subr_sleepqueue.c revision 297466
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 * 14126324Sjhb * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15126324Sjhb * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16126324Sjhb * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17126324Sjhb * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18126324Sjhb * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19126324Sjhb * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20126324Sjhb * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21126324Sjhb * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22126324Sjhb * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23126324Sjhb * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24126324Sjhb * SUCH DAMAGE. 25126324Sjhb */ 26126324Sjhb 27126324Sjhb/* 28126324Sjhb * Implementation of sleep queues used to hold queue of threads blocked on 29126324Sjhb * a wait channel. Sleep queues different from turnstiles in that wait 30126324Sjhb * channels are not owned by anyone, so there is no priority propagation. 31126324Sjhb * Sleep queues can also provide a timeout and can also be interrupted by 32126324Sjhb * signals. That said, there are several similarities between the turnstile 33126324Sjhb * and sleep queue implementations. (Note: turnstiles were implemented 34126324Sjhb * first.) For example, both use a hash table of the same size where each 35126324Sjhb * bucket is referred to as a "chain" that contains both a spin lock and 36126324Sjhb * a linked list of queues. An individual queue is located by using a hash 37126324Sjhb * to pick a chain, locking the chain, and then walking the chain searching 38126324Sjhb * for the queue. This means that a wait channel object does not need to 39126324Sjhb * embed it's queue head just as locks do not embed their turnstile queue 40126324Sjhb * head. Threads also carry around a sleep queue that they lend to the 41126324Sjhb * wait channel when blocking. Just as in turnstiles, the queue includes 42126324Sjhb * a free list of the sleep queues of other threads blocked on the same 43126324Sjhb * wait channel in the case of multiple waiters. 44126324Sjhb * 45126324Sjhb * Some additional functionality provided by sleep queues include the 46126324Sjhb * ability to set a timeout. The timeout is managed using a per-thread 47126324Sjhb * callout that resumes a thread if it is asleep. A thread may also 48126324Sjhb * catch signals while it is asleep (aka an interruptible sleep). The 49126324Sjhb * signal code uses sleepq_abort() to interrupt a sleeping thread. Finally, 50126324Sjhb * sleep queues also provide some extra assertions. One is not allowed to 51126324Sjhb * mix the sleep/wakeup and cv APIs for a given wait channel. Also, one 52126324Sjhb * must consistently use the same lock to synchronize with a wait channel, 53126324Sjhb * though this check is currently only a warning for sleep/wakeup due to 54126324Sjhb * pre-existing abuse of that API. The same lock must also be held when 55126324Sjhb * awakening threads, though that is currently only enforced for condition 56126324Sjhb * variables. 57126324Sjhb */ 58126324Sjhb 59126324Sjhb#include <sys/cdefs.h> 60126324Sjhb__FBSDID("$FreeBSD: head/sys/kern/subr_sleepqueue.c 297466 2016-03-31 18:10:29Z jhb $"); 61126324Sjhb 62154936Sjhb#include "opt_sleepqueue_profiling.h" 63154936Sjhb#include "opt_ddb.h" 64170640Sjeff#include "opt_sched.h" 65296973Scem#include "opt_stack.h" 66154936Sjhb 67126324Sjhb#include <sys/param.h> 68126324Sjhb#include <sys/systm.h> 69126324Sjhb#include <sys/lock.h> 70126324Sjhb#include <sys/kernel.h> 71126324Sjhb#include <sys/ktr.h> 72126324Sjhb#include <sys/mutex.h> 73126324Sjhb#include <sys/proc.h> 74177372Sjeff#include <sys/sbuf.h> 75126324Sjhb#include <sys/sched.h> 76235459Srstone#include <sys/sdt.h> 77126324Sjhb#include <sys/signalvar.h> 78126324Sjhb#include <sys/sleepqueue.h> 79296927Scem#include <sys/stack.h> 80131259Sjhb#include <sys/sysctl.h> 81126324Sjhb 82169666Sjeff#include <vm/uma.h> 83169666Sjeff 84154936Sjhb#ifdef DDB 85154936Sjhb#include <ddb/ddb.h> 86154936Sjhb#endif 87154936Sjhb 88296927Scem 89126324Sjhb/* 90248186Smav * Constants for the hash table of sleep queue chains. 91248186Smav * SC_TABLESIZE must be a power of two for SC_MASK to work properly. 92126324Sjhb */ 93248186Smav#define SC_TABLESIZE 256 /* Must be power of 2. */ 94126324Sjhb#define SC_MASK (SC_TABLESIZE - 1) 95126324Sjhb#define SC_SHIFT 8 96248186Smav#define SC_HASH(wc) ((((uintptr_t)(wc) >> SC_SHIFT) ^ (uintptr_t)(wc)) & \ 97248186Smav 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. */ 120200447Sattilio u_int sq_blockedcnt[NR_SLEEPQS]; /* (c) N. of blocked threads. */ 121126324Sjhb LIST_ENTRY(sleepqueue) sq_hash; /* (c) Chain and free list. */ 122126324Sjhb LIST_HEAD(, sleepqueue) sq_free; /* (c) Free queues. */ 123126324Sjhb void *sq_wchan; /* (c) Wait channel. */ 124201879Sattilio int sq_type; /* (c) Queue type. */ 125136445Sjhb#ifdef INVARIANTS 126164325Spjd struct lock_object *sq_lock; /* (c) Associated lock. */ 127126324Sjhb#endif 128126324Sjhb}; 129126324Sjhb 130126324Sjhbstruct sleepqueue_chain { 131126324Sjhb LIST_HEAD(, sleepqueue) sc_queues; /* List of sleep queues. */ 132126324Sjhb struct mtx sc_lock; /* Spin lock for this chain. */ 133131259Sjhb#ifdef SLEEPQUEUE_PROFILING 134131259Sjhb u_int sc_depth; /* Length of sc_queues. */ 135131259Sjhb u_int sc_max_depth; /* Max length of sc_queues. */ 136131259Sjhb#endif 137126324Sjhb}; 138126324Sjhb 139131259Sjhb#ifdef SLEEPQUEUE_PROFILING 140131259Sjhbu_int sleepq_max_depth; 141227309Sedstatic SYSCTL_NODE(_debug, OID_AUTO, sleepq, CTLFLAG_RD, 0, "sleepq profiling"); 142227309Sedstatic SYSCTL_NODE(_debug_sleepq, OID_AUTO, chains, CTLFLAG_RD, 0, 143131259Sjhb "sleepq chain stats"); 144131259SjhbSYSCTL_UINT(_debug_sleepq, OID_AUTO, max_depth, CTLFLAG_RD, &sleepq_max_depth, 145131259Sjhb 0, "maxmimum depth achieved of a single chain"); 146177372Sjeff 147177372Sjeffstatic void sleepq_profile(const char *wmesg); 148177372Sjeffstatic int prof_enabled; 149131259Sjhb#endif 150126324Sjhbstatic struct sleepqueue_chain sleepq_chains[SC_TABLESIZE]; 151169666Sjeffstatic uma_zone_t sleepq_zone; 152126324Sjhb 153126324Sjhb/* 154126324Sjhb * Prototypes for non-exported routines. 155126324Sjhb */ 156177085Sjeffstatic int sleepq_catch_signals(void *wchan, int pri); 157165272Skmacystatic int sleepq_check_signals(void); 158277528Shselaskystatic int sleepq_check_timeout(void); 159169666Sjeff#ifdef INVARIANTS 160169666Sjeffstatic void sleepq_dtor(void *mem, int size, void *arg); 161169666Sjeff#endif 162169666Sjeffstatic int sleepq_init(void *mem, int size, int flags); 163181334Sjhbstatic int sleepq_resume_thread(struct sleepqueue *sq, struct thread *td, 164169666Sjeff int pri); 165177085Sjeffstatic void sleepq_switch(void *wchan, int pri); 166126324Sjhbstatic void sleepq_timeout(void *arg); 167126324Sjhb 168235459SrstoneSDT_PROBE_DECLARE(sched, , , sleep); 169235459SrstoneSDT_PROBE_DECLARE(sched, , , wakeup); 170235459Srstone 171126324Sjhb/* 172267820Sattilio * Initialize SLEEPQUEUE_PROFILING specific sysctl nodes. 173267820Sattilio * Note that it must happen after sleepinit() has been fully executed, so 174267820Sattilio * it must happen after SI_SUB_KMEM SYSINIT() subsystem setup. 175126324Sjhb */ 176267820Sattilio#ifdef SLEEPQUEUE_PROFILING 177267820Sattiliostatic void 178267820Sattilioinit_sleepqueue_profiling(void) 179126324Sjhb{ 180267820Sattilio char chain_name[10]; 181131259Sjhb struct sysctl_oid *chain_oid; 182267820Sattilio u_int i; 183126324Sjhb 184126324Sjhb for (i = 0; i < SC_TABLESIZE; i++) { 185267820Sattilio snprintf(chain_name, sizeof(chain_name), "%u", i); 186131259Sjhb chain_oid = SYSCTL_ADD_NODE(NULL, 187131259Sjhb SYSCTL_STATIC_CHILDREN(_debug_sleepq_chains), OID_AUTO, 188131259Sjhb chain_name, CTLFLAG_RD, NULL, "sleepq chain stats"); 189131259Sjhb SYSCTL_ADD_UINT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO, 190131259Sjhb "depth", CTLFLAG_RD, &sleepq_chains[i].sc_depth, 0, NULL); 191131259Sjhb SYSCTL_ADD_UINT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO, 192131259Sjhb "max_depth", CTLFLAG_RD, &sleepq_chains[i].sc_max_depth, 0, 193131259Sjhb NULL); 194267820Sattilio } 195267820Sattilio} 196267820Sattilio 197267820SattilioSYSINIT(sleepqueue_profiling, SI_SUB_LOCK, SI_ORDER_ANY, 198267820Sattilio init_sleepqueue_profiling, NULL); 199131259Sjhb#endif 200267820Sattilio 201267820Sattilio/* 202267820Sattilio * Early initialization of sleep queues that is called from the sleepinit() 203267820Sattilio * SYSINIT. 204267820Sattilio */ 205267820Sattiliovoid 206267820Sattilioinit_sleepqueues(void) 207267820Sattilio{ 208267820Sattilio int i; 209267820Sattilio 210267820Sattilio for (i = 0; i < SC_TABLESIZE; i++) { 211267820Sattilio LIST_INIT(&sleepq_chains[i].sc_queues); 212267820Sattilio mtx_init(&sleepq_chains[i].sc_lock, "sleepq chain", NULL, 213267820Sattilio MTX_SPIN | MTX_RECURSE); 214126324Sjhb } 215169666Sjeff sleepq_zone = uma_zcreate("SLEEPQUEUE", sizeof(struct sleepqueue), 216169666Sjeff#ifdef INVARIANTS 217169666Sjeff NULL, sleepq_dtor, sleepq_init, NULL, UMA_ALIGN_CACHE, 0); 218169666Sjeff#else 219169666Sjeff NULL, NULL, sleepq_init, NULL, UMA_ALIGN_CACHE, 0); 220169666Sjeff#endif 221169666Sjeff 222126324Sjhb thread0.td_sleepqueue = sleepq_alloc(); 223126324Sjhb} 224126324Sjhb 225126324Sjhb/* 226169666Sjeff * Get a sleep queue for a new thread. 227126324Sjhb */ 228126324Sjhbstruct sleepqueue * 229126324Sjhbsleepq_alloc(void) 230126324Sjhb{ 231126324Sjhb 232169666Sjeff return (uma_zalloc(sleepq_zone, M_WAITOK)); 233126324Sjhb} 234126324Sjhb 235126324Sjhb/* 236126324Sjhb * Free a sleep queue when a thread is destroyed. 237126324Sjhb */ 238126324Sjhbvoid 239126324Sjhbsleepq_free(struct sleepqueue *sq) 240126324Sjhb{ 241126324Sjhb 242169666Sjeff uma_zfree(sleepq_zone, sq); 243126324Sjhb} 244126324Sjhb 245126324Sjhb/* 246136445Sjhb * Lock the sleep queue chain associated with the specified wait channel. 247136445Sjhb */ 248136445Sjhbvoid 249136445Sjhbsleepq_lock(void *wchan) 250136445Sjhb{ 251136445Sjhb struct sleepqueue_chain *sc; 252136445Sjhb 253136445Sjhb sc = SC_LOOKUP(wchan); 254136445Sjhb mtx_lock_spin(&sc->sc_lock); 255136445Sjhb} 256136445Sjhb 257136445Sjhb/* 258126324Sjhb * Look up the sleep queue associated with a given wait channel in the hash 259136445Sjhb * table locking the associated sleep queue chain. If no queue is found in 260136445Sjhb * the table, NULL is returned. 261126324Sjhb */ 262126324Sjhbstruct sleepqueue * 263126324Sjhbsleepq_lookup(void *wchan) 264126324Sjhb{ 265126324Sjhb struct sleepqueue_chain *sc; 266126324Sjhb struct sleepqueue *sq; 267126324Sjhb 268126324Sjhb KASSERT(wchan != NULL, ("%s: invalid NULL wait channel", __func__)); 269126324Sjhb sc = SC_LOOKUP(wchan); 270136445Sjhb mtx_assert(&sc->sc_lock, MA_OWNED); 271126324Sjhb LIST_FOREACH(sq, &sc->sc_queues, sq_hash) 272126324Sjhb if (sq->sq_wchan == wchan) 273126324Sjhb return (sq); 274126324Sjhb return (NULL); 275126324Sjhb} 276126324Sjhb 277126324Sjhb/* 278126324Sjhb * Unlock the sleep queue chain associated with a given wait channel. 279126324Sjhb */ 280126324Sjhbvoid 281126324Sjhbsleepq_release(void *wchan) 282126324Sjhb{ 283126324Sjhb struct sleepqueue_chain *sc; 284126324Sjhb 285126324Sjhb sc = SC_LOOKUP(wchan); 286126324Sjhb mtx_unlock_spin(&sc->sc_lock); 287126324Sjhb} 288126324Sjhb 289126324Sjhb/* 290137277Sjhb * Places the current thread on the sleep queue for the specified wait 291126324Sjhb * channel. If INVARIANTS is enabled, then it associates the passed in 292126324Sjhb * lock with the sleepq to make sure it is held when that sleep queue is 293126324Sjhb * woken up. 294126324Sjhb */ 295126324Sjhbvoid 296165272Skmacysleepq_add(void *wchan, struct lock_object *lock, const char *wmesg, int flags, 297165272Skmacy int queue) 298126324Sjhb{ 299126324Sjhb struct sleepqueue_chain *sc; 300136445Sjhb struct sleepqueue *sq; 301137277Sjhb struct thread *td; 302126324Sjhb 303126324Sjhb td = curthread; 304126324Sjhb sc = SC_LOOKUP(wchan); 305126324Sjhb mtx_assert(&sc->sc_lock, MA_OWNED); 306126324Sjhb MPASS(td->td_sleepqueue != NULL); 307126324Sjhb MPASS(wchan != NULL); 308165272Skmacy MPASS((queue >= 0) && (queue < NR_SLEEPQS)); 309126324Sjhb 310150177Sjhb /* If this thread is not allowed to sleep, die a horrible death. */ 311247588Sjhb KASSERT(td->td_no_sleeping == 0, 312247588Sjhb ("%s: td %p to sleep on wchan %p with sleeping prohibited", 313240423Sattilio __func__, td, wchan)); 314150177Sjhb 315136445Sjhb /* Look up the sleep queue associated with the wait channel 'wchan'. */ 316136445Sjhb sq = sleepq_lookup(wchan); 317136445Sjhb 318136445Sjhb /* 319136445Sjhb * If the wait channel does not already have a sleep queue, use 320136445Sjhb * this thread's sleep queue. Otherwise, insert the current thread 321136445Sjhb * into the sleep queue already in use by this wait channel. 322136445Sjhb */ 323126324Sjhb if (sq == NULL) { 324165272Skmacy#ifdef INVARIANTS 325165292Skmacy int i; 326165291Sache 327165292Skmacy sq = td->td_sleepqueue; 328200447Sattilio for (i = 0; i < NR_SLEEPQS; i++) { 329165292Skmacy KASSERT(TAILQ_EMPTY(&sq->sq_blocked[i]), 330200447Sattilio ("thread's sleep queue %d is not empty", i)); 331200447Sattilio KASSERT(sq->sq_blockedcnt[i] == 0, 332200447Sattilio ("thread's sleep queue %d count mismatches", i)); 333200447Sattilio } 334165272Skmacy KASSERT(LIST_EMPTY(&sq->sq_free), 335165272Skmacy ("thread's sleep queue has a non-empty free list")); 336165272Skmacy KASSERT(sq->sq_wchan == NULL, ("stale sq_wchan pointer")); 337165292Skmacy sq->sq_lock = lock; 338165272Skmacy#endif 339131259Sjhb#ifdef SLEEPQUEUE_PROFILING 340131259Sjhb sc->sc_depth++; 341131259Sjhb if (sc->sc_depth > sc->sc_max_depth) { 342131259Sjhb sc->sc_max_depth = sc->sc_depth; 343131259Sjhb if (sc->sc_max_depth > sleepq_max_depth) 344131259Sjhb sleepq_max_depth = sc->sc_max_depth; 345131259Sjhb } 346131259Sjhb#endif 347165292Skmacy sq = td->td_sleepqueue; 348126324Sjhb LIST_INSERT_HEAD(&sc->sc_queues, sq, sq_hash); 349126324Sjhb sq->sq_wchan = wchan; 350201879Sattilio sq->sq_type = flags & SLEEPQ_TYPE; 351126324Sjhb } else { 352126324Sjhb MPASS(wchan == sq->sq_wchan); 353126488Sjhb MPASS(lock == sq->sq_lock); 354136445Sjhb MPASS((flags & SLEEPQ_TYPE) == sq->sq_type); 355126324Sjhb LIST_INSERT_HEAD(&sq->sq_free, td->td_sleepqueue, sq_hash); 356126324Sjhb } 357172155Sattilio thread_lock(td); 358165272Skmacy TAILQ_INSERT_TAIL(&sq->sq_blocked[queue], td, td_slpq); 359200447Sattilio sq->sq_blockedcnt[queue]++; 360126324Sjhb td->td_sleepqueue = NULL; 361165272Skmacy td->td_sqqueue = queue; 362126324Sjhb td->td_wchan = wchan; 363126324Sjhb td->td_wmesg = wmesg; 364155741Sdavidxu if (flags & SLEEPQ_INTERRUPTIBLE) { 365134013Sjhb td->td_flags |= TDF_SINTR; 366155741Sdavidxu td->td_flags &= ~TDF_SLEEPABORT; 367155741Sdavidxu } 368172155Sattilio thread_unlock(td); 369126324Sjhb} 370126324Sjhb 371126324Sjhb/* 372126324Sjhb * Sets a timeout that will remove the current thread from the specified 373126324Sjhb * sleep queue after timo ticks if the thread has not already been awakened. 374126324Sjhb */ 375126324Sjhbvoid 376247783Sdavidesleepq_set_timeout_sbt(void *wchan, sbintime_t sbt, sbintime_t pr, 377247783Sdavide int flags) 378126324Sjhb{ 379277528Shselasky struct sleepqueue_chain *sc; 380126324Sjhb struct thread *td; 381126324Sjhb 382126324Sjhb td = curthread; 383277528Shselasky sc = SC_LOOKUP(wchan); 384277528Shselasky mtx_assert(&sc->sc_lock, MA_OWNED); 385277528Shselasky MPASS(TD_ON_SLEEPQ(td)); 386277528Shselasky MPASS(td->td_sleepqueue == NULL); 387277528Shselasky MPASS(wchan != NULL); 388297466Sjhb if (cold) 389297466Sjhb panic("timed sleep before timers are working"); 390247783Sdavide callout_reset_sbt_on(&td->td_slpcallout, sbt, pr, 391247783Sdavide sleepq_timeout, td, PCPU_GET(cpuid), flags | C_DIRECT_EXEC); 392126324Sjhb} 393126324Sjhb 394126324Sjhb/* 395200447Sattilio * Return the number of actual sleepers for the specified queue. 396200447Sattilio */ 397200447Sattiliou_int 398200447Sattiliosleepq_sleepcnt(void *wchan, int queue) 399200447Sattilio{ 400200447Sattilio struct sleepqueue *sq; 401200447Sattilio 402200447Sattilio KASSERT(wchan != NULL, ("%s: invalid NULL wait channel", __func__)); 403200447Sattilio MPASS((queue >= 0) && (queue < NR_SLEEPQS)); 404200447Sattilio sq = sleepq_lookup(wchan); 405200447Sattilio if (sq == NULL) 406200447Sattilio return (0); 407200447Sattilio return (sq->sq_blockedcnt[queue]); 408200447Sattilio} 409200447Sattilio 410200447Sattilio/* 411126324Sjhb * Marks the pending sleep of the current thread as interruptible and 412126324Sjhb * makes an initial check for pending signals before putting a thread 413170294Sjeff * to sleep. Enters and exits with the thread lock held. Thread lock 414170294Sjeff * may have transitioned from the sleepq lock to a run lock. 415126324Sjhb */ 416155741Sdavidxustatic int 417177085Sjeffsleepq_catch_signals(void *wchan, int pri) 418126324Sjhb{ 419126324Sjhb struct sleepqueue_chain *sc; 420126324Sjhb struct sleepqueue *sq; 421126324Sjhb struct thread *td; 422126324Sjhb struct proc *p; 423155741Sdavidxu struct sigacts *ps; 424248470Sjhb int sig, ret; 425126324Sjhb 426126324Sjhb td = curthread; 427155741Sdavidxu p = curproc; 428126324Sjhb sc = SC_LOOKUP(wchan); 429126324Sjhb mtx_assert(&sc->sc_lock, MA_OWNED); 430126324Sjhb MPASS(wchan != NULL); 431211523Sdavidxu if ((td->td_pflags & TDP_WAKEUP) != 0) { 432211523Sdavidxu td->td_pflags &= ~TDP_WAKEUP; 433211523Sdavidxu ret = EINTR; 434211534Sdavidxu thread_lock(td); 435211523Sdavidxu goto out; 436211523Sdavidxu } 437211523Sdavidxu 438177375Sjeff /* 439177375Sjeff * See if there are any pending signals for this thread. If not 440177375Sjeff * we can switch immediately. Otherwise do the signal processing 441177375Sjeff * directly. 442177375Sjeff */ 443177375Sjeff thread_lock(td); 444177471Sjeff if ((td->td_flags & (TDF_NEEDSIGCHK | TDF_NEEDSUSPCHK)) == 0) { 445177375Sjeff sleepq_switch(wchan, pri); 446177375Sjeff return (0); 447177375Sjeff } 448177375Sjeff thread_unlock(td); 449177375Sjeff mtx_unlock_spin(&sc->sc_lock); 450129241Sbde CTR3(KTR_PROC, "sleepq catching signals: thread %p (pid %ld, %s)", 451173601Sjulian (void *)td, (long)p->p_pid, td->td_name); 452126324Sjhb PROC_LOCK(p); 453155741Sdavidxu ps = p->p_sigacts; 454155741Sdavidxu mtx_lock(&ps->ps_mtx); 455248470Sjhb sig = cursig(td); 456155741Sdavidxu if (sig == 0) { 457155741Sdavidxu mtx_unlock(&ps->ps_mtx); 458155741Sdavidxu ret = thread_suspend_check(1); 459155741Sdavidxu MPASS(ret == 0 || ret == EINTR || ret == ERESTART); 460155741Sdavidxu } else { 461155741Sdavidxu if (SIGISMEMBER(ps->ps_sigintr, sig)) 462155741Sdavidxu ret = EINTR; 463155741Sdavidxu else 464155741Sdavidxu ret = ERESTART; 465155741Sdavidxu mtx_unlock(&ps->ps_mtx); 466155741Sdavidxu } 467184667Sdavidxu /* 468184667Sdavidxu * Lock the per-process spinlock prior to dropping the PROC_LOCK 469184667Sdavidxu * to avoid a signal delivery race. PROC_LOCK, PROC_SLOCK, and 470209612Sjhb * thread_lock() are currently held in tdsendsignal(). 471184667Sdavidxu */ 472184667Sdavidxu PROC_SLOCK(p); 473170294Sjeff mtx_lock_spin(&sc->sc_lock); 474184667Sdavidxu PROC_UNLOCK(p); 475170294Sjeff thread_lock(td); 476184667Sdavidxu PROC_SUNLOCK(p); 477185502Sdavidxu if (ret == 0) { 478185502Sdavidxu sleepq_switch(wchan, pri); 479185502Sdavidxu return (0); 480185502Sdavidxu } 481211523Sdavidxuout: 482155936Sdavidxu /* 483155936Sdavidxu * There were pending signals and this thread is still 484155936Sdavidxu * on the sleep queue, remove it from the sleep queue. 485155936Sdavidxu */ 486170294Sjeff if (TD_ON_SLEEPQ(td)) { 487170294Sjeff sq = sleepq_lookup(wchan); 488181334Sjhb if (sleepq_resume_thread(sq, td, 0)) { 489181334Sjhb#ifdef INVARIANTS 490181334Sjhb /* 491181334Sjhb * This thread hasn't gone to sleep yet, so it 492181334Sjhb * should not be swapped out. 493181334Sjhb */ 494181334Sjhb panic("not waking up swapper"); 495181334Sjhb#endif 496181334Sjhb } 497170294Sjeff } 498170294Sjeff mtx_unlock_spin(&sc->sc_lock); 499170294Sjeff MPASS(td->td_lock != &sc->sc_lock); 500155741Sdavidxu return (ret); 501126324Sjhb} 502126324Sjhb 503126324Sjhb/* 504170294Sjeff * Switches to another thread if we are still asleep on a sleep queue. 505170294Sjeff * Returns with thread lock. 506126324Sjhb */ 507126324Sjhbstatic void 508177085Sjeffsleepq_switch(void *wchan, int pri) 509126324Sjhb{ 510126324Sjhb struct sleepqueue_chain *sc; 511175654Sjhb struct sleepqueue *sq; 512126324Sjhb struct thread *td; 513126324Sjhb 514126324Sjhb td = curthread; 515126324Sjhb sc = SC_LOOKUP(wchan); 516126324Sjhb mtx_assert(&sc->sc_lock, MA_OWNED); 517170294Sjeff THREAD_LOCK_ASSERT(td, MA_OWNED); 518175654Sjhb 519175654Sjhb /* 520175654Sjhb * If we have a sleep queue, then we've already been woken up, so 521175654Sjhb * just return. 522175654Sjhb */ 523126324Sjhb if (td->td_sleepqueue != NULL) { 524126324Sjhb mtx_unlock_spin(&sc->sc_lock); 525126324Sjhb return; 526126324Sjhb } 527175654Sjhb 528175654Sjhb /* 529175654Sjhb * If TDF_TIMEOUT is set, then our sleep has been timed out 530175654Sjhb * already but we are still on the sleep queue, so dequeue the 531175654Sjhb * thread and return. 532175654Sjhb */ 533175654Sjhb if (td->td_flags & TDF_TIMEOUT) { 534175654Sjhb MPASS(TD_ON_SLEEPQ(td)); 535175654Sjhb sq = sleepq_lookup(wchan); 536181334Sjhb if (sleepq_resume_thread(sq, td, 0)) { 537181334Sjhb#ifdef INVARIANTS 538181334Sjhb /* 539181334Sjhb * This thread hasn't gone to sleep yet, so it 540181334Sjhb * should not be swapped out. 541181334Sjhb */ 542181334Sjhb panic("not waking up swapper"); 543181334Sjhb#endif 544181334Sjhb } 545175654Sjhb mtx_unlock_spin(&sc->sc_lock); 546175654Sjhb return; 547175654Sjhb } 548177372Sjeff#ifdef SLEEPQUEUE_PROFILING 549177372Sjeff if (prof_enabled) 550177372Sjeff sleepq_profile(td->td_wmesg); 551177372Sjeff#endif 552177085Sjeff MPASS(td->td_sleepqueue == NULL); 553177085Sjeff sched_sleep(td, pri); 554170294Sjeff thread_lock_set(td, &sc->sc_lock); 555235459Srstone SDT_PROBE0(sched, , , sleep); 556126324Sjhb TD_SET_SLEEPING(td); 557178272Sjeff mi_switch(SW_VOL | SWT_SLEEPQ, NULL); 558126324Sjhb KASSERT(TD_IS_RUNNING(td), ("running but not TDS_RUNNING")); 559129241Sbde CTR3(KTR_PROC, "sleepq resume: thread %p (pid %ld, %s)", 560173600Sjulian (void *)td, (long)td->td_proc->p_pid, (void *)td->td_name); 561126324Sjhb} 562126324Sjhb 563126324Sjhb/* 564126324Sjhb * Check to see if we timed out. 565126324Sjhb */ 566126324Sjhbstatic int 567277528Shselaskysleepq_check_timeout(void) 568126324Sjhb{ 569277528Shselasky struct thread *td; 570277528Shselasky 571277528Shselasky td = curthread; 572170294Sjeff THREAD_LOCK_ASSERT(td, MA_OWNED); 573126324Sjhb 574126324Sjhb /* 575126324Sjhb * If TDF_TIMEOUT is set, we timed out. 576126324Sjhb */ 577126324Sjhb if (td->td_flags & TDF_TIMEOUT) { 578126324Sjhb td->td_flags &= ~TDF_TIMEOUT; 579126324Sjhb return (EWOULDBLOCK); 580126324Sjhb } 581277528Shselasky 582277528Shselasky /* 583277528Shselasky * If TDF_TIMOFAIL is set, the timeout ran after we had 584277528Shselasky * already been woken up. 585277528Shselasky */ 586277528Shselasky if (td->td_flags & TDF_TIMOFAIL) 587277528Shselasky td->td_flags &= ~TDF_TIMOFAIL; 588277528Shselasky 589277528Shselasky /* 590277528Shselasky * If callout_stop() fails, then the timeout is running on 591277528Shselasky * another CPU, so synchronize with it to avoid having it 592277528Shselasky * accidentally wake up a subsequent sleep. 593277528Shselasky */ 594296320Skib else if (_callout_stop_safe(&td->td_slpcallout, CS_MIGRBLOCK, NULL) 595296320Skib == 0) { 596277528Shselasky td->td_flags |= TDF_TIMEOUT; 597277528Shselasky TD_SET_SLEEPING(td); 598277528Shselasky mi_switch(SW_INVOL | SWT_SLEEPQTIMO, NULL); 599277528Shselasky } 600126324Sjhb return (0); 601126324Sjhb} 602126324Sjhb 603126324Sjhb/* 604126324Sjhb * Check to see if we were awoken by a signal. 605126324Sjhb */ 606126324Sjhbstatic int 607126324Sjhbsleepq_check_signals(void) 608126324Sjhb{ 609126324Sjhb struct thread *td; 610126324Sjhb 611126324Sjhb td = curthread; 612170294Sjeff THREAD_LOCK_ASSERT(td, MA_OWNED); 613126324Sjhb 614126324Sjhb /* We are no longer in an interruptible sleep. */ 615155741Sdavidxu if (td->td_flags & TDF_SINTR) 616246417Sjhb td->td_flags &= ~TDF_SINTR; 617126324Sjhb 618155741Sdavidxu if (td->td_flags & TDF_SLEEPABORT) { 619155741Sdavidxu td->td_flags &= ~TDF_SLEEPABORT; 620155741Sdavidxu return (td->td_intrval); 621155741Sdavidxu } 622155741Sdavidxu 623126324Sjhb return (0); 624126324Sjhb} 625126324Sjhb 626126324Sjhb/* 627126324Sjhb * Block the current thread until it is awakened from its sleep queue. 628126324Sjhb */ 629126324Sjhbvoid 630177085Sjeffsleepq_wait(void *wchan, int pri) 631126324Sjhb{ 632170294Sjeff struct thread *td; 633126324Sjhb 634170294Sjeff td = curthread; 635170294Sjeff MPASS(!(td->td_flags & TDF_SINTR)); 636170294Sjeff thread_lock(td); 637177085Sjeff sleepq_switch(wchan, pri); 638170294Sjeff thread_unlock(td); 639126324Sjhb} 640126324Sjhb 641126324Sjhb/* 642126324Sjhb * Block the current thread until it is awakened from its sleep queue 643126324Sjhb * or it is interrupted by a signal. 644126324Sjhb */ 645126324Sjhbint 646177085Sjeffsleepq_wait_sig(void *wchan, int pri) 647126324Sjhb{ 648155741Sdavidxu int rcatch; 649126324Sjhb int rval; 650126324Sjhb 651177085Sjeff rcatch = sleepq_catch_signals(wchan, pri); 652126324Sjhb rval = sleepq_check_signals(); 653170294Sjeff thread_unlock(curthread); 654155741Sdavidxu if (rcatch) 655155741Sdavidxu return (rcatch); 656126324Sjhb return (rval); 657126324Sjhb} 658126324Sjhb 659126324Sjhb/* 660126324Sjhb * Block the current thread until it is awakened from its sleep queue 661126324Sjhb * or it times out while waiting. 662126324Sjhb */ 663126324Sjhbint 664177085Sjeffsleepq_timedwait(void *wchan, int pri) 665126324Sjhb{ 666170294Sjeff struct thread *td; 667126324Sjhb int rval; 668126324Sjhb 669170294Sjeff td = curthread; 670170294Sjeff MPASS(!(td->td_flags & TDF_SINTR)); 671170294Sjeff thread_lock(td); 672177085Sjeff sleepq_switch(wchan, pri); 673277528Shselasky rval = sleepq_check_timeout(); 674170294Sjeff thread_unlock(td); 675170294Sjeff 676131249Sjhb return (rval); 677126324Sjhb} 678126324Sjhb 679126324Sjhb/* 680126324Sjhb * Block the current thread until it is awakened from its sleep queue, 681126324Sjhb * it is interrupted by a signal, or it times out waiting to be awakened. 682126324Sjhb */ 683126324Sjhbint 684177085Sjeffsleepq_timedwait_sig(void *wchan, int pri) 685126324Sjhb{ 686155741Sdavidxu int rcatch, rvalt, rvals; 687126324Sjhb 688177085Sjeff rcatch = sleepq_catch_signals(wchan, pri); 689277528Shselasky rvalt = sleepq_check_timeout(); 690126324Sjhb rvals = sleepq_check_signals(); 691277528Shselasky thread_unlock(curthread); 692155741Sdavidxu if (rcatch) 693155741Sdavidxu return (rcatch); 694155741Sdavidxu if (rvals) 695126324Sjhb return (rvals); 696155741Sdavidxu return (rvalt); 697126324Sjhb} 698126324Sjhb 699126324Sjhb/* 700201879Sattilio * Returns the type of sleepqueue given a waitchannel. 701201879Sattilio */ 702201879Sattilioint 703201879Sattiliosleepq_type(void *wchan) 704201879Sattilio{ 705201879Sattilio struct sleepqueue *sq; 706201879Sattilio int type; 707201879Sattilio 708201879Sattilio MPASS(wchan != NULL); 709201879Sattilio 710201879Sattilio sleepq_lock(wchan); 711201879Sattilio sq = sleepq_lookup(wchan); 712201879Sattilio if (sq == NULL) { 713201879Sattilio sleepq_release(wchan); 714201879Sattilio return (-1); 715201879Sattilio } 716201879Sattilio type = sq->sq_type; 717201879Sattilio sleepq_release(wchan); 718201879Sattilio return (type); 719201879Sattilio} 720201879Sattilio 721201879Sattilio/* 722145056Sjhb * Removes a thread from a sleep queue and makes it 723145056Sjhb * runnable. 724126324Sjhb */ 725181334Sjhbstatic int 726145056Sjhbsleepq_resume_thread(struct sleepqueue *sq, struct thread *td, int pri) 727126324Sjhb{ 728126324Sjhb struct sleepqueue_chain *sc; 729126324Sjhb 730126324Sjhb MPASS(td != NULL); 731126324Sjhb MPASS(sq->sq_wchan != NULL); 732126324Sjhb MPASS(td->td_wchan == sq->sq_wchan); 733165272Skmacy MPASS(td->td_sqqueue < NR_SLEEPQS && td->td_sqqueue >= 0); 734170294Sjeff THREAD_LOCK_ASSERT(td, MA_OWNED); 735126324Sjhb sc = SC_LOOKUP(sq->sq_wchan); 736126324Sjhb mtx_assert(&sc->sc_lock, MA_OWNED); 737126324Sjhb 738235459Srstone SDT_PROBE2(sched, , , wakeup, td, td->td_proc); 739235459Srstone 740126324Sjhb /* Remove the thread from the queue. */ 741200447Sattilio sq->sq_blockedcnt[td->td_sqqueue]--; 742165272Skmacy TAILQ_REMOVE(&sq->sq_blocked[td->td_sqqueue], td, td_slpq); 743126324Sjhb 744126324Sjhb /* 745126324Sjhb * Get a sleep queue for this thread. If this is the last waiter, 746126324Sjhb * use the queue itself and take it out of the chain, otherwise, 747126324Sjhb * remove a queue from the free list. 748126324Sjhb */ 749126324Sjhb if (LIST_EMPTY(&sq->sq_free)) { 750126324Sjhb td->td_sleepqueue = sq; 751126324Sjhb#ifdef INVARIANTS 752126324Sjhb sq->sq_wchan = NULL; 753126324Sjhb#endif 754131259Sjhb#ifdef SLEEPQUEUE_PROFILING 755131259Sjhb sc->sc_depth--; 756131259Sjhb#endif 757126324Sjhb } else 758126324Sjhb td->td_sleepqueue = LIST_FIRST(&sq->sq_free); 759126324Sjhb LIST_REMOVE(td->td_sleepqueue, sq_hash); 760126324Sjhb 761129188Sjhb td->td_wmesg = NULL; 762129188Sjhb td->td_wchan = NULL; 763246417Sjhb td->td_flags &= ~TDF_SINTR; 764129188Sjhb 765129241Sbde CTR3(KTR_PROC, "sleepq_wakeup: thread %p (pid %ld, %s)", 766173600Sjulian (void *)td, (long)td->td_proc->p_pid, td->td_name); 767126324Sjhb 768126324Sjhb /* Adjust priority if requested. */ 769177085Sjeff MPASS(pri == 0 || (pri >= PRI_MIN && pri <= PRI_MAX)); 770217410Sjhb if (pri != 0 && td->td_priority > pri && 771217410Sjhb PRI_BASE(td->td_pri_class) == PRI_TIMESHARE) 772136439Sups sched_prio(td, pri); 773184653Sjhb 774184653Sjhb /* 775184653Sjhb * Note that thread td might not be sleeping if it is running 776184653Sjhb * sleepq_catch_signals() on another CPU or is blocked on its 777184653Sjhb * proc lock to check signals. There's no need to mark the 778184653Sjhb * thread runnable in that case. 779184653Sjhb */ 780184653Sjhb if (TD_IS_SLEEPING(td)) { 781184653Sjhb TD_CLR_SLEEPING(td); 782184653Sjhb return (setrunnable(td)); 783184653Sjhb } 784184653Sjhb return (0); 785126324Sjhb} 786126324Sjhb 787169666Sjeff#ifdef INVARIANTS 788126324Sjhb/* 789169666Sjeff * UMA zone item deallocator. 790169666Sjeff */ 791169666Sjeffstatic void 792169666Sjeffsleepq_dtor(void *mem, int size, void *arg) 793169666Sjeff{ 794169666Sjeff struct sleepqueue *sq; 795169666Sjeff int i; 796169666Sjeff 797169666Sjeff sq = mem; 798200447Sattilio for (i = 0; i < NR_SLEEPQS; i++) { 799169666Sjeff MPASS(TAILQ_EMPTY(&sq->sq_blocked[i])); 800200447Sattilio MPASS(sq->sq_blockedcnt[i] == 0); 801200447Sattilio } 802169666Sjeff} 803169666Sjeff#endif 804169666Sjeff 805169666Sjeff/* 806169666Sjeff * UMA zone item initializer. 807169666Sjeff */ 808169666Sjeffstatic int 809169666Sjeffsleepq_init(void *mem, int size, int flags) 810169666Sjeff{ 811169666Sjeff struct sleepqueue *sq; 812169666Sjeff int i; 813169666Sjeff 814169666Sjeff bzero(mem, size); 815169666Sjeff sq = mem; 816200447Sattilio for (i = 0; i < NR_SLEEPQS; i++) { 817169666Sjeff TAILQ_INIT(&sq->sq_blocked[i]); 818200447Sattilio sq->sq_blockedcnt[i] = 0; 819200447Sattilio } 820169666Sjeff LIST_INIT(&sq->sq_free); 821169666Sjeff return (0); 822169666Sjeff} 823169666Sjeff 824169666Sjeff/* 825126324Sjhb * Find the highest priority thread sleeping on a wait channel and resume it. 826126324Sjhb */ 827181334Sjhbint 828165272Skmacysleepq_signal(void *wchan, int flags, int pri, int queue) 829126324Sjhb{ 830126324Sjhb struct sleepqueue *sq; 831137277Sjhb struct thread *td, *besttd; 832181334Sjhb int wakeup_swapper; 833126324Sjhb 834126324Sjhb CTR2(KTR_PROC, "sleepq_signal(%p, %d)", wchan, flags); 835126324Sjhb KASSERT(wchan != NULL, ("%s: invalid NULL wait channel", __func__)); 836165272Skmacy MPASS((queue >= 0) && (queue < NR_SLEEPQS)); 837126324Sjhb sq = sleepq_lookup(wchan); 838170294Sjeff if (sq == NULL) 839181334Sjhb return (0); 840134013Sjhb KASSERT(sq->sq_type == (flags & SLEEPQ_TYPE), 841126324Sjhb ("%s: mismatch between sleep/wakeup and cv_*", __func__)); 842129188Sjhb 843137277Sjhb /* 844137277Sjhb * Find the highest priority thread on the queue. If there is a 845137277Sjhb * tie, use the thread that first appears in the queue as it has 846137277Sjhb * been sleeping the longest since threads are always added to 847137277Sjhb * the tail of sleep queues. 848137277Sjhb */ 849137277Sjhb besttd = NULL; 850165272Skmacy TAILQ_FOREACH(td, &sq->sq_blocked[queue], td_slpq) { 851137277Sjhb if (besttd == NULL || td->td_priority < besttd->td_priority) 852137277Sjhb besttd = td; 853137277Sjhb } 854137277Sjhb MPASS(besttd != NULL); 855170294Sjeff thread_lock(besttd); 856181334Sjhb wakeup_swapper = sleepq_resume_thread(sq, besttd, pri); 857170294Sjeff thread_unlock(besttd); 858181334Sjhb return (wakeup_swapper); 859126324Sjhb} 860126324Sjhb 861126324Sjhb/* 862126324Sjhb * Resume all threads sleeping on a specified wait channel. 863126324Sjhb */ 864181334Sjhbint 865165272Skmacysleepq_broadcast(void *wchan, int flags, int pri, int queue) 866126324Sjhb{ 867126324Sjhb struct sleepqueue *sq; 868182875Sjhb struct thread *td, *tdn; 869181334Sjhb int wakeup_swapper; 870126324Sjhb 871126324Sjhb CTR2(KTR_PROC, "sleepq_broadcast(%p, %d)", wchan, flags); 872126324Sjhb KASSERT(wchan != NULL, ("%s: invalid NULL wait channel", __func__)); 873165272Skmacy MPASS((queue >= 0) && (queue < NR_SLEEPQS)); 874126324Sjhb sq = sleepq_lookup(wchan); 875177085Sjeff if (sq == NULL) 876181334Sjhb return (0); 877134013Sjhb KASSERT(sq->sq_type == (flags & SLEEPQ_TYPE), 878126324Sjhb ("%s: mismatch between sleep/wakeup and cv_*", __func__)); 879129188Sjhb 880145056Sjhb /* Resume all blocked threads on the sleep queue. */ 881181334Sjhb wakeup_swapper = 0; 882182875Sjhb TAILQ_FOREACH_SAFE(td, &sq->sq_blocked[queue], td_slpq, tdn) { 883170294Sjeff thread_lock(td); 884181334Sjhb if (sleepq_resume_thread(sq, td, pri)) 885181334Sjhb wakeup_swapper = 1; 886170294Sjeff thread_unlock(td); 887170294Sjeff } 888181334Sjhb return (wakeup_swapper); 889126324Sjhb} 890126324Sjhb 891126324Sjhb/* 892126324Sjhb * Time sleeping threads out. When the timeout expires, the thread is 893126324Sjhb * removed from the sleep queue and made runnable if it is still asleep. 894126324Sjhb */ 895126324Sjhbstatic void 896126324Sjhbsleepq_timeout(void *arg) 897126324Sjhb{ 898277528Shselasky struct sleepqueue_chain *sc; 899277528Shselasky struct sleepqueue *sq; 900277528Shselasky struct thread *td; 901277528Shselasky void *wchan; 902277528Shselasky int wakeup_swapper; 903126324Sjhb 904277528Shselasky td = arg; 905277528Shselasky wakeup_swapper = 0; 906129241Sbde CTR3(KTR_PROC, "sleepq_timeout: thread %p (pid %ld, %s)", 907173600Sjulian (void *)td, (long)td->td_proc->p_pid, (void *)td->td_name); 908126324Sjhb 909277528Shselasky /* 910277528Shselasky * First, see if the thread is asleep and get the wait channel if 911277528Shselasky * it is. 912277528Shselasky */ 913277528Shselasky thread_lock(td); 914277528Shselasky if (TD_IS_SLEEPING(td) && TD_ON_SLEEPQ(td)) { 915277528Shselasky wchan = td->td_wchan; 916277528Shselasky sc = SC_LOOKUP(wchan); 917277528Shselasky THREAD_LOCKPTR_ASSERT(td, &sc->sc_lock); 918277528Shselasky sq = sleepq_lookup(wchan); 919277528Shselasky MPASS(sq != NULL); 920277528Shselasky td->td_flags |= TDF_TIMEOUT; 921277528Shselasky wakeup_swapper = sleepq_resume_thread(sq, td, 0); 922277528Shselasky thread_unlock(td); 923277528Shselasky if (wakeup_swapper) 924277528Shselasky kick_proc0(); 925277528Shselasky return; 926277528Shselasky } 927277213Shselasky 928277528Shselasky /* 929277528Shselasky * If the thread is on the SLEEPQ but isn't sleeping yet, it 930277528Shselasky * can either be on another CPU in between sleepq_add() and 931277528Shselasky * one of the sleepq_*wait*() routines or it can be in 932277528Shselasky * sleepq_catch_signals(). 933277528Shselasky */ 934277213Shselasky if (TD_ON_SLEEPQ(td)) { 935277528Shselasky td->td_flags |= TDF_TIMEOUT; 936277528Shselasky thread_unlock(td); 937277528Shselasky return; 938277528Shselasky } 939175654Sjhb 940277528Shselasky /* 941277528Shselasky * Now check for the edge cases. First, if TDF_TIMEOUT is set, 942277528Shselasky * then the other thread has already yielded to us, so clear 943277528Shselasky * the flag and resume it. If TDF_TIMEOUT is not set, then the 944277528Shselasky * we know that the other thread is not on a sleep queue, but it 945277528Shselasky * hasn't resumed execution yet. In that case, set TDF_TIMOFAIL 946277528Shselasky * to let it know that the timeout has already run and doesn't 947277528Shselasky * need to be canceled. 948277528Shselasky */ 949277528Shselasky if (td->td_flags & TDF_TIMEOUT) { 950277528Shselasky MPASS(TD_IS_SLEEPING(td)); 951277528Shselasky td->td_flags &= ~TDF_TIMEOUT; 952277528Shselasky TD_CLR_SLEEPING(td); 953277528Shselasky wakeup_swapper = setrunnable(td); 954277528Shselasky } else 955277528Shselasky td->td_flags |= TDF_TIMOFAIL; 956170294Sjeff thread_unlock(td); 957181334Sjhb if (wakeup_swapper) 958181334Sjhb kick_proc0(); 959126324Sjhb} 960126324Sjhb 961126324Sjhb/* 962126324Sjhb * Resumes a specific thread from the sleep queue associated with a specific 963126324Sjhb * wait channel if it is on that queue. 964126324Sjhb */ 965126324Sjhbvoid 966126324Sjhbsleepq_remove(struct thread *td, void *wchan) 967126324Sjhb{ 968126324Sjhb struct sleepqueue *sq; 969181334Sjhb int wakeup_swapper; 970126324Sjhb 971126324Sjhb /* 972126324Sjhb * Look up the sleep queue for this wait channel, then re-check 973126324Sjhb * that the thread is asleep on that channel, if it is not, then 974126324Sjhb * bail. 975126324Sjhb */ 976126324Sjhb MPASS(wchan != NULL); 977136445Sjhb sleepq_lock(wchan); 978126324Sjhb sq = sleepq_lookup(wchan); 979170294Sjeff /* 980170294Sjeff * We can not lock the thread here as it may be sleeping on a 981170294Sjeff * different sleepq. However, holding the sleepq lock for this 982170294Sjeff * wchan can guarantee that we do not miss a wakeup for this 983170294Sjeff * channel. The asserts below will catch any false positives. 984170294Sjeff */ 985126324Sjhb if (!TD_ON_SLEEPQ(td) || td->td_wchan != wchan) { 986126324Sjhb sleepq_release(wchan); 987126324Sjhb return; 988126324Sjhb } 989170294Sjeff /* Thread is asleep on sleep queue sq, so wake it up. */ 990170294Sjeff thread_lock(td); 991126324Sjhb MPASS(sq != NULL); 992170294Sjeff MPASS(td->td_wchan == wchan); 993181334Sjhb wakeup_swapper = sleepq_resume_thread(sq, td, 0); 994170294Sjeff thread_unlock(td); 995126324Sjhb sleepq_release(wchan); 996181334Sjhb if (wakeup_swapper) 997181334Sjhb kick_proc0(); 998126324Sjhb} 999126324Sjhb 1000126324Sjhb/* 1001129241Sbde * Abort a thread as if an interrupt had occurred. Only abort 1002129241Sbde * interruptible waits (unfortunately it isn't safe to abort others). 1003126324Sjhb */ 1004181334Sjhbint 1005155741Sdavidxusleepq_abort(struct thread *td, int intrval) 1006126324Sjhb{ 1007170294Sjeff struct sleepqueue *sq; 1008126324Sjhb void *wchan; 1009126324Sjhb 1010170294Sjeff THREAD_LOCK_ASSERT(td, MA_OWNED); 1011126324Sjhb MPASS(TD_ON_SLEEPQ(td)); 1012126324Sjhb MPASS(td->td_flags & TDF_SINTR); 1013155741Sdavidxu MPASS(intrval == EINTR || intrval == ERESTART); 1014126324Sjhb 1015126324Sjhb /* 1016126324Sjhb * If the TDF_TIMEOUT flag is set, just leave. A 1017126324Sjhb * timeout is scheduled anyhow. 1018126324Sjhb */ 1019126324Sjhb if (td->td_flags & TDF_TIMEOUT) 1020181334Sjhb return (0); 1021126324Sjhb 1022129241Sbde CTR3(KTR_PROC, "sleepq_abort: thread %p (pid %ld, %s)", 1023173600Sjulian (void *)td, (long)td->td_proc->p_pid, (void *)td->td_name); 1024170294Sjeff td->td_intrval = intrval; 1025170294Sjeff td->td_flags |= TDF_SLEEPABORT; 1026170294Sjeff /* 1027170294Sjeff * If the thread has not slept yet it will find the signal in 1028170294Sjeff * sleepq_catch_signals() and call sleepq_resume_thread. Otherwise 1029170294Sjeff * we have to do it here. 1030170294Sjeff */ 1031170294Sjeff if (!TD_IS_SLEEPING(td)) 1032181334Sjhb return (0); 1033126324Sjhb wchan = td->td_wchan; 1034170294Sjeff MPASS(wchan != NULL); 1035170294Sjeff sq = sleepq_lookup(wchan); 1036170294Sjeff MPASS(sq != NULL); 1037170294Sjeff 1038170294Sjeff /* Thread is asleep on sleep queue sq, so wake it up. */ 1039181334Sjhb return (sleepq_resume_thread(sq, td, 0)); 1040126324Sjhb} 1041154936Sjhb 1042296927Scem/* 1043296927Scem * Prints the stacks of all threads presently sleeping on wchan/queue to 1044296927Scem * the sbuf sb. Sets count_stacks_printed to the number of stacks actually 1045296927Scem * printed. Typically, this will equal the number of threads sleeping on the 1046296927Scem * queue, but may be less if sb overflowed before all stacks were printed. 1047296927Scem */ 1048296973Scem#ifdef STACK 1049296927Scemint 1050296927Scemsleepq_sbuf_print_stacks(struct sbuf *sb, void *wchan, int queue, 1051296927Scem int *count_stacks_printed) 1052296927Scem{ 1053296927Scem struct thread *td, *td_next; 1054296927Scem struct sleepqueue *sq; 1055296927Scem struct stack **st; 1056296927Scem struct sbuf **td_infos; 1057296927Scem int i, stack_idx, error, stacks_to_allocate; 1058296927Scem bool finished, partial_print; 1059296927Scem 1060296927Scem error = 0; 1061296927Scem finished = false; 1062296927Scem partial_print = false; 1063296927Scem 1064296927Scem KASSERT(wchan != NULL, ("%s: invalid NULL wait channel", __func__)); 1065296927Scem MPASS((queue >= 0) && (queue < NR_SLEEPQS)); 1066296927Scem 1067296927Scem stacks_to_allocate = 10; 1068296927Scem for (i = 0; i < 3 && !finished ; i++) { 1069296927Scem /* We cannot malloc while holding the queue's spinlock, so 1070296927Scem * we do our mallocs now, and hope it is enough. If it 1071296927Scem * isn't, we will free these, drop the lock, malloc more, 1072296927Scem * and try again, up to a point. After that point we will 1073296927Scem * give up and report ENOMEM. We also cannot write to sb 1074296927Scem * during this time since the client may have set the 1075296927Scem * SBUF_AUTOEXTEND flag on their sbuf, which could cause a 1076296927Scem * malloc as we print to it. So we defer actually printing 1077296927Scem * to sb until after we drop the spinlock. 1078296927Scem */ 1079296927Scem 1080296927Scem /* Where we will store the stacks. */ 1081296927Scem st = malloc(sizeof(struct stack *) * stacks_to_allocate, 1082296927Scem M_TEMP, M_WAITOK); 1083296927Scem for (stack_idx = 0; stack_idx < stacks_to_allocate; 1084296927Scem stack_idx++) 1085296927Scem st[stack_idx] = stack_create(); 1086296927Scem 1087296927Scem /* Where we will store the td name, tid, etc. */ 1088296927Scem td_infos = malloc(sizeof(struct sbuf *) * stacks_to_allocate, 1089296927Scem M_TEMP, M_WAITOK); 1090296927Scem for (stack_idx = 0; stack_idx < stacks_to_allocate; 1091296927Scem stack_idx++) 1092296927Scem td_infos[stack_idx] = sbuf_new(NULL, NULL, 1093296927Scem MAXCOMLEN + sizeof(struct thread *) * 2 + 40, 1094296927Scem SBUF_FIXEDLEN); 1095296927Scem 1096296927Scem sleepq_lock(wchan); 1097296927Scem sq = sleepq_lookup(wchan); 1098296927Scem if (sq == NULL) { 1099296927Scem /* This sleepq does not exist; exit and return ENOENT. */ 1100296927Scem error = ENOENT; 1101296927Scem finished = true; 1102296927Scem sleepq_release(wchan); 1103296927Scem goto loop_end; 1104296927Scem } 1105296927Scem 1106296927Scem stack_idx = 0; 1107296927Scem /* Save thread info */ 1108296927Scem TAILQ_FOREACH_SAFE(td, &sq->sq_blocked[queue], td_slpq, 1109296927Scem td_next) { 1110296927Scem if (stack_idx >= stacks_to_allocate) 1111296927Scem goto loop_end; 1112296927Scem 1113296927Scem /* Note the td_lock is equal to the sleepq_lock here. */ 1114296927Scem stack_save_td(st[stack_idx], td); 1115296927Scem 1116296927Scem sbuf_printf(td_infos[stack_idx], "%d: %s %p", 1117296927Scem td->td_tid, td->td_name, td); 1118296927Scem 1119296927Scem ++stack_idx; 1120296927Scem } 1121296927Scem 1122296927Scem finished = true; 1123296927Scem sleepq_release(wchan); 1124296927Scem 1125296927Scem /* Print the stacks */ 1126296927Scem for (i = 0; i < stack_idx; i++) { 1127296927Scem sbuf_finish(td_infos[i]); 1128296927Scem sbuf_printf(sb, "--- thread %s: ---\n", sbuf_data(td_infos[i])); 1129296927Scem stack_sbuf_print(sb, st[i]); 1130296927Scem sbuf_printf(sb, "\n"); 1131296927Scem 1132296927Scem error = sbuf_error(sb); 1133296927Scem if (error == 0) 1134296927Scem *count_stacks_printed = stack_idx; 1135296927Scem } 1136296927Scem 1137296927Scemloop_end: 1138296927Scem if (!finished) 1139296927Scem sleepq_release(wchan); 1140296927Scem for (stack_idx = 0; stack_idx < stacks_to_allocate; 1141296927Scem stack_idx++) 1142296927Scem stack_destroy(st[stack_idx]); 1143296927Scem for (stack_idx = 0; stack_idx < stacks_to_allocate; 1144296927Scem stack_idx++) 1145296927Scem sbuf_delete(td_infos[stack_idx]); 1146296927Scem free(st, M_TEMP); 1147296927Scem free(td_infos, M_TEMP); 1148296927Scem stacks_to_allocate *= 10; 1149296927Scem } 1150296927Scem 1151296927Scem if (!finished && error == 0) 1152296927Scem error = ENOMEM; 1153296927Scem 1154296927Scem return (error); 1155296927Scem} 1156296973Scem#endif 1157296927Scem 1158177372Sjeff#ifdef SLEEPQUEUE_PROFILING 1159177372Sjeff#define SLEEPQ_PROF_LOCATIONS 1024 1160212750Smdf#define SLEEPQ_SBUFSIZE 512 1161177372Sjeffstruct sleepq_prof { 1162177372Sjeff LIST_ENTRY(sleepq_prof) sp_link; 1163177372Sjeff const char *sp_wmesg; 1164177372Sjeff long sp_count; 1165177372Sjeff}; 1166177372Sjeff 1167177372SjeffLIST_HEAD(sqphead, sleepq_prof); 1168177372Sjeff 1169177372Sjeffstruct sqphead sleepq_prof_free; 1170177372Sjeffstruct sqphead sleepq_hash[SC_TABLESIZE]; 1171177372Sjeffstatic struct sleepq_prof sleepq_profent[SLEEPQ_PROF_LOCATIONS]; 1172177372Sjeffstatic struct mtx sleepq_prof_lock; 1173177372SjeffMTX_SYSINIT(sleepq_prof_lock, &sleepq_prof_lock, "sleepq_prof", MTX_SPIN); 1174177372Sjeff 1175177372Sjeffstatic void 1176177372Sjeffsleepq_profile(const char *wmesg) 1177177372Sjeff{ 1178177372Sjeff struct sleepq_prof *sp; 1179177372Sjeff 1180177372Sjeff mtx_lock_spin(&sleepq_prof_lock); 1181177372Sjeff if (prof_enabled == 0) 1182177372Sjeff goto unlock; 1183177372Sjeff LIST_FOREACH(sp, &sleepq_hash[SC_HASH(wmesg)], sp_link) 1184177372Sjeff if (sp->sp_wmesg == wmesg) 1185177372Sjeff goto done; 1186177372Sjeff sp = LIST_FIRST(&sleepq_prof_free); 1187177372Sjeff if (sp == NULL) 1188177372Sjeff goto unlock; 1189177372Sjeff sp->sp_wmesg = wmesg; 1190177372Sjeff LIST_REMOVE(sp, sp_link); 1191177372Sjeff LIST_INSERT_HEAD(&sleepq_hash[SC_HASH(wmesg)], sp, sp_link); 1192177372Sjeffdone: 1193177372Sjeff sp->sp_count++; 1194177372Sjeffunlock: 1195177372Sjeff mtx_unlock_spin(&sleepq_prof_lock); 1196177372Sjeff return; 1197177372Sjeff} 1198177372Sjeff 1199177372Sjeffstatic void 1200177372Sjeffsleepq_prof_reset(void) 1201177372Sjeff{ 1202177372Sjeff struct sleepq_prof *sp; 1203177372Sjeff int enabled; 1204177372Sjeff int i; 1205177372Sjeff 1206177372Sjeff mtx_lock_spin(&sleepq_prof_lock); 1207177372Sjeff enabled = prof_enabled; 1208177372Sjeff prof_enabled = 0; 1209177372Sjeff for (i = 0; i < SC_TABLESIZE; i++) 1210177372Sjeff LIST_INIT(&sleepq_hash[i]); 1211177372Sjeff LIST_INIT(&sleepq_prof_free); 1212177372Sjeff for (i = 0; i < SLEEPQ_PROF_LOCATIONS; i++) { 1213177372Sjeff sp = &sleepq_profent[i]; 1214177372Sjeff sp->sp_wmesg = NULL; 1215177372Sjeff sp->sp_count = 0; 1216177372Sjeff LIST_INSERT_HEAD(&sleepq_prof_free, sp, sp_link); 1217177372Sjeff } 1218177372Sjeff prof_enabled = enabled; 1219177372Sjeff mtx_unlock_spin(&sleepq_prof_lock); 1220177372Sjeff} 1221177372Sjeff 1222177372Sjeffstatic int 1223177372Sjeffenable_sleepq_prof(SYSCTL_HANDLER_ARGS) 1224177372Sjeff{ 1225177372Sjeff int error, v; 1226177372Sjeff 1227177372Sjeff v = prof_enabled; 1228177372Sjeff error = sysctl_handle_int(oidp, &v, v, req); 1229177372Sjeff if (error) 1230177372Sjeff return (error); 1231177372Sjeff if (req->newptr == NULL) 1232177372Sjeff return (error); 1233177372Sjeff if (v == prof_enabled) 1234177372Sjeff return (0); 1235177372Sjeff if (v == 1) 1236177372Sjeff sleepq_prof_reset(); 1237177372Sjeff mtx_lock_spin(&sleepq_prof_lock); 1238177372Sjeff prof_enabled = !!v; 1239177372Sjeff mtx_unlock_spin(&sleepq_prof_lock); 1240177372Sjeff 1241177372Sjeff return (0); 1242177372Sjeff} 1243177372Sjeff 1244177372Sjeffstatic int 1245177372Sjeffreset_sleepq_prof_stats(SYSCTL_HANDLER_ARGS) 1246177372Sjeff{ 1247177372Sjeff int error, v; 1248177372Sjeff 1249177372Sjeff v = 0; 1250177372Sjeff error = sysctl_handle_int(oidp, &v, 0, req); 1251177372Sjeff if (error) 1252177372Sjeff return (error); 1253177372Sjeff if (req->newptr == NULL) 1254177372Sjeff return (error); 1255177372Sjeff if (v == 0) 1256177372Sjeff return (0); 1257177372Sjeff sleepq_prof_reset(); 1258177372Sjeff 1259177372Sjeff return (0); 1260177372Sjeff} 1261177372Sjeff 1262177372Sjeffstatic int 1263177372Sjeffdump_sleepq_prof_stats(SYSCTL_HANDLER_ARGS) 1264177372Sjeff{ 1265177372Sjeff struct sleepq_prof *sp; 1266177372Sjeff struct sbuf *sb; 1267177372Sjeff int enabled; 1268177372Sjeff int error; 1269177372Sjeff int i; 1270177372Sjeff 1271217916Smdf error = sysctl_wire_old_buffer(req, 0); 1272217916Smdf if (error != 0) 1273217916Smdf return (error); 1274212750Smdf sb = sbuf_new_for_sysctl(NULL, NULL, SLEEPQ_SBUFSIZE, req); 1275177372Sjeff sbuf_printf(sb, "\nwmesg\tcount\n"); 1276177372Sjeff enabled = prof_enabled; 1277177372Sjeff mtx_lock_spin(&sleepq_prof_lock); 1278177372Sjeff prof_enabled = 0; 1279177372Sjeff mtx_unlock_spin(&sleepq_prof_lock); 1280177372Sjeff for (i = 0; i < SC_TABLESIZE; i++) { 1281177372Sjeff LIST_FOREACH(sp, &sleepq_hash[i], sp_link) { 1282177372Sjeff sbuf_printf(sb, "%s\t%ld\n", 1283177372Sjeff sp->sp_wmesg, sp->sp_count); 1284177372Sjeff } 1285177372Sjeff } 1286177372Sjeff mtx_lock_spin(&sleepq_prof_lock); 1287177372Sjeff prof_enabled = enabled; 1288177372Sjeff mtx_unlock_spin(&sleepq_prof_lock); 1289177372Sjeff 1290212750Smdf error = sbuf_finish(sb); 1291177372Sjeff sbuf_delete(sb); 1292177372Sjeff return (error); 1293177372Sjeff} 1294177372Sjeff 1295177372SjeffSYSCTL_PROC(_debug_sleepq, OID_AUTO, stats, CTLTYPE_STRING | CTLFLAG_RD, 1296177372Sjeff NULL, 0, dump_sleepq_prof_stats, "A", "Sleepqueue profiling statistics"); 1297177372SjeffSYSCTL_PROC(_debug_sleepq, OID_AUTO, reset, CTLTYPE_INT | CTLFLAG_RW, 1298177372Sjeff NULL, 0, reset_sleepq_prof_stats, "I", 1299177372Sjeff "Reset sleepqueue profiling statistics"); 1300177372SjeffSYSCTL_PROC(_debug_sleepq, OID_AUTO, enable, CTLTYPE_INT | CTLFLAG_RW, 1301177372Sjeff NULL, 0, enable_sleepq_prof, "I", "Enable sleepqueue profiling"); 1302177372Sjeff#endif 1303177372Sjeff 1304154936Sjhb#ifdef DDB 1305154936SjhbDB_SHOW_COMMAND(sleepq, db_show_sleepqueue) 1306154936Sjhb{ 1307154936Sjhb struct sleepqueue_chain *sc; 1308154936Sjhb struct sleepqueue *sq; 1309154944Simp#ifdef INVARIANTS 1310154936Sjhb struct lock_object *lock; 1311154944Simp#endif 1312154936Sjhb struct thread *td; 1313154936Sjhb void *wchan; 1314154936Sjhb int i; 1315154936Sjhb 1316154936Sjhb if (!have_addr) 1317154936Sjhb return; 1318154936Sjhb 1319154936Sjhb /* 1320154936Sjhb * First, see if there is an active sleep queue for the wait channel 1321154936Sjhb * indicated by the address. 1322154936Sjhb */ 1323154936Sjhb wchan = (void *)addr; 1324154936Sjhb sc = SC_LOOKUP(wchan); 1325154936Sjhb LIST_FOREACH(sq, &sc->sc_queues, sq_hash) 1326154936Sjhb if (sq->sq_wchan == wchan) 1327154936Sjhb goto found; 1328154936Sjhb 1329154936Sjhb /* 1330154936Sjhb * Second, see if there is an active sleep queue at the address 1331154936Sjhb * indicated. 1332154936Sjhb */ 1333154936Sjhb for (i = 0; i < SC_TABLESIZE; i++) 1334154936Sjhb LIST_FOREACH(sq, &sleepq_chains[i].sc_queues, sq_hash) { 1335154936Sjhb if (sq == (struct sleepqueue *)addr) 1336154936Sjhb goto found; 1337154936Sjhb } 1338154936Sjhb 1339154936Sjhb db_printf("Unable to locate a sleep queue via %p\n", (void *)addr); 1340154936Sjhb return; 1341154936Sjhbfound: 1342154936Sjhb db_printf("Wait channel: %p\n", sq->sq_wchan); 1343201879Sattilio db_printf("Queue type: %d\n", sq->sq_type); 1344154936Sjhb#ifdef INVARIANTS 1345154936Sjhb if (sq->sq_lock) { 1346164325Spjd lock = sq->sq_lock; 1347154936Sjhb db_printf("Associated Interlock: %p - (%s) %s\n", lock, 1348154936Sjhb LOCK_CLASS(lock)->lc_name, lock->lo_name); 1349154936Sjhb } 1350154936Sjhb#endif 1351154936Sjhb db_printf("Blocked threads:\n"); 1352165272Skmacy for (i = 0; i < NR_SLEEPQS; i++) { 1353165272Skmacy db_printf("\nQueue[%d]:\n", i); 1354165272Skmacy if (TAILQ_EMPTY(&sq->sq_blocked[i])) 1355165272Skmacy db_printf("\tempty\n"); 1356165272Skmacy else 1357165272Skmacy TAILQ_FOREACH(td, &sq->sq_blocked[0], 1358165272Skmacy td_slpq) { 1359165272Skmacy db_printf("\t%p (tid %d, pid %d, \"%s\")\n", td, 1360165272Skmacy td->td_tid, td->td_proc->p_pid, 1361180930Sjhb td->td_name); 1362165272Skmacy } 1363200447Sattilio db_printf("(expected: %u)\n", sq->sq_blockedcnt[i]); 1364165272Skmacy } 1365154936Sjhb} 1366157823Sjhb 1367157823Sjhb/* Alias 'show sleepqueue' to 'show sleepq'. */ 1368183054SsamDB_SHOW_ALIAS(sleepqueue, db_show_sleepqueue); 1369154936Sjhb#endif 1370