subr_sleepqueue.c revision 173601
1139804Simp/*- 2126324Sjhb * Copyright (c) 2004 John Baldwin <jhb@FreeBSD.org> 3126324Sjhb * All rights reserved. 4126324Sjhb * 5126324Sjhb * Redistribution and use in source and binary forms, with or without 6126324Sjhb * modification, are permitted provided that the following conditions 7126324Sjhb * are met: 8126324Sjhb * 1. Redistributions of source code must retain the above copyright 9126324Sjhb * notice, this list of conditions and the following disclaimer. 10126324Sjhb * 2. Redistributions in binary form must reproduce the above copyright 11126324Sjhb * notice, this list of conditions and the following disclaimer in the 12126324Sjhb * documentation and/or other materials provided with the distribution. 13126324Sjhb * 3. Neither the name of the author nor the names of any co-contributors 14126324Sjhb * may be used to endorse or promote products derived from this software 15126324Sjhb * without specific prior written permission. 16126324Sjhb * 17126324Sjhb * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18126324Sjhb * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19126324Sjhb * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20126324Sjhb * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21126324Sjhb * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22126324Sjhb * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23126324Sjhb * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24126324Sjhb * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25126324Sjhb * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26126324Sjhb * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27126324Sjhb * SUCH DAMAGE. 28126324Sjhb */ 29126324Sjhb 30126324Sjhb/* 31126324Sjhb * Implementation of sleep queues used to hold queue of threads blocked on 32126324Sjhb * a wait channel. Sleep queues different from turnstiles in that wait 33126324Sjhb * channels are not owned by anyone, so there is no priority propagation. 34126324Sjhb * Sleep queues can also provide a timeout and can also be interrupted by 35126324Sjhb * signals. That said, there are several similarities between the turnstile 36126324Sjhb * and sleep queue implementations. (Note: turnstiles were implemented 37126324Sjhb * first.) For example, both use a hash table of the same size where each 38126324Sjhb * bucket is referred to as a "chain" that contains both a spin lock and 39126324Sjhb * a linked list of queues. An individual queue is located by using a hash 40126324Sjhb * to pick a chain, locking the chain, and then walking the chain searching 41126324Sjhb * for the queue. This means that a wait channel object does not need to 42126324Sjhb * embed it's queue head just as locks do not embed their turnstile queue 43126324Sjhb * head. Threads also carry around a sleep queue that they lend to the 44126324Sjhb * wait channel when blocking. Just as in turnstiles, the queue includes 45126324Sjhb * a free list of the sleep queues of other threads blocked on the same 46126324Sjhb * wait channel in the case of multiple waiters. 47126324Sjhb * 48126324Sjhb * Some additional functionality provided by sleep queues include the 49126324Sjhb * ability to set a timeout. The timeout is managed using a per-thread 50126324Sjhb * callout that resumes a thread if it is asleep. A thread may also 51126324Sjhb * catch signals while it is asleep (aka an interruptible sleep). The 52126324Sjhb * signal code uses sleepq_abort() to interrupt a sleeping thread. Finally, 53126324Sjhb * sleep queues also provide some extra assertions. One is not allowed to 54126324Sjhb * mix the sleep/wakeup and cv APIs for a given wait channel. Also, one 55126324Sjhb * must consistently use the same lock to synchronize with a wait channel, 56126324Sjhb * though this check is currently only a warning for sleep/wakeup due to 57126324Sjhb * pre-existing abuse of that API. The same lock must also be held when 58126324Sjhb * awakening threads, though that is currently only enforced for condition 59126324Sjhb * variables. 60126324Sjhb */ 61126324Sjhb 62126324Sjhb#include <sys/cdefs.h> 63126324Sjhb__FBSDID("$FreeBSD: head/sys/kern/subr_sleepqueue.c 173601 2007-11-14 06:51:33Z julian $"); 64126324Sjhb 65154936Sjhb#include "opt_sleepqueue_profiling.h" 66154936Sjhb#include "opt_ddb.h" 67170640Sjeff#include "opt_sched.h" 68154936Sjhb 69126324Sjhb#include <sys/param.h> 70126324Sjhb#include <sys/systm.h> 71126324Sjhb#include <sys/lock.h> 72126324Sjhb#include <sys/kernel.h> 73126324Sjhb#include <sys/ktr.h> 74126324Sjhb#include <sys/mutex.h> 75126324Sjhb#include <sys/proc.h> 76126324Sjhb#include <sys/sched.h> 77126324Sjhb#include <sys/signalvar.h> 78126324Sjhb#include <sys/sleepqueue.h> 79131259Sjhb#include <sys/sysctl.h> 80126324Sjhb 81169666Sjeff#include <vm/uma.h> 82169666Sjeff 83154936Sjhb#ifdef DDB 84154936Sjhb#include <ddb/ddb.h> 85154936Sjhb#endif 86154936Sjhb 87126324Sjhb/* 88126324Sjhb * Constants for the hash table of sleep queue chains. These constants are 89126324Sjhb * the same ones that 4BSD (and possibly earlier versions of BSD) used. 90126324Sjhb * Basically, we ignore the lower 8 bits of the address since most wait 91126324Sjhb * channel pointers are aligned and only look at the next 7 bits for the 92126324Sjhb * hash. SC_TABLESIZE must be a power of two for SC_MASK to work properly. 93126324Sjhb */ 94126324Sjhb#define SC_TABLESIZE 128 /* Must be power of 2. */ 95126324Sjhb#define SC_MASK (SC_TABLESIZE - 1) 96126324Sjhb#define SC_SHIFT 8 97126324Sjhb#define SC_HASH(wc) (((uintptr_t)(wc) >> SC_SHIFT) & SC_MASK) 98126324Sjhb#define SC_LOOKUP(wc) &sleepq_chains[SC_HASH(wc)] 99165272Skmacy#define NR_SLEEPQS 2 100126324Sjhb/* 101126324Sjhb * There two different lists of sleep queues. Both lists are connected 102126324Sjhb * via the sq_hash entries. The first list is the sleep queue chain list 103126324Sjhb * that a sleep queue is on when it is attached to a wait channel. The 104126324Sjhb * second list is the free list hung off of a sleep queue that is attached 105126324Sjhb * to a wait channel. 106126324Sjhb * 107126324Sjhb * Each sleep queue also contains the wait channel it is attached to, the 108126324Sjhb * list of threads blocked on that wait channel, flags specific to the 109126324Sjhb * wait channel, and the lock used to synchronize with a wait channel. 110126324Sjhb * The flags are used to catch mismatches between the various consumers 111126324Sjhb * of the sleep queue API (e.g. sleep/wakeup and condition variables). 112126324Sjhb * The lock pointer is only used when invariants are enabled for various 113126324Sjhb * debugging checks. 114126324Sjhb * 115126324Sjhb * Locking key: 116126324Sjhb * c - sleep queue chain lock 117126324Sjhb */ 118126324Sjhbstruct sleepqueue { 119165272Skmacy TAILQ_HEAD(, thread) sq_blocked[NR_SLEEPQS]; /* (c) Blocked threads. */ 120126324Sjhb LIST_ENTRY(sleepqueue) sq_hash; /* (c) Chain and free list. */ 121126324Sjhb LIST_HEAD(, sleepqueue) sq_free; /* (c) Free queues. */ 122126324Sjhb void *sq_wchan; /* (c) Wait channel. */ 123136445Sjhb#ifdef INVARIANTS 124134013Sjhb int sq_type; /* (c) Queue type. */ 125164325Spjd struct lock_object *sq_lock; /* (c) Associated lock. */ 126126324Sjhb#endif 127126324Sjhb}; 128126324Sjhb 129126324Sjhbstruct sleepqueue_chain { 130126324Sjhb LIST_HEAD(, sleepqueue) sc_queues; /* List of sleep queues. */ 131126324Sjhb struct mtx sc_lock; /* Spin lock for this chain. */ 132131259Sjhb#ifdef SLEEPQUEUE_PROFILING 133131259Sjhb u_int sc_depth; /* Length of sc_queues. */ 134131259Sjhb u_int sc_max_depth; /* Max length of sc_queues. */ 135131259Sjhb#endif 136126324Sjhb}; 137126324Sjhb 138131259Sjhb#ifdef SLEEPQUEUE_PROFILING 139131259Sjhbu_int sleepq_max_depth; 140131259SjhbSYSCTL_NODE(_debug, OID_AUTO, sleepq, CTLFLAG_RD, 0, "sleepq profiling"); 141131259SjhbSYSCTL_NODE(_debug_sleepq, OID_AUTO, chains, CTLFLAG_RD, 0, 142131259Sjhb "sleepq chain stats"); 143131259SjhbSYSCTL_UINT(_debug_sleepq, OID_AUTO, max_depth, CTLFLAG_RD, &sleepq_max_depth, 144131259Sjhb 0, "maxmimum depth achieved of a single chain"); 145131259Sjhb#endif 146126324Sjhbstatic struct sleepqueue_chain sleepq_chains[SC_TABLESIZE]; 147169666Sjeffstatic uma_zone_t sleepq_zone; 148126324Sjhb 149126324Sjhb/* 150126324Sjhb * Prototypes for non-exported routines. 151126324Sjhb */ 152165272Skmacystatic int sleepq_catch_signals(void *wchan); 153165272Skmacystatic int sleepq_check_signals(void); 154126324Sjhbstatic int sleepq_check_timeout(void); 155169666Sjeff#ifdef INVARIANTS 156169666Sjeffstatic void sleepq_dtor(void *mem, int size, void *arg); 157169666Sjeff#endif 158169666Sjeffstatic int sleepq_init(void *mem, int size, int flags); 159169666Sjeffstatic void sleepq_resume_thread(struct sleepqueue *sq, struct thread *td, 160169666Sjeff int pri); 161126324Sjhbstatic void sleepq_switch(void *wchan); 162126324Sjhbstatic void sleepq_timeout(void *arg); 163126324Sjhb 164126324Sjhb/* 165126324Sjhb * Early initialization of sleep queues that is called from the sleepinit() 166126324Sjhb * SYSINIT. 167126324Sjhb */ 168126324Sjhbvoid 169126324Sjhbinit_sleepqueues(void) 170126324Sjhb{ 171131259Sjhb#ifdef SLEEPQUEUE_PROFILING 172131259Sjhb struct sysctl_oid *chain_oid; 173131259Sjhb char chain_name[10]; 174131259Sjhb#endif 175126324Sjhb int i; 176126324Sjhb 177126324Sjhb for (i = 0; i < SC_TABLESIZE; i++) { 178126324Sjhb LIST_INIT(&sleepq_chains[i].sc_queues); 179126324Sjhb mtx_init(&sleepq_chains[i].sc_lock, "sleepq chain", NULL, 180126324Sjhb MTX_SPIN); 181131259Sjhb#ifdef SLEEPQUEUE_PROFILING 182131259Sjhb snprintf(chain_name, sizeof(chain_name), "%d", i); 183131259Sjhb chain_oid = SYSCTL_ADD_NODE(NULL, 184131259Sjhb SYSCTL_STATIC_CHILDREN(_debug_sleepq_chains), OID_AUTO, 185131259Sjhb chain_name, CTLFLAG_RD, NULL, "sleepq chain stats"); 186131259Sjhb SYSCTL_ADD_UINT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO, 187131259Sjhb "depth", CTLFLAG_RD, &sleepq_chains[i].sc_depth, 0, NULL); 188131259Sjhb SYSCTL_ADD_UINT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO, 189131259Sjhb "max_depth", CTLFLAG_RD, &sleepq_chains[i].sc_max_depth, 0, 190131259Sjhb NULL); 191131259Sjhb#endif 192126324Sjhb } 193169666Sjeff sleepq_zone = uma_zcreate("SLEEPQUEUE", sizeof(struct sleepqueue), 194169666Sjeff#ifdef INVARIANTS 195169666Sjeff NULL, sleepq_dtor, sleepq_init, NULL, UMA_ALIGN_CACHE, 0); 196169666Sjeff#else 197169666Sjeff NULL, NULL, sleepq_init, NULL, UMA_ALIGN_CACHE, 0); 198169666Sjeff#endif 199169666Sjeff 200126324Sjhb thread0.td_sleepqueue = sleepq_alloc(); 201126324Sjhb} 202126324Sjhb 203126324Sjhb/* 204169666Sjeff * Get a sleep queue for a new thread. 205126324Sjhb */ 206126324Sjhbstruct sleepqueue * 207126324Sjhbsleepq_alloc(void) 208126324Sjhb{ 209126324Sjhb 210169666Sjeff return (uma_zalloc(sleepq_zone, M_WAITOK)); 211126324Sjhb} 212126324Sjhb 213126324Sjhb/* 214126324Sjhb * Free a sleep queue when a thread is destroyed. 215126324Sjhb */ 216126324Sjhbvoid 217126324Sjhbsleepq_free(struct sleepqueue *sq) 218126324Sjhb{ 219126324Sjhb 220169666Sjeff uma_zfree(sleepq_zone, sq); 221126324Sjhb} 222126324Sjhb 223126324Sjhb/* 224136445Sjhb * Lock the sleep queue chain associated with the specified wait channel. 225136445Sjhb */ 226136445Sjhbvoid 227136445Sjhbsleepq_lock(void *wchan) 228136445Sjhb{ 229136445Sjhb struct sleepqueue_chain *sc; 230136445Sjhb 231136445Sjhb sc = SC_LOOKUP(wchan); 232136445Sjhb mtx_lock_spin(&sc->sc_lock); 233136445Sjhb} 234136445Sjhb 235136445Sjhb/* 236126324Sjhb * Look up the sleep queue associated with a given wait channel in the hash 237136445Sjhb * table locking the associated sleep queue chain. If no queue is found in 238136445Sjhb * the table, NULL is returned. 239126324Sjhb */ 240126324Sjhbstruct sleepqueue * 241126324Sjhbsleepq_lookup(void *wchan) 242126324Sjhb{ 243126324Sjhb struct sleepqueue_chain *sc; 244126324Sjhb struct sleepqueue *sq; 245126324Sjhb 246126324Sjhb KASSERT(wchan != NULL, ("%s: invalid NULL wait channel", __func__)); 247126324Sjhb sc = SC_LOOKUP(wchan); 248136445Sjhb mtx_assert(&sc->sc_lock, MA_OWNED); 249126324Sjhb LIST_FOREACH(sq, &sc->sc_queues, sq_hash) 250126324Sjhb if (sq->sq_wchan == wchan) 251126324Sjhb return (sq); 252126324Sjhb return (NULL); 253126324Sjhb} 254126324Sjhb 255126324Sjhb/* 256126324Sjhb * Unlock the sleep queue chain associated with a given wait channel. 257126324Sjhb */ 258126324Sjhbvoid 259126324Sjhbsleepq_release(void *wchan) 260126324Sjhb{ 261126324Sjhb struct sleepqueue_chain *sc; 262126324Sjhb 263126324Sjhb sc = SC_LOOKUP(wchan); 264126324Sjhb mtx_unlock_spin(&sc->sc_lock); 265126324Sjhb} 266126324Sjhb 267126324Sjhb/* 268137277Sjhb * Places the current thread on the sleep queue for the specified wait 269126324Sjhb * channel. If INVARIANTS is enabled, then it associates the passed in 270126324Sjhb * lock with the sleepq to make sure it is held when that sleep queue is 271126324Sjhb * woken up. 272126324Sjhb */ 273126324Sjhbvoid 274165272Skmacysleepq_add(void *wchan, struct lock_object *lock, const char *wmesg, int flags, 275165272Skmacy int queue) 276126324Sjhb{ 277126324Sjhb struct sleepqueue_chain *sc; 278136445Sjhb struct sleepqueue *sq; 279137277Sjhb struct thread *td; 280126324Sjhb 281126324Sjhb td = curthread; 282126324Sjhb sc = SC_LOOKUP(wchan); 283126324Sjhb mtx_assert(&sc->sc_lock, MA_OWNED); 284126324Sjhb MPASS(td->td_sleepqueue != NULL); 285126324Sjhb MPASS(wchan != NULL); 286165272Skmacy MPASS((queue >= 0) && (queue < NR_SLEEPQS)); 287126324Sjhb 288150177Sjhb /* If this thread is not allowed to sleep, die a horrible death. */ 289150177Sjhb KASSERT(!(td->td_pflags & TDP_NOSLEEPING), 290152221Simp ("Trying sleep, but thread marked as sleeping prohibited")); 291150177Sjhb 292136445Sjhb /* Look up the sleep queue associated with the wait channel 'wchan'. */ 293136445Sjhb sq = sleepq_lookup(wchan); 294136445Sjhb 295136445Sjhb /* 296136445Sjhb * If the wait channel does not already have a sleep queue, use 297136445Sjhb * this thread's sleep queue. Otherwise, insert the current thread 298136445Sjhb * into the sleep queue already in use by this wait channel. 299136445Sjhb */ 300126324Sjhb if (sq == NULL) { 301165272Skmacy#ifdef INVARIANTS 302165292Skmacy int i; 303165291Sache 304165292Skmacy sq = td->td_sleepqueue; 305165292Skmacy for (i = 0; i < NR_SLEEPQS; i++) 306165292Skmacy KASSERT(TAILQ_EMPTY(&sq->sq_blocked[i]), 307165272Skmacy ("thread's sleep queue %d is not empty", i)); 308165272Skmacy KASSERT(LIST_EMPTY(&sq->sq_free), 309165272Skmacy ("thread's sleep queue has a non-empty free list")); 310165272Skmacy KASSERT(sq->sq_wchan == NULL, ("stale sq_wchan pointer")); 311165292Skmacy sq->sq_lock = lock; 312165292Skmacy sq->sq_type = flags & SLEEPQ_TYPE; 313165272Skmacy#endif 314131259Sjhb#ifdef SLEEPQUEUE_PROFILING 315131259Sjhb sc->sc_depth++; 316131259Sjhb if (sc->sc_depth > sc->sc_max_depth) { 317131259Sjhb sc->sc_max_depth = sc->sc_depth; 318131259Sjhb if (sc->sc_max_depth > sleepq_max_depth) 319131259Sjhb sleepq_max_depth = sc->sc_max_depth; 320131259Sjhb } 321131259Sjhb#endif 322165292Skmacy sq = td->td_sleepqueue; 323126324Sjhb LIST_INSERT_HEAD(&sc->sc_queues, sq, sq_hash); 324126324Sjhb sq->sq_wchan = wchan; 325126324Sjhb } else { 326126324Sjhb MPASS(wchan == sq->sq_wchan); 327126488Sjhb MPASS(lock == sq->sq_lock); 328136445Sjhb MPASS((flags & SLEEPQ_TYPE) == sq->sq_type); 329126324Sjhb LIST_INSERT_HEAD(&sq->sq_free, td->td_sleepqueue, sq_hash); 330126324Sjhb } 331172155Sattilio thread_lock(td); 332165272Skmacy TAILQ_INSERT_TAIL(&sq->sq_blocked[queue], td, td_slpq); 333126324Sjhb td->td_sleepqueue = NULL; 334165272Skmacy td->td_sqqueue = queue; 335126324Sjhb td->td_wchan = wchan; 336126324Sjhb td->td_wmesg = wmesg; 337155741Sdavidxu if (flags & SLEEPQ_INTERRUPTIBLE) { 338134013Sjhb td->td_flags |= TDF_SINTR; 339155741Sdavidxu td->td_flags &= ~TDF_SLEEPABORT; 340155741Sdavidxu } 341172155Sattilio thread_unlock(td); 342126324Sjhb} 343126324Sjhb 344126324Sjhb/* 345126324Sjhb * Sets a timeout that will remove the current thread from the specified 346126324Sjhb * sleep queue after timo ticks if the thread has not already been awakened. 347126324Sjhb */ 348126324Sjhbvoid 349126885Sjhbsleepq_set_timeout(void *wchan, int timo) 350126324Sjhb{ 351126324Sjhb struct sleepqueue_chain *sc; 352126324Sjhb struct thread *td; 353126324Sjhb 354126324Sjhb td = curthread; 355126324Sjhb sc = SC_LOOKUP(wchan); 356126324Sjhb mtx_assert(&sc->sc_lock, MA_OWNED); 357126324Sjhb MPASS(TD_ON_SLEEPQ(td)); 358126324Sjhb MPASS(td->td_sleepqueue == NULL); 359126324Sjhb MPASS(wchan != NULL); 360126324Sjhb callout_reset(&td->td_slpcallout, timo, sleepq_timeout, td); 361126324Sjhb} 362126324Sjhb 363126324Sjhb/* 364126324Sjhb * Marks the pending sleep of the current thread as interruptible and 365126324Sjhb * makes an initial check for pending signals before putting a thread 366170294Sjeff * to sleep. Enters and exits with the thread lock held. Thread lock 367170294Sjeff * may have transitioned from the sleepq lock to a run lock. 368126324Sjhb */ 369155741Sdavidxustatic int 370126324Sjhbsleepq_catch_signals(void *wchan) 371126324Sjhb{ 372126324Sjhb struct sleepqueue_chain *sc; 373126324Sjhb struct sleepqueue *sq; 374126324Sjhb struct thread *td; 375126324Sjhb struct proc *p; 376155741Sdavidxu struct sigacts *ps; 377155741Sdavidxu int sig, ret; 378126324Sjhb 379126324Sjhb td = curthread; 380155741Sdavidxu p = curproc; 381126324Sjhb sc = SC_LOOKUP(wchan); 382126324Sjhb mtx_assert(&sc->sc_lock, MA_OWNED); 383126324Sjhb MPASS(wchan != NULL); 384129241Sbde CTR3(KTR_PROC, "sleepq catching signals: thread %p (pid %ld, %s)", 385173601Sjulian (void *)td, (long)p->p_pid, td->td_name); 386126324Sjhb 387155741Sdavidxu mtx_unlock_spin(&sc->sc_lock); 388126324Sjhb 389126324Sjhb /* See if there are any pending signals for this thread. */ 390126324Sjhb PROC_LOCK(p); 391155741Sdavidxu ps = p->p_sigacts; 392155741Sdavidxu mtx_lock(&ps->ps_mtx); 393126324Sjhb sig = cursig(td); 394155741Sdavidxu if (sig == 0) { 395155741Sdavidxu mtx_unlock(&ps->ps_mtx); 396155741Sdavidxu ret = thread_suspend_check(1); 397155741Sdavidxu MPASS(ret == 0 || ret == EINTR || ret == ERESTART); 398155741Sdavidxu } else { 399155741Sdavidxu if (SIGISMEMBER(ps->ps_sigintr, sig)) 400155741Sdavidxu ret = EINTR; 401155741Sdavidxu else 402155741Sdavidxu ret = ERESTART; 403155741Sdavidxu mtx_unlock(&ps->ps_mtx); 404155741Sdavidxu } 405170294Sjeff /* 406170294Sjeff * Lock sleepq chain before unlocking proc 407170294Sjeff * without this, we could lose a race. 408170294Sjeff */ 409170294Sjeff mtx_lock_spin(&sc->sc_lock); 410170294Sjeff PROC_UNLOCK(p); 411170294Sjeff thread_lock(td); 412155932Sdavidxu if (ret == 0) { 413170294Sjeff if (!(td->td_flags & TDF_INTERRUPT)) { 414170294Sjeff sleepq_switch(wchan); 415155932Sdavidxu return (0); 416170294Sjeff } 417155932Sdavidxu /* KSE threads tried unblocking us. */ 418155932Sdavidxu ret = td->td_intrval; 419170294Sjeff MPASS(ret == EINTR || ret == ERESTART || ret == EWOULDBLOCK); 420155741Sdavidxu } 421155936Sdavidxu /* 422155936Sdavidxu * There were pending signals and this thread is still 423155936Sdavidxu * on the sleep queue, remove it from the sleep queue. 424155936Sdavidxu */ 425170294Sjeff if (TD_ON_SLEEPQ(td)) { 426170294Sjeff sq = sleepq_lookup(wchan); 427155932Sdavidxu sleepq_resume_thread(sq, td, -1); 428170294Sjeff } 429170294Sjeff mtx_unlock_spin(&sc->sc_lock); 430170294Sjeff MPASS(td->td_lock != &sc->sc_lock); 431155741Sdavidxu return (ret); 432126324Sjhb} 433126324Sjhb 434126324Sjhb/* 435170294Sjeff * Switches to another thread if we are still asleep on a sleep queue. 436170294Sjeff * Returns with thread lock. 437126324Sjhb */ 438126324Sjhbstatic void 439126324Sjhbsleepq_switch(void *wchan) 440126324Sjhb{ 441126324Sjhb struct sleepqueue_chain *sc; 442126324Sjhb struct thread *td; 443126324Sjhb 444126324Sjhb td = curthread; 445126324Sjhb sc = SC_LOOKUP(wchan); 446126324Sjhb mtx_assert(&sc->sc_lock, MA_OWNED); 447170294Sjeff THREAD_LOCK_ASSERT(td, MA_OWNED); 448170294Sjeff /* We were removed */ 449126324Sjhb if (td->td_sleepqueue != NULL) { 450126324Sjhb mtx_unlock_spin(&sc->sc_lock); 451126324Sjhb return; 452126324Sjhb } 453170294Sjeff thread_lock_set(td, &sc->sc_lock); 454126324Sjhb 455170294Sjeff MPASS(td->td_sleepqueue == NULL); 456126324Sjhb sched_sleep(td); 457126324Sjhb TD_SET_SLEEPING(td); 458170294Sjeff SCHED_STAT_INC(switch_sleepq); 459131473Sjhb mi_switch(SW_VOL, NULL); 460126324Sjhb KASSERT(TD_IS_RUNNING(td), ("running but not TDS_RUNNING")); 461129241Sbde CTR3(KTR_PROC, "sleepq resume: thread %p (pid %ld, %s)", 462173600Sjulian (void *)td, (long)td->td_proc->p_pid, (void *)td->td_name); 463126324Sjhb} 464126324Sjhb 465126324Sjhb/* 466126324Sjhb * Check to see if we timed out. 467126324Sjhb */ 468126324Sjhbstatic int 469126324Sjhbsleepq_check_timeout(void) 470126324Sjhb{ 471126324Sjhb struct thread *td; 472126324Sjhb 473126324Sjhb td = curthread; 474170294Sjeff THREAD_LOCK_ASSERT(td, MA_OWNED); 475126324Sjhb 476126324Sjhb /* 477126324Sjhb * If TDF_TIMEOUT is set, we timed out. 478126324Sjhb */ 479126324Sjhb if (td->td_flags & TDF_TIMEOUT) { 480126324Sjhb td->td_flags &= ~TDF_TIMEOUT; 481126324Sjhb return (EWOULDBLOCK); 482126324Sjhb } 483126324Sjhb 484126324Sjhb /* 485126324Sjhb * If TDF_TIMOFAIL is set, the timeout ran after we had 486126324Sjhb * already been woken up. 487126324Sjhb */ 488126324Sjhb if (td->td_flags & TDF_TIMOFAIL) 489126324Sjhb td->td_flags &= ~TDF_TIMOFAIL; 490126324Sjhb 491126324Sjhb /* 492126324Sjhb * If callout_stop() fails, then the timeout is running on 493126324Sjhb * another CPU, so synchronize with it to avoid having it 494126324Sjhb * accidentally wake up a subsequent sleep. 495126324Sjhb */ 496126324Sjhb else if (callout_stop(&td->td_slpcallout) == 0) { 497126324Sjhb td->td_flags |= TDF_TIMEOUT; 498126324Sjhb TD_SET_SLEEPING(td); 499170294Sjeff SCHED_STAT_INC(switch_sleepqtimo); 500131473Sjhb mi_switch(SW_INVOL, NULL); 501126324Sjhb } 502126324Sjhb return (0); 503126324Sjhb} 504126324Sjhb 505126324Sjhb/* 506126324Sjhb * Check to see if we were awoken by a signal. 507126324Sjhb */ 508126324Sjhbstatic int 509126324Sjhbsleepq_check_signals(void) 510126324Sjhb{ 511126324Sjhb struct thread *td; 512126324Sjhb 513126324Sjhb td = curthread; 514170294Sjeff THREAD_LOCK_ASSERT(td, MA_OWNED); 515126324Sjhb 516126324Sjhb /* We are no longer in an interruptible sleep. */ 517155741Sdavidxu if (td->td_flags & TDF_SINTR) 518155741Sdavidxu td->td_flags &= ~TDF_SINTR; 519126324Sjhb 520155741Sdavidxu if (td->td_flags & TDF_SLEEPABORT) { 521155741Sdavidxu td->td_flags &= ~TDF_SLEEPABORT; 522155741Sdavidxu return (td->td_intrval); 523155741Sdavidxu } 524155741Sdavidxu 525126324Sjhb if (td->td_flags & TDF_INTERRUPT) 526126324Sjhb return (td->td_intrval); 527155741Sdavidxu 528126324Sjhb return (0); 529126324Sjhb} 530126324Sjhb 531126324Sjhb/* 532126324Sjhb * Block the current thread until it is awakened from its sleep queue. 533126324Sjhb */ 534126324Sjhbvoid 535126324Sjhbsleepq_wait(void *wchan) 536126324Sjhb{ 537170294Sjeff struct thread *td; 538126324Sjhb 539170294Sjeff td = curthread; 540170294Sjeff MPASS(!(td->td_flags & TDF_SINTR)); 541170294Sjeff thread_lock(td); 542126324Sjhb sleepq_switch(wchan); 543170294Sjeff thread_unlock(td); 544126324Sjhb} 545126324Sjhb 546126324Sjhb/* 547126324Sjhb * Block the current thread until it is awakened from its sleep queue 548126324Sjhb * or it is interrupted by a signal. 549126324Sjhb */ 550126324Sjhbint 551126324Sjhbsleepq_wait_sig(void *wchan) 552126324Sjhb{ 553155741Sdavidxu int rcatch; 554126324Sjhb int rval; 555126324Sjhb 556155741Sdavidxu rcatch = sleepq_catch_signals(wchan); 557126324Sjhb rval = sleepq_check_signals(); 558170294Sjeff thread_unlock(curthread); 559155741Sdavidxu if (rcatch) 560155741Sdavidxu return (rcatch); 561126324Sjhb return (rval); 562126324Sjhb} 563126324Sjhb 564126324Sjhb/* 565126324Sjhb * Block the current thread until it is awakened from its sleep queue 566126324Sjhb * or it times out while waiting. 567126324Sjhb */ 568126324Sjhbint 569131249Sjhbsleepq_timedwait(void *wchan) 570126324Sjhb{ 571170294Sjeff struct thread *td; 572126324Sjhb int rval; 573126324Sjhb 574170294Sjeff td = curthread; 575170294Sjeff MPASS(!(td->td_flags & TDF_SINTR)); 576170294Sjeff thread_lock(td); 577126324Sjhb sleepq_switch(wchan); 578126324Sjhb rval = sleepq_check_timeout(); 579170294Sjeff thread_unlock(td); 580170294Sjeff 581131249Sjhb return (rval); 582126324Sjhb} 583126324Sjhb 584126324Sjhb/* 585126324Sjhb * Block the current thread until it is awakened from its sleep queue, 586126324Sjhb * it is interrupted by a signal, or it times out waiting to be awakened. 587126324Sjhb */ 588126324Sjhbint 589155741Sdavidxusleepq_timedwait_sig(void *wchan) 590126324Sjhb{ 591155741Sdavidxu int rcatch, rvalt, rvals; 592126324Sjhb 593155741Sdavidxu rcatch = sleepq_catch_signals(wchan); 594126324Sjhb rvalt = sleepq_check_timeout(); 595126324Sjhb rvals = sleepq_check_signals(); 596170294Sjeff thread_unlock(curthread); 597155741Sdavidxu if (rcatch) 598155741Sdavidxu return (rcatch); 599155741Sdavidxu if (rvals) 600126324Sjhb return (rvals); 601155741Sdavidxu return (rvalt); 602126324Sjhb} 603126324Sjhb 604126324Sjhb/* 605145056Sjhb * Removes a thread from a sleep queue and makes it 606145056Sjhb * runnable. 607126324Sjhb */ 608126324Sjhbstatic void 609145056Sjhbsleepq_resume_thread(struct sleepqueue *sq, struct thread *td, int pri) 610126324Sjhb{ 611126324Sjhb struct sleepqueue_chain *sc; 612126324Sjhb 613126324Sjhb MPASS(td != NULL); 614126324Sjhb MPASS(sq->sq_wchan != NULL); 615126324Sjhb MPASS(td->td_wchan == sq->sq_wchan); 616165272Skmacy MPASS(td->td_sqqueue < NR_SLEEPQS && td->td_sqqueue >= 0); 617170294Sjeff THREAD_LOCK_ASSERT(td, MA_OWNED); 618126324Sjhb sc = SC_LOOKUP(sq->sq_wchan); 619126324Sjhb mtx_assert(&sc->sc_lock, MA_OWNED); 620126324Sjhb 621126324Sjhb /* Remove the thread from the queue. */ 622165272Skmacy TAILQ_REMOVE(&sq->sq_blocked[td->td_sqqueue], td, td_slpq); 623126324Sjhb 624126324Sjhb /* 625126324Sjhb * Get a sleep queue for this thread. If this is the last waiter, 626126324Sjhb * use the queue itself and take it out of the chain, otherwise, 627126324Sjhb * remove a queue from the free list. 628126324Sjhb */ 629126324Sjhb if (LIST_EMPTY(&sq->sq_free)) { 630126324Sjhb td->td_sleepqueue = sq; 631126324Sjhb#ifdef INVARIANTS 632126324Sjhb sq->sq_wchan = NULL; 633126324Sjhb#endif 634131259Sjhb#ifdef SLEEPQUEUE_PROFILING 635131259Sjhb sc->sc_depth--; 636131259Sjhb#endif 637126324Sjhb } else 638126324Sjhb td->td_sleepqueue = LIST_FIRST(&sq->sq_free); 639126324Sjhb LIST_REMOVE(td->td_sleepqueue, sq_hash); 640126324Sjhb 641129188Sjhb td->td_wmesg = NULL; 642129188Sjhb td->td_wchan = NULL; 643157743Sdavidxu td->td_flags &= ~TDF_SINTR; 644129188Sjhb 645126324Sjhb /* 646129188Sjhb * Note that thread td might not be sleeping if it is running 647129188Sjhb * sleepq_catch_signals() on another CPU or is blocked on 648129188Sjhb * its proc lock to check signals. It doesn't hurt to clear 649129188Sjhb * the sleeping flag if it isn't set though, so we just always 650129188Sjhb * do it. However, we can't assert that it is set. 651126324Sjhb */ 652129241Sbde CTR3(KTR_PROC, "sleepq_wakeup: thread %p (pid %ld, %s)", 653173600Sjulian (void *)td, (long)td->td_proc->p_pid, td->td_name); 654126324Sjhb TD_CLR_SLEEPING(td); 655126324Sjhb 656126324Sjhb /* Adjust priority if requested. */ 657126324Sjhb MPASS(pri == -1 || (pri >= PRI_MIN && pri <= PRI_MAX)); 658126324Sjhb if (pri != -1 && td->td_priority > pri) 659136439Sups sched_prio(td, pri); 660126324Sjhb setrunnable(td); 661126324Sjhb} 662126324Sjhb 663169666Sjeff#ifdef INVARIANTS 664126324Sjhb/* 665169666Sjeff * UMA zone item deallocator. 666169666Sjeff */ 667169666Sjeffstatic void 668169666Sjeffsleepq_dtor(void *mem, int size, void *arg) 669169666Sjeff{ 670169666Sjeff struct sleepqueue *sq; 671169666Sjeff int i; 672169666Sjeff 673169666Sjeff sq = mem; 674169666Sjeff for (i = 0; i < NR_SLEEPQS; i++) 675169666Sjeff MPASS(TAILQ_EMPTY(&sq->sq_blocked[i])); 676169666Sjeff} 677169666Sjeff#endif 678169666Sjeff 679169666Sjeff/* 680169666Sjeff * UMA zone item initializer. 681169666Sjeff */ 682169666Sjeffstatic int 683169666Sjeffsleepq_init(void *mem, int size, int flags) 684169666Sjeff{ 685169666Sjeff struct sleepqueue *sq; 686169666Sjeff int i; 687169666Sjeff 688169666Sjeff bzero(mem, size); 689169666Sjeff sq = mem; 690169666Sjeff for (i = 0; i < NR_SLEEPQS; i++) 691169666Sjeff TAILQ_INIT(&sq->sq_blocked[i]); 692169666Sjeff LIST_INIT(&sq->sq_free); 693169666Sjeff return (0); 694169666Sjeff} 695169666Sjeff 696169666Sjeff/* 697126324Sjhb * Find the highest priority thread sleeping on a wait channel and resume it. 698126324Sjhb */ 699126324Sjhbvoid 700165272Skmacysleepq_signal(void *wchan, int flags, int pri, int queue) 701126324Sjhb{ 702126324Sjhb struct sleepqueue *sq; 703137277Sjhb struct thread *td, *besttd; 704126324Sjhb 705126324Sjhb CTR2(KTR_PROC, "sleepq_signal(%p, %d)", wchan, flags); 706126324Sjhb KASSERT(wchan != NULL, ("%s: invalid NULL wait channel", __func__)); 707165272Skmacy MPASS((queue >= 0) && (queue < NR_SLEEPQS)); 708126324Sjhb sq = sleepq_lookup(wchan); 709170294Sjeff if (sq == NULL) 710126324Sjhb return; 711134013Sjhb KASSERT(sq->sq_type == (flags & SLEEPQ_TYPE), 712126324Sjhb ("%s: mismatch between sleep/wakeup and cv_*", __func__)); 713129188Sjhb 714137277Sjhb /* 715137277Sjhb * Find the highest priority thread on the queue. If there is a 716137277Sjhb * tie, use the thread that first appears in the queue as it has 717137277Sjhb * been sleeping the longest since threads are always added to 718137277Sjhb * the tail of sleep queues. 719137277Sjhb */ 720137277Sjhb besttd = NULL; 721165272Skmacy TAILQ_FOREACH(td, &sq->sq_blocked[queue], td_slpq) { 722137277Sjhb if (besttd == NULL || td->td_priority < besttd->td_priority) 723137277Sjhb besttd = td; 724137277Sjhb } 725137277Sjhb MPASS(besttd != NULL); 726170294Sjeff thread_lock(besttd); 727145056Sjhb sleepq_resume_thread(sq, besttd, pri); 728170294Sjeff thread_unlock(besttd); 729126324Sjhb} 730126324Sjhb 731126324Sjhb/* 732126324Sjhb * Resume all threads sleeping on a specified wait channel. 733126324Sjhb */ 734126324Sjhbvoid 735165272Skmacysleepq_broadcast(void *wchan, int flags, int pri, int queue) 736126324Sjhb{ 737126324Sjhb struct sleepqueue *sq; 738170294Sjeff struct thread *td; 739126324Sjhb 740126324Sjhb CTR2(KTR_PROC, "sleepq_broadcast(%p, %d)", wchan, flags); 741126324Sjhb KASSERT(wchan != NULL, ("%s: invalid NULL wait channel", __func__)); 742165272Skmacy MPASS((queue >= 0) && (queue < NR_SLEEPQS)); 743126324Sjhb sq = sleepq_lookup(wchan); 744126324Sjhb if (sq == NULL) { 745126324Sjhb sleepq_release(wchan); 746126324Sjhb return; 747126324Sjhb } 748134013Sjhb KASSERT(sq->sq_type == (flags & SLEEPQ_TYPE), 749126324Sjhb ("%s: mismatch between sleep/wakeup and cv_*", __func__)); 750129188Sjhb 751145056Sjhb /* Resume all blocked threads on the sleep queue. */ 752170294Sjeff while (!TAILQ_EMPTY(&sq->sq_blocked[queue])) { 753170294Sjeff td = TAILQ_FIRST(&sq->sq_blocked[queue]); 754170294Sjeff thread_lock(td); 755170294Sjeff sleepq_resume_thread(sq, td, pri); 756170294Sjeff thread_unlock(td); 757170294Sjeff } 758126324Sjhb sleepq_release(wchan); 759126324Sjhb} 760126324Sjhb 761126324Sjhb/* 762126324Sjhb * Time sleeping threads out. When the timeout expires, the thread is 763126324Sjhb * removed from the sleep queue and made runnable if it is still asleep. 764126324Sjhb */ 765126324Sjhbstatic void 766126324Sjhbsleepq_timeout(void *arg) 767126324Sjhb{ 768170294Sjeff struct sleepqueue_chain *sc; 769126324Sjhb struct sleepqueue *sq; 770126324Sjhb struct thread *td; 771126324Sjhb void *wchan; 772126324Sjhb 773129241Sbde td = arg; 774129241Sbde CTR3(KTR_PROC, "sleepq_timeout: thread %p (pid %ld, %s)", 775173600Sjulian (void *)td, (long)td->td_proc->p_pid, (void *)td->td_name); 776126324Sjhb 777126324Sjhb /* 778126324Sjhb * First, see if the thread is asleep and get the wait channel if 779126324Sjhb * it is. 780126324Sjhb */ 781170294Sjeff thread_lock(td); 782170294Sjeff if (TD_IS_SLEEPING(td) && TD_ON_SLEEPQ(td)) { 783126324Sjhb wchan = td->td_wchan; 784170294Sjeff sc = SC_LOOKUP(wchan); 785170294Sjeff MPASS(td->td_lock == &sc->sc_lock); 786126324Sjhb sq = sleepq_lookup(wchan); 787170294Sjeff MPASS(sq != NULL); 788170294Sjeff td->td_flags |= TDF_TIMEOUT; 789170294Sjeff sleepq_resume_thread(sq, td, -1); 790170294Sjeff thread_unlock(td); 791170294Sjeff return; 792126324Sjhb } 793126324Sjhb /* 794170294Sjeff * If the thread is on the SLEEPQ but not sleeping and we have it 795170294Sjeff * locked it must be in sleepq_catch_signals(). Let it know we've 796170294Sjeff * timedout here so it can remove itself. 797126324Sjhb */ 798126324Sjhb if (TD_ON_SLEEPQ(td)) { 799170294Sjeff td->td_flags |= TDF_TIMEOUT | TDF_INTERRUPT; 800170294Sjeff td->td_intrval = EWOULDBLOCK; 801170294Sjeff thread_unlock(td); 802126324Sjhb return; 803170294Sjeff } 804126324Sjhb 805126324Sjhb /* 806126324Sjhb * Now check for the edge cases. First, if TDF_TIMEOUT is set, 807126324Sjhb * then the other thread has already yielded to us, so clear 808126324Sjhb * the flag and resume it. If TDF_TIMEOUT is not set, then the 809126324Sjhb * we know that the other thread is not on a sleep queue, but it 810126324Sjhb * hasn't resumed execution yet. In that case, set TDF_TIMOFAIL 811126324Sjhb * to let it know that the timeout has already run and doesn't 812126324Sjhb * need to be canceled. 813126324Sjhb */ 814126324Sjhb if (td->td_flags & TDF_TIMEOUT) { 815127085Sjhb MPASS(TD_IS_SLEEPING(td)); 816126324Sjhb td->td_flags &= ~TDF_TIMEOUT; 817126324Sjhb TD_CLR_SLEEPING(td); 818126324Sjhb setrunnable(td); 819126324Sjhb } else 820126324Sjhb td->td_flags |= TDF_TIMOFAIL; 821170294Sjeff thread_unlock(td); 822126324Sjhb} 823126324Sjhb 824126324Sjhb/* 825126324Sjhb * Resumes a specific thread from the sleep queue associated with a specific 826126324Sjhb * wait channel if it is on that queue. 827126324Sjhb */ 828126324Sjhbvoid 829126324Sjhbsleepq_remove(struct thread *td, void *wchan) 830126324Sjhb{ 831126324Sjhb struct sleepqueue *sq; 832126324Sjhb 833126324Sjhb /* 834126324Sjhb * Look up the sleep queue for this wait channel, then re-check 835126324Sjhb * that the thread is asleep on that channel, if it is not, then 836126324Sjhb * bail. 837126324Sjhb */ 838126324Sjhb MPASS(wchan != NULL); 839136445Sjhb sleepq_lock(wchan); 840126324Sjhb sq = sleepq_lookup(wchan); 841170294Sjeff /* 842170294Sjeff * We can not lock the thread here as it may be sleeping on a 843170294Sjeff * different sleepq. However, holding the sleepq lock for this 844170294Sjeff * wchan can guarantee that we do not miss a wakeup for this 845170294Sjeff * channel. The asserts below will catch any false positives. 846170294Sjeff */ 847126324Sjhb if (!TD_ON_SLEEPQ(td) || td->td_wchan != wchan) { 848126324Sjhb sleepq_release(wchan); 849126324Sjhb return; 850126324Sjhb } 851170294Sjeff /* Thread is asleep on sleep queue sq, so wake it up. */ 852170294Sjeff thread_lock(td); 853126324Sjhb MPASS(sq != NULL); 854170294Sjeff MPASS(td->td_wchan == wchan); 855145056Sjhb sleepq_resume_thread(sq, td, -1); 856170294Sjeff thread_unlock(td); 857126324Sjhb sleepq_release(wchan); 858126324Sjhb} 859126324Sjhb 860126324Sjhb/* 861129241Sbde * Abort a thread as if an interrupt had occurred. Only abort 862129241Sbde * interruptible waits (unfortunately it isn't safe to abort others). 863126324Sjhb */ 864126324Sjhbvoid 865155741Sdavidxusleepq_abort(struct thread *td, int intrval) 866126324Sjhb{ 867170294Sjeff struct sleepqueue *sq; 868126324Sjhb void *wchan; 869126324Sjhb 870170294Sjeff THREAD_LOCK_ASSERT(td, MA_OWNED); 871126324Sjhb MPASS(TD_ON_SLEEPQ(td)); 872126324Sjhb MPASS(td->td_flags & TDF_SINTR); 873155741Sdavidxu MPASS(intrval == EINTR || intrval == ERESTART); 874126324Sjhb 875126324Sjhb /* 876126324Sjhb * If the TDF_TIMEOUT flag is set, just leave. A 877126324Sjhb * timeout is scheduled anyhow. 878126324Sjhb */ 879126324Sjhb if (td->td_flags & TDF_TIMEOUT) 880126324Sjhb return; 881126324Sjhb 882129241Sbde CTR3(KTR_PROC, "sleepq_abort: thread %p (pid %ld, %s)", 883173600Sjulian (void *)td, (long)td->td_proc->p_pid, (void *)td->td_name); 884170294Sjeff td->td_intrval = intrval; 885170294Sjeff td->td_flags |= TDF_SLEEPABORT; 886170294Sjeff /* 887170294Sjeff * If the thread has not slept yet it will find the signal in 888170294Sjeff * sleepq_catch_signals() and call sleepq_resume_thread. Otherwise 889170294Sjeff * we have to do it here. 890170294Sjeff */ 891170294Sjeff if (!TD_IS_SLEEPING(td)) 892170294Sjeff return; 893126324Sjhb wchan = td->td_wchan; 894170294Sjeff MPASS(wchan != NULL); 895170294Sjeff sq = sleepq_lookup(wchan); 896170294Sjeff MPASS(sq != NULL); 897170294Sjeff 898170294Sjeff /* Thread is asleep on sleep queue sq, so wake it up. */ 899170294Sjeff sleepq_resume_thread(sq, td, -1); 900126324Sjhb} 901154936Sjhb 902154936Sjhb#ifdef DDB 903154936SjhbDB_SHOW_COMMAND(sleepq, db_show_sleepqueue) 904154936Sjhb{ 905154936Sjhb struct sleepqueue_chain *sc; 906154936Sjhb struct sleepqueue *sq; 907154944Simp#ifdef INVARIANTS 908154936Sjhb struct lock_object *lock; 909154944Simp#endif 910154936Sjhb struct thread *td; 911154936Sjhb void *wchan; 912154936Sjhb int i; 913154936Sjhb 914154936Sjhb if (!have_addr) 915154936Sjhb return; 916154936Sjhb 917154936Sjhb /* 918154936Sjhb * First, see if there is an active sleep queue for the wait channel 919154936Sjhb * indicated by the address. 920154936Sjhb */ 921154936Sjhb wchan = (void *)addr; 922154936Sjhb sc = SC_LOOKUP(wchan); 923154936Sjhb LIST_FOREACH(sq, &sc->sc_queues, sq_hash) 924154936Sjhb if (sq->sq_wchan == wchan) 925154936Sjhb goto found; 926154936Sjhb 927154936Sjhb /* 928154936Sjhb * Second, see if there is an active sleep queue at the address 929154936Sjhb * indicated. 930154936Sjhb */ 931154936Sjhb for (i = 0; i < SC_TABLESIZE; i++) 932154936Sjhb LIST_FOREACH(sq, &sleepq_chains[i].sc_queues, sq_hash) { 933154936Sjhb if (sq == (struct sleepqueue *)addr) 934154936Sjhb goto found; 935154936Sjhb } 936154936Sjhb 937154936Sjhb db_printf("Unable to locate a sleep queue via %p\n", (void *)addr); 938154936Sjhb return; 939154936Sjhbfound: 940154936Sjhb db_printf("Wait channel: %p\n", sq->sq_wchan); 941154936Sjhb#ifdef INVARIANTS 942154936Sjhb db_printf("Queue type: %d\n", sq->sq_type); 943154936Sjhb if (sq->sq_lock) { 944164325Spjd lock = sq->sq_lock; 945154936Sjhb db_printf("Associated Interlock: %p - (%s) %s\n", lock, 946154936Sjhb LOCK_CLASS(lock)->lc_name, lock->lo_name); 947154936Sjhb } 948154936Sjhb#endif 949154936Sjhb db_printf("Blocked threads:\n"); 950165272Skmacy for (i = 0; i < NR_SLEEPQS; i++) { 951165272Skmacy db_printf("\nQueue[%d]:\n", i); 952165272Skmacy if (TAILQ_EMPTY(&sq->sq_blocked[i])) 953165272Skmacy db_printf("\tempty\n"); 954165272Skmacy else 955165272Skmacy TAILQ_FOREACH(td, &sq->sq_blocked[0], 956165272Skmacy td_slpq) { 957165272Skmacy db_printf("\t%p (tid %d, pid %d, \"%s\")\n", td, 958165272Skmacy td->td_tid, td->td_proc->p_pid, 959165272Skmacy td->td_name[i] != '\0' ? td->td_name : 960173600Sjulian td->td_name); 961165272Skmacy } 962165272Skmacy } 963154936Sjhb} 964157823Sjhb 965157823Sjhb/* Alias 'show sleepqueue' to 'show sleepq'. */ 966157823SjhbDB_SET(sleepqueue, db_show_sleepqueue, db_show_cmd_set, 0, NULL); 967154936Sjhb#endif 968