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33 /* ksched: Soft real time scheduling based on "rtprio". */
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
38 #include "opt_posix.h"
40 #include <sys/param.h>
41 #include <sys/systm.h>
43 #include <sys/sysctl.h>
44 #include <sys/kernel.h>
45 #include <sys/mutex.h>
47 #include <sys/posix4.h>
48 #include <sys/resource.h>
49 #include <sys/sched.h>
51 FEATURE(kposix_priority_scheduling, "POSIX P1003.1B realtime extensions");
53 /* ksched: Real-time extension to support POSIX priority scheduling. */
56 struct timespec rr_interval;
60 ksched_attach(struct ksched **p)
62 struct ksched *ksched;
64 ksched = malloc(sizeof(*ksched), M_P31B, M_WAITOK);
65 ksched->rr_interval.tv_sec = 0;
66 ksched->rr_interval.tv_nsec = 1000000000L / hz * sched_rr_interval();
72 ksched_detach(struct ksched *ks)
80 * XXX About priorities
82 * POSIX 1003.1b requires that numerically higher priorities be of
83 * higher priority. It also permits sched_setparam to be
84 * implementation defined for SCHED_OTHER. I don't like
85 * the notion of inverted priorites for normal processes when
86 * you can use "setpriority" for that.
90 /* Macros to convert between the unix (lower numerically is higher priority)
91 * and POSIX 1003.1b (higher numerically is higher priority)
94 #define p4prio_to_rtpprio(P) (RTP_PRIO_MAX - (P))
95 #define rtpprio_to_p4prio(P) (RTP_PRIO_MAX - (P))
97 #define p4prio_to_tsprio(P) ((PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE) - (P))
98 #define tsprio_to_p4prio(P) ((PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE) - (P))
100 /* These improve readability a bit for me:
102 #define P1B_PRIO_MIN rtpprio_to_p4prio(RTP_PRIO_MAX)
103 #define P1B_PRIO_MAX rtpprio_to_p4prio(RTP_PRIO_MIN)
106 getscheduler(struct ksched *ksched, struct thread *td, int *policy)
112 pri_to_rtp(td, &rtp);
115 *policy = SCHED_FIFO;
117 case RTP_PRIO_REALTIME:
121 *policy = SCHED_OTHER;
128 ksched_setparam(struct ksched *ksched,
129 struct thread *td, const struct sched_param *param)
133 e = getscheduler(ksched, td, &policy);
135 e = ksched_setscheduler(ksched, td, policy, param);
140 ksched_getparam(struct ksched *ksched, struct thread *td,
141 struct sched_param *param)
145 pri_to_rtp(td, &rtp);
146 if (RTP_PRIO_IS_REALTIME(rtp.type))
147 param->sched_priority = rtpprio_to_p4prio(rtp.prio);
149 if (PRI_MIN_TIMESHARE < rtp.prio)
151 * The interactive score has it to min realtime
152 * so we must show max (64 most likely).
154 param->sched_priority = PRI_MAX_TIMESHARE -
157 param->sched_priority = tsprio_to_p4prio(rtp.prio);
163 * XXX The priority and scheduler modifications should
164 * be moved into published interfaces in kern/kern_sync.
166 * The permissions to modify process p were checked in "p31b_proc()".
170 ksched_setscheduler(struct ksched *ksched, struct thread *td, int policy,
171 const struct sched_param *param)
180 if (param->sched_priority >= P1B_PRIO_MIN &&
181 param->sched_priority <= P1B_PRIO_MAX) {
182 rtp.prio = p4prio_to_rtpprio(param->sched_priority);
183 rtp.type = (policy == SCHED_FIFO) ? RTP_PRIO_FIFO :
185 rtp_to_pri(&rtp, td);
191 if (param->sched_priority >= 0 && param->sched_priority <=
192 (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE)) {
193 rtp.type = RTP_PRIO_NORMAL;
194 rtp.prio = p4prio_to_tsprio(param->sched_priority);
195 rtp_to_pri(&rtp, td);
208 ksched_getscheduler(struct ksched *ksched, struct thread *td, int *policy)
211 return (getscheduler(ksched, td, policy));
214 /* ksched_yield: Yield the CPU. */
216 ksched_yield(struct ksched *ksched)
219 sched_relinquish(curthread);
224 ksched_get_priority_max(struct ksched *ksched, int policy, int *prio)
232 *prio = P1B_PRIO_MAX;
235 *prio = PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE;
245 ksched_get_priority_min(struct ksched *ksched, int policy, int *prio)
253 *prio = P1B_PRIO_MIN;
266 ksched_rr_get_interval(struct ksched *ksched, struct thread *td,
267 struct timespec *timespec)
270 *timespec = ksched->rr_interval;