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kern_sleepq.c revision 1.4.2.12
      1  1.4.2.12     ad /*	$NetBSD: kern_sleepq.c,v 1.4.2.12 2007/04/16 23:31:20 ad Exp $	*/
      2       1.2     ad 
      3       1.2     ad /*-
      4       1.2     ad  * Copyright (c) 2006, 2007 The NetBSD Foundation, Inc.
      5       1.2     ad  * All rights reserved.
      6       1.2     ad  *
      7       1.2     ad  * This code is derived from software contributed to The NetBSD Foundation
      8       1.2     ad  * by Andrew Doran.
      9       1.2     ad  *
     10       1.2     ad  * Redistribution and use in source and binary forms, with or without
     11       1.2     ad  * modification, are permitted provided that the following conditions
     12       1.2     ad  * are met:
     13       1.2     ad  * 1. Redistributions of source code must retain the above copyright
     14       1.2     ad  *    notice, this list of conditions and the following disclaimer.
     15       1.2     ad  * 2. Redistributions in binary form must reproduce the above copyright
     16       1.2     ad  *    notice, this list of conditions and the following disclaimer in the
     17       1.2     ad  *    documentation and/or other materials provided with the distribution.
     18       1.2     ad  * 3. All advertising materials mentioning features or use of this software
     19       1.2     ad  *    must display the following acknowledgement:
     20       1.2     ad  *	This product includes software developed by the NetBSD
     21       1.2     ad  *	Foundation, Inc. and its contributors.
     22       1.2     ad  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23       1.2     ad  *    contributors may be used to endorse or promote products derived
     24       1.2     ad  *    from this software without specific prior written permission.
     25       1.2     ad  *
     26       1.2     ad  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27       1.2     ad  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28       1.2     ad  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29       1.2     ad  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30       1.2     ad  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31       1.2     ad  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32       1.2     ad  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33       1.2     ad  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34       1.2     ad  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35       1.2     ad  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36       1.2     ad  * POSSIBILITY OF SUCH DAMAGE.
     37       1.2     ad  */
     38       1.2     ad 
     39       1.2     ad /*
     40       1.2     ad  * Sleep queue implementation, used by turnstiles and general sleep/wakeup
     41       1.2     ad  * interfaces.
     42       1.2     ad  */
     43       1.2     ad 
     44       1.2     ad #include <sys/cdefs.h>
     45  1.4.2.12     ad __KERNEL_RCSID(0, "$NetBSD: kern_sleepq.c,v 1.4.2.12 2007/04/16 23:31:20 ad Exp $");
     46       1.2     ad 
     47       1.2     ad #include "opt_ktrace.h"
     48       1.2     ad 
     49       1.2     ad #include <sys/param.h>
     50       1.2     ad #include <sys/lock.h>
     51       1.2     ad #include <sys/kernel.h>
     52   1.4.2.2   yamt #include <sys/cpu.h>
     53       1.2     ad #include <sys/pool.h>
     54       1.2     ad #include <sys/proc.h>
     55       1.2     ad #include <sys/resourcevar.h>
     56       1.2     ad #include <sys/sched.h>
     57       1.2     ad #include <sys/systm.h>
     58       1.2     ad #include <sys/sleepq.h>
     59       1.2     ad #ifdef KTRACE
     60       1.2     ad #include <sys/ktrace.h>
     61       1.2     ad #endif
     62       1.2     ad 
     63       1.4     ad #include <uvm/uvm_extern.h>
     64       1.4     ad 
     65  1.4.2.11   yamt int	sleepq_sigtoerror(lwp_t *, int);
     66       1.2     ad 
     67       1.2     ad /* General purpose sleep table, used by ltsleep() and condition variables. */
     68       1.2     ad sleeptab_t	sleeptab;
     69       1.2     ad 
     70       1.2     ad /*
     71       1.2     ad  * sleeptab_init:
     72       1.2     ad  *
     73       1.2     ad  *	Initialize a sleep table.
     74       1.2     ad  */
     75       1.2     ad void
     76       1.2     ad sleeptab_init(sleeptab_t *st)
     77       1.2     ad {
     78       1.2     ad 	sleepq_t *sq;
     79       1.2     ad 	int i;
     80       1.2     ad 
     81       1.2     ad 	for (i = 0; i < SLEEPTAB_HASH_SIZE; i++) {
     82       1.2     ad 		sq = &st->st_queues[i].st_queue;
     83       1.2     ad 		mutex_init(&st->st_queues[i].st_mutex, MUTEX_SPIN, IPL_SCHED);
     84       1.2     ad 		sleepq_init(sq, &st->st_queues[i].st_mutex);
     85       1.2     ad 	}
     86       1.2     ad }
     87       1.2     ad 
     88       1.2     ad /*
     89       1.2     ad  * sleepq_init:
     90       1.2     ad  *
     91       1.2     ad  *	Prepare a sleep queue for use.
     92       1.2     ad  */
     93       1.2     ad void
     94       1.2     ad sleepq_init(sleepq_t *sq, kmutex_t *mtx)
     95       1.2     ad {
     96       1.2     ad 
     97       1.2     ad 	sq->sq_waiters = 0;
     98       1.2     ad 	sq->sq_mutex = mtx;
     99       1.2     ad 	TAILQ_INIT(&sq->sq_queue);
    100       1.2     ad }
    101       1.2     ad 
    102       1.2     ad /*
    103       1.2     ad  * sleepq_remove:
    104       1.2     ad  *
    105       1.2     ad  *	Remove an LWP from a sleep queue and wake it up.  Return non-zero if
    106       1.2     ad  *	the LWP is swapped out; if so the caller needs to awaken the swapper
    107       1.2     ad  *	to bring the LWP into memory.
    108       1.2     ad  */
    109       1.2     ad int
    110  1.4.2.11   yamt sleepq_remove(sleepq_t *sq, lwp_t *l)
    111       1.2     ad {
    112       1.2     ad 	struct cpu_info *ci;
    113       1.2     ad 
    114       1.4     ad 	KASSERT(lwp_locked(l, sq->sq_mutex));
    115       1.2     ad 	KASSERT(sq->sq_waiters > 0);
    116       1.2     ad 
    117       1.2     ad 	sq->sq_waiters--;
    118       1.2     ad 	TAILQ_REMOVE(&sq->sq_queue, l, l_sleepchain);
    119       1.2     ad 
    120       1.2     ad #ifdef DIAGNOSTIC
    121       1.2     ad 	if (sq->sq_waiters == 0)
    122       1.2     ad 		KASSERT(TAILQ_FIRST(&sq->sq_queue) == NULL);
    123       1.2     ad 	else
    124       1.2     ad 		KASSERT(TAILQ_FIRST(&sq->sq_queue) != NULL);
    125       1.2     ad #endif
    126       1.2     ad 
    127       1.2     ad 	l->l_syncobj = &sched_syncobj;
    128       1.2     ad 	l->l_wchan = NULL;
    129       1.2     ad 	l->l_sleepq = NULL;
    130   1.4.2.4   yamt 	l->l_flag &= ~LW_SINTR;
    131       1.2     ad 
    132   1.4.2.9  rmind 	ci = l->l_cpu;
    133   1.4.2.9  rmind 
    134       1.2     ad 	/*
    135       1.2     ad 	 * If not sleeping, the LWP must have been suspended.  Let whoever
    136       1.2     ad 	 * holds it stopped set it running again.
    137       1.2     ad 	 */
    138       1.2     ad 	if (l->l_stat != LSSLEEP) {
    139       1.2     ad 	 	KASSERT(l->l_stat == LSSTOP || l->l_stat == LSSUSPENDED);
    140   1.4.2.9  rmind 		lwp_setlock(l, ci->ci_schedstate.spc_mutex);
    141       1.2     ad 		return 0;
    142       1.2     ad 	}
    143       1.2     ad 
    144       1.2     ad 	/*
    145       1.2     ad 	 * If the LWP is still on the CPU, mark it as LSONPROC.  It may be
    146       1.2     ad 	 * about to call mi_switch(), in which case it will yield.
    147       1.2     ad 	 */
    148   1.4.2.7     ad 	if ((l->l_flag & LW_RUNNING) != 0) {
    149       1.2     ad 		l->l_stat = LSONPROC;
    150       1.2     ad 		l->l_slptime = 0;
    151   1.4.2.9  rmind 		lwp_setlock(l, ci->ci_schedstate.spc_mutex);
    152       1.2     ad 		return 0;
    153       1.2     ad 	}
    154       1.2     ad 
    155       1.2     ad 	/*
    156       1.2     ad 	 * Set it running.  We'll try to get the last CPU that ran
    157       1.2     ad 	 * this LWP to pick it up again.
    158       1.2     ad 	 */
    159  1.4.2.12     ad 	spc_lock(ci);
    160   1.4.2.9  rmind 	lwp_setlock(l, ci->ci_schedstate.spc_mutex);
    161   1.4.2.1  rmind 	sched_setrunnable(l);
    162       1.2     ad 	l->l_stat = LSRUN;
    163       1.2     ad 	l->l_slptime = 0;
    164   1.4.2.4   yamt 	if ((l->l_flag & LW_INMEM) != 0) {
    165   1.4.2.6  rmind 		sched_enqueue(l, false);
    166   1.4.2.4   yamt 		if (lwp_eprio(l) < ci->ci_schedstate.spc_curpriority)
    167   1.4.2.3   yamt 			cpu_need_resched(ci, 0);
    168  1.4.2.12     ad 		spc_unlock(ci);
    169       1.2     ad 		return 0;
    170       1.2     ad 	}
    171       1.2     ad 
    172  1.4.2.12     ad 	spc_unlock(ci);
    173       1.2     ad 	return 1;
    174       1.2     ad }
    175       1.2     ad 
    176       1.2     ad /*
    177       1.2     ad  * sleepq_insert:
    178       1.2     ad  *
    179       1.2     ad  *	Insert an LWP into the sleep queue, optionally sorting by priority.
    180       1.2     ad  */
    181       1.2     ad inline void
    182  1.4.2.11   yamt sleepq_insert(sleepq_t *sq, lwp_t *l, syncobj_t *sobj)
    183       1.2     ad {
    184  1.4.2.11   yamt 	lwp_t *l2;
    185   1.4.2.4   yamt 	const int pri = lwp_eprio(l);
    186       1.2     ad 
    187       1.2     ad 	if ((sobj->sobj_flag & SOBJ_SLEEPQ_SORTED) != 0) {
    188       1.2     ad 		TAILQ_FOREACH(l2, &sq->sq_queue, l_sleepchain) {
    189   1.4.2.4   yamt 			if (lwp_eprio(l2) > pri) {
    190       1.2     ad 				TAILQ_INSERT_BEFORE(l2, l, l_sleepchain);
    191       1.2     ad 				return;
    192       1.2     ad 			}
    193       1.2     ad 		}
    194       1.2     ad 	}
    195       1.2     ad 
    196       1.2     ad 	TAILQ_INSERT_TAIL(&sq->sq_queue, l, l_sleepchain);
    197       1.2     ad }
    198       1.2     ad 
    199       1.2     ad void
    200   1.4.2.4   yamt sleepq_enqueue(sleepq_t *sq, pri_t pri, wchan_t wchan, const char *wmesg,
    201   1.4.2.4   yamt     syncobj_t *sobj)
    202       1.2     ad {
    203  1.4.2.11   yamt 	lwp_t *l = curlwp;
    204       1.2     ad 
    205       1.4     ad 	KASSERT(mutex_owned(sq->sq_mutex));
    206       1.2     ad 	KASSERT(l->l_stat == LSONPROC);
    207       1.2     ad 	KASSERT(l->l_wchan == NULL && l->l_sleepq == NULL);
    208       1.2     ad 
    209       1.2     ad 	l->l_syncobj = sobj;
    210       1.2     ad 	l->l_wchan = wchan;
    211       1.2     ad 	l->l_sleepq = sq;
    212       1.2     ad 	l->l_wmesg = wmesg;
    213       1.2     ad 	l->l_slptime = 0;
    214       1.2     ad 	l->l_priority = pri;
    215       1.2     ad 	l->l_stat = LSSLEEP;
    216       1.2     ad 	l->l_sleeperr = 0;
    217       1.2     ad 	l->l_nvcsw++;
    218       1.2     ad 
    219       1.2     ad 	sq->sq_waiters++;
    220   1.4.2.4   yamt 	sleepq_insert(sq, l, sobj);
    221   1.4.2.4   yamt }
    222   1.4.2.4   yamt 
    223   1.4.2.4   yamt void
    224  1.4.2.11   yamt sleepq_switch(int timo, bool catch)
    225   1.4.2.4   yamt {
    226  1.4.2.11   yamt 	lwp_t *l = curlwp;
    227       1.2     ad 
    228       1.4     ad #ifdef KTRACE
    229       1.4     ad 	if (KTRPOINT(l->l_proc, KTR_CSW))
    230       1.4     ad 		ktrcsw(l, 1, 0);
    231       1.4     ad #endif
    232       1.4     ad 
    233       1.2     ad 	/*
    234       1.2     ad 	 * If sleeping interruptably, check for pending signals, exits or
    235       1.2     ad 	 * core dump events.
    236       1.2     ad 	 */
    237       1.2     ad 	if (catch) {
    238   1.4.2.4   yamt 		l->l_flag |= LW_SINTR;
    239   1.4.2.4   yamt 		if ((l->l_flag & LW_PENDSIG) != 0 && sigispending(l, 0)) {
    240       1.2     ad 			l->l_sleeperr = EPASSTHROUGH;
    241       1.2     ad 			/* lwp_unsleep() will release the lock */
    242       1.2     ad 			lwp_unsleep(l);
    243       1.2     ad 			return;
    244       1.2     ad 		}
    245   1.4.2.4   yamt 		if ((l->l_flag & (LW_CANCELLED|LW_WEXIT|LW_WCORE)) != 0) {
    246   1.4.2.4   yamt 			l->l_flag &= ~LW_CANCELLED;
    247       1.2     ad 			l->l_sleeperr = EINTR;
    248       1.2     ad 			/* lwp_unsleep() will release the lock */
    249       1.2     ad 			lwp_unsleep(l);
    250       1.2     ad 			return;
    251       1.2     ad 		}
    252       1.2     ad 	}
    253       1.2     ad 
    254       1.2     ad 	if (timo)
    255       1.2     ad 		callout_reset(&l->l_tsleep_ch, timo, sleepq_timeout, l);
    256       1.2     ad 
    257   1.4.2.5  rmind 	mi_switch(l);
    258       1.2     ad 	l->l_cpu->ci_schedstate.spc_curpriority = l->l_usrpri;
    259       1.2     ad 
    260       1.2     ad 	/*
    261       1.2     ad 	 * When we reach this point, the LWP and sleep queue are unlocked.
    262       1.2     ad 	 */
    263       1.2     ad 	KASSERT(l->l_wchan == NULL && l->l_sleepq == NULL);
    264       1.2     ad }
    265       1.2     ad 
    266       1.2     ad /*
    267   1.4.2.4   yamt  * sleepq_block:
    268   1.4.2.4   yamt  *
    269   1.4.2.4   yamt  *	Enter an LWP into the sleep queue and prepare for sleep.  The sleep
    270   1.4.2.4   yamt  *	queue must already be locked, and any interlock (such as the kernel
    271   1.4.2.4   yamt  *	lock) must have be released (see sleeptab_lookup(), sleepq_enter()).
    272   1.4.2.4   yamt  *
    273   1.4.2.4   yamt  * 	sleepq_block() may return early under exceptional conditions, for
    274   1.4.2.4   yamt  * 	example if the LWP's containing process is exiting.
    275   1.4.2.4   yamt  */
    276   1.4.2.4   yamt void
    277   1.4.2.4   yamt sleepq_block(sleepq_t *sq, pri_t pri, wchan_t wchan, const char *wmesg,
    278  1.4.2.11   yamt 	     int timo, bool catch, syncobj_t *sobj)
    279   1.4.2.4   yamt {
    280   1.4.2.4   yamt 
    281   1.4.2.4   yamt 	sleepq_enqueue(sq, pri, wchan, wmesg, sobj);
    282   1.4.2.4   yamt 	sleepq_switch(timo, catch);
    283   1.4.2.4   yamt }
    284   1.4.2.4   yamt 
    285   1.4.2.4   yamt /*
    286       1.2     ad  * sleepq_unblock:
    287       1.2     ad  *
    288       1.2     ad  *	After any intermediate step such as updating statistics, re-acquire
    289       1.2     ad  *	the kernel lock and record the switch for ktrace.  Note that we are
    290       1.2     ad  *	no longer on the sleep queue at this point.
    291       1.2     ad  *
    292       1.2     ad  *	This is split out from sleepq_block() in expectation that at some
    293       1.2     ad  *	point in the future, LWPs may awake on different kernel stacks than
    294       1.2     ad  *	those they went asleep on.
    295       1.2     ad  */
    296       1.2     ad int
    297  1.4.2.11   yamt sleepq_unblock(int timo, bool catch)
    298       1.2     ad {
    299       1.2     ad 	int error, expired, sig;
    300       1.2     ad 	struct proc *p;
    301  1.4.2.11   yamt 	lwp_t *l;
    302       1.2     ad 
    303       1.2     ad 	l = curlwp;
    304       1.2     ad 	error = l->l_sleeperr;
    305       1.2     ad 
    306       1.2     ad 	if (timo) {
    307       1.2     ad 		/*
    308       1.2     ad 		 * Even if the callout appears to have fired, we need to
    309       1.2     ad 		 * stop it in order to synchronise with other CPUs.
    310       1.2     ad 		 */
    311       1.2     ad 		expired = callout_expired(&l->l_tsleep_ch);
    312       1.2     ad 		callout_stop(&l->l_tsleep_ch);
    313       1.2     ad 		if (expired && error == 0)
    314       1.2     ad 			error = EWOULDBLOCK;
    315       1.2     ad 	}
    316       1.2     ad 
    317       1.2     ad 	if (catch && (error == 0 || error == EPASSTHROUGH)) {
    318       1.2     ad 		l->l_sleeperr = 0;
    319       1.2     ad 		p = l->l_proc;
    320   1.4.2.4   yamt 		if ((l->l_flag & (LW_CANCELLED | LW_WEXIT | LW_WCORE)) != 0)
    321       1.2     ad 			error = EINTR;
    322   1.4.2.4   yamt 		else if ((l->l_flag & LW_PENDSIG) != 0) {
    323       1.2     ad 			KERNEL_LOCK(1, l);	/* XXXSMP pool_put() */
    324       1.2     ad 			mutex_enter(&p->p_smutex);
    325       1.2     ad 			if ((sig = issignal(l)) != 0)
    326       1.2     ad 				error = sleepq_sigtoerror(l, sig);
    327       1.2     ad 			mutex_exit(&p->p_smutex);
    328       1.2     ad 			KERNEL_UNLOCK_LAST(l);
    329       1.2     ad 		}
    330       1.2     ad 		if (error == EPASSTHROUGH) {
    331       1.2     ad 			/* Raced */
    332       1.2     ad 			error = EINTR;
    333       1.2     ad 		}
    334       1.2     ad 	}
    335       1.2     ad 
    336       1.2     ad #ifdef KTRACE
    337       1.2     ad 	if (KTRPOINT(l->l_proc, KTR_CSW))
    338       1.2     ad 		ktrcsw(l, 0, 0);
    339       1.2     ad #endif
    340       1.2     ad 
    341       1.2     ad 	KERNEL_LOCK(l->l_biglocks, l);
    342       1.2     ad 	return error;
    343       1.2     ad }
    344       1.2     ad 
    345       1.2     ad /*
    346       1.2     ad  * sleepq_wake:
    347       1.2     ad  *
    348       1.2     ad  *	Wake zero or more LWPs blocked on a single wait channel.
    349       1.2     ad  */
    350  1.4.2.11   yamt lwp_t *
    351       1.2     ad sleepq_wake(sleepq_t *sq, wchan_t wchan, u_int expected)
    352       1.2     ad {
    353  1.4.2.11   yamt 	lwp_t *l, *next;
    354       1.2     ad 	int swapin = 0;
    355       1.2     ad 
    356       1.4     ad 	KASSERT(mutex_owned(sq->sq_mutex));
    357       1.2     ad 
    358       1.2     ad 	for (l = TAILQ_FIRST(&sq->sq_queue); l != NULL; l = next) {
    359       1.2     ad 		KASSERT(l->l_sleepq == sq);
    360       1.2     ad 		next = TAILQ_NEXT(l, l_sleepchain);
    361       1.2     ad 		if (l->l_wchan != wchan)
    362       1.2     ad 			continue;
    363       1.2     ad 		swapin |= sleepq_remove(sq, l);
    364       1.2     ad 		if (--expected == 0)
    365       1.2     ad 			break;
    366       1.2     ad 	}
    367       1.2     ad 
    368       1.2     ad 	sleepq_unlock(sq);
    369       1.2     ad 
    370       1.2     ad 	/*
    371       1.2     ad 	 * If there are newly awakend threads that need to be swapped in,
    372       1.2     ad 	 * then kick the swapper into action.
    373       1.2     ad 	 */
    374       1.2     ad 	if (swapin)
    375       1.4     ad 		uvm_kick_scheduler();
    376  1.4.2.11   yamt 
    377  1.4.2.11   yamt 	return l;
    378       1.2     ad }
    379       1.2     ad 
    380       1.2     ad /*
    381       1.2     ad  * sleepq_unsleep:
    382       1.2     ad  *
    383       1.2     ad  *	Remove an LWP from its sleep queue and set it runnable again.
    384       1.2     ad  *	sleepq_unsleep() is called with the LWP's mutex held, and will
    385       1.2     ad  *	always release it.
    386       1.2     ad  */
    387       1.2     ad void
    388  1.4.2.11   yamt sleepq_unsleep(lwp_t *l)
    389       1.2     ad {
    390       1.2     ad 	sleepq_t *sq = l->l_sleepq;
    391       1.2     ad 	int swapin;
    392       1.2     ad 
    393       1.4     ad 	KASSERT(lwp_locked(l, NULL));
    394       1.2     ad 	KASSERT(l->l_wchan != NULL);
    395       1.2     ad 	KASSERT(l->l_mutex == sq->sq_mutex);
    396       1.2     ad 
    397       1.2     ad 	swapin = sleepq_remove(sq, l);
    398       1.2     ad 	sleepq_unlock(sq);
    399       1.2     ad 
    400       1.2     ad 	if (swapin)
    401       1.4     ad 		uvm_kick_scheduler();
    402       1.2     ad }
    403       1.2     ad 
    404       1.2     ad /*
    405       1.2     ad  * sleepq_timeout:
    406       1.2     ad  *
    407       1.2     ad  *	Entered via the callout(9) subsystem to time out an LWP that is on a
    408       1.2     ad  *	sleep queue.
    409       1.2     ad  */
    410       1.2     ad void
    411       1.2     ad sleepq_timeout(void *arg)
    412       1.2     ad {
    413  1.4.2.11   yamt 	lwp_t *l = arg;
    414       1.2     ad 
    415       1.2     ad 	/*
    416       1.2     ad 	 * Lock the LWP.  Assuming it's still on the sleep queue, its
    417       1.2     ad 	 * current mutex will also be the sleep queue mutex.
    418       1.2     ad 	 */
    419       1.2     ad 	lwp_lock(l);
    420       1.2     ad 
    421       1.2     ad 	if (l->l_wchan == NULL) {
    422       1.2     ad 		/* Somebody beat us to it. */
    423       1.2     ad 		lwp_unlock(l);
    424       1.2     ad 		return;
    425       1.2     ad 	}
    426       1.2     ad 
    427       1.2     ad 	lwp_unsleep(l);
    428       1.2     ad }
    429       1.2     ad 
    430       1.2     ad /*
    431       1.2     ad  * sleepq_sigtoerror:
    432       1.2     ad  *
    433       1.2     ad  *	Given a signal number, interpret and return an error code.
    434       1.2     ad  */
    435       1.2     ad int
    436  1.4.2.11   yamt sleepq_sigtoerror(lwp_t *l, int sig)
    437       1.2     ad {
    438       1.2     ad 	struct proc *p = l->l_proc;
    439       1.2     ad 	int error;
    440       1.2     ad 
    441       1.4     ad 	KASSERT(mutex_owned(&p->p_smutex));
    442       1.2     ad 
    443       1.2     ad 	/*
    444       1.2     ad 	 * If this sleep was canceled, don't let the syscall restart.
    445       1.2     ad 	 */
    446       1.2     ad 	if ((SIGACTION(p, sig).sa_flags & SA_RESTART) == 0)
    447       1.2     ad 		error = EINTR;
    448       1.2     ad 	else
    449       1.2     ad 		error = ERESTART;
    450       1.2     ad 
    451       1.2     ad 	return error;
    452       1.2     ad }
    453       1.2     ad 
    454       1.2     ad /*
    455       1.2     ad  * sleepq_abort:
    456       1.2     ad  *
    457       1.2     ad  *	After a panic or during autoconfiguration, lower the interrupt
    458       1.2     ad  *	priority level to give pending interrupts a chance to run, and
    459       1.2     ad  *	then return.  Called if sleepq_dontsleep() returns non-zero, and
    460       1.2     ad  *	always returns zero.
    461       1.2     ad  */
    462       1.2     ad int
    463       1.2     ad sleepq_abort(kmutex_t *mtx, int unlock)
    464       1.2     ad {
    465       1.2     ad 	extern int safepri;
    466       1.2     ad 	int s;
    467       1.2     ad 
    468       1.2     ad 	s = splhigh();
    469       1.2     ad 	splx(safepri);
    470       1.2     ad 	splx(s);
    471       1.2     ad 	if (mtx != NULL && unlock != 0)
    472       1.2     ad 		mutex_exit(mtx);
    473       1.2     ad 
    474       1.2     ad 	return 0;
    475       1.2     ad }
    476       1.2     ad 
    477       1.2     ad /*
    478       1.2     ad  * sleepq_changepri:
    479       1.2     ad  *
    480       1.2     ad  *	Adjust the priority of an LWP residing on a sleepq.  This method
    481       1.2     ad  *	will only alter the user priority; the effective priority is
    482       1.2     ad  *	assumed to have been fixed at the time of insertion into the queue.
    483       1.2     ad  */
    484       1.2     ad void
    485  1.4.2.11   yamt sleepq_changepri(lwp_t *l, pri_t pri)
    486       1.2     ad {
    487       1.2     ad 
    488       1.2     ad 	KASSERT(lwp_locked(l, l->l_sleepq->sq_mutex));
    489       1.2     ad 	l->l_usrpri = pri;
    490       1.2     ad }
    491   1.4.2.4   yamt 
    492   1.4.2.4   yamt void
    493  1.4.2.11   yamt sleepq_lendpri(lwp_t *l, pri_t pri)
    494   1.4.2.4   yamt {
    495   1.4.2.4   yamt 	sleepq_t *sq = l->l_sleepq;
    496   1.4.2.4   yamt 	pri_t opri;
    497   1.4.2.4   yamt 
    498   1.4.2.4   yamt 	KASSERT(lwp_locked(l, sq->sq_mutex));
    499   1.4.2.4   yamt 
    500   1.4.2.4   yamt 	opri = lwp_eprio(l);
    501   1.4.2.4   yamt 	l->l_inheritedprio = pri;
    502   1.4.2.4   yamt 
    503   1.4.2.4   yamt 	if (lwp_eprio(l) != opri &&
    504   1.4.2.4   yamt 	    (l->l_syncobj->sobj_flag & SOBJ_SLEEPQ_SORTED) != 0) {
    505   1.4.2.4   yamt 		TAILQ_REMOVE(&sq->sq_queue, l, l_sleepchain);
    506   1.4.2.4   yamt 		sleepq_insert(sq, l, l->l_syncobj);
    507   1.4.2.4   yamt 	}
    508   1.4.2.4   yamt }
    509