freebsd-dev/sys/kern/ksched.c
Julian Elischer ad1e7d285a Threading cleanup.. part 2 of several.
Make part of John Birrell's KSE patch permanent..
Specifically, remove:
Any reference of the ksegrp structure. This feature was
never fully utilised and made things overly complicated.
All code in the scheduler that tried to make threaded programs
fair to unthreaded programs.  Libpthread processes will already
do this to some extent and libthr processes already disable it.

Also:
Since this makes such a big change to the scheduler(s), take the opportunity
to rename some structures and elements that had to be moved anyhow.
This makes the code a lot more readable.

The ULE scheduler compiles again but I have no idea if it works.

The 4bsd scheduler still reqires a little cleaning and some functions that now do
ALMOST nothing will go away, but I thought I'd do that as a separate commit.

Tested by David Xu, and Dan Eischen using libthr and libpthread.
2006-12-06 06:34:57 +00:00

286 lines
6.1 KiB
C

/*-
* 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/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_posix.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/posix4.h>
#include <sys/resource.h>
#include <sys/sched.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 / sched_rr_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(struct ksched *ksched, struct thread *td, int *policy)
{
struct rtprio rtp;
int e = 0;
mtx_lock_spin(&sched_lock);
pri_to_rtp(td, &rtp);
mtx_unlock_spin(&sched_lock);
switch (rtp.type)
{
case RTP_PRIO_FIFO:
*policy = SCHED_FIFO;
break;
case RTP_PRIO_REALTIME:
*policy = SCHED_RR;
break;
default:
*policy = SCHED_OTHER;
break;
}
return e;
}
int
ksched_setparam(struct ksched *ksched,
struct thread *td, const struct sched_param *param)
{
int policy;
int e;
e = getscheduler(ksched, td, &policy);
if (e == 0)
{
if (policy == SCHED_OTHER)
e = EINVAL;
else
e = ksched_setscheduler(ksched, td, policy, param);
}
return e;
}
int
ksched_getparam(struct ksched *ksched,
struct thread *td, struct sched_param *param)
{
struct rtprio rtp;
mtx_lock_spin(&sched_lock);
pri_to_rtp(td, &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(struct ksched *ksched,
struct thread *td, 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;
mtx_lock_spin(&sched_lock);
rtp_to_pri(&rtp, td);
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, td);
mtx_unlock_spin(&sched_lock);
}
break;
default:
e = EINVAL;
break;
}
return e;
}
int
ksched_getscheduler(struct ksched *ksched, struct thread *td, int *policy)
{
return getscheduler(ksched, td, policy);
}
/* ksched_yield: Yield the CPU.
*/
int
ksched_yield(struct ksched *ksched)
{
sched_relinquish(curthread);
return 0;
}
int
ksched_get_priority_max(struct ksched *ksched, int policy, int *prio)
{
int e = 0;
switch (policy)
{
case SCHED_FIFO:
case SCHED_RR:
*prio = RTP_PRIO_MAX;
break;
case SCHED_OTHER:
*prio = PRI_MAX_TIMESHARE - PRI_MIN_TIMESHARE;
break;
default:
e = EINVAL;
}
return e;
}
int
ksched_get_priority_min(struct ksched *ksched, int policy, int *prio)
{
int e = 0;
switch (policy)
{
case SCHED_FIFO:
case SCHED_RR:
*prio = P1B_PRIO_MIN;
break;
case SCHED_OTHER:
*prio = 0;
break;
default:
e = EINVAL;
}
return e;
}
int
ksched_rr_get_interval(struct ksched *ksched,
struct thread *td, struct timespec *timespec)
{
*timespec = ksched->rr_interval;
return 0;
}