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 * $FreeBSD$ 33 */ 34 35 /* ksched: Soft real time scheduling based on "rtprio". 36 */ 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/lock.h> 41 #include <sys/mutex.h> 42 #include <sys/proc.h> 43 #include <sys/resource.h> 44 45 #include <posix4/posix4.h> 46 47 /* ksched: Real-time extension to support POSIX priority scheduling. 48 */ 49 50 struct ksched { 51 struct timespec rr_interval; 52 }; 53 54 int ksched_attach(struct ksched **p) 55 { 56 struct ksched *ksched= p31b_malloc(sizeof(*ksched)); 57 58 ksched->rr_interval.tv_sec = 0; 59 ksched->rr_interval.tv_nsec = 1000000000L / roundrobin_interval(); 60 61 *p = ksched; 62 return 0; 63 } 64 65 int ksched_detach(struct ksched *ks) 66 { 67 p31b_free(ks); 68 69 return 0; 70 } 71 72 /* 73 * XXX About priorities 74 * 75 * POSIX 1003.1b requires that numerically higher priorities be of 76 * higher priority. It also permits sched_setparam to be 77 * implementation defined for SCHED_OTHER. I don't like 78 * the notion of inverted priorites for normal processes when 79 * you can use "setpriority" for that. 80 * 81 * I'm rejecting sched_setparam for SCHED_OTHER with EINVAL. 82 */ 83 84 /* Macros to convert between the unix (lower numerically is higher priority) 85 * and POSIX 1003.1b (higher numerically is higher priority) 86 */ 87 88 #define p4prio_to_rtpprio(P) (RTP_PRIO_MAX - (P)) 89 #define rtpprio_to_p4prio(P) (RTP_PRIO_MAX - (P)) 90 91 /* These improve readability a bit for me: 92 */ 93 #define P1B_PRIO_MIN rtpprio_to_p4prio(RTP_PRIO_MAX) 94 #define P1B_PRIO_MAX rtpprio_to_p4prio(RTP_PRIO_MIN) 95 96 static __inline int 97 getscheduler(register_t *ret, struct ksched *ksched, struct thread *td) 98 { 99 struct rtprio rtp; 100 int e = 0; 101 102 mtx_lock_spin(&sched_lock); 103 pri_to_rtp(td->td_ksegrp, &rtp); 104 mtx_unlock_spin(&sched_lock); 105 switch (rtp.type) 106 { 107 case RTP_PRIO_FIFO: 108 *ret = SCHED_FIFO; 109 break; 110 111 case RTP_PRIO_REALTIME: 112 *ret = SCHED_RR; 113 break; 114 115 default: 116 *ret = SCHED_OTHER; 117 break; 118 } 119 120 return e; 121 } 122 123 int ksched_setparam(register_t *ret, struct ksched *ksched, 124 struct thread *td, const struct sched_param *param) 125 { 126 register_t policy; 127 int e; 128 129 e = getscheduler(&policy, ksched, td); 130 131 if (e == 0) 132 { 133 if (policy == SCHED_OTHER) 134 e = EINVAL; 135 else 136 e = ksched_setscheduler(ret, ksched, td, policy, param); 137 } 138 139 return e; 140 } 141 142 int ksched_getparam(register_t *ret, struct ksched *ksched, 143 struct thread *td, struct sched_param *param) 144 { 145 struct rtprio rtp; 146 147 mtx_lock_spin(&sched_lock); 148 pri_to_rtp(td->td_ksegrp, &rtp); 149 mtx_unlock_spin(&sched_lock); 150 if (RTP_PRIO_IS_REALTIME(rtp.type)) 151 param->sched_priority = rtpprio_to_p4prio(rtp.prio); 152 153 return 0; 154 } 155 156 /* 157 * XXX The priority and scheduler modifications should 158 * be moved into published interfaces in kern/kern_sync. 159 * 160 * The permissions to modify process p were checked in "p31b_proc()". 161 * 162 */ 163 int ksched_setscheduler(register_t *ret, struct ksched *ksched, 164 struct thread *td, int policy, const struct sched_param *param) 165 { 166 int e = 0; 167 struct rtprio rtp; 168 struct ksegrp *kg = td->td_ksegrp; 169 170 switch(policy) 171 { 172 case SCHED_RR: 173 case SCHED_FIFO: 174 175 if (param->sched_priority >= P1B_PRIO_MIN && 176 param->sched_priority <= P1B_PRIO_MAX) 177 { 178 rtp.prio = p4prio_to_rtpprio(param->sched_priority); 179 rtp.type = (policy == SCHED_FIFO) 180 ? RTP_PRIO_FIFO : RTP_PRIO_REALTIME; 181 182 mtx_lock_spin(&sched_lock); 183 rtp_to_pri(&rtp, kg); 184 td->td_last_kse->ke_flags |= KEF_NEEDRESCHED; /* XXXKSE */ 185 mtx_unlock_spin(&sched_lock); 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 mtx_lock_spin(&sched_lock); 198 rtp_to_pri(&rtp, kg); 199 200 /* XXX Simply revert to whatever we had for last 201 * normal scheduler priorities. 202 * This puts a requirement 203 * on the scheduling code: You must leave the 204 * scheduling info alone. 205 */ 206 td->td_last_kse->ke_flags |= KEF_NEEDRESCHED; /* XXXKSE */ 207 mtx_unlock_spin(&sched_lock); 208 } 209 break; 210 } 211 212 return e; 213 } 214 215 int ksched_getscheduler(register_t *ret, struct ksched *ksched, struct thread *td) 216 { 217 return getscheduler(ret, ksched, td); 218 } 219 220 /* ksched_yield: Yield the CPU. 221 */ 222 int ksched_yield(register_t *ret, struct ksched *ksched) 223 { 224 mtx_lock_spin(&sched_lock); 225 curthread->td_kse->ke_flags |= KEF_NEEDRESCHED; 226 mtx_unlock_spin(&sched_lock); 227 return 0; 228 } 229 230 int ksched_get_priority_max(register_t*ret, struct ksched *ksched, int policy) 231 { 232 int e = 0; 233 234 switch (policy) 235 { 236 case SCHED_FIFO: 237 case SCHED_RR: 238 *ret = RTP_PRIO_MAX; 239 break; 240 241 case SCHED_OTHER: 242 *ret = PRIO_MAX; 243 break; 244 245 default: 246 e = EINVAL; 247 } 248 249 return e; 250 } 251 252 int ksched_get_priority_min(register_t *ret, struct ksched *ksched, int policy) 253 { 254 int e = 0; 255 256 switch (policy) 257 { 258 case SCHED_FIFO: 259 case SCHED_RR: 260 *ret = P1B_PRIO_MIN; 261 break; 262 263 case SCHED_OTHER: 264 *ret = PRIO_MIN; 265 break; 266 267 default: 268 e = EINVAL; 269 } 270 271 return e; 272 } 273 274 int ksched_rr_get_interval(register_t *ret, struct ksched *ksched, 275 struct thread *td, struct timespec *timespec) 276 { 277 *timespec = ksched->rr_interval; 278 279 return 0; 280 } 281