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33 /* ksched: Soft real time scheduling based on "rtprio".
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
39 #include "opt_posix.h"
41 #include <sys/param.h>
42 #include <sys/systm.h>
44 #include <sys/sysctl.h>
45 #include <sys/kernel.h>
46 #include <sys/mutex.h>
48 #include <sys/posix4.h>
49 #include <sys/resource.h>
50 #include <sys/sched.h>
52 FEATURE(kposix_priority_scheduling, "POSIX P1003.1B realtime extensions");
54 /* ksched: Real-time extension to support POSIX priority scheduling.
58 struct timespec rr_interval;
62 ksched_attach(struct ksched **p)
64 struct ksched *ksched= p31b_malloc(sizeof(*ksched));
66 ksched->rr_interval.tv_sec = 0;
67 ksched->rr_interval.tv_nsec = 1000000000L / sched_rr_interval();
74 ksched_detach(struct ksched *ks)
82 * XXX About priorities
84 * POSIX 1003.1b requires that numerically higher priorities be of
85 * higher priority. It also permits sched_setparam to be
86 * implementation defined for SCHED_OTHER. I don't like
87 * the notion of inverted priorites for normal processes when
88 * you can use "setpriority" for that.
92 /* Macros to convert between the unix (lower numerically is higher priority)
93 * and POSIX 1003.1b (higher numerically is higher priority)
96 #define p4prio_to_rtpprio(P) (RTP_PRIO_MAX - (P))
97 #define rtpprio_to_p4prio(P) (RTP_PRIO_MAX - (P))
99 #define p4prio_to_tsprio(P) ((PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE) - (P))
100 #define tsprio_to_p4prio(P) ((PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE) - (P))
102 /* These improve readability a bit for me:
104 #define P1B_PRIO_MIN rtpprio_to_p4prio(RTP_PRIO_MAX)
105 #define P1B_PRIO_MAX rtpprio_to_p4prio(RTP_PRIO_MIN)
108 getscheduler(struct ksched *ksched, struct thread *td, int *policy)
113 pri_to_rtp(td, &rtp);
117 *policy = SCHED_FIFO;
120 case RTP_PRIO_REALTIME:
125 *policy = SCHED_OTHER;
133 ksched_setparam(struct ksched *ksched,
134 struct thread *td, const struct sched_param *param)
139 e = getscheduler(ksched, td, &policy);
143 e = ksched_setscheduler(ksched, td, policy, param);
150 ksched_getparam(struct ksched *ksched,
151 struct thread *td, struct sched_param *param)
155 pri_to_rtp(td, &rtp);
156 if (RTP_PRIO_IS_REALTIME(rtp.type))
157 param->sched_priority = rtpprio_to_p4prio(rtp.prio);
159 if (PRI_MIN_TIMESHARE < rtp.prio)
161 * The interactive score has it to min realtime
162 * so we must show max (64 most likely
164 param->sched_priority = (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE);
166 param->sched_priority = tsprio_to_p4prio(rtp.prio);
172 * XXX The priority and scheduler modifications should
173 * be moved into published interfaces in kern/kern_sync.
175 * The permissions to modify process p were checked in "p31b_proc()".
179 ksched_setscheduler(struct ksched *ksched,
180 struct thread *td, int policy, const struct sched_param *param)
190 if (param->sched_priority >= P1B_PRIO_MIN &&
191 param->sched_priority <= P1B_PRIO_MAX)
193 rtp.prio = p4prio_to_rtpprio(param->sched_priority);
194 rtp.type = (policy == SCHED_FIFO)
195 ? RTP_PRIO_FIFO : RTP_PRIO_REALTIME;
197 rtp_to_pri(&rtp, td);
206 if (param->sched_priority >= 0 &&
207 param->sched_priority <= (PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE)) {
208 rtp.type = RTP_PRIO_NORMAL;
209 rtp.prio = p4prio_to_tsprio(param->sched_priority);
210 rtp_to_pri(&rtp, td);
225 ksched_getscheduler(struct ksched *ksched, struct thread *td, int *policy)
227 return getscheduler(ksched, td, policy);
230 /* ksched_yield: Yield the CPU.
233 ksched_yield(struct ksched *ksched)
235 sched_relinquish(curthread);
240 ksched_get_priority_max(struct ksched *ksched, int policy, int *prio)
248 *prio = RTP_PRIO_MAX;
252 *prio = PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE;
263 ksched_get_priority_min(struct ksched *ksched, int policy, int *prio)
271 *prio = P1B_PRIO_MIN;
286 ksched_rr_get_interval(struct ksched *ksched,
287 struct thread *td, struct timespec *timespec)
289 *timespec = ksched->rr_interval;