diff options
Diffstat (limited to 'sys/kern/ksched.c')
| -rw-r--r-- | sys/kern/ksched.c | 280 |
1 files changed, 280 insertions, 0 deletions
diff --git a/sys/kern/ksched.c b/sys/kern/ksched.c new file mode 100644 index 0000000..c9081c3 --- /dev/null +++ b/sys/kern/ksched.c @@ -0,0 +1,280 @@ +/* + * 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. + * + * $FreeBSD$ + */ + +/* ksched: Soft real time scheduling based on "rtprio". + */ + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/lock.h> +#include <sys/mutex.h> +#include <sys/proc.h> +#include <sys/resource.h> + +#include <posix4/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 / roundrobin_interval(); + + *p = ksched; + return 0; +} + +int ksched_detach(struct ksched *ks) +{ + p31b_free(ks); + + 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 thread *td) +{ + struct rtprio rtp; + int e = 0; + + mtx_lock_spin(&sched_lock); + pri_to_rtp(td->td_ksegrp, &rtp); + mtx_unlock_spin(&sched_lock); + switch (rtp.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 thread *td, const struct sched_param *param) +{ + register_t policy; + int e; + + e = getscheduler(&policy, ksched, td); + + if (e == 0) + { + if (policy == SCHED_OTHER) + e = EINVAL; + else + e = ksched_setscheduler(ret, ksched, td, policy, param); + } + + return e; +} + +int ksched_getparam(register_t *ret, struct ksched *ksched, + struct thread *td, struct sched_param *param) +{ + struct rtprio rtp; + + mtx_lock_spin(&sched_lock); + pri_to_rtp(td->td_ksegrp, &rtp); + mtx_unlock_spin(&sched_lock); + if (RTP_PRIO_IS_REALTIME(rtp.type)) + param->sched_priority = rtpprio_to_p4prio(rtp.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 thread *td, int policy, const struct sched_param *param) +{ + int e = 0; + struct rtprio rtp; + struct ksegrp *kg = td->td_ksegrp; + + 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; + + mtx_lock_spin(&sched_lock); + rtp_to_pri(&rtp, kg); + td->td_last_kse->ke_flags |= KEF_NEEDRESCHED; /* XXXKSE */ + mtx_unlock_spin(&sched_lock); + } + else + e = EPERM; + + + break; + + case SCHED_OTHER: + { + rtp.type = RTP_PRIO_NORMAL; + rtp.prio = p4prio_to_rtpprio(param->sched_priority); + mtx_lock_spin(&sched_lock); + rtp_to_pri(&rtp, kg); + + /* 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. + */ + td->td_last_kse->ke_flags |= KEF_NEEDRESCHED; /* XXXKSE */ + mtx_unlock_spin(&sched_lock); + } + break; + } + + return e; +} + +int ksched_getscheduler(register_t *ret, struct ksched *ksched, struct thread *td) +{ + return getscheduler(ret, ksched, td); +} + +/* ksched_yield: Yield the CPU. + */ +int ksched_yield(register_t *ret, struct ksched *ksched) +{ + mtx_lock_spin(&sched_lock); + curthread->td_kse->ke_flags |= KEF_NEEDRESCHED; + mtx_unlock_spin(&sched_lock); + 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 thread *td, struct timespec *timespec) +{ + *timespec = ksched->rr_interval; + + return 0; +} |
