688ebe120c
the process of exiting the kernel. The ast() function now loops as long as the PS_ASTPENDING or PS_NEEDRESCHED flags are set. It returns with preemption disabled so that any further AST's that arrive via an interrupt will be delayed until the low-level MD code returns to user mode. - Use u_int's to store the tick counts for profiling purposes so that we do not need sched_lock just to read p_sticks. This also closes a problem where the call to addupc_task() could screw up the arithmetic due to non-atomic reads of p_sticks. - Axe need_proftick(), aston(), astoff(), astpending(), need_resched(), clear_resched(), and resched_wanted() in favor of direct bit operations on p_sflag. - Fix up locking with sched_lock some. In addupc_intr(), use sched_lock to ensure pr_addr and pr_ticks are updated atomically with setting PS_OWEUPC. In ast() we clear pr_ticks atomically with clearing PS_OWEUPC. We also do not grab the lock just to test a flag. - Simplify the handling of Giant in ast() slightly. Reviewed by: bde (mostly)
276 lines
6.3 KiB
C
276 lines
6.3 KiB
C
/*
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* Copyright (c) 1996, 1997
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* HD Associates, Inc. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by HD Associates, Inc
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* 4. Neither the name of the author nor the names of any co-contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY HD ASSOCIATES AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL HD ASSOCIATES OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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/* ksched: Soft real time scheduling based on "rtprio".
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/lock.h>
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#include <sys/mutex.h>
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#include <sys/proc.h>
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#include <sys/resource.h>
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#include <posix4/posix4.h>
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/* ksched: Real-time extension to support POSIX priority scheduling.
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*/
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struct ksched {
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struct timespec rr_interval;
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};
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int ksched_attach(struct ksched **p)
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{
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struct ksched *ksched= p31b_malloc(sizeof(*ksched));
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ksched->rr_interval.tv_sec = 0;
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ksched->rr_interval.tv_nsec = 1000000000L / roundrobin_interval();
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*p = ksched;
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return 0;
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}
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int ksched_detach(struct ksched *p)
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{
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p31b_free(p);
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return 0;
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}
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/*
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* XXX About priorities
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*
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* POSIX 1003.1b requires that numerically higher priorities be of
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* higher priority. It also permits sched_setparam to be
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* implementation defined for SCHED_OTHER. I don't like
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* the notion of inverted priorites for normal processes when
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* you can use "setpriority" for that.
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*
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* I'm rejecting sched_setparam for SCHED_OTHER with EINVAL.
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*/
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/* Macros to convert between the unix (lower numerically is higher priority)
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* and POSIX 1003.1b (higher numerically is higher priority)
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*/
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#define p4prio_to_rtpprio(P) (RTP_PRIO_MAX - (P))
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#define rtpprio_to_p4prio(P) (RTP_PRIO_MAX - (P))
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/* These improve readability a bit for me:
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*/
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#define P1B_PRIO_MIN rtpprio_to_p4prio(RTP_PRIO_MAX)
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#define P1B_PRIO_MAX rtpprio_to_p4prio(RTP_PRIO_MIN)
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static __inline int
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getscheduler(register_t *ret, struct ksched *ksched, struct proc *p)
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{
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struct rtprio rtp;
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int e = 0;
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pri_to_rtp(&p->p_pri, &rtp);
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switch (rtp.type)
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{
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case RTP_PRIO_FIFO:
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*ret = SCHED_FIFO;
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break;
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case RTP_PRIO_REALTIME:
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*ret = SCHED_RR;
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break;
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default:
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*ret = SCHED_OTHER;
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break;
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}
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return e;
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}
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int ksched_setparam(register_t *ret, struct ksched *ksched,
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struct proc *p, const struct sched_param *param)
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{
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register_t policy;
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int e;
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e = getscheduler(&policy, ksched, p);
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if (e == 0)
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{
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if (policy == SCHED_OTHER)
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e = EINVAL;
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else
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e = ksched_setscheduler(ret, ksched, p, policy, param);
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}
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return e;
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}
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int ksched_getparam(register_t *ret, struct ksched *ksched,
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struct proc *p, struct sched_param *param)
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{
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struct rtprio rtp;
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pri_to_rtp(&p->p_pri, &rtp);
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if (RTP_PRIO_IS_REALTIME(rtp.type))
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param->sched_priority = rtpprio_to_p4prio(rtp.prio);
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return 0;
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}
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/*
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* XXX The priority and scheduler modifications should
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* be moved into published interfaces in kern/kern_sync.
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*
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* The permissions to modify process p were checked in "p31b_proc()".
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*
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*/
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int ksched_setscheduler(register_t *ret, struct ksched *ksched,
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struct proc *p, int policy, const struct sched_param *param)
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{
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int e = 0;
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struct rtprio rtp;
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switch(policy)
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{
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case SCHED_RR:
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case SCHED_FIFO:
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if (param->sched_priority >= P1B_PRIO_MIN &&
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param->sched_priority <= P1B_PRIO_MAX)
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{
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rtp.prio = p4prio_to_rtpprio(param->sched_priority);
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rtp.type = (policy == SCHED_FIFO)
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? RTP_PRIO_FIFO : RTP_PRIO_REALTIME;
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mtx_lock_spin(&sched_lock);
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rtp_to_pri(&rtp, &p->p_pri);
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p->p_sflag |= PS_NEEDRESCHED;
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mtx_unlock_spin(&sched_lock);
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}
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else
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e = EPERM;
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break;
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case SCHED_OTHER:
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{
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rtp.type = RTP_PRIO_NORMAL;
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rtp.prio = p4prio_to_rtpprio(param->sched_priority);
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mtx_lock_spin(&sched_lock);
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rtp_to_pri(&rtp, &p->p_pri);
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/* XXX Simply revert to whatever we had for last
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* normal scheduler priorities.
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* This puts a requirement
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* on the scheduling code: You must leave the
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* scheduling info alone.
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*/
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p->p_sflag |= PS_NEEDRESCHED;
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mtx_unlock_spin(&sched_lock);
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}
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break;
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}
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return e;
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}
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int ksched_getscheduler(register_t *ret, struct ksched *ksched, struct proc *p)
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{
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return getscheduler(ret, ksched, p);
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}
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/* ksched_yield: Yield the CPU.
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*/
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int ksched_yield(register_t *ret, struct ksched *ksched)
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{
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mtx_lock_spin(&sched_lock);
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curproc->p_sflag |= PS_NEEDRESCHED;
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mtx_unlock_spin(&sched_lock);
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return 0;
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}
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int ksched_get_priority_max(register_t*ret, struct ksched *ksched, int policy)
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{
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int e = 0;
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switch (policy)
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{
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case SCHED_FIFO:
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case SCHED_RR:
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*ret = RTP_PRIO_MAX;
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break;
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case SCHED_OTHER:
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*ret = PRIO_MAX;
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break;
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default:
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e = EINVAL;
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}
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return e;
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}
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int ksched_get_priority_min(register_t *ret, struct ksched *ksched, int policy)
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{
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int e = 0;
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switch (policy)
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{
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case SCHED_FIFO:
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case SCHED_RR:
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*ret = P1B_PRIO_MIN;
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break;
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case SCHED_OTHER:
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*ret = PRIO_MIN;
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break;
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default:
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e = EINVAL;
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}
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return e;
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}
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int ksched_rr_get_interval(register_t *ret, struct ksched *ksched,
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struct proc *p, struct timespec *timespec)
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{
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*timespec = ksched->rr_interval;
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return 0;
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}
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