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 pri_to_rtp(td, &rtp); 108 switch (rtp.type) 109 { 110 case RTP_PRIO_FIFO: 111 *policy = SCHED_FIFO; 112 break; 113 114 case RTP_PRIO_REALTIME: 115 *policy = SCHED_RR; 116 break; 117 118 default: 119 *policy = SCHED_OTHER; 120 break; 121 } 122 123 return e; 124 } 125 126 int 127 ksched_setparam(struct ksched *ksched, 128 struct thread *td, const struct sched_param *param) 129 { 130 int policy; 131 int e; 132 133 e = getscheduler(ksched, td, &policy); 134 135 if (e == 0) 136 { 137 if (policy == SCHED_OTHER) 138 e = EINVAL; 139 else 140 e = ksched_setscheduler(ksched, td, policy, param); 141 } 142 143 return e; 144 } 145 146 int 147 ksched_getparam(struct ksched *ksched, 148 struct thread *td, struct sched_param *param) 149 { 150 struct rtprio rtp; 151 152 pri_to_rtp(td, &rtp); 153 if (RTP_PRIO_IS_REALTIME(rtp.type)) 154 param->sched_priority = rtpprio_to_p4prio(rtp.prio); 155 156 return 0; 157 } 158 159 /* 160 * XXX The priority and scheduler modifications should 161 * be moved into published interfaces in kern/kern_sync. 162 * 163 * The permissions to modify process p were checked in "p31b_proc()". 164 * 165 */ 166 int 167 ksched_setscheduler(struct ksched *ksched, 168 struct thread *td, int policy, const struct sched_param *param) 169 { 170 int e = 0; 171 struct rtprio rtp; 172 173 switch(policy) 174 { 175 case SCHED_RR: 176 case SCHED_FIFO: 177 178 if (param->sched_priority >= P1B_PRIO_MIN && 179 param->sched_priority <= P1B_PRIO_MAX) 180 { 181 rtp.prio = p4prio_to_rtpprio(param->sched_priority); 182 rtp.type = (policy == SCHED_FIFO) 183 ? RTP_PRIO_FIFO : RTP_PRIO_REALTIME; 184 185 rtp_to_pri(&rtp, td); 186 } 187 else 188 e = EPERM; 189 190 191 break; 192 193 case SCHED_OTHER: 194 { 195 rtp.type = RTP_PRIO_NORMAL; 196 rtp.prio = p4prio_to_rtpprio(param->sched_priority); 197 rtp_to_pri(&rtp, td); 198 } 199 break; 200 201 default: 202 e = EINVAL; 203 break; 204 } 205 206 return e; 207 } 208 209 int 210 ksched_getscheduler(struct ksched *ksched, struct thread *td, int *policy) 211 { 212 return getscheduler(ksched, td, policy); 213 } 214 215 /* ksched_yield: Yield the CPU. 216 */ 217 int 218 ksched_yield(struct ksched *ksched) 219 { 220 sched_relinquish(curthread); 221 return 0; 222 } 223 224 int 225 ksched_get_priority_max(struct ksched *ksched, int policy, int *prio) 226 { 227 int e = 0; 228 229 switch (policy) 230 { 231 case SCHED_FIFO: 232 case SCHED_RR: 233 *prio = RTP_PRIO_MAX; 234 break; 235 236 case SCHED_OTHER: 237 *prio = PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE; 238 break; 239 240 default: 241 e = EINVAL; 242 } 243 244 return e; 245 } 246 247 int 248 ksched_get_priority_min(struct ksched *ksched, int policy, int *prio) 249 { 250 int e = 0; 251 252 switch (policy) 253 { 254 case SCHED_FIFO: 255 case SCHED_RR: 256 *prio = P1B_PRIO_MIN; 257 break; 258 259 case SCHED_OTHER: 260 *prio = 0; 261 break; 262 263 default: 264 e = EINVAL; 265 } 266 267 return e; 268 } 269 270 int 271 ksched_rr_get_interval(struct ksched *ksched, 272 struct thread *td, struct timespec *timespec) 273 { 274 *timespec = ksched->rr_interval; 275 276 return 0; 277 } 278