/* * Copyright (c) 1996, 1997 * HD Associates, Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by HD Associates, Inc * 4. Neither the name of the author nor the names of any co-contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $FreeBSD: src/sys/posix4/ksched.c,v 1.7.2.1 2000/05/16 06:58:13 dillon Exp $ * $DragonFly: src/sys/kern/kern_sched.c,v 1.6 2005/11/14 18:50:00 dillon Exp $ */ /* ksched: Soft real time scheduling based on "rtprio". */ #include #include #include #include #include #include /* For need_user_resched */ #include /* For need_user_resched */ #include "posix4.h" /* ksched: Real-time extension to support POSIX priority scheduling. */ struct ksched { struct timespec rr_interval; }; int ksched_attach(struct ksched **p) { struct ksched *ksched= p31b_malloc(sizeof(*ksched)); ksched->rr_interval.tv_sec = 0; ksched->rr_interval.tv_nsec = 1000000000L / 10; /* XXX */ *p = ksched; return 0; } int ksched_detach(struct ksched *p) { p31b_free(p); return 0; } /* * XXX About priorities * * POSIX 1003.1b requires that numerically higher priorities be of * higher priority. It also permits sched_setparam to be * implementation defined for SCHED_OTHER. I don't like * the notion of inverted priorites for normal processes when * you can use "setpriority" for that. * * I'm rejecting sched_setparam for SCHED_OTHER with EINVAL. */ /* Macros to convert between the unix (lower numerically is higher priority) * and POSIX 1003.1b (higher numerically is higher priority) */ #define p4prio_to_rtpprio(P) (RTP_PRIO_MAX - (P)) #define rtpprio_to_p4prio(P) (RTP_PRIO_MAX - (P)) /* These improve readability a bit for me: */ #define P1B_PRIO_MIN rtpprio_to_p4prio(RTP_PRIO_MAX) #define P1B_PRIO_MAX rtpprio_to_p4prio(RTP_PRIO_MIN) static __inline int getscheduler(register_t *ret, struct ksched *ksched, struct proc *p) { int e = 0; switch (p->p_lwp.lwp_rtprio.type) { case RTP_PRIO_FIFO: *ret = SCHED_FIFO; break; case RTP_PRIO_REALTIME: *ret = SCHED_RR; break; default: *ret = SCHED_OTHER; break; } return e; } int ksched_setparam(register_t *ret, struct ksched *ksched, struct proc *p, const struct sched_param *param) { register_t policy; int e; e = getscheduler(&policy, ksched, p); if (e == 0) { if (policy == SCHED_OTHER) e = EINVAL; else e = ksched_setscheduler(ret, ksched, p, policy, param); } return e; } int ksched_getparam(register_t *ret, struct ksched *ksched, struct proc *p, struct sched_param *param) { if (RTP_PRIO_IS_REALTIME(p->p_lwp.lwp_rtprio.type)) param->sched_priority = rtpprio_to_p4prio(p->p_rtprio.prio); return 0; } /* * XXX The priority and scheduler modifications should * be moved into published interfaces in kern/kern_sync. * * The permissions to modify process p were checked in "p31b_proc()". * */ int ksched_setscheduler(register_t *ret, struct ksched *ksched, struct proc *p, int policy, const struct sched_param *param) { int e = 0; struct rtprio rtp; switch(policy) { case SCHED_RR: case SCHED_FIFO: if (param->sched_priority >= P1B_PRIO_MIN && param->sched_priority <= P1B_PRIO_MAX) { rtp.prio = p4prio_to_rtpprio(param->sched_priority); rtp.type = (policy == SCHED_FIFO) ? RTP_PRIO_FIFO : RTP_PRIO_REALTIME; p->p_lwp.lwp_rtprio = rtp; need_user_resched(); } else e = EPERM; break; case SCHED_OTHER: { rtp.type = RTP_PRIO_NORMAL; rtp.prio = p4prio_to_rtpprio(param->sched_priority); p->p_lwp.lwp_rtprio = rtp; /* XXX Simply revert to whatever we had for last * normal scheduler priorities. * This puts a requirement * on the scheduling code: You must leave the * scheduling info alone. */ need_user_resched(); } break; } return e; } int ksched_getscheduler(register_t *ret, struct ksched *ksched, struct proc *p) { return getscheduler(ret, ksched, p); } /* ksched_yield: Yield the CPU. */ int ksched_yield(register_t *ret, struct ksched *ksched) { need_user_resched(); return 0; } int ksched_get_priority_max(register_t*ret, struct ksched *ksched, int policy) { int e = 0; switch (policy) { case SCHED_FIFO: case SCHED_RR: *ret = RTP_PRIO_MAX; break; case SCHED_OTHER: *ret = PRIO_MAX; break; default: e = EINVAL; } return e; } int ksched_get_priority_min(register_t *ret, struct ksched *ksched, int policy) { int e = 0; switch (policy) { case SCHED_FIFO: case SCHED_RR: *ret = P1B_PRIO_MIN; break; case SCHED_OTHER: *ret = PRIO_MIN; break; default: e = EINVAL; } return e; } int ksched_rr_get_interval(register_t *ret, struct ksched *ksched, struct proc *p, struct timespec *timespec) { *timespec = ksched->rr_interval; return 0; }