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32 * $FreeBSD: src/sys/posix4/ksched.c,v 1.7.2.1 2000/05/16 06:58:13 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;
56 ksched_attach(struct ksched **p)
58 struct ksched *ksched= p31b_malloc(sizeof(*ksched));
60 ksched->rr_interval.tv_sec = 0;
61 ksched->rr_interval.tv_nsec = 1000000000L / 10; /* XXX */
68 ksched_detach(struct ksched *p)
76 * XXX About priorities
78 * POSIX 1003.1b requires that numerically higher priorities be of
79 * higher priority. It also permits sched_setparam to be
80 * implementation defined for SCHED_OTHER. I don't like
81 * the notion of inverted priorites for normal processes when
82 * you can use "setpriority" for that.
84 * I'm rejecting sched_setparam for SCHED_OTHER with EINVAL.
87 /* Macros to convert between the unix (lower numerically is higher priority)
88 * and POSIX 1003.1b (higher numerically is higher priority)
91 #define p4prio_to_rtpprio(P) (RTP_PRIO_MAX - (P))
92 #define rtpprio_to_p4prio(P) (RTP_PRIO_MAX - (P))
95 * These improve readability a bit for me:
97 #define P1B_PRIO_MIN rtpprio_to_p4prio(RTP_PRIO_MAX)
98 #define P1B_PRIO_MAX rtpprio_to_p4prio(RTP_PRIO_MIN)
101 getscheduler(register_t *ret, struct ksched *ksched, struct lwp *lp)
105 switch (lp->lwp_rtprio.type) {
109 case RTP_PRIO_REALTIME:
121 ksched_setparam(register_t *ret, struct ksched *ksched,
122 struct lwp *lp, const struct sched_param *param)
127 e = getscheduler(&policy, ksched, lp);
130 if (policy == SCHED_OTHER)
133 e = ksched_setscheduler(ret, ksched, lp, policy, param);
140 ksched_getparam(register_t *ret, struct ksched *ksched,
141 struct lwp *lp, struct sched_param *param)
143 if (RTP_PRIO_IS_REALTIME(lp->lwp_rtprio.type))
144 param->sched_priority = rtpprio_to_p4prio(lp->lwp_rtprio.prio);
150 * XXX The priority and scheduler modifications should
151 * be moved into published interfaces in kern/kern_sync.
153 * The permissions to modify process p were checked in "p31b_proc()".
157 ksched_setscheduler(register_t *ret, struct ksched *ksched,
158 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) {
168 rtp.prio = p4prio_to_rtpprio(param->sched_priority);
169 rtp.type = (policy == SCHED_FIFO) ?
170 RTP_PRIO_FIFO : RTP_PRIO_REALTIME;
172 lp->lwp_rtprio = rtp;
179 rtp.type = RTP_PRIO_NORMAL;
180 rtp.prio = p4prio_to_rtpprio(param->sched_priority);
181 lp->lwp_rtprio = rtp;
184 * XXX Simply revert to whatever we had for last
185 * normal scheduler priorities.
186 * This puts a requirement
187 * on the scheduling code: You must leave the
188 * scheduling info alone.
198 ksched_getscheduler(register_t *ret, struct ksched *ksched, struct lwp *lp)
200 return getscheduler(ret, ksched, lp);
204 * ksched_yield: Yield the CPU.
209 ksched_yield(register_t *ret, struct ksched *ksched)
213 if ((lp = curthread->td_lwp) != NULL)
214 lp->lwp_proc->p_usched->yield(lp);
222 ksched_get_priority_max(register_t*ret, struct ksched *ksched, int policy)
246 ksched_get_priority_min(register_t *ret, struct ksched *ksched, int policy)
269 ksched_rr_get_interval(register_t *ret, struct ksched *ksched,
270 struct lwp *lp, struct timespec *timespec)
272 *timespec = ksched->rr_interval;