1994-05-24 10:09:53 +00:00
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/*-
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* Copyright (c) 1982, 1986, 1990, 1991, 1993
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* The Regents of the University of California. All rights reserved.
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* (c) UNIX System Laboratories, Inc.
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* All or some portions of this file are derived from material licensed
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* to the University of California by American Telephone and Telegraph
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* Co. or Unix System Laboratories, Inc. and are reproduced herein with
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* the permission of UNIX System Laboratories, Inc.
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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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* 4. Neither the name of the University nor the names of its 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 THE REGENTS 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 THE REGENTS 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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1996-03-11 05:48:57 +00:00
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* @(#)kern_synch.c 8.9 (Berkeley) 5/19/95
|
1994-05-24 10:09:53 +00:00
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*/
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|
2003-06-11 00:56:59 +00:00
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#include <sys/cdefs.h>
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|
|
__FBSDID("$FreeBSD$");
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1996-01-03 21:42:35 +00:00
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|
#include "opt_ktrace.h"
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|
|
|
1994-05-24 10:09:53 +00:00
|
|
|
#include <sys/param.h>
|
|
|
|
#include <sys/systm.h>
|
2001-03-28 11:52:56 +00:00
|
|
|
#include <sys/condvar.h>
|
2004-07-10 21:36:01 +00:00
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|
|
#include <sys/kdb.h>
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1994-05-24 10:09:53 +00:00
|
|
|
#include <sys/kernel.h>
|
2000-09-07 01:33:02 +00:00
|
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|
#include <sys/ktr.h>
|
2000-12-06 00:33:58 +00:00
|
|
|
#include <sys/lock.h>
|
2000-10-20 07:52:10 +00:00
|
|
|
#include <sys/mutex.h>
|
2001-03-28 11:52:56 +00:00
|
|
|
#include <sys/proc.h>
|
1994-05-24 10:09:53 +00:00
|
|
|
#include <sys/resourcevar.h>
|
2002-10-12 05:32:24 +00:00
|
|
|
#include <sys/sched.h>
|
2001-03-28 11:52:56 +00:00
|
|
|
#include <sys/signalvar.h>
|
Switch the sleep/wakeup and condition variable implementations to use the
sleep queue interface:
- Sleep queues attempt to merge some of the benefits of both sleep queues
and condition variables. Having sleep qeueus in a hash table avoids
having to allocate a queue head for each wait channel. Thus, struct cv
has shrunk down to just a single char * pointer now. However, the
hash table does not hold threads directly, but queue heads. This means
that once you have located a queue in the hash bucket, you no longer have
to walk the rest of the hash chain looking for threads. Instead, you have
a list of all the threads sleeping on that wait channel.
- Outside of the sleepq code and the sleep/cv code the kernel no longer
differentiates between cv's and sleep/wakeup. For example, calls to
abortsleep() and cv_abort() are replaced with a call to sleepq_abort().
Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and
cv_waitq_remove() have been replaced with calls to sleepq_remove().
- The sched_sleep() function no longer accepts a priority argument as
sleep's no longer inherently bump the priority. Instead, this is soley
a propery of msleep() which explicitly calls sched_prio() before
blocking.
- The TDF_ONSLEEPQ flag has been dropped as it was never used. The
associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been
dropped and replaced with a single explicit clearing of td_wchan.
TD_SET_ONSLEEPQ() would really have only made sense if it had taken
the wait channel and message as arguments anyway. Now that that only
happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
|
|
|
#include <sys/sleepqueue.h>
|
2001-04-27 19:28:25 +00:00
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|
|
#include <sys/smp.h>
|
2001-03-28 11:52:56 +00:00
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|
#include <sys/sx.h>
|
1997-08-08 22:48:57 +00:00
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|
#include <sys/sysctl.h>
|
2000-12-02 05:41:30 +00:00
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|
#include <sys/sysproto.h>
|
2001-03-28 11:52:56 +00:00
|
|
|
#include <sys/vmmeter.h>
|
1994-05-24 10:09:53 +00:00
|
|
|
#ifdef KTRACE
|
1998-03-28 10:33:27 +00:00
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|
|
#include <sys/uio.h>
|
1994-05-24 10:09:53 +00:00
|
|
|
#include <sys/ktrace.h>
|
|
|
|
#endif
|
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|
|
|
|
|
#include <machine/cpu.h>
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|
|
2004-01-25 07:49:45 +00:00
|
|
|
static void synch_setup(void *dummy);
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|
|
SYSINIT(synch_setup, SI_SUB_KICK_SCHEDULER, SI_ORDER_FIRST, synch_setup, NULL)
|
1995-08-28 09:19:25 +00:00
|
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|
|
1999-02-22 16:57:48 +00:00
|
|
|
int hogticks;
|
1999-03-03 18:15:29 +00:00
|
|
|
int lbolt;
|
2007-02-23 16:22:09 +00:00
|
|
|
static int pause_wchan;
|
1994-05-24 10:09:53 +00:00
|
|
|
|
2004-02-01 05:37:36 +00:00
|
|
|
static struct callout loadav_callout;
|
2002-11-21 08:57:08 +00:00
|
|
|
static struct callout lbolt_callout;
|
2000-11-27 22:52:31 +00:00
|
|
|
|
2001-10-20 13:10:43 +00:00
|
|
|
struct loadavg averunnable =
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|
|
{ {0, 0, 0}, FSCALE }; /* load average, of runnable procs */
|
|
|
|
/*
|
|
|
|
* Constants for averages over 1, 5, and 15 minutes
|
|
|
|
* when sampling at 5 second intervals.
|
|
|
|
*/
|
|
|
|
static fixpt_t cexp[3] = {
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|
|
|
0.9200444146293232 * FSCALE, /* exp(-1/12) */
|
|
|
|
0.9834714538216174 * FSCALE, /* exp(-1/60) */
|
|
|
|
0.9944598480048967 * FSCALE, /* exp(-1/180) */
|
|
|
|
};
|
|
|
|
|
2002-11-21 08:57:08 +00:00
|
|
|
/* kernel uses `FSCALE', userland (SHOULD) use kern.fscale */
|
|
|
|
static int fscale __unused = FSCALE;
|
|
|
|
SYSCTL_INT(_kern, OID_AUTO, fscale, CTLFLAG_RD, 0, FSCALE, "");
|
|
|
|
|
2004-02-01 05:37:36 +00:00
|
|
|
static void loadav(void *arg);
|
2002-11-21 08:57:08 +00:00
|
|
|
static void lboltcb(void *arg);
|
1994-05-24 10:09:53 +00:00
|
|
|
|
1996-07-31 09:26:54 +00:00
|
|
|
void
|
1999-03-03 18:15:29 +00:00
|
|
|
sleepinit(void)
|
1996-07-31 09:26:54 +00:00
|
|
|
{
|
|
|
|
|
2002-10-12 05:32:24 +00:00
|
|
|
hogticks = (hz / 10) * 2; /* Default only. */
|
Switch the sleep/wakeup and condition variable implementations to use the
sleep queue interface:
- Sleep queues attempt to merge some of the benefits of both sleep queues
and condition variables. Having sleep qeueus in a hash table avoids
having to allocate a queue head for each wait channel. Thus, struct cv
has shrunk down to just a single char * pointer now. However, the
hash table does not hold threads directly, but queue heads. This means
that once you have located a queue in the hash bucket, you no longer have
to walk the rest of the hash chain looking for threads. Instead, you have
a list of all the threads sleeping on that wait channel.
- Outside of the sleepq code and the sleep/cv code the kernel no longer
differentiates between cv's and sleep/wakeup. For example, calls to
abortsleep() and cv_abort() are replaced with a call to sleepq_abort().
Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and
cv_waitq_remove() have been replaced with calls to sleepq_remove().
- The sched_sleep() function no longer accepts a priority argument as
sleep's no longer inherently bump the priority. Instead, this is soley
a propery of msleep() which explicitly calls sched_prio() before
blocking.
- The TDF_ONSLEEPQ flag has been dropped as it was never used. The
associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been
dropped and replaced with a single explicit clearing of td_wchan.
TD_SET_ONSLEEPQ() would really have only made sense if it had taken
the wait channel and message as arguments anyway. Now that that only
happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
|
|
|
init_sleepqueues();
|
1996-07-31 09:26:54 +00:00
|
|
|
}
|
|
|
|
|
1994-05-24 10:09:53 +00:00
|
|
|
/*
|
2006-02-22 20:46:10 +00:00
|
|
|
* General sleep call. Suspends the current thread until a wakeup is
|
|
|
|
* performed on the specified identifier. The thread will then be made
|
1994-05-24 10:09:53 +00:00
|
|
|
* runnable with the specified priority. Sleeps at most timo/hz seconds
|
|
|
|
* (0 means no timeout). If pri includes PCATCH flag, signals are checked
|
|
|
|
* before and after sleeping, else signals are not checked. Returns 0 if
|
|
|
|
* awakened, EWOULDBLOCK if the timeout expires. If PCATCH is set and a
|
|
|
|
* signal needs to be delivered, ERESTART is returned if the current system
|
|
|
|
* call should be restarted if possible, and EINTR is returned if the system
|
|
|
|
* call should be interrupted by the signal (return EINTR).
|
2000-09-11 00:20:02 +00:00
|
|
|
*
|
2007-03-09 22:41:01 +00:00
|
|
|
* The lock argument is unlocked before the caller is suspended, and
|
|
|
|
* re-locked before _sleep() returns. If priority includes the PDROP
|
|
|
|
* flag the lock is not re-locked before returning.
|
1994-05-24 10:09:53 +00:00
|
|
|
*/
|
|
|
|
int
|
2007-03-09 22:41:01 +00:00
|
|
|
_sleep(ident, lock, priority, wmesg, timo)
|
1994-05-24 10:09:53 +00:00
|
|
|
void *ident;
|
2007-03-09 22:41:01 +00:00
|
|
|
struct lock_object *lock;
|
1994-05-24 10:09:53 +00:00
|
|
|
int priority, timo;
|
1997-11-21 11:37:03 +00:00
|
|
|
const char *wmesg;
|
1994-05-24 10:09:53 +00:00
|
|
|
{
|
Switch the sleep/wakeup and condition variable implementations to use the
sleep queue interface:
- Sleep queues attempt to merge some of the benefits of both sleep queues
and condition variables. Having sleep qeueus in a hash table avoids
having to allocate a queue head for each wait channel. Thus, struct cv
has shrunk down to just a single char * pointer now. However, the
hash table does not hold threads directly, but queue heads. This means
that once you have located a queue in the hash bucket, you no longer have
to walk the rest of the hash chain looking for threads. Instead, you have
a list of all the threads sleeping on that wait channel.
- Outside of the sleepq code and the sleep/cv code the kernel no longer
differentiates between cv's and sleep/wakeup. For example, calls to
abortsleep() and cv_abort() are replaced with a call to sleepq_abort().
Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and
cv_waitq_remove() have been replaced with calls to sleepq_remove().
- The sched_sleep() function no longer accepts a priority argument as
sleep's no longer inherently bump the priority. Instead, this is soley
a propery of msleep() which explicitly calls sched_prio() before
blocking.
- The TDF_ONSLEEPQ flag has been dropped as it was never used. The
associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been
dropped and replaced with a single explicit clearing of td_wchan.
TD_SET_ONSLEEPQ() would really have only made sense if it had taken
the wait channel and message as arguments anyway. Now that that only
happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
|
|
|
struct thread *td;
|
|
|
|
struct proc *p;
|
2007-03-09 22:41:01 +00:00
|
|
|
struct lock_class *class;
|
|
|
|
int catch, flags, lock_state, pri, rval;
|
|
|
|
WITNESS_SAVE_DECL(lock_witness);
|
1994-05-24 10:09:53 +00:00
|
|
|
|
Switch the sleep/wakeup and condition variable implementations to use the
sleep queue interface:
- Sleep queues attempt to merge some of the benefits of both sleep queues
and condition variables. Having sleep qeueus in a hash table avoids
having to allocate a queue head for each wait channel. Thus, struct cv
has shrunk down to just a single char * pointer now. However, the
hash table does not hold threads directly, but queue heads. This means
that once you have located a queue in the hash bucket, you no longer have
to walk the rest of the hash chain looking for threads. Instead, you have
a list of all the threads sleeping on that wait channel.
- Outside of the sleepq code and the sleep/cv code the kernel no longer
differentiates between cv's and sleep/wakeup. For example, calls to
abortsleep() and cv_abort() are replaced with a call to sleepq_abort().
Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and
cv_waitq_remove() have been replaced with calls to sleepq_remove().
- The sched_sleep() function no longer accepts a priority argument as
sleep's no longer inherently bump the priority. Instead, this is soley
a propery of msleep() which explicitly calls sched_prio() before
blocking.
- The TDF_ONSLEEPQ flag has been dropped as it was never used. The
associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been
dropped and replaced with a single explicit clearing of td_wchan.
TD_SET_ONSLEEPQ() would really have only made sense if it had taken
the wait channel and message as arguments anyway. Now that that only
happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
|
|
|
td = curthread;
|
|
|
|
p = td->td_proc;
|
1994-05-24 10:09:53 +00:00
|
|
|
#ifdef KTRACE
|
2002-06-07 05:39:16 +00:00
|
|
|
if (KTRPOINT(td, KTR_CSW))
|
|
|
|
ktrcsw(1, 0);
|
1994-05-24 10:09:53 +00:00
|
|
|
#endif
|
2007-03-09 22:41:01 +00:00
|
|
|
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, lock,
|
|
|
|
"Sleeping on \"%s\"", wmesg);
|
|
|
|
KASSERT(timo != 0 || mtx_owned(&Giant) || lock != NULL ||
|
|
|
|
ident == &lbolt, ("sleeping without a lock"));
|
Switch the sleep/wakeup and condition variable implementations to use the
sleep queue interface:
- Sleep queues attempt to merge some of the benefits of both sleep queues
and condition variables. Having sleep qeueus in a hash table avoids
having to allocate a queue head for each wait channel. Thus, struct cv
has shrunk down to just a single char * pointer now. However, the
hash table does not hold threads directly, but queue heads. This means
that once you have located a queue in the hash bucket, you no longer have
to walk the rest of the hash chain looking for threads. Instead, you have
a list of all the threads sleeping on that wait channel.
- Outside of the sleepq code and the sleep/cv code the kernel no longer
differentiates between cv's and sleep/wakeup. For example, calls to
abortsleep() and cv_abort() are replaced with a call to sleepq_abort().
Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and
cv_waitq_remove() have been replaced with calls to sleepq_remove().
- The sched_sleep() function no longer accepts a priority argument as
sleep's no longer inherently bump the priority. Instead, this is soley
a propery of msleep() which explicitly calls sched_prio() before
blocking.
- The TDF_ONSLEEPQ flag has been dropped as it was never used. The
associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been
dropped and replaced with a single explicit clearing of td_wchan.
TD_SET_ONSLEEPQ() would really have only made sense if it had taken
the wait channel and message as arguments anyway. Now that that only
happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
|
|
|
KASSERT(p != NULL, ("msleep1"));
|
|
|
|
KASSERT(ident != NULL && TD_IS_RUNNING(td), ("msleep"));
|
2007-03-09 22:41:01 +00:00
|
|
|
if (lock != NULL)
|
|
|
|
class = LOCK_CLASS(lock);
|
|
|
|
else
|
|
|
|
class = NULL;
|
Switch the sleep/wakeup and condition variable implementations to use the
sleep queue interface:
- Sleep queues attempt to merge some of the benefits of both sleep queues
and condition variables. Having sleep qeueus in a hash table avoids
having to allocate a queue head for each wait channel. Thus, struct cv
has shrunk down to just a single char * pointer now. However, the
hash table does not hold threads directly, but queue heads. This means
that once you have located a queue in the hash bucket, you no longer have
to walk the rest of the hash chain looking for threads. Instead, you have
a list of all the threads sleeping on that wait channel.
- Outside of the sleepq code and the sleep/cv code the kernel no longer
differentiates between cv's and sleep/wakeup. For example, calls to
abortsleep() and cv_abort() are replaced with a call to sleepq_abort().
Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and
cv_waitq_remove() have been replaced with calls to sleepq_remove().
- The sched_sleep() function no longer accepts a priority argument as
sleep's no longer inherently bump the priority. Instead, this is soley
a propery of msleep() which explicitly calls sched_prio() before
blocking.
- The TDF_ONSLEEPQ flag has been dropped as it was never used. The
associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been
dropped and replaced with a single explicit clearing of td_wchan.
TD_SET_ONSLEEPQ() would really have only made sense if it had taken
the wait channel and message as arguments anyway. Now that that only
happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
|
|
|
|
|
|
|
if (cold) {
|
|
|
|
/*
|
|
|
|
* During autoconfiguration, just return;
|
2004-05-14 20:51:42 +00:00
|
|
|
* don't run any other threads or panic below,
|
|
|
|
* in case this is the idle thread and already asleep.
|
Switch the sleep/wakeup and condition variable implementations to use the
sleep queue interface:
- Sleep queues attempt to merge some of the benefits of both sleep queues
and condition variables. Having sleep qeueus in a hash table avoids
having to allocate a queue head for each wait channel. Thus, struct cv
has shrunk down to just a single char * pointer now. However, the
hash table does not hold threads directly, but queue heads. This means
that once you have located a queue in the hash bucket, you no longer have
to walk the rest of the hash chain looking for threads. Instead, you have
a list of all the threads sleeping on that wait channel.
- Outside of the sleepq code and the sleep/cv code the kernel no longer
differentiates between cv's and sleep/wakeup. For example, calls to
abortsleep() and cv_abort() are replaced with a call to sleepq_abort().
Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and
cv_waitq_remove() have been replaced with calls to sleepq_remove().
- The sched_sleep() function no longer accepts a priority argument as
sleep's no longer inherently bump the priority. Instead, this is soley
a propery of msleep() which explicitly calls sched_prio() before
blocking.
- The TDF_ONSLEEPQ flag has been dropped as it was never used. The
associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been
dropped and replaced with a single explicit clearing of td_wchan.
TD_SET_ONSLEEPQ() would really have only made sense if it had taken
the wait channel and message as arguments anyway. Now that that only
happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
|
|
|
* XXX: this used to do "s = splhigh(); splx(safepri);
|
|
|
|
* splx(s);" to give interrupts a chance, but there is
|
|
|
|
* no way to give interrupts a chance now.
|
|
|
|
*/
|
2007-03-09 22:41:01 +00:00
|
|
|
if (lock != NULL && priority & PDROP)
|
|
|
|
class->lc_unlock(lock);
|
Switch the sleep/wakeup and condition variable implementations to use the
sleep queue interface:
- Sleep queues attempt to merge some of the benefits of both sleep queues
and condition variables. Having sleep qeueus in a hash table avoids
having to allocate a queue head for each wait channel. Thus, struct cv
has shrunk down to just a single char * pointer now. However, the
hash table does not hold threads directly, but queue heads. This means
that once you have located a queue in the hash bucket, you no longer have
to walk the rest of the hash chain looking for threads. Instead, you have
a list of all the threads sleeping on that wait channel.
- Outside of the sleepq code and the sleep/cv code the kernel no longer
differentiates between cv's and sleep/wakeup. For example, calls to
abortsleep() and cv_abort() are replaced with a call to sleepq_abort().
Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and
cv_waitq_remove() have been replaced with calls to sleepq_remove().
- The sched_sleep() function no longer accepts a priority argument as
sleep's no longer inherently bump the priority. Instead, this is soley
a propery of msleep() which explicitly calls sched_prio() before
blocking.
- The TDF_ONSLEEPQ flag has been dropped as it was never used. The
associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been
dropped and replaced with a single explicit clearing of td_wchan.
TD_SET_ONSLEEPQ() would really have only made sense if it had taken
the wait channel and message as arguments anyway. Now that that only
happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
|
|
|
return (0);
|
|
|
|
}
|
|
|
|
catch = priority & PCATCH;
|
|
|
|
rval = 0;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If we are already on a sleep queue, then remove us from that
|
|
|
|
* sleep queue first. We have to do this to handle recursive
|
|
|
|
* sleeps.
|
|
|
|
*/
|
|
|
|
if (TD_ON_SLEEPQ(td))
|
|
|
|
sleepq_remove(td, td->td_wchan);
|
|
|
|
|
2007-02-23 16:22:09 +00:00
|
|
|
if (ident == &pause_wchan)
|
|
|
|
flags = SLEEPQ_PAUSE;
|
|
|
|
else
|
2007-03-09 22:41:01 +00:00
|
|
|
flags = SLEEPQ_SLEEP;
|
2006-02-23 00:13:58 +00:00
|
|
|
if (catch)
|
|
|
|
flags |= SLEEPQ_INTERRUPTIBLE;
|
|
|
|
|
2004-10-12 18:36:20 +00:00
|
|
|
sleepq_lock(ident);
|
2007-03-09 22:41:01 +00:00
|
|
|
CTR5(KTR_PROC, "sleep: thread %ld (pid %ld, %s) on %s (%p)",
|
2007-11-14 06:51:33 +00:00
|
|
|
td->td_tid, p->p_pid, td->td_name, wmesg, ident);
|
Switch the sleep/wakeup and condition variable implementations to use the
sleep queue interface:
- Sleep queues attempt to merge some of the benefits of both sleep queues
and condition variables. Having sleep qeueus in a hash table avoids
having to allocate a queue head for each wait channel. Thus, struct cv
has shrunk down to just a single char * pointer now. However, the
hash table does not hold threads directly, but queue heads. This means
that once you have located a queue in the hash bucket, you no longer have
to walk the rest of the hash chain looking for threads. Instead, you have
a list of all the threads sleeping on that wait channel.
- Outside of the sleepq code and the sleep/cv code the kernel no longer
differentiates between cv's and sleep/wakeup. For example, calls to
abortsleep() and cv_abort() are replaced with a call to sleepq_abort().
Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and
cv_waitq_remove() have been replaced with calls to sleepq_remove().
- The sched_sleep() function no longer accepts a priority argument as
sleep's no longer inherently bump the priority. Instead, this is soley
a propery of msleep() which explicitly calls sched_prio() before
blocking.
- The TDF_ONSLEEPQ flag has been dropped as it was never used. The
associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been
dropped and replaced with a single explicit clearing of td_wchan.
TD_SET_ONSLEEPQ() would really have only made sense if it had taken
the wait channel and message as arguments anyway. Now that that only
happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
|
|
|
|
Change the preemption code for software interrupt thread schedules and
mutex releases to not require flags for the cases when preemption is
not allowed:
The purpose of the MTX_NOSWITCH and SWI_NOSWITCH flags is to prevent
switching to a higher priority thread on mutex releease and swi schedule,
respectively when that switch is not safe. Now that the critical section
API maintains a per-thread nesting count, the kernel can easily check
whether or not it should switch without relying on flags from the
programmer. This fixes a few bugs in that all current callers of
swi_sched() used SWI_NOSWITCH, when in fact, only the ones called from
fast interrupt handlers and the swi_sched of softclock needed this flag.
Note that to ensure that swi_sched()'s in clock and fast interrupt
handlers do not switch, these handlers have to be explicitly wrapped
in critical_enter/exit pairs. Presently, just wrapping the handlers is
sufficient, but in the future with the fully preemptive kernel, the
interrupt must be EOI'd before critical_exit() is called. (critical_exit()
can switch due to a deferred preemption in a fully preemptive kernel.)
I've tested the changes to the interrupt code on i386 and alpha. I have
not tested ia64, but the interrupt code is almost identical to the alpha
code, so I expect it will work fine. PowerPC and ARM do not yet have
interrupt code in the tree so they shouldn't be broken. Sparc64 is
broken, but that's been ok'd by jake and tmm who will be fixing the
interrupt code for sparc64 shortly.
Reviewed by: peter
Tested on: i386, alpha
2002-01-05 08:47:13 +00:00
|
|
|
DROP_GIANT();
|
2007-05-08 21:49:59 +00:00
|
|
|
if (lock != NULL && !(class->lc_flags & LC_SLEEPABLE)) {
|
2007-03-09 22:41:01 +00:00
|
|
|
WITNESS_SAVE(lock, lock_witness);
|
|
|
|
lock_state = class->lc_unlock(lock);
|
|
|
|
} else
|
|
|
|
/* GCC needs to follow the Yellow Brick Road */
|
|
|
|
lock_state = -1;
|
2001-09-12 08:38:13 +00:00
|
|
|
|
1994-05-24 10:09:53 +00:00
|
|
|
/*
|
|
|
|
* We put ourselves on the sleep queue and start our timeout
|
Switch the sleep/wakeup and condition variable implementations to use the
sleep queue interface:
- Sleep queues attempt to merge some of the benefits of both sleep queues
and condition variables. Having sleep qeueus in a hash table avoids
having to allocate a queue head for each wait channel. Thus, struct cv
has shrunk down to just a single char * pointer now. However, the
hash table does not hold threads directly, but queue heads. This means
that once you have located a queue in the hash bucket, you no longer have
to walk the rest of the hash chain looking for threads. Instead, you have
a list of all the threads sleeping on that wait channel.
- Outside of the sleepq code and the sleep/cv code the kernel no longer
differentiates between cv's and sleep/wakeup. For example, calls to
abortsleep() and cv_abort() are replaced with a call to sleepq_abort().
Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and
cv_waitq_remove() have been replaced with calls to sleepq_remove().
- The sched_sleep() function no longer accepts a priority argument as
sleep's no longer inherently bump the priority. Instead, this is soley
a propery of msleep() which explicitly calls sched_prio() before
blocking.
- The TDF_ONSLEEPQ flag has been dropped as it was never used. The
associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been
dropped and replaced with a single explicit clearing of td_wchan.
TD_SET_ONSLEEPQ() would really have only made sense if it had taken
the wait channel and message as arguments anyway. Now that that only
happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
|
|
|
* before calling thread_suspend_check, as we could stop there,
|
|
|
|
* and a wakeup or a SIGCONT (or both) could occur while we were
|
|
|
|
* stopped without resuming us. Thus, we must be ready for sleep
|
|
|
|
* when cursig() is called. If the wakeup happens while we're
|
|
|
|
* stopped, then td will no longer be on a sleep queue upon
|
|
|
|
* return from cursig().
|
1994-05-24 10:09:53 +00:00
|
|
|
*/
|
2007-03-09 22:41:01 +00:00
|
|
|
sleepq_add(ident, ident == &lbolt ? NULL : lock, wmesg, flags, 0);
|
Switch the sleep/wakeup and condition variable implementations to use the
sleep queue interface:
- Sleep queues attempt to merge some of the benefits of both sleep queues
and condition variables. Having sleep qeueus in a hash table avoids
having to allocate a queue head for each wait channel. Thus, struct cv
has shrunk down to just a single char * pointer now. However, the
hash table does not hold threads directly, but queue heads. This means
that once you have located a queue in the hash bucket, you no longer have
to walk the rest of the hash chain looking for threads. Instead, you have
a list of all the threads sleeping on that wait channel.
- Outside of the sleepq code and the sleep/cv code the kernel no longer
differentiates between cv's and sleep/wakeup. For example, calls to
abortsleep() and cv_abort() are replaced with a call to sleepq_abort().
Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and
cv_waitq_remove() have been replaced with calls to sleepq_remove().
- The sched_sleep() function no longer accepts a priority argument as
sleep's no longer inherently bump the priority. Instead, this is soley
a propery of msleep() which explicitly calls sched_prio() before
blocking.
- The TDF_ONSLEEPQ flag has been dropped as it was never used. The
associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been
dropped and replaced with a single explicit clearing of td_wchan.
TD_SET_ONSLEEPQ() would really have only made sense if it had taken
the wait channel and message as arguments anyway. Now that that only
happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
|
|
|
if (timo)
|
2004-03-12 19:06:18 +00:00
|
|
|
sleepq_set_timeout(ident, timo);
|
2007-05-08 21:49:59 +00:00
|
|
|
if (lock != NULL && class->lc_flags & LC_SLEEPABLE) {
|
|
|
|
sleepq_release(ident);
|
|
|
|
WITNESS_SAVE(lock, lock_witness);
|
|
|
|
lock_state = class->lc_unlock(lock);
|
|
|
|
sleepq_lock(ident);
|
|
|
|
}
|
2002-10-12 05:32:24 +00:00
|
|
|
|
|
|
|
/*
|
2006-11-30 08:27:38 +00:00
|
|
|
* Adjust this thread's priority, if necessary.
|
2002-10-12 05:32:24 +00:00
|
|
|
*/
|
2006-11-30 08:27:38 +00:00
|
|
|
pri = priority & PRIMASK;
|
|
|
|
if (pri != 0 && pri != td->td_priority) {
|
Commit 2/14 of sched_lock decomposition.
- Adapt sleepqueues to the new thread_lock() mechanism.
- Delay assigning the sleep queue spinlock as the thread lock until after
we've checked for signals. It is illegal for a thread to return in
mi_switch() with any lock assigned to td_lock other than the scheduler
locks.
- Change sleepq_catch_signals() to do the switch if necessary to simplify
the callers.
- Simplify timeout handling now that locking a sleeping thread has the
side-effect of locking the sleepqueue. Some previous races are no
longer possible.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-04 23:50:56 +00:00
|
|
|
thread_lock(td);
|
2006-11-30 08:27:38 +00:00
|
|
|
sched_prio(td, pri);
|
Commit 2/14 of sched_lock decomposition.
- Adapt sleepqueues to the new thread_lock() mechanism.
- Delay assigning the sleep queue spinlock as the thread lock until after
we've checked for signals. It is illegal for a thread to return in
mi_switch() with any lock assigned to td_lock other than the scheduler
locks.
- Change sleepq_catch_signals() to do the switch if necessary to simplify
the callers.
- Simplify timeout handling now that locking a sleeping thread has the
side-effect of locking the sleepqueue. Some previous races are no
longer possible.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-04 23:50:56 +00:00
|
|
|
thread_unlock(td);
|
2006-04-17 18:20:38 +00:00
|
|
|
}
|
2002-10-12 05:32:24 +00:00
|
|
|
|
Switch the sleep/wakeup and condition variable implementations to use the
sleep queue interface:
- Sleep queues attempt to merge some of the benefits of both sleep queues
and condition variables. Having sleep qeueus in a hash table avoids
having to allocate a queue head for each wait channel. Thus, struct cv
has shrunk down to just a single char * pointer now. However, the
hash table does not hold threads directly, but queue heads. This means
that once you have located a queue in the hash bucket, you no longer have
to walk the rest of the hash chain looking for threads. Instead, you have
a list of all the threads sleeping on that wait channel.
- Outside of the sleepq code and the sleep/cv code the kernel no longer
differentiates between cv's and sleep/wakeup. For example, calls to
abortsleep() and cv_abort() are replaced with a call to sleepq_abort().
Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and
cv_waitq_remove() have been replaced with calls to sleepq_remove().
- The sched_sleep() function no longer accepts a priority argument as
sleep's no longer inherently bump the priority. Instead, this is soley
a propery of msleep() which explicitly calls sched_prio() before
blocking.
- The TDF_ONSLEEPQ flag has been dropped as it was never used. The
associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been
dropped and replaced with a single explicit clearing of td_wchan.
TD_SET_ONSLEEPQ() would really have only made sense if it had taken
the wait channel and message as arguments anyway. Now that that only
happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
|
|
|
if (timo && catch)
|
Fix a long standing race between sleep queue and thread
suspension code. When a thread A is going to sleep, it calls
sleepq_catch_signals() to detect any pending signals or thread
suspension request, if nothing happens, it returns without
holding process lock or scheduler lock, this opens a race
window which allows thread B to come in and do process
suspension work, however since A is still at running state,
thread B can do nothing to A, thread A continues, and puts
itself into actually sleeping state, but B has never seen it,
and it sits there forever until B is woken up by other threads
sometimes later(this can be very long delay or never
happen). Fix this bug by forcing sleepq_catch_signals to
return with scheduler lock held.
Fix sleepq_abort() by passing it an interrupted code, previously,
it worked as wakeup_one(), and the interruption can not be
identified correctly by sleep queue code when the sleeping
thread is resumed.
Let thread_suspend_check() returns EINTR or ERESTART, so sleep
queue no longer has to use SIGSTOP as a hack to build a return
value.
Reviewed by: jhb
MFC after: 1 week
2006-02-15 23:52:01 +00:00
|
|
|
rval = sleepq_timedwait_sig(ident);
|
Switch the sleep/wakeup and condition variable implementations to use the
sleep queue interface:
- Sleep queues attempt to merge some of the benefits of both sleep queues
and condition variables. Having sleep qeueus in a hash table avoids
having to allocate a queue head for each wait channel. Thus, struct cv
has shrunk down to just a single char * pointer now. However, the
hash table does not hold threads directly, but queue heads. This means
that once you have located a queue in the hash bucket, you no longer have
to walk the rest of the hash chain looking for threads. Instead, you have
a list of all the threads sleeping on that wait channel.
- Outside of the sleepq code and the sleep/cv code the kernel no longer
differentiates between cv's and sleep/wakeup. For example, calls to
abortsleep() and cv_abort() are replaced with a call to sleepq_abort().
Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and
cv_waitq_remove() have been replaced with calls to sleepq_remove().
- The sched_sleep() function no longer accepts a priority argument as
sleep's no longer inherently bump the priority. Instead, this is soley
a propery of msleep() which explicitly calls sched_prio() before
blocking.
- The TDF_ONSLEEPQ flag has been dropped as it was never used. The
associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been
dropped and replaced with a single explicit clearing of td_wchan.
TD_SET_ONSLEEPQ() would really have only made sense if it had taken
the wait channel and message as arguments anyway. Now that that only
happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
|
|
|
else if (timo)
|
2004-06-28 18:57:06 +00:00
|
|
|
rval = sleepq_timedwait(ident);
|
Switch the sleep/wakeup and condition variable implementations to use the
sleep queue interface:
- Sleep queues attempt to merge some of the benefits of both sleep queues
and condition variables. Having sleep qeueus in a hash table avoids
having to allocate a queue head for each wait channel. Thus, struct cv
has shrunk down to just a single char * pointer now. However, the
hash table does not hold threads directly, but queue heads. This means
that once you have located a queue in the hash bucket, you no longer have
to walk the rest of the hash chain looking for threads. Instead, you have
a list of all the threads sleeping on that wait channel.
- Outside of the sleepq code and the sleep/cv code the kernel no longer
differentiates between cv's and sleep/wakeup. For example, calls to
abortsleep() and cv_abort() are replaced with a call to sleepq_abort().
Thus, the TDF_CVWAITQ flag is removed. Also, calls to unsleep() and
cv_waitq_remove() have been replaced with calls to sleepq_remove().
- The sched_sleep() function no longer accepts a priority argument as
sleep's no longer inherently bump the priority. Instead, this is soley
a propery of msleep() which explicitly calls sched_prio() before
blocking.
- The TDF_ONSLEEPQ flag has been dropped as it was never used. The
associated TDF_SET_ONSLEEPQ and TDF_CLR_ON_SLEEPQ macros have also been
dropped and replaced with a single explicit clearing of td_wchan.
TD_SET_ONSLEEPQ() would really have only made sense if it had taken
the wait channel and message as arguments anyway. Now that that only
happens in one place, a macro would be overkill.
2004-02-27 18:52:44 +00:00
|
|
|
else if (catch)
|
|
|
|
rval = sleepq_wait_sig(ident);
|
|
|
|
else {
|
|
|
|
sleepq_wait(ident);
|
|
|
|
rval = 0;
|
2001-06-22 23:11:26 +00:00
|
|
|
}
|
1994-05-24 10:09:53 +00:00
|
|
|
#ifdef KTRACE
|
2002-06-07 05:39:16 +00:00
|
|
|
if (KTRPOINT(td, KTR_CSW))
|
|
|
|
ktrcsw(0, 0);
|
1994-05-24 10:09:53 +00:00
|
|
|
#endif
|
2002-06-07 05:39:16 +00:00
|
|
|
PICKUP_GIANT();
|
2007-03-09 22:41:01 +00:00
|
|
|
if (lock != NULL && !(priority & PDROP)) {
|
|
|
|
class->lc_lock(lock, lock_state);
|
|
|
|
WITNESS_RESTORE(lock, lock_witness);
|
2000-09-11 00:20:02 +00:00
|
|
|
}
|
2000-09-07 01:33:02 +00:00
|
|
|
return (rval);
|
1994-05-24 10:09:53 +00:00
|
|
|
}
|
|
|
|
|
2005-12-29 20:57:45 +00:00
|
|
|
int
|
|
|
|
msleep_spin(ident, mtx, wmesg, timo)
|
|
|
|
void *ident;
|
|
|
|
struct mtx *mtx;
|
|
|
|
const char *wmesg;
|
|
|
|
int timo;
|
|
|
|
{
|
|
|
|
struct thread *td;
|
|
|
|
struct proc *p;
|
|
|
|
int rval;
|
|
|
|
WITNESS_SAVE_DECL(mtx);
|
|
|
|
|
|
|
|
td = curthread;
|
|
|
|
p = td->td_proc;
|
|
|
|
KASSERT(mtx != NULL, ("sleeping without a mutex"));
|
|
|
|
KASSERT(p != NULL, ("msleep1"));
|
|
|
|
KASSERT(ident != NULL && TD_IS_RUNNING(td), ("msleep"));
|
|
|
|
|
|
|
|
if (cold) {
|
|
|
|
/*
|
|
|
|
* During autoconfiguration, just return;
|
|
|
|
* don't run any other threads or panic below,
|
|
|
|
* in case this is the idle thread and already asleep.
|
|
|
|
* XXX: this used to do "s = splhigh(); splx(safepri);
|
|
|
|
* splx(s);" to give interrupts a chance, but there is
|
|
|
|
* no way to give interrupts a chance now.
|
|
|
|
*/
|
|
|
|
return (0);
|
|
|
|
}
|
|
|
|
|
|
|
|
sleepq_lock(ident);
|
2007-02-27 18:46:07 +00:00
|
|
|
CTR5(KTR_PROC, "msleep_spin: thread %ld (pid %ld, %s) on %s (%p)",
|
2007-11-14 06:51:33 +00:00
|
|
|
td->td_tid, p->p_pid, td->td_name, wmesg, ident);
|
2005-12-29 20:57:45 +00:00
|
|
|
|
|
|
|
DROP_GIANT();
|
|
|
|
mtx_assert(mtx, MA_OWNED | MA_NOTRECURSED);
|
2007-03-21 21:20:51 +00:00
|
|
|
WITNESS_SAVE(&mtx->lock_object, mtx);
|
2005-12-29 20:57:45 +00:00
|
|
|
mtx_unlock_spin(mtx);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* We put ourselves on the sleep queue and start our timeout.
|
|
|
|
*/
|
2007-03-21 21:20:51 +00:00
|
|
|
sleepq_add(ident, &mtx->lock_object, wmesg, SLEEPQ_SLEEP, 0);
|
2005-12-29 20:57:45 +00:00
|
|
|
if (timo)
|
|
|
|
sleepq_set_timeout(ident, timo);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Can't call ktrace with any spin locks held so it can lock the
|
|
|
|
* ktrace_mtx lock, and WITNESS_WARN considers it an error to hold
|
|
|
|
* any spin lock. Thus, we have to drop the sleepq spin lock while
|
|
|
|
* we handle those requests. This is safe since we have placed our
|
|
|
|
* thread on the sleep queue already.
|
|
|
|
*/
|
|
|
|
#ifdef KTRACE
|
|
|
|
if (KTRPOINT(td, KTR_CSW)) {
|
|
|
|
sleepq_release(ident);
|
|
|
|
ktrcsw(1, 0);
|
|
|
|
sleepq_lock(ident);
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
#ifdef WITNESS
|
|
|
|
sleepq_release(ident);
|
|
|
|
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "Sleeping on \"%s\"",
|
|
|
|
wmesg);
|
|
|
|
sleepq_lock(ident);
|
|
|
|
#endif
|
|
|
|
if (timo)
|
|
|
|
rval = sleepq_timedwait(ident);
|
|
|
|
else {
|
|
|
|
sleepq_wait(ident);
|
|
|
|
rval = 0;
|
|
|
|
}
|
|
|
|
#ifdef KTRACE
|
|
|
|
if (KTRPOINT(td, KTR_CSW))
|
|
|
|
ktrcsw(0, 0);
|
|
|
|
#endif
|
|
|
|
PICKUP_GIANT();
|
|
|
|
mtx_lock_spin(mtx);
|
2007-03-21 21:20:51 +00:00
|
|
|
WITNESS_RESTORE(&mtx->lock_object, mtx);
|
2005-12-29 20:57:45 +00:00
|
|
|
return (rval);
|
|
|
|
}
|
|
|
|
|
2007-02-23 16:22:09 +00:00
|
|
|
/*
|
|
|
|
* pause() is like tsleep() except that the intention is to not be
|
|
|
|
* explicitly woken up by another thread. Instead, the current thread
|
|
|
|
* simply wishes to sleep until the timeout expires. It is
|
|
|
|
* implemented using a dummy wait channel.
|
|
|
|
*/
|
|
|
|
int
|
|
|
|
pause(wmesg, timo)
|
|
|
|
const char *wmesg;
|
|
|
|
int timo;
|
|
|
|
{
|
|
|
|
|
|
|
|
KASSERT(timo != 0, ("pause: timeout required"));
|
|
|
|
return (tsleep(&pause_wchan, 0, wmesg, timo));
|
|
|
|
}
|
|
|
|
|
1994-05-24 10:09:53 +00:00
|
|
|
/*
|
2004-05-14 20:51:42 +00:00
|
|
|
* Make all threads sleeping on the specified identifier runnable.
|
1994-05-24 10:09:53 +00:00
|
|
|
*/
|
|
|
|
void
|
2001-07-06 01:16:43 +00:00
|
|
|
wakeup(ident)
|
1994-05-24 10:09:53 +00:00
|
|
|
register void *ident;
|
|
|
|
{
|
|
|
|
|
2004-10-12 18:36:20 +00:00
|
|
|
sleepq_lock(ident);
|
2007-03-09 22:41:01 +00:00
|
|
|
sleepq_broadcast(ident, SLEEPQ_SLEEP, -1, 0);
|
1996-07-31 09:26:54 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
2004-05-14 20:51:42 +00:00
|
|
|
* Make a thread sleeping on the specified identifier runnable.
|
|
|
|
* May wake more than one thread if a target thread is currently
|
2001-07-06 01:16:43 +00:00
|
|
|
* swapped out.
|
1996-07-31 09:26:54 +00:00
|
|
|
*/
|
|
|
|
void
|
2001-07-06 01:16:43 +00:00
|
|
|
wakeup_one(ident)
|
1996-07-31 09:26:54 +00:00
|
|
|
register void *ident;
|
|
|
|
{
|
|
|
|
|
2004-10-12 18:36:20 +00:00
|
|
|
sleepq_lock(ident);
|
2007-03-09 22:41:01 +00:00
|
|
|
sleepq_signal(ident, SLEEPQ_SLEEP, -1, 0);
|
Commit 2/14 of sched_lock decomposition.
- Adapt sleepqueues to the new thread_lock() mechanism.
- Delay assigning the sleep queue spinlock as the thread lock until after
we've checked for signals. It is illegal for a thread to return in
mi_switch() with any lock assigned to td_lock other than the scheduler
locks.
- Change sleepq_catch_signals() to do the switch if necessary to simplify
the callers.
- Simplify timeout handling now that locking a sleeping thread has the
side-effect of locking the sleepqueue. Some previous races are no
longer possible.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-04 23:50:56 +00:00
|
|
|
sleepq_release(ident);
|
1994-05-24 10:09:53 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
2004-05-14 20:51:42 +00:00
|
|
|
* The machine independent parts of context switching.
|
1994-05-24 10:09:53 +00:00
|
|
|
*/
|
|
|
|
void
|
2004-07-02 19:09:50 +00:00
|
|
|
mi_switch(int flags, struct thread *newtd)
|
1994-05-24 10:09:53 +00:00
|
|
|
{
|
2008-01-10 22:11:20 +00:00
|
|
|
uint64_t runtime, new_switchtime;
|
2003-04-02 23:53:30 +00:00
|
|
|
struct thread *td;
|
|
|
|
struct proc *p;
|
1994-05-24 10:09:53 +00:00
|
|
|
|
2003-04-02 23:53:30 +00:00
|
|
|
td = curthread; /* XXX */
|
Commit 2/14 of sched_lock decomposition.
- Adapt sleepqueues to the new thread_lock() mechanism.
- Delay assigning the sleep queue spinlock as the thread lock until after
we've checked for signals. It is illegal for a thread to return in
mi_switch() with any lock assigned to td_lock other than the scheduler
locks.
- Change sleepq_catch_signals() to do the switch if necessary to simplify
the callers.
- Simplify timeout handling now that locking a sleeping thread has the
side-effect of locking the sleepqueue. Some previous races are no
longer possible.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-04 23:50:56 +00:00
|
|
|
THREAD_LOCK_ASSERT(td, MA_OWNED | MA_NOTRECURSED);
|
2003-04-02 23:53:30 +00:00
|
|
|
p = td->td_proc; /* XXX */
|
2002-09-11 08:13:56 +00:00
|
|
|
KASSERT(!TD_ON_RUNQ(td), ("mi_switch: called by old code"));
|
2001-10-23 17:52:49 +00:00
|
|
|
#ifdef INVARIANTS
|
2003-05-05 21:12:36 +00:00
|
|
|
if (!TD_ON_LOCK(td) && !TD_IS_RUNNING(td))
|
2001-10-23 17:52:49 +00:00
|
|
|
mtx_assert(&Giant, MA_NOTOWNED);
|
|
|
|
#endif
|
2004-07-02 20:21:44 +00:00
|
|
|
KASSERT(td->td_critnest == 1 || (td->td_critnest == 2 &&
|
2005-04-08 03:37:53 +00:00
|
|
|
(td->td_owepreempt) && (flags & SW_INVOL) != 0 &&
|
2005-03-31 20:36:44 +00:00
|
|
|
newtd == NULL) || panicstr,
|
2002-07-17 02:46:13 +00:00
|
|
|
("mi_switch: switch in a critical section"));
|
2004-01-25 03:54:52 +00:00
|
|
|
KASSERT((flags & (SW_INVOL | SW_VOL)) != 0,
|
|
|
|
("mi_switch: switch must be voluntary or involuntary"));
|
2004-07-16 21:04:55 +00:00
|
|
|
KASSERT(newtd != curthread, ("mi_switch: preempting back to ourself"));
|
2000-09-07 01:33:02 +00:00
|
|
|
|
2006-06-03 20:49:44 +00:00
|
|
|
/*
|
|
|
|
* Don't perform context switches from the debugger.
|
|
|
|
*/
|
|
|
|
if (kdb_active) {
|
Commit 2/14 of sched_lock decomposition.
- Adapt sleepqueues to the new thread_lock() mechanism.
- Delay assigning the sleep queue spinlock as the thread lock until after
we've checked for signals. It is illegal for a thread to return in
mi_switch() with any lock assigned to td_lock other than the scheduler
locks.
- Change sleepq_catch_signals() to do the switch if necessary to simplify
the callers.
- Simplify timeout handling now that locking a sleeping thread has the
side-effect of locking the sleepqueue. Some previous races are no
longer possible.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-04 23:50:56 +00:00
|
|
|
thread_unlock(td);
|
2006-06-03 20:49:44 +00:00
|
|
|
kdb_backtrace();
|
|
|
|
kdb_reenter();
|
|
|
|
panic("%s: did not reenter debugger", __func__);
|
|
|
|
}
|
2004-01-25 03:54:52 +00:00
|
|
|
if (flags & SW_VOL)
|
2007-06-01 01:12:45 +00:00
|
|
|
td->td_ru.ru_nvcsw++;
|
2004-01-25 03:54:52 +00:00
|
|
|
else
|
2007-06-01 01:12:45 +00:00
|
|
|
td->td_ru.ru_nivcsw++;
|
1994-05-24 10:09:53 +00:00
|
|
|
/*
|
|
|
|
* Compute the amount of time during which the current
|
2007-06-01 01:12:45 +00:00
|
|
|
* thread was running, and add that to its total so far.
|
1994-05-24 10:09:53 +00:00
|
|
|
*/
|
2006-02-07 21:22:02 +00:00
|
|
|
new_switchtime = cpu_ticks();
|
2008-01-10 22:11:20 +00:00
|
|
|
runtime = new_switchtime - PCPU_GET(switchtime);
|
|
|
|
td->td_runtime += runtime;
|
|
|
|
td->td_incruntime += runtime;
|
2007-06-01 01:12:45 +00:00
|
|
|
PCPU_SET(switchtime, new_switchtime);
|
2003-10-05 09:35:08 +00:00
|
|
|
td->td_generation++; /* bump preempt-detect counter */
|
2007-06-04 21:45:18 +00:00
|
|
|
PCPU_INC(cnt.v_swtch);
|
2003-10-29 15:23:09 +00:00
|
|
|
PCPU_SET(switchticks, ticks);
|
2007-02-27 18:46:07 +00:00
|
|
|
CTR4(KTR_PROC, "mi_switch: old thread %ld (kse %p, pid %ld, %s)",
|
2007-11-14 06:51:33 +00:00
|
|
|
td->td_tid, td->td_sched, p->p_pid, td->td_name);
|
2004-12-26 00:14:21 +00:00
|
|
|
#if (KTR_COMPILE & KTR_SCHED) != 0
|
2007-03-08 06:44:34 +00:00
|
|
|
if (TD_IS_IDLETHREAD(td))
|
2004-12-26 00:14:21 +00:00
|
|
|
CTR3(KTR_SCHED, "mi_switch: %p(%s) prio %d idle",
|
2007-11-14 06:21:24 +00:00
|
|
|
td, td->td_name, td->td_priority);
|
2004-12-26 00:14:21 +00:00
|
|
|
else if (newtd != NULL)
|
|
|
|
CTR5(KTR_SCHED,
|
|
|
|
"mi_switch: %p(%s) prio %d preempted by %p(%s)",
|
2007-11-14 06:21:24 +00:00
|
|
|
td, td->td_name, td->td_priority, newtd,
|
|
|
|
newtd->td_name);
|
2004-12-26 00:14:21 +00:00
|
|
|
else
|
|
|
|
CTR6(KTR_SCHED,
|
|
|
|
"mi_switch: %p(%s) prio %d inhibit %d wmesg %s lock %s",
|
2007-11-14 06:21:24 +00:00
|
|
|
td, td->td_name, td->td_priority,
|
2004-12-26 00:14:21 +00:00
|
|
|
td->td_inhibitors, td->td_wmesg, td->td_lockname);
|
2007-01-03 02:38:41 +00:00
|
|
|
#endif
|
|
|
|
/*
|
|
|
|
* We call thread_switchout after the KTR_SCHED prints above so kse
|
|
|
|
* selecting a new thread to run does not show up as a preemption.
|
|
|
|
*/
|
|
|
|
#ifdef KSE
|
|
|
|
if ((flags & SW_VOL) && (td->td_proc->p_flag & P_SA))
|
|
|
|
newtd = thread_switchout(td, flags, newtd);
|
2004-12-26 00:14:21 +00:00
|
|
|
#endif
|
2004-09-10 21:04:38 +00:00
|
|
|
sched_switch(td, newtd, flags);
|
2004-12-26 00:14:21 +00:00
|
|
|
CTR3(KTR_SCHED, "mi_switch: running %p(%s) prio %d",
|
2007-11-14 06:21:24 +00:00
|
|
|
td, td->td_name, td->td_priority);
|
2002-10-12 05:32:24 +00:00
|
|
|
|
2007-02-27 18:46:07 +00:00
|
|
|
CTR4(KTR_PROC, "mi_switch: new thread %ld (kse %p, pid %ld, %s)",
|
2007-11-14 06:51:33 +00:00
|
|
|
td->td_tid, td->td_sched, p->p_pid, td->td_name);
|
2003-10-29 15:23:09 +00:00
|
|
|
|
2002-12-10 02:33:45 +00:00
|
|
|
/*
|
|
|
|
* If the last thread was exiting, finish cleaning it up.
|
|
|
|
*/
|
|
|
|
if ((td = PCPU_GET(deadthread))) {
|
|
|
|
PCPU_SET(deadthread, NULL);
|
|
|
|
thread_stash(td);
|
|
|
|
}
|
1994-05-24 10:09:53 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Change process state to be runnable,
|
|
|
|
* placing it on the run queue if it is in memory,
|
|
|
|
* and awakening the swapper if it isn't in memory.
|
|
|
|
*/
|
|
|
|
void
|
2001-09-12 08:38:13 +00:00
|
|
|
setrunnable(struct thread *td)
|
1994-05-24 10:09:53 +00:00
|
|
|
{
|
2001-09-21 19:16:12 +00:00
|
|
|
|
Commit 2/14 of sched_lock decomposition.
- Adapt sleepqueues to the new thread_lock() mechanism.
- Delay assigning the sleep queue spinlock as the thread lock until after
we've checked for signals. It is illegal for a thread to return in
mi_switch() with any lock assigned to td_lock other than the scheduler
locks.
- Change sleepq_catch_signals() to do the switch if necessary to simplify
the callers.
- Simplify timeout handling now that locking a sleeping thread has the
side-effect of locking the sleepqueue. Some previous races are no
longer possible.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-04 23:50:56 +00:00
|
|
|
THREAD_LOCK_ASSERT(td, MA_OWNED);
|
2007-09-17 05:31:39 +00:00
|
|
|
KASSERT(td->td_proc->p_state != PRS_ZOMBIE,
|
|
|
|
("setrunnable: pid %d is a zombie", td->td_proc->p_pid));
|
Part 1 of KSE-III
The ability to schedule multiple threads per process
(one one cpu) by making ALL system calls optionally asynchronous.
to come: ia64 and power-pc patches, patches for gdb, test program (in tools)
Reviewed by: Almost everyone who counts
(at various times, peter, jhb, matt, alfred, mini, bernd,
and a cast of thousands)
NOTE: this is still Beta code, and contains lots of debugging stuff.
expect slight instability in signals..
2002-06-29 17:26:22 +00:00
|
|
|
switch (td->td_state) {
|
|
|
|
case TDS_RUNNING:
|
2002-09-11 08:13:56 +00:00
|
|
|
case TDS_RUNQ:
|
|
|
|
return;
|
|
|
|
case TDS_INHIBITED:
|
|
|
|
/*
|
|
|
|
* If we are only inhibited because we are swapped out
|
|
|
|
* then arange to swap in this process. Otherwise just return.
|
|
|
|
*/
|
|
|
|
if (td->td_inhibitors != TDI_SWAPPED)
|
|
|
|
return;
|
2003-05-31 20:13:58 +00:00
|
|
|
/* XXX: intentional fall-through ? */
|
2002-09-11 08:13:56 +00:00
|
|
|
case TDS_CAN_RUN:
|
|
|
|
break;
|
1994-05-24 10:09:53 +00:00
|
|
|
default:
|
2002-09-11 08:13:56 +00:00
|
|
|
printf("state is 0x%x", td->td_state);
|
2001-09-12 08:38:13 +00:00
|
|
|
panic("setrunnable(2)");
|
1994-05-24 10:09:53 +00:00
|
|
|
}
|
2007-09-17 05:31:39 +00:00
|
|
|
if ((td->td_flags & TDF_INMEM) == 0) {
|
|
|
|
if ((td->td_flags & TDF_SWAPINREQ) == 0) {
|
|
|
|
td->td_flags |= TDF_SWAPINREQ;
|
2004-08-04 20:24:40 +00:00
|
|
|
/*
|
Commit 2/14 of sched_lock decomposition.
- Adapt sleepqueues to the new thread_lock() mechanism.
- Delay assigning the sleep queue spinlock as the thread lock until after
we've checked for signals. It is illegal for a thread to return in
mi_switch() with any lock assigned to td_lock other than the scheduler
locks.
- Change sleepq_catch_signals() to do the switch if necessary to simplify
the callers.
- Simplify timeout handling now that locking a sleeping thread has the
side-effect of locking the sleepqueue. Some previous races are no
longer possible.
Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)
2007-06-04 23:50:56 +00:00
|
|
|
* due to a LOR between the thread lock and
|
2005-05-23 23:01:53 +00:00
|
|
|
* the sleepqueue chain locks, use
|
|
|
|
* lower level scheduling functions.
|
2004-08-04 20:24:40 +00:00
|
|
|
*/
|
2005-05-23 23:01:53 +00:00
|
|
|
kick_proc0();
|
2002-07-30 06:54:05 +00:00
|
|
|
}
|
2002-10-12 05:32:24 +00:00
|
|
|
} else
|
|
|
|
sched_wakeup(td);
|
1994-05-24 10:09:53 +00:00
|
|
|
}
|
1997-11-25 07:07:48 +00:00
|
|
|
|
2001-10-20 13:10:43 +00:00
|
|
|
/*
|
|
|
|
* Compute a tenex style load average of a quantity on
|
|
|
|
* 1, 5 and 15 minute intervals.
|
|
|
|
* XXXKSE Needs complete rewrite when correct info is available.
|
|
|
|
* Completely Bogus.. only works with 1:1 (but compiles ok now :-)
|
|
|
|
*/
|
|
|
|
static void
|
2004-02-01 05:37:36 +00:00
|
|
|
loadav(void *arg)
|
2001-10-20 13:10:43 +00:00
|
|
|
{
|
|
|
|
int i, nrun;
|
2001-10-20 16:07:17 +00:00
|
|
|
struct loadavg *avg;
|
2001-10-20 13:10:43 +00:00
|
|
|
|
2004-02-01 02:51:33 +00:00
|
|
|
nrun = sched_load();
|
2001-10-20 16:07:17 +00:00
|
|
|
avg = &averunnable;
|
2004-02-01 02:51:33 +00:00
|
|
|
|
2001-10-20 13:10:43 +00:00
|
|
|
for (i = 0; i < 3; i++)
|
|
|
|
avg->ldavg[i] = (cexp[i] * avg->ldavg[i] +
|
|
|
|
nrun * FSCALE * (FSCALE - cexp[i])) >> FSHIFT;
|
2001-10-20 16:07:17 +00:00
|
|
|
|
2004-02-01 05:37:36 +00:00
|
|
|
/*
|
|
|
|
* Schedule the next update to occur after 5 seconds, but add a
|
|
|
|
* random variation to avoid synchronisation with processes that
|
|
|
|
* run at regular intervals.
|
|
|
|
*/
|
|
|
|
callout_reset(&loadav_callout, hz * 4 + (int)(random() % (hz * 2 + 1)),
|
|
|
|
loadav, NULL);
|
2001-10-20 13:10:43 +00:00
|
|
|
}
|
|
|
|
|
2002-11-21 08:57:08 +00:00
|
|
|
static void
|
|
|
|
lboltcb(void *arg)
|
|
|
|
{
|
|
|
|
wakeup(&lbolt);
|
|
|
|
callout_reset(&lbolt_callout, hz, lboltcb, NULL);
|
|
|
|
}
|
|
|
|
|
1997-11-25 07:07:48 +00:00
|
|
|
/* ARGSUSED */
|
|
|
|
static void
|
2004-01-25 07:49:45 +00:00
|
|
|
synch_setup(dummy)
|
1997-11-25 07:07:48 +00:00
|
|
|
void *dummy;
|
|
|
|
{
|
2004-03-08 22:01:19 +00:00
|
|
|
callout_init(&loadav_callout, CALLOUT_MPSAFE);
|
2003-08-19 17:51:11 +00:00
|
|
|
callout_init(&lbolt_callout, CALLOUT_MPSAFE);
|
2000-11-27 22:52:31 +00:00
|
|
|
|
1997-11-25 07:07:48 +00:00
|
|
|
/* Kick off timeout driven events by calling first time. */
|
2004-02-01 05:37:36 +00:00
|
|
|
loadav(NULL);
|
2002-11-21 08:57:08 +00:00
|
|
|
lboltcb(NULL);
|
1997-11-25 07:07:48 +00:00
|
|
|
}
|
|
|
|
|
2000-12-02 05:41:30 +00:00
|
|
|
/*
|
2007-03-05 13:10:58 +00:00
|
|
|
* General purpose yield system call.
|
2000-12-02 05:41:30 +00:00
|
|
|
*/
|
|
|
|
int
|
2001-09-12 08:38:13 +00:00
|
|
|
yield(struct thread *td, struct yield_args *uap)
|
2000-12-02 05:41:30 +00:00
|
|
|
{
|
2007-10-08 23:40:40 +00:00
|
|
|
|
|
|
|
thread_lock(td);
|
|
|
|
sched_prio(td, PRI_MAX_TIMESHARE);
|
|
|
|
mi_switch(SW_VOL, NULL);
|
|
|
|
thread_unlock(td);
|
|
|
|
td->td_retval[0] = 0;
|
2000-12-02 05:41:30 +00:00
|
|
|
return (0);
|
|
|
|
}
|