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Diffstat (limited to 'sys/posix4/ksched.c')
-rw-r--r-- | sys/posix4/ksched.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/sys/posix4/ksched.c b/sys/posix4/ksched.c new file mode 100644 index 0000000..7ff85d6 --- /dev/null +++ b/sys/posix4/ksched.c @@ -0,0 +1,252 @@ +/* + * 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. + * + */ + +/* ksched: Soft real time scheduling based on "rtprio". + */ + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/proc.h> +#include <sys/kernel.h> +#include <machine/cpu.h> /* For need_resched */ +#include <fcntl.h> + +#include <sys/posix4.h> + +/* ksched: Real-time extension to support POSIX priority scheduling. + */ + +static struct timespec rr_interval; + +int ksched_attach(int p4_instance, int fac_code, void **p) +{ + rr_interval.tv_sec = 0; + rr_interval.tv_nsec = 1000000000L / roundrobin_interval(); + + *p = 0; + + return 0; +} + +int ksched_detach(void *p) +{ + return 0; +} + +/* + * XXX About priorities + * + * POSIX4 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 POSIX4 (higher numerically is higher priority) + */ + +#define p4prio_to_rtpprio(P) (RTP_PRIO_MAX - (P)) +#define rtpprio_to_p4prio(P) (RTP_PRIO_MAX - (P)) + +static inline int +getscheduler(int *ret, void *hook, struct proc *p) +{ + int e = 0; + + switch (p->p_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(int *ret, void *hook, + struct proc *p, const struct sched_param *param) +{ + int e, policy; + + e = getscheduler(&policy, hook, p); + + if (e == 0) + { + if (policy == SCHED_OTHER) + e = EINVAL; + else + e = ksched_setscheduler(ret, hook, p, policy, param); + } + + return e; +} + +int ksched_getparam(int *ret, void *hook, + struct proc *p, struct sched_param *param) +{ + if (RTP_PRIO_IS_REALTIME(p->p_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 "posix4proc()". + * + */ +int ksched_setscheduler(int *ret, void *hook, + 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 >= RTP_PRIO_MIN && + param->sched_priority <= RTP_PRIO_MAX) + { + rtp.type = (policy == SCHED_FIFO) + ? RTP_PRIO_FIFO : RTP_PRIO_REALTIME; + + rtp.prio = p4prio_to_rtpprio(RTP_PRIO_MAX); + p->p_rtprio = rtp; + (void)resetpriority(p); + } + else + e = EPERM; + + + break; + + case SCHED_OTHER: + { + rtp.type = RTP_PRIO_NORMAL; + rtp.prio = p4prio_to_rtpprio(RTP_PRIO_MIN); + p->p_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. + */ + (void)resetpriority(p); + } + break; + } + + return e; +} + +int ksched_getscheduler(int *ret, void *hook, struct proc *p) +{ + return getscheduler(ret, hook, p); +} + +/* ksched_yield: Yield the CPU. + */ +int ksched_yield(int *ret, void *hook) +{ + need_resched(); + return 0; +} + +int ksched_get_priority_max(int *ret, void *hook, 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(int *ret, void *hook, int policy) +{ + int e = 0; + + switch (policy) + { + case SCHED_FIFO: + case SCHED_RR: + *ret = RTP_PRIO_MIN; + break; + + case SCHED_OTHER: + *ret = PRIO_MIN; + break; + + default: + e = EINVAL; + } + + return e; +} + +int ksched_rr_get_interval(int *ret, void *hook, + struct proc *p, struct timespec *timespec) +{ + *timespec = rr_interval; + + return 0; +} |