct ksched *ksched, 280 struct thread *td, struct timespec *timespec) 281 { 282 *timespec = ksched->rr_interval; 283 284 return 0; 285 } 286