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 */ 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 #define p4prio_to_tsprio(P) ((PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE) - (P)) 96 #define tsprio_to_p4prio(P) ((PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE) - (P)) 97 98 /* These improve readability a bit for me: 99 */ 100 #define P1B_PRIO_MIN rtpprio_to_p4prio(RTP_PRIO_MAX) 101 #define P1B_PRIO_MAX rtpprio_to_p4prio(RTP_PRIO_MIN) 102 103 static __inline int 104 getscheduler(struct ksched *ksched, struct thread *td, int *policy) 105 { 106 struct rtprio rtp; 107 int e = 0; 108 109 pri_to_rtp(td, &rtp); 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 e = ksched_setscheduler(ksched, td, policy, param); 140 } 141 142 return e; 143 } 144 145 int 146 ksched_getparam(struct ksched *ksched, 147 struct thread *td, struct sched_param *param) 148 { 149 struct rtprio rtp; 150 151 pri_to_rtp(td, &rtp); 152 if (RTP_PRIO_IS_REALTIME(rtp.type)) 153 param->sched_priority = rtpprio_to_p4prio(rtp.prio); 154 else { 155 if (PRI_MIN_TIMESHARE < rtp.prio) 156 /* 157 * The interactive score has it to min realtime 158 * so we must show max (64 most likely 159 */ 160 param->sched_priority = (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE); 161 else 162 param->sched_priority = tsprio_to_p4prio(rtp.prio); 163 } 164 return 0; 165 } 166 167 /* 168 * XXX The priority and scheduler modifications should 169 * be moved into published interfaces in kern/kern_sync. 170 * 171 * The permissions to modify process p were checked in "p31b_proc()". 172 * 173 */ 174 int 175 ksched_setscheduler(struct ksched *ksched, 176 struct thread *td, int policy, const struct sched_param *param) 177 { 178 int e = 0; 179 struct rtprio rtp; 180 181 switch(policy) 182 { 183 case SCHED_RR: 184 case SCHED_FIFO: 185 186 if (param->sched_priority >= P1B_PRIO_MIN && 187 param->sched_priority <= P1B_PRIO_MAX) 188 { 189 rtp.prio = p4prio_to_rtpprio(param->sched_priority); 190 rtp.type = (policy == SCHED_FIFO) 191 ? RTP_PRIO_FIFO : RTP_PRIO_REALTIME; 192 193 rtp_to_pri(&rtp, td); 194 } 195 else 196 e = EPERM; 197 198 199 break; 200 201 case SCHED_OTHER: 202 if (param->sched_priority >= 0 && 203 param->sched_priority <= (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE)) { 204 rtp.type = RTP_PRIO_NORMAL; 205 rtp.prio = p4prio_to_rtpprio(param->sched_priority); 206 rtp_to_pri(&rtp, td); 207 } else 208 e = EINVAL; 209 210 break; 211 212 default: 213 e = EINVAL; 214 break; 215 } 216 217 return e; 218 } 219 220 int 221 ksched_getscheduler(struct ksched *ksched, struct thread *td, int *policy) 222 { 223 return getscheduler(ksched, td, policy); 224 } 225 226 /* ksched_yield: Yield the CPU. 227 */ 228 int 229 ksched_yield(struct ksched *ksched) 230 { 231 sched_relinquish(curthread); 232 return 0; 233 } 234 235 int 236 ksched_get_priority_max(struct ksched *ksched, int policy, int *prio) 237 { 238 int e = 0; 239 240 switch (policy) 241 { 242 case SCHED_FIFO: 243 case SCHED_RR: 244 *prio = RTP_PRIO_MAX; 245 break; 246 247 case SCHED_OTHER: 248 *prio = PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE; 249 break; 250 251 default: 252 e = EINVAL; 253 } 254 255 return e; 256 } 257 258 int 259 ksched_get_priority_min(struct ksched *ksched, int policy, int *prio) 260 { 261 int e = 0; 262 263 switch (policy) 264 { 265 case SCHED_FIFO: 266 case SCHED_RR: 267 *prio = P1B_PRIO_MIN; 268 break; 269 270 case SCHED_OTHER: 271 *prio = 0; 272 break; 273 274 default: 275 e = EINVAL; 276 } 277 278 return e; 279 } 280 281 int 282 ksched_rr_get_interval(struct ksched *ksched, 283 struct thread *td, struct timespec *timespec) 284 { 285 *timespec = ksched->rr_interval; 286 287 return 0; 288 } 289