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32 * $FreeBSD: src/sys/posix4/ksched.c,v 1.7.2.1 2000/05/16 06:58:13 dillon Exp $
33 * $DragonFly: src/sys/kern/kern_sched.c,v 1.10 2008/04/21 15:24:46 dillon Exp $
36 /* ksched: Soft real time scheduling based on "rtprio".
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/posix4.h>
43 #include <sys/kernel.h>
44 #include <sys/resource.h>
45 #include <machine/cpu.h> /* For need_user_resched */
48 /* ksched: Real-time extension to support POSIX priority scheduling.
52 struct timespec rr_interval;
55 int ksched_attach(struct ksched **p)
57 struct ksched *ksched= p31b_malloc(sizeof(*ksched));
59 ksched->rr_interval.tv_sec = 0;
60 ksched->rr_interval.tv_nsec = 1000000000L / 10; /* XXX */
66 int ksched_detach(struct ksched *p)
74 * XXX About priorities
76 * POSIX 1003.1b requires that numerically higher priorities be of
77 * higher priority. It also permits sched_setparam to be
78 * implementation defined for SCHED_OTHER. I don't like
79 * the notion of inverted priorites for normal processes when
80 * you can use "setpriority" for that.
82 * I'm rejecting sched_setparam for SCHED_OTHER with EINVAL.
85 /* Macros to convert between the unix (lower numerically is higher priority)
86 * and POSIX 1003.1b (higher numerically is higher priority)
89 #define p4prio_to_rtpprio(P) (RTP_PRIO_MAX - (P))
90 #define rtpprio_to_p4prio(P) (RTP_PRIO_MAX - (P))
92 /* These improve readability a bit for me:
94 #define P1B_PRIO_MIN rtpprio_to_p4prio(RTP_PRIO_MAX)
95 #define P1B_PRIO_MAX rtpprio_to_p4prio(RTP_PRIO_MIN)
98 getscheduler(register_t *ret, struct ksched *ksched, struct lwp *lp)
102 switch (lp->lwp_rtprio.type)
108 case RTP_PRIO_REALTIME:
120 int ksched_setparam(register_t *ret, struct ksched *ksched,
121 struct lwp *lp, const struct sched_param *param)
126 e = getscheduler(&policy, ksched, lp);
130 if (policy == SCHED_OTHER)
133 e = ksched_setscheduler(ret, ksched, lp, policy, param);
139 int ksched_getparam(register_t *ret, struct ksched *ksched,
140 struct lwp *lp, struct sched_param *param)
142 if (RTP_PRIO_IS_REALTIME(lp->lwp_rtprio.type))
143 param->sched_priority = rtpprio_to_p4prio(lp->lwp_rtprio.prio);
149 * XXX The priority and scheduler modifications should
150 * be moved into published interfaces in kern/kern_sync.
152 * The permissions to modify process p were checked in "p31b_proc()".
155 int ksched_setscheduler(register_t *ret, struct ksched *ksched,
156 struct lwp *lp, int policy, const struct sched_param *param)
166 if (param->sched_priority >= P1B_PRIO_MIN &&
167 param->sched_priority <= P1B_PRIO_MAX)
169 rtp.prio = p4prio_to_rtpprio(param->sched_priority);
170 rtp.type = (policy == SCHED_FIFO)
171 ? RTP_PRIO_FIFO : RTP_PRIO_REALTIME;
173 lp->lwp_rtprio = rtp;
184 rtp.type = RTP_PRIO_NORMAL;
185 rtp.prio = p4prio_to_rtpprio(param->sched_priority);
186 lp->lwp_rtprio = rtp;
188 /* XXX Simply revert to whatever we had for last
189 * normal scheduler priorities.
190 * This puts a requirement
191 * on the scheduling code: You must leave the
192 * scheduling info alone.
202 int ksched_getscheduler(register_t *ret, struct ksched *ksched, struct lwp *lp)
204 return getscheduler(ret, ksched, lp);
208 * ksched_yield: Yield the CPU.
213 ksched_yield(register_t *ret, struct ksched *ksched)
217 if ((lp = curthread->td_lwp) != NULL) {
218 lp->lwp_proc->p_usched->yield(lp);
227 ksched_get_priority_max(register_t*ret, struct ksched *ksched, int policy)
251 ksched_get_priority_min(register_t *ret, struct ksched *ksched, int policy)
274 ksched_rr_get_interval(register_t *ret, struct ksched *ksched,
275 struct lwp *lp, struct timespec *timespec)
277 *timespec = ksched->rr_interval;