subr_sleepqueue.c revision 247783
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 247783 2013-03-04 11:51:46Z davide $"); 64126324Sjhb 65154936Sjhb#include "opt_sleepqueue_profiling.h" 66154936Sjhb#include "opt_ddb.h" 67235459Srstone#include "opt_kdtrace.h" 68170640Sjeff#include "opt_sched.h" 69154936Sjhb 70126324Sjhb#include <sys/param.h> 71126324Sjhb#include <sys/systm.h> 72126324Sjhb#include <sys/lock.h> 73126324Sjhb#include <sys/kernel.h> 74126324Sjhb#include <sys/ktr.h> 75126324Sjhb#include <sys/mutex.h> 76126324Sjhb#include <sys/proc.h> 77177372Sjeff#include <sys/sbuf.h> 78126324Sjhb#include <sys/sched.h> 79235459Srstone#include <sys/sdt.h> 80126324Sjhb#include <sys/signalvar.h> 81126324Sjhb#include <sys/sleepqueue.h> 82131259Sjhb#include <sys/sysctl.h> 83126324Sjhb 84169666Sjeff#include <vm/uma.h> 85169666Sjeff 86154936Sjhb#ifdef DDB 87154936Sjhb#include <ddb/ddb.h> 88154936Sjhb#endif 89154936Sjhb 90126324Sjhb/* 91126324Sjhb * Constants for the hash table of sleep queue chains. These constants are 92126324Sjhb * the same ones that 4BSD (and possibly earlier versions of BSD) used. 93126324Sjhb * Basically, we ignore the lower 8 bits of the address since most wait 94126324Sjhb * channel pointers are aligned and only look at the next 7 bits for the 95126324Sjhb * hash. SC_TABLESIZE must be a power of two for SC_MASK to work properly. 96126324Sjhb */ 97126324Sjhb#define SC_TABLESIZE 128 /* Must be power of 2. */ 98126324Sjhb#define SC_MASK (SC_TABLESIZE - 1) 99126324Sjhb#define SC_SHIFT 8 100126324Sjhb#define SC_HASH(wc) (((uintptr_t)(wc) >> SC_SHIFT) & SC_MASK) 101126324Sjhb#define SC_LOOKUP(wc) &sleepq_chains[SC_HASH(wc)] 102165272Skmacy#define NR_SLEEPQS 2 103126324Sjhb/* 104126324Sjhb * There two different lists of sleep queues. Both lists are connected 105126324Sjhb * via the sq_hash entries. The first list is the sleep queue chain list 106126324Sjhb * that a sleep queue is on when it is attached to a wait channel. The 107126324Sjhb * second list is the free list hung off of a sleep queue that is attached 108126324Sjhb * to a wait channel. 109126324Sjhb * 110126324Sjhb * Each sleep queue also contains the wait channel it is attached to, the 111126324Sjhb * list of threads blocked on that wait channel, flags specific to the 112126324Sjhb * wait channel, and the lock used to synchronize with a wait channel. 113126324Sjhb * The flags are used to catch mismatches between the various consumers 114126324Sjhb * of the sleep queue API (e.g. sleep/wakeup and condition variables). 115126324Sjhb * The lock pointer is only used when invariants are enabled for various 116126324Sjhb * debugging checks. 117126324Sjhb * 118126324Sjhb * Locking key: 119126324Sjhb * c - sleep queue chain lock 120126324Sjhb */ 121126324Sjhbstruct sleepqueue { 122165272Skmacy TAILQ_HEAD(, thread) sq_blocked[NR_SLEEPQS]; /* (c) Blocked threads. */ 123200447Sattilio u_int sq_blockedcnt[NR_SLEEPQS]; /* (c) N. of blocked threads. */ 124126324Sjhb LIST_ENTRY(sleepqueue) sq_hash; /* (c) Chain and free list. */ 125126324Sjhb LIST_HEAD(, sleepqueue) sq_free; /* (c) Free queues. */ 126126324Sjhb void *sq_wchan; /* (c) Wait channel. */ 127201879Sattilio int sq_type; /* (c) Queue type. */ 128136445Sjhb#ifdef INVARIANTS 129164325Spjd struct lock_object *sq_lock; /* (c) Associated lock. */ 130126324Sjhb#endif 131126324Sjhb}; 132126324Sjhb 133126324Sjhbstruct sleepqueue_chain { 134126324Sjhb LIST_HEAD(, sleepqueue) sc_queues; /* List of sleep queues. */ 135126324Sjhb struct mtx sc_lock; /* Spin lock for this chain. */ 136131259Sjhb#ifdef SLEEPQUEUE_PROFILING 137131259Sjhb u_int sc_depth; /* Length of sc_queues. */ 138131259Sjhb u_int sc_max_depth; /* Max length of sc_queues. */ 139131259Sjhb#endif 140126324Sjhb}; 141126324Sjhb 142131259Sjhb#ifdef SLEEPQUEUE_PROFILING 143131259Sjhbu_int sleepq_max_depth; 144227309Sedstatic SYSCTL_NODE(_debug, OID_AUTO, sleepq, CTLFLAG_RD, 0, "sleepq profiling"); 145227309Sedstatic SYSCTL_NODE(_debug_sleepq, OID_AUTO, chains, CTLFLAG_RD, 0, 146131259Sjhb "sleepq chain stats"); 147131259SjhbSYSCTL_UINT(_debug_sleepq, OID_AUTO, max_depth, CTLFLAG_RD, &sleepq_max_depth, 148131259Sjhb 0, "maxmimum depth achieved of a single chain"); 149177372Sjeff 150177372Sjeffstatic void sleepq_profile(const char *wmesg); 151177372Sjeffstatic int prof_enabled; 152131259Sjhb#endif 153126324Sjhbstatic struct sleepqueue_chain sleepq_chains[SC_TABLESIZE]; 154169666Sjeffstatic uma_zone_t sleepq_zone; 155126324Sjhb 156126324Sjhb/* 157126324Sjhb * Prototypes for non-exported routines. 158126324Sjhb */ 159177085Sjeffstatic int sleepq_catch_signals(void *wchan, int pri); 160165272Skmacystatic int sleepq_check_signals(void); 161126324Sjhbstatic int sleepq_check_timeout(void); 162169666Sjeff#ifdef INVARIANTS 163169666Sjeffstatic void sleepq_dtor(void *mem, int size, void *arg); 164169666Sjeff#endif 165169666Sjeffstatic int sleepq_init(void *mem, int size, int flags); 166181334Sjhbstatic int sleepq_resume_thread(struct sleepqueue *sq, struct thread *td, 167169666Sjeff int pri); 168177085Sjeffstatic void sleepq_switch(void *wchan, int pri); 169126324Sjhbstatic void sleepq_timeout(void *arg); 170126324Sjhb 171235459SrstoneSDT_PROBE_DECLARE(sched, , , sleep); 172235459SrstoneSDT_PROBE_DECLARE(sched, , , wakeup); 173235459Srstone 174126324Sjhb/* 175126324Sjhb * Early initialization of sleep queues that is called from the sleepinit() 176126324Sjhb * SYSINIT. 177126324Sjhb */ 178126324Sjhbvoid 179126324Sjhbinit_sleepqueues(void) 180126324Sjhb{ 181131259Sjhb#ifdef SLEEPQUEUE_PROFILING 182131259Sjhb struct sysctl_oid *chain_oid; 183131259Sjhb char chain_name[10]; 184131259Sjhb#endif 185126324Sjhb int i; 186126324Sjhb 187126324Sjhb for (i = 0; i < SC_TABLESIZE; i++) { 188126324Sjhb LIST_INIT(&sleepq_chains[i].sc_queues); 189126324Sjhb mtx_init(&sleepq_chains[i].sc_lock, "sleepq chain", NULL, 190176258Sjhb MTX_SPIN | MTX_RECURSE); 191131259Sjhb#ifdef SLEEPQUEUE_PROFILING 192131259Sjhb snprintf(chain_name, sizeof(chain_name), "%d", i); 193131259Sjhb chain_oid = SYSCTL_ADD_NODE(NULL, 194131259Sjhb SYSCTL_STATIC_CHILDREN(_debug_sleepq_chains), OID_AUTO, 195131259Sjhb chain_name, CTLFLAG_RD, NULL, "sleepq chain stats"); 196131259Sjhb SYSCTL_ADD_UINT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO, 197131259Sjhb "depth", CTLFLAG_RD, &sleepq_chains[i].sc_depth, 0, NULL); 198131259Sjhb SYSCTL_ADD_UINT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO, 199131259Sjhb "max_depth", CTLFLAG_RD, &sleepq_chains[i].sc_max_depth, 0, 200131259Sjhb NULL); 201131259Sjhb#endif 202126324Sjhb } 203169666Sjeff sleepq_zone = uma_zcreate("SLEEPQUEUE", sizeof(struct sleepqueue), 204169666Sjeff#ifdef INVARIANTS 205169666Sjeff NULL, sleepq_dtor, sleepq_init, NULL, UMA_ALIGN_CACHE, 0); 206169666Sjeff#else 207169666Sjeff NULL, NULL, sleepq_init, NULL, UMA_ALIGN_CACHE, 0); 208169666Sjeff#endif 209169666Sjeff 210126324Sjhb thread0.td_sleepqueue = sleepq_alloc(); 211126324Sjhb} 212126324Sjhb 213126324Sjhb/* 214169666Sjeff * Get a sleep queue for a new thread. 215126324Sjhb */ 216126324Sjhbstruct sleepqueue * 217126324Sjhbsleepq_alloc(void) 218126324Sjhb{ 219126324Sjhb 220169666Sjeff return (uma_zalloc(sleepq_zone, M_WAITOK)); 221126324Sjhb} 222126324Sjhb 223126324Sjhb/* 224126324Sjhb * Free a sleep queue when a thread is destroyed. 225126324Sjhb */ 226126324Sjhbvoid 227126324Sjhbsleepq_free(struct sleepqueue *sq) 228126324Sjhb{ 229126324Sjhb 230169666Sjeff uma_zfree(sleepq_zone, sq); 231126324Sjhb} 232126324Sjhb 233126324Sjhb/* 234136445Sjhb * Lock the sleep queue chain associated with the specified wait channel. 235136445Sjhb */ 236136445Sjhbvoid 237136445Sjhbsleepq_lock(void *wchan) 238136445Sjhb{ 239136445Sjhb struct sleepqueue_chain *sc; 240136445Sjhb 241136445Sjhb sc = SC_LOOKUP(wchan); 242136445Sjhb mtx_lock_spin(&sc->sc_lock); 243136445Sjhb} 244136445Sjhb 245136445Sjhb/* 246126324Sjhb * Look up the sleep queue associated with a given wait channel in the hash 247136445Sjhb * table locking the associated sleep queue chain. If no queue is found in 248136445Sjhb * the table, NULL is returned. 249126324Sjhb */ 250126324Sjhbstruct sleepqueue * 251126324Sjhbsleepq_lookup(void *wchan) 252126324Sjhb{ 253126324Sjhb struct sleepqueue_chain *sc; 254126324Sjhb struct sleepqueue *sq; 255126324Sjhb 256126324Sjhb KASSERT(wchan != NULL, ("%s: invalid NULL wait channel", __func__)); 257126324Sjhb sc = SC_LOOKUP(wchan); 258136445Sjhb mtx_assert(&sc->sc_lock, MA_OWNED); 259126324Sjhb LIST_FOREACH(sq, &sc->sc_queues, sq_hash) 260126324Sjhb if (sq->sq_wchan == wchan) 261126324Sjhb return (sq); 262126324Sjhb return (NULL); 263126324Sjhb} 264126324Sjhb 265126324Sjhb/* 266126324Sjhb * Unlock the sleep queue chain associated with a given wait channel. 267126324Sjhb */ 268126324Sjhbvoid 269126324Sjhbsleepq_release(void *wchan) 270126324Sjhb{ 271126324Sjhb struct sleepqueue_chain *sc; 272126324Sjhb 273126324Sjhb sc = SC_LOOKUP(wchan); 274126324Sjhb mtx_unlock_spin(&sc->sc_lock); 275126324Sjhb} 276126324Sjhb 277126324Sjhb/* 278137277Sjhb * Places the current thread on the sleep queue for the specified wait 279126324Sjhb * channel. If INVARIANTS is enabled, then it associates the passed in 280126324Sjhb * lock with the sleepq to make sure it is held when that sleep queue is 281126324Sjhb * woken up. 282126324Sjhb */ 283126324Sjhbvoid 284165272Skmacysleepq_add(void *wchan, struct lock_object *lock, const char *wmesg, int flags, 285165272Skmacy int queue) 286126324Sjhb{ 287126324Sjhb struct sleepqueue_chain *sc; 288136445Sjhb struct sleepqueue *sq; 289137277Sjhb struct thread *td; 290126324Sjhb 291126324Sjhb td = curthread; 292126324Sjhb sc = SC_LOOKUP(wchan); 293126324Sjhb mtx_assert(&sc->sc_lock, MA_OWNED); 294126324Sjhb MPASS(td->td_sleepqueue != NULL); 295126324Sjhb MPASS(wchan != NULL); 296165272Skmacy MPASS((queue >= 0) && (queue < NR_SLEEPQS)); 297126324Sjhb 298150177Sjhb /* If this thread is not allowed to sleep, die a horrible death. */ 299247588Sjhb KASSERT(td->td_no_sleeping == 0, 300247588Sjhb ("%s: td %p to sleep on wchan %p with sleeping prohibited", 301240423Sattilio __func__, td, wchan)); 302150177Sjhb 303136445Sjhb /* Look up the sleep queue associated with the wait channel 'wchan'. */ 304136445Sjhb sq = sleepq_lookup(wchan); 305136445Sjhb 306136445Sjhb /* 307136445Sjhb * If the wait channel does not already have a sleep queue, use 308136445Sjhb * this thread's sleep queue. Otherwise, insert the current thread 309136445Sjhb * into the sleep queue already in use by this wait channel. 310136445Sjhb */ 311126324Sjhb if (sq == NULL) { 312165272Skmacy#ifdef INVARIANTS 313165292Skmacy int i; 314165291Sache 315165292Skmacy sq = td->td_sleepqueue; 316200447Sattilio for (i = 0; i < NR_SLEEPQS; i++) { 317165292Skmacy KASSERT(TAILQ_EMPTY(&sq->sq_blocked[i]), 318200447Sattilio ("thread's sleep queue %d is not empty", i)); 319200447Sattilio KASSERT(sq->sq_blockedcnt[i] == 0, 320200447Sattilio ("thread's sleep queue %d count mismatches", i)); 321200447Sattilio } 322165272Skmacy KASSERT(LIST_EMPTY(&sq->sq_free), 323165272Skmacy ("thread's sleep queue has a non-empty free list")); 324165272Skmacy KASSERT(sq->sq_wchan == NULL, ("stale sq_wchan pointer")); 325165292Skmacy sq->sq_lock = lock; 326165272Skmacy#endif 327131259Sjhb#ifdef SLEEPQUEUE_PROFILING 328131259Sjhb sc->sc_depth++; 329131259Sjhb if (sc->sc_depth > sc->sc_max_depth) { 330131259Sjhb sc->sc_max_depth = sc->sc_depth; 331131259Sjhb if (sc->sc_max_depth > sleepq_max_depth) 332131259Sjhb sleepq_max_depth = sc->sc_max_depth; 333131259Sjhb } 334131259Sjhb#endif 335165292Skmacy sq = td->td_sleepqueue; 336126324Sjhb LIST_INSERT_HEAD(&sc->sc_queues, sq, sq_hash); 337126324Sjhb sq->sq_wchan = wchan; 338201879Sattilio sq->sq_type = flags & SLEEPQ_TYPE; 339126324Sjhb } else { 340126324Sjhb MPASS(wchan == sq->sq_wchan); 341126488Sjhb MPASS(lock == sq->sq_lock); 342136445Sjhb MPASS((flags & SLEEPQ_TYPE) == sq->sq_type); 343126324Sjhb LIST_INSERT_HEAD(&sq->sq_free, td->td_sleepqueue, sq_hash); 344126324Sjhb } 345172155Sattilio thread_lock(td); 346165272Skmacy TAILQ_INSERT_TAIL(&sq->sq_blocked[queue], td, td_slpq); 347200447Sattilio sq->sq_blockedcnt[queue]++; 348126324Sjhb td->td_sleepqueue = NULL; 349165272Skmacy td->td_sqqueue = queue; 350126324Sjhb td->td_wchan = wchan; 351126324Sjhb td->td_wmesg = wmesg; 352155741Sdavidxu if (flags & SLEEPQ_INTERRUPTIBLE) { 353134013Sjhb td->td_flags |= TDF_SINTR; 354155741Sdavidxu td->td_flags &= ~TDF_SLEEPABORT; 355155741Sdavidxu } 356172155Sattilio thread_unlock(td); 357126324Sjhb} 358126324Sjhb 359126324Sjhb/* 360126324Sjhb * Sets a timeout that will remove the current thread from the specified 361126324Sjhb * sleep queue after timo ticks if the thread has not already been awakened. 362126324Sjhb */ 363126324Sjhbvoid 364247783Sdavidesleepq_set_timeout_sbt(void *wchan, sbintime_t sbt, sbintime_t pr, 365247783Sdavide int flags) 366126324Sjhb{ 367126324Sjhb struct sleepqueue_chain *sc; 368126324Sjhb struct thread *td; 369126324Sjhb 370126324Sjhb td = curthread; 371126324Sjhb sc = SC_LOOKUP(wchan); 372126324Sjhb mtx_assert(&sc->sc_lock, MA_OWNED); 373126324Sjhb MPASS(TD_ON_SLEEPQ(td)); 374126324Sjhb MPASS(td->td_sleepqueue == NULL); 375126324Sjhb MPASS(wchan != NULL); 376247783Sdavide callout_reset_sbt_on(&td->td_slpcallout, sbt, pr, 377247783Sdavide sleepq_timeout, td, PCPU_GET(cpuid), flags | C_DIRECT_EXEC); 378126324Sjhb} 379126324Sjhb 380126324Sjhb/* 381200447Sattilio * Return the number of actual sleepers for the specified queue. 382200447Sattilio */ 383200447Sattiliou_int 384200447Sattiliosleepq_sleepcnt(void *wchan, int queue) 385200447Sattilio{ 386200447Sattilio struct sleepqueue *sq; 387200447Sattilio 388200447Sattilio KASSERT(wchan != NULL, ("%s: invalid NULL wait channel", __func__)); 389200447Sattilio MPASS((queue >= 0) && (queue < NR_SLEEPQS)); 390200447Sattilio sq = sleepq_lookup(wchan); 391200447Sattilio if (sq == NULL) 392200447Sattilio return (0); 393200447Sattilio return (sq->sq_blockedcnt[queue]); 394200447Sattilio} 395200447Sattilio 396200447Sattilio/* 397126324Sjhb * Marks the pending sleep of the current thread as interruptible and 398126324Sjhb * makes an initial check for pending signals before putting a thread 399170294Sjeff * to sleep. Enters and exits with the thread lock held. Thread lock 400170294Sjeff * may have transitioned from the sleepq lock to a run lock. 401126324Sjhb */ 402155741Sdavidxustatic int 403177085Sjeffsleepq_catch_signals(void *wchan, int pri) 404126324Sjhb{ 405126324Sjhb struct sleepqueue_chain *sc; 406126324Sjhb struct sleepqueue *sq; 407126324Sjhb struct thread *td; 408126324Sjhb struct proc *p; 409155741Sdavidxu struct sigacts *ps; 410195702Skib int sig, ret, stop_allowed; 411126324Sjhb 412126324Sjhb td = curthread; 413155741Sdavidxu p = curproc; 414126324Sjhb sc = SC_LOOKUP(wchan); 415126324Sjhb mtx_assert(&sc->sc_lock, MA_OWNED); 416126324Sjhb MPASS(wchan != NULL); 417211523Sdavidxu if ((td->td_pflags & TDP_WAKEUP) != 0) { 418211523Sdavidxu td->td_pflags &= ~TDP_WAKEUP; 419211523Sdavidxu ret = EINTR; 420211534Sdavidxu thread_lock(td); 421211523Sdavidxu goto out; 422211523Sdavidxu } 423211523Sdavidxu 424177375Sjeff /* 425177375Sjeff * See if there are any pending signals for this thread. If not 426177375Sjeff * we can switch immediately. Otherwise do the signal processing 427177375Sjeff * directly. 428177375Sjeff */ 429177375Sjeff thread_lock(td); 430177471Sjeff if ((td->td_flags & (TDF_NEEDSIGCHK | TDF_NEEDSUSPCHK)) == 0) { 431177375Sjeff sleepq_switch(wchan, pri); 432177375Sjeff return (0); 433177375Sjeff } 434195702Skib stop_allowed = (td->td_flags & TDF_SBDRY) ? SIG_STOP_NOT_ALLOWED : 435195702Skib SIG_STOP_ALLOWED; 436177375Sjeff thread_unlock(td); 437177375Sjeff mtx_unlock_spin(&sc->sc_lock); 438129241Sbde CTR3(KTR_PROC, "sleepq catching signals: thread %p (pid %ld, %s)", 439173601Sjulian (void *)td, (long)p->p_pid, td->td_name); 440126324Sjhb PROC_LOCK(p); 441155741Sdavidxu ps = p->p_sigacts; 442155741Sdavidxu mtx_lock(&ps->ps_mtx); 443195702Skib sig = cursig(td, stop_allowed); 444155741Sdavidxu if (sig == 0) { 445155741Sdavidxu mtx_unlock(&ps->ps_mtx); 446155741Sdavidxu ret = thread_suspend_check(1); 447155741Sdavidxu MPASS(ret == 0 || ret == EINTR || ret == ERESTART); 448155741Sdavidxu } else { 449155741Sdavidxu if (SIGISMEMBER(ps->ps_sigintr, sig)) 450155741Sdavidxu ret = EINTR; 451155741Sdavidxu else 452155741Sdavidxu ret = ERESTART; 453155741Sdavidxu mtx_unlock(&ps->ps_mtx); 454155741Sdavidxu } 455184667Sdavidxu /* 456184667Sdavidxu * Lock the per-process spinlock prior to dropping the PROC_LOCK 457184667Sdavidxu * to avoid a signal delivery race. PROC_LOCK, PROC_SLOCK, and 458209612Sjhb * thread_lock() are currently held in tdsendsignal(). 459184667Sdavidxu */ 460184667Sdavidxu PROC_SLOCK(p); 461170294Sjeff mtx_lock_spin(&sc->sc_lock); 462184667Sdavidxu PROC_UNLOCK(p); 463170294Sjeff thread_lock(td); 464184667Sdavidxu PROC_SUNLOCK(p); 465185502Sdavidxu if (ret == 0) { 466185502Sdavidxu sleepq_switch(wchan, pri); 467185502Sdavidxu return (0); 468185502Sdavidxu } 469211523Sdavidxuout: 470155936Sdavidxu /* 471155936Sdavidxu * There were pending signals and this thread is still 472155936Sdavidxu * on the sleep queue, remove it from the sleep queue. 473155936Sdavidxu */ 474170294Sjeff if (TD_ON_SLEEPQ(td)) { 475170294Sjeff sq = sleepq_lookup(wchan); 476181334Sjhb if (sleepq_resume_thread(sq, td, 0)) { 477181334Sjhb#ifdef INVARIANTS 478181334Sjhb /* 479181334Sjhb * This thread hasn't gone to sleep yet, so it 480181334Sjhb * should not be swapped out. 481181334Sjhb */ 482181334Sjhb panic("not waking up swapper"); 483181334Sjhb#endif 484181334Sjhb } 485170294Sjeff } 486170294Sjeff mtx_unlock_spin(&sc->sc_lock); 487170294Sjeff MPASS(td->td_lock != &sc->sc_lock); 488155741Sdavidxu return (ret); 489126324Sjhb} 490126324Sjhb 491126324Sjhb/* 492170294Sjeff * Switches to another thread if we are still asleep on a sleep queue. 493170294Sjeff * Returns with thread lock. 494126324Sjhb */ 495126324Sjhbstatic void 496177085Sjeffsleepq_switch(void *wchan, int pri) 497126324Sjhb{ 498126324Sjhb struct sleepqueue_chain *sc; 499175654Sjhb struct sleepqueue *sq; 500126324Sjhb struct thread *td; 501126324Sjhb 502126324Sjhb td = curthread; 503126324Sjhb sc = SC_LOOKUP(wchan); 504126324Sjhb mtx_assert(&sc->sc_lock, MA_OWNED); 505170294Sjeff THREAD_LOCK_ASSERT(td, MA_OWNED); 506175654Sjhb 507175654Sjhb /* 508175654Sjhb * If we have a sleep queue, then we've already been woken up, so 509175654Sjhb * just return. 510175654Sjhb */ 511126324Sjhb if (td->td_sleepqueue != NULL) { 512126324Sjhb mtx_unlock_spin(&sc->sc_lock); 513126324Sjhb return; 514126324Sjhb } 515175654Sjhb 516175654Sjhb /* 517175654Sjhb * If TDF_TIMEOUT is set, then our sleep has been timed out 518175654Sjhb * already but we are still on the sleep queue, so dequeue the 519175654Sjhb * thread and return. 520175654Sjhb */ 521175654Sjhb if (td->td_flags & TDF_TIMEOUT) { 522175654Sjhb MPASS(TD_ON_SLEEPQ(td)); 523175654Sjhb sq = sleepq_lookup(wchan); 524181334Sjhb if (sleepq_resume_thread(sq, td, 0)) { 525181334Sjhb#ifdef INVARIANTS 526181334Sjhb /* 527181334Sjhb * This thread hasn't gone to sleep yet, so it 528181334Sjhb * should not be swapped out. 529181334Sjhb */ 530181334Sjhb panic("not waking up swapper"); 531181334Sjhb#endif 532181334Sjhb } 533175654Sjhb mtx_unlock_spin(&sc->sc_lock); 534175654Sjhb return; 535175654Sjhb } 536177372Sjeff#ifdef SLEEPQUEUE_PROFILING 537177372Sjeff if (prof_enabled) 538177372Sjeff sleepq_profile(td->td_wmesg); 539177372Sjeff#endif 540177085Sjeff MPASS(td->td_sleepqueue == NULL); 541177085Sjeff sched_sleep(td, pri); 542170294Sjeff thread_lock_set(td, &sc->sc_lock); 543235459Srstone SDT_PROBE0(sched, , , sleep); 544126324Sjhb TD_SET_SLEEPING(td); 545178272Sjeff mi_switch(SW_VOL | SWT_SLEEPQ, NULL); 546126324Sjhb KASSERT(TD_IS_RUNNING(td), ("running but not TDS_RUNNING")); 547129241Sbde CTR3(KTR_PROC, "sleepq resume: thread %p (pid %ld, %s)", 548173600Sjulian (void *)td, (long)td->td_proc->p_pid, (void *)td->td_name); 549126324Sjhb} 550126324Sjhb 551126324Sjhb/* 552126324Sjhb * Check to see if we timed out. 553126324Sjhb */ 554126324Sjhbstatic int 555126324Sjhbsleepq_check_timeout(void) 556126324Sjhb{ 557126324Sjhb struct thread *td; 558126324Sjhb 559126324Sjhb td = curthread; 560170294Sjeff THREAD_LOCK_ASSERT(td, MA_OWNED); 561126324Sjhb 562126324Sjhb /* 563126324Sjhb * If TDF_TIMEOUT is set, we timed out. 564126324Sjhb */ 565126324Sjhb if (td->td_flags & TDF_TIMEOUT) { 566126324Sjhb td->td_flags &= ~TDF_TIMEOUT; 567126324Sjhb return (EWOULDBLOCK); 568126324Sjhb } 569126324Sjhb 570126324Sjhb /* 571126324Sjhb * If TDF_TIMOFAIL is set, the timeout ran after we had 572126324Sjhb * already been woken up. 573126324Sjhb */ 574126324Sjhb if (td->td_flags & TDF_TIMOFAIL) 575126324Sjhb td->td_flags &= ~TDF_TIMOFAIL; 576126324Sjhb 577126324Sjhb /* 578126324Sjhb * If callout_stop() fails, then the timeout is running on 579126324Sjhb * another CPU, so synchronize with it to avoid having it 580126324Sjhb * accidentally wake up a subsequent sleep. 581126324Sjhb */ 582126324Sjhb else if (callout_stop(&td->td_slpcallout) == 0) { 583126324Sjhb td->td_flags |= TDF_TIMEOUT; 584126324Sjhb TD_SET_SLEEPING(td); 585178272Sjeff mi_switch(SW_INVOL | SWT_SLEEPQTIMO, NULL); 586126324Sjhb } 587126324Sjhb return (0); 588126324Sjhb} 589126324Sjhb 590126324Sjhb/* 591126324Sjhb * Check to see if we were awoken by a signal. 592126324Sjhb */ 593126324Sjhbstatic int 594126324Sjhbsleepq_check_signals(void) 595126324Sjhb{ 596126324Sjhb struct thread *td; 597126324Sjhb 598126324Sjhb td = curthread; 599170294Sjeff THREAD_LOCK_ASSERT(td, MA_OWNED); 600126324Sjhb 601126324Sjhb /* We are no longer in an interruptible sleep. */ 602155741Sdavidxu if (td->td_flags & TDF_SINTR) 603246417Sjhb td->td_flags &= ~TDF_SINTR; 604126324Sjhb 605155741Sdavidxu if (td->td_flags & TDF_SLEEPABORT) { 606155741Sdavidxu td->td_flags &= ~TDF_SLEEPABORT; 607155741Sdavidxu return (td->td_intrval); 608155741Sdavidxu } 609155741Sdavidxu 610126324Sjhb return (0); 611126324Sjhb} 612126324Sjhb 613126324Sjhb/* 614126324Sjhb * Block the current thread until it is awakened from its sleep queue. 615126324Sjhb */ 616126324Sjhbvoid 617177085Sjeffsleepq_wait(void *wchan, int pri) 618126324Sjhb{ 619170294Sjeff struct thread *td; 620126324Sjhb 621170294Sjeff td = curthread; 622170294Sjeff MPASS(!(td->td_flags & TDF_SINTR)); 623170294Sjeff thread_lock(td); 624177085Sjeff sleepq_switch(wchan, pri); 625170294Sjeff thread_unlock(td); 626126324Sjhb} 627126324Sjhb 628126324Sjhb/* 629126324Sjhb * Block the current thread until it is awakened from its sleep queue 630126324Sjhb * or it is interrupted by a signal. 631126324Sjhb */ 632126324Sjhbint 633177085Sjeffsleepq_wait_sig(void *wchan, int pri) 634126324Sjhb{ 635155741Sdavidxu int rcatch; 636126324Sjhb int rval; 637126324Sjhb 638177085Sjeff rcatch = sleepq_catch_signals(wchan, pri); 639126324Sjhb rval = sleepq_check_signals(); 640170294Sjeff thread_unlock(curthread); 641155741Sdavidxu if (rcatch) 642155741Sdavidxu return (rcatch); 643126324Sjhb return (rval); 644126324Sjhb} 645126324Sjhb 646126324Sjhb/* 647126324Sjhb * Block the current thread until it is awakened from its sleep queue 648126324Sjhb * or it times out while waiting. 649126324Sjhb */ 650126324Sjhbint 651177085Sjeffsleepq_timedwait(void *wchan, int pri) 652126324Sjhb{ 653170294Sjeff struct thread *td; 654126324Sjhb int rval; 655126324Sjhb 656170294Sjeff td = curthread; 657170294Sjeff MPASS(!(td->td_flags & TDF_SINTR)); 658170294Sjeff thread_lock(td); 659177085Sjeff sleepq_switch(wchan, pri); 660126324Sjhb rval = sleepq_check_timeout(); 661170294Sjeff thread_unlock(td); 662170294Sjeff 663131249Sjhb return (rval); 664126324Sjhb} 665126324Sjhb 666126324Sjhb/* 667126324Sjhb * Block the current thread until it is awakened from its sleep queue, 668126324Sjhb * it is interrupted by a signal, or it times out waiting to be awakened. 669126324Sjhb */ 670126324Sjhbint 671177085Sjeffsleepq_timedwait_sig(void *wchan, int pri) 672126324Sjhb{ 673155741Sdavidxu int rcatch, rvalt, rvals; 674126324Sjhb 675177085Sjeff rcatch = sleepq_catch_signals(wchan, pri); 676126324Sjhb rvalt = sleepq_check_timeout(); 677126324Sjhb rvals = sleepq_check_signals(); 678170294Sjeff thread_unlock(curthread); 679155741Sdavidxu if (rcatch) 680155741Sdavidxu return (rcatch); 681155741Sdavidxu if (rvals) 682126324Sjhb return (rvals); 683155741Sdavidxu return (rvalt); 684126324Sjhb} 685126324Sjhb 686126324Sjhb/* 687201879Sattilio * Returns the type of sleepqueue given a waitchannel. 688201879Sattilio */ 689201879Sattilioint 690201879Sattiliosleepq_type(void *wchan) 691201879Sattilio{ 692201879Sattilio struct sleepqueue *sq; 693201879Sattilio int type; 694201879Sattilio 695201879Sattilio MPASS(wchan != NULL); 696201879Sattilio 697201879Sattilio sleepq_lock(wchan); 698201879Sattilio sq = sleepq_lookup(wchan); 699201879Sattilio if (sq == NULL) { 700201879Sattilio sleepq_release(wchan); 701201879Sattilio return (-1); 702201879Sattilio } 703201879Sattilio type = sq->sq_type; 704201879Sattilio sleepq_release(wchan); 705201879Sattilio return (type); 706201879Sattilio} 707201879Sattilio 708201879Sattilio/* 709145056Sjhb * Removes a thread from a sleep queue and makes it 710145056Sjhb * runnable. 711126324Sjhb */ 712181334Sjhbstatic int 713145056Sjhbsleepq_resume_thread(struct sleepqueue *sq, struct thread *td, int pri) 714126324Sjhb{ 715126324Sjhb struct sleepqueue_chain *sc; 716126324Sjhb 717126324Sjhb MPASS(td != NULL); 718126324Sjhb MPASS(sq->sq_wchan != NULL); 719126324Sjhb MPASS(td->td_wchan == sq->sq_wchan); 720165272Skmacy MPASS(td->td_sqqueue < NR_SLEEPQS && td->td_sqqueue >= 0); 721170294Sjeff THREAD_LOCK_ASSERT(td, MA_OWNED); 722126324Sjhb sc = SC_LOOKUP(sq->sq_wchan); 723126324Sjhb mtx_assert(&sc->sc_lock, MA_OWNED); 724126324Sjhb 725235459Srstone SDT_PROBE2(sched, , , wakeup, td, td->td_proc); 726235459Srstone 727126324Sjhb /* Remove the thread from the queue. */ 728200447Sattilio sq->sq_blockedcnt[td->td_sqqueue]--; 729165272Skmacy TAILQ_REMOVE(&sq->sq_blocked[td->td_sqqueue], td, td_slpq); 730126324Sjhb 731126324Sjhb /* 732126324Sjhb * Get a sleep queue for this thread. If this is the last waiter, 733126324Sjhb * use the queue itself and take it out of the chain, otherwise, 734126324Sjhb * remove a queue from the free list. 735126324Sjhb */ 736126324Sjhb if (LIST_EMPTY(&sq->sq_free)) { 737126324Sjhb td->td_sleepqueue = sq; 738126324Sjhb#ifdef INVARIANTS 739126324Sjhb sq->sq_wchan = NULL; 740126324Sjhb#endif 741131259Sjhb#ifdef SLEEPQUEUE_PROFILING 742131259Sjhb sc->sc_depth--; 743131259Sjhb#endif 744126324Sjhb } else 745126324Sjhb td->td_sleepqueue = LIST_FIRST(&sq->sq_free); 746126324Sjhb LIST_REMOVE(td->td_sleepqueue, sq_hash); 747126324Sjhb 748129188Sjhb td->td_wmesg = NULL; 749129188Sjhb td->td_wchan = NULL; 750246417Sjhb td->td_flags &= ~TDF_SINTR; 751129188Sjhb 752129241Sbde CTR3(KTR_PROC, "sleepq_wakeup: thread %p (pid %ld, %s)", 753173600Sjulian (void *)td, (long)td->td_proc->p_pid, td->td_name); 754126324Sjhb 755126324Sjhb /* Adjust priority if requested. */ 756177085Sjeff MPASS(pri == 0 || (pri >= PRI_MIN && pri <= PRI_MAX)); 757217410Sjhb if (pri != 0 && td->td_priority > pri && 758217410Sjhb PRI_BASE(td->td_pri_class) == PRI_TIMESHARE) 759136439Sups sched_prio(td, pri); 760184653Sjhb 761184653Sjhb /* 762184653Sjhb * Note that thread td might not be sleeping if it is running 763184653Sjhb * sleepq_catch_signals() on another CPU or is blocked on its 764184653Sjhb * proc lock to check signals. There's no need to mark the 765184653Sjhb * thread runnable in that case. 766184653Sjhb */ 767184653Sjhb if (TD_IS_SLEEPING(td)) { 768184653Sjhb TD_CLR_SLEEPING(td); 769184653Sjhb return (setrunnable(td)); 770184653Sjhb } 771184653Sjhb return (0); 772126324Sjhb} 773126324Sjhb 774169666Sjeff#ifdef INVARIANTS 775126324Sjhb/* 776169666Sjeff * UMA zone item deallocator. 777169666Sjeff */ 778169666Sjeffstatic void 779169666Sjeffsleepq_dtor(void *mem, int size, void *arg) 780169666Sjeff{ 781169666Sjeff struct sleepqueue *sq; 782169666Sjeff int i; 783169666Sjeff 784169666Sjeff sq = mem; 785200447Sattilio for (i = 0; i < NR_SLEEPQS; i++) { 786169666Sjeff MPASS(TAILQ_EMPTY(&sq->sq_blocked[i])); 787200447Sattilio MPASS(sq->sq_blockedcnt[i] == 0); 788200447Sattilio } 789169666Sjeff} 790169666Sjeff#endif 791169666Sjeff 792169666Sjeff/* 793169666Sjeff * UMA zone item initializer. 794169666Sjeff */ 795169666Sjeffstatic int 796169666Sjeffsleepq_init(void *mem, int size, int flags) 797169666Sjeff{ 798169666Sjeff struct sleepqueue *sq; 799169666Sjeff int i; 800169666Sjeff 801169666Sjeff bzero(mem, size); 802169666Sjeff sq = mem; 803200447Sattilio for (i = 0; i < NR_SLEEPQS; i++) { 804169666Sjeff TAILQ_INIT(&sq->sq_blocked[i]); 805200447Sattilio sq->sq_blockedcnt[i] = 0; 806200447Sattilio } 807169666Sjeff LIST_INIT(&sq->sq_free); 808169666Sjeff return (0); 809169666Sjeff} 810169666Sjeff 811169666Sjeff/* 812126324Sjhb * Find the highest priority thread sleeping on a wait channel and resume it. 813126324Sjhb */ 814181334Sjhbint 815165272Skmacysleepq_signal(void *wchan, int flags, int pri, int queue) 816126324Sjhb{ 817126324Sjhb struct sleepqueue *sq; 818137277Sjhb struct thread *td, *besttd; 819181334Sjhb int wakeup_swapper; 820126324Sjhb 821126324Sjhb CTR2(KTR_PROC, "sleepq_signal(%p, %d)", wchan, flags); 822126324Sjhb KASSERT(wchan != NULL, ("%s: invalid NULL wait channel", __func__)); 823165272Skmacy MPASS((queue >= 0) && (queue < NR_SLEEPQS)); 824126324Sjhb sq = sleepq_lookup(wchan); 825170294Sjeff if (sq == NULL) 826181334Sjhb return (0); 827134013Sjhb KASSERT(sq->sq_type == (flags & SLEEPQ_TYPE), 828126324Sjhb ("%s: mismatch between sleep/wakeup and cv_*", __func__)); 829129188Sjhb 830137277Sjhb /* 831137277Sjhb * Find the highest priority thread on the queue. If there is a 832137277Sjhb * tie, use the thread that first appears in the queue as it has 833137277Sjhb * been sleeping the longest since threads are always added to 834137277Sjhb * the tail of sleep queues. 835137277Sjhb */ 836137277Sjhb besttd = NULL; 837165272Skmacy TAILQ_FOREACH(td, &sq->sq_blocked[queue], td_slpq) { 838137277Sjhb if (besttd == NULL || td->td_priority < besttd->td_priority) 839137277Sjhb besttd = td; 840137277Sjhb } 841137277Sjhb MPASS(besttd != NULL); 842170294Sjeff thread_lock(besttd); 843181334Sjhb wakeup_swapper = sleepq_resume_thread(sq, besttd, pri); 844170294Sjeff thread_unlock(besttd); 845181334Sjhb return (wakeup_swapper); 846126324Sjhb} 847126324Sjhb 848126324Sjhb/* 849126324Sjhb * Resume all threads sleeping on a specified wait channel. 850126324Sjhb */ 851181334Sjhbint 852165272Skmacysleepq_broadcast(void *wchan, int flags, int pri, int queue) 853126324Sjhb{ 854126324Sjhb struct sleepqueue *sq; 855182875Sjhb struct thread *td, *tdn; 856181334Sjhb int wakeup_swapper; 857126324Sjhb 858126324Sjhb CTR2(KTR_PROC, "sleepq_broadcast(%p, %d)", wchan, flags); 859126324Sjhb KASSERT(wchan != NULL, ("%s: invalid NULL wait channel", __func__)); 860165272Skmacy MPASS((queue >= 0) && (queue < NR_SLEEPQS)); 861126324Sjhb sq = sleepq_lookup(wchan); 862177085Sjeff if (sq == NULL) 863181334Sjhb return (0); 864134013Sjhb KASSERT(sq->sq_type == (flags & SLEEPQ_TYPE), 865126324Sjhb ("%s: mismatch between sleep/wakeup and cv_*", __func__)); 866129188Sjhb 867145056Sjhb /* Resume all blocked threads on the sleep queue. */ 868181334Sjhb wakeup_swapper = 0; 869182875Sjhb TAILQ_FOREACH_SAFE(td, &sq->sq_blocked[queue], td_slpq, tdn) { 870170294Sjeff thread_lock(td); 871181334Sjhb if (sleepq_resume_thread(sq, td, pri)) 872181334Sjhb wakeup_swapper = 1; 873170294Sjeff thread_unlock(td); 874170294Sjeff } 875181334Sjhb return (wakeup_swapper); 876126324Sjhb} 877126324Sjhb 878126324Sjhb/* 879126324Sjhb * Time sleeping threads out. When the timeout expires, the thread is 880126324Sjhb * removed from the sleep queue and made runnable if it is still asleep. 881126324Sjhb */ 882126324Sjhbstatic void 883126324Sjhbsleepq_timeout(void *arg) 884126324Sjhb{ 885170294Sjeff struct sleepqueue_chain *sc; 886126324Sjhb struct sleepqueue *sq; 887126324Sjhb struct thread *td; 888126324Sjhb void *wchan; 889181334Sjhb int wakeup_swapper; 890126324Sjhb 891129241Sbde td = arg; 892181334Sjhb wakeup_swapper = 0; 893129241Sbde CTR3(KTR_PROC, "sleepq_timeout: thread %p (pid %ld, %s)", 894173600Sjulian (void *)td, (long)td->td_proc->p_pid, (void *)td->td_name); 895126324Sjhb 896126324Sjhb /* 897126324Sjhb * First, see if the thread is asleep and get the wait channel if 898126324Sjhb * it is. 899126324Sjhb */ 900170294Sjeff thread_lock(td); 901170294Sjeff if (TD_IS_SLEEPING(td) && TD_ON_SLEEPQ(td)) { 902126324Sjhb wchan = td->td_wchan; 903170294Sjeff sc = SC_LOOKUP(wchan); 904176078Sjeff THREAD_LOCKPTR_ASSERT(td, &sc->sc_lock); 905126324Sjhb sq = sleepq_lookup(wchan); 906170294Sjeff MPASS(sq != NULL); 907170294Sjeff td->td_flags |= TDF_TIMEOUT; 908181334Sjhb wakeup_swapper = sleepq_resume_thread(sq, td, 0); 909170294Sjeff thread_unlock(td); 910181334Sjhb if (wakeup_swapper) 911181334Sjhb kick_proc0(); 912170294Sjeff return; 913126324Sjhb } 914175654Sjhb 915126324Sjhb /* 916175654Sjhb * If the thread is on the SLEEPQ but isn't sleeping yet, it 917175654Sjhb * can either be on another CPU in between sleepq_add() and 918175654Sjhb * one of the sleepq_*wait*() routines or it can be in 919175654Sjhb * sleepq_catch_signals(). 920126324Sjhb */ 921126324Sjhb if (TD_ON_SLEEPQ(td)) { 922175664Sjhb td->td_flags |= TDF_TIMEOUT; 923170294Sjeff thread_unlock(td); 924126324Sjhb return; 925170294Sjeff } 926126324Sjhb 927126324Sjhb /* 928126324Sjhb * Now check for the edge cases. First, if TDF_TIMEOUT is set, 929126324Sjhb * then the other thread has already yielded to us, so clear 930126324Sjhb * the flag and resume it. If TDF_TIMEOUT is not set, then the 931126324Sjhb * we know that the other thread is not on a sleep queue, but it 932126324Sjhb * hasn't resumed execution yet. In that case, set TDF_TIMOFAIL 933126324Sjhb * to let it know that the timeout has already run and doesn't 934126324Sjhb * need to be canceled. 935126324Sjhb */ 936126324Sjhb if (td->td_flags & TDF_TIMEOUT) { 937127085Sjhb MPASS(TD_IS_SLEEPING(td)); 938126324Sjhb td->td_flags &= ~TDF_TIMEOUT; 939126324Sjhb TD_CLR_SLEEPING(td); 940181334Sjhb wakeup_swapper = setrunnable(td); 941126324Sjhb } else 942126324Sjhb td->td_flags |= TDF_TIMOFAIL; 943170294Sjeff thread_unlock(td); 944181334Sjhb if (wakeup_swapper) 945181334Sjhb kick_proc0(); 946126324Sjhb} 947126324Sjhb 948126324Sjhb/* 949126324Sjhb * Resumes a specific thread from the sleep queue associated with a specific 950126324Sjhb * wait channel if it is on that queue. 951126324Sjhb */ 952126324Sjhbvoid 953126324Sjhbsleepq_remove(struct thread *td, void *wchan) 954126324Sjhb{ 955126324Sjhb struct sleepqueue *sq; 956181334Sjhb int wakeup_swapper; 957126324Sjhb 958126324Sjhb /* 959126324Sjhb * Look up the sleep queue for this wait channel, then re-check 960126324Sjhb * that the thread is asleep on that channel, if it is not, then 961126324Sjhb * bail. 962126324Sjhb */ 963126324Sjhb MPASS(wchan != NULL); 964136445Sjhb sleepq_lock(wchan); 965126324Sjhb sq = sleepq_lookup(wchan); 966170294Sjeff /* 967170294Sjeff * We can not lock the thread here as it may be sleeping on a 968170294Sjeff * different sleepq. However, holding the sleepq lock for this 969170294Sjeff * wchan can guarantee that we do not miss a wakeup for this 970170294Sjeff * channel. The asserts below will catch any false positives. 971170294Sjeff */ 972126324Sjhb if (!TD_ON_SLEEPQ(td) || td->td_wchan != wchan) { 973126324Sjhb sleepq_release(wchan); 974126324Sjhb return; 975126324Sjhb } 976170294Sjeff /* Thread is asleep on sleep queue sq, so wake it up. */ 977170294Sjeff thread_lock(td); 978126324Sjhb MPASS(sq != NULL); 979170294Sjeff MPASS(td->td_wchan == wchan); 980181334Sjhb wakeup_swapper = sleepq_resume_thread(sq, td, 0); 981170294Sjeff thread_unlock(td); 982126324Sjhb sleepq_release(wchan); 983181334Sjhb if (wakeup_swapper) 984181334Sjhb kick_proc0(); 985126324Sjhb} 986126324Sjhb 987126324Sjhb/* 988129241Sbde * Abort a thread as if an interrupt had occurred. Only abort 989129241Sbde * interruptible waits (unfortunately it isn't safe to abort others). 990126324Sjhb */ 991181334Sjhbint 992155741Sdavidxusleepq_abort(struct thread *td, int intrval) 993126324Sjhb{ 994170294Sjeff struct sleepqueue *sq; 995126324Sjhb void *wchan; 996126324Sjhb 997170294Sjeff THREAD_LOCK_ASSERT(td, MA_OWNED); 998126324Sjhb MPASS(TD_ON_SLEEPQ(td)); 999126324Sjhb MPASS(td->td_flags & TDF_SINTR); 1000155741Sdavidxu MPASS(intrval == EINTR || intrval == ERESTART); 1001126324Sjhb 1002126324Sjhb /* 1003126324Sjhb * If the TDF_TIMEOUT flag is set, just leave. A 1004126324Sjhb * timeout is scheduled anyhow. 1005126324Sjhb */ 1006126324Sjhb if (td->td_flags & TDF_TIMEOUT) 1007181334Sjhb return (0); 1008126324Sjhb 1009129241Sbde CTR3(KTR_PROC, "sleepq_abort: thread %p (pid %ld, %s)", 1010173600Sjulian (void *)td, (long)td->td_proc->p_pid, (void *)td->td_name); 1011170294Sjeff td->td_intrval = intrval; 1012170294Sjeff td->td_flags |= TDF_SLEEPABORT; 1013170294Sjeff /* 1014170294Sjeff * If the thread has not slept yet it will find the signal in 1015170294Sjeff * sleepq_catch_signals() and call sleepq_resume_thread. Otherwise 1016170294Sjeff * we have to do it here. 1017170294Sjeff */ 1018170294Sjeff if (!TD_IS_SLEEPING(td)) 1019181334Sjhb return (0); 1020126324Sjhb wchan = td->td_wchan; 1021170294Sjeff MPASS(wchan != NULL); 1022170294Sjeff sq = sleepq_lookup(wchan); 1023170294Sjeff MPASS(sq != NULL); 1024170294Sjeff 1025170294Sjeff /* Thread is asleep on sleep queue sq, so wake it up. */ 1026181334Sjhb return (sleepq_resume_thread(sq, td, 0)); 1027126324Sjhb} 1028154936Sjhb 1029177372Sjeff#ifdef SLEEPQUEUE_PROFILING 1030177372Sjeff#define SLEEPQ_PROF_LOCATIONS 1024 1031212750Smdf#define SLEEPQ_SBUFSIZE 512 1032177372Sjeffstruct sleepq_prof { 1033177372Sjeff LIST_ENTRY(sleepq_prof) sp_link; 1034177372Sjeff const char *sp_wmesg; 1035177372Sjeff long sp_count; 1036177372Sjeff}; 1037177372Sjeff 1038177372SjeffLIST_HEAD(sqphead, sleepq_prof); 1039177372Sjeff 1040177372Sjeffstruct sqphead sleepq_prof_free; 1041177372Sjeffstruct sqphead sleepq_hash[SC_TABLESIZE]; 1042177372Sjeffstatic struct sleepq_prof sleepq_profent[SLEEPQ_PROF_LOCATIONS]; 1043177372Sjeffstatic struct mtx sleepq_prof_lock; 1044177372SjeffMTX_SYSINIT(sleepq_prof_lock, &sleepq_prof_lock, "sleepq_prof", MTX_SPIN); 1045177372Sjeff 1046177372Sjeffstatic void 1047177372Sjeffsleepq_profile(const char *wmesg) 1048177372Sjeff{ 1049177372Sjeff struct sleepq_prof *sp; 1050177372Sjeff 1051177372Sjeff mtx_lock_spin(&sleepq_prof_lock); 1052177372Sjeff if (prof_enabled == 0) 1053177372Sjeff goto unlock; 1054177372Sjeff LIST_FOREACH(sp, &sleepq_hash[SC_HASH(wmesg)], sp_link) 1055177372Sjeff if (sp->sp_wmesg == wmesg) 1056177372Sjeff goto done; 1057177372Sjeff sp = LIST_FIRST(&sleepq_prof_free); 1058177372Sjeff if (sp == NULL) 1059177372Sjeff goto unlock; 1060177372Sjeff sp->sp_wmesg = wmesg; 1061177372Sjeff LIST_REMOVE(sp, sp_link); 1062177372Sjeff LIST_INSERT_HEAD(&sleepq_hash[SC_HASH(wmesg)], sp, sp_link); 1063177372Sjeffdone: 1064177372Sjeff sp->sp_count++; 1065177372Sjeffunlock: 1066177372Sjeff mtx_unlock_spin(&sleepq_prof_lock); 1067177372Sjeff return; 1068177372Sjeff} 1069177372Sjeff 1070177372Sjeffstatic void 1071177372Sjeffsleepq_prof_reset(void) 1072177372Sjeff{ 1073177372Sjeff struct sleepq_prof *sp; 1074177372Sjeff int enabled; 1075177372Sjeff int i; 1076177372Sjeff 1077177372Sjeff mtx_lock_spin(&sleepq_prof_lock); 1078177372Sjeff enabled = prof_enabled; 1079177372Sjeff prof_enabled = 0; 1080177372Sjeff for (i = 0; i < SC_TABLESIZE; i++) 1081177372Sjeff LIST_INIT(&sleepq_hash[i]); 1082177372Sjeff LIST_INIT(&sleepq_prof_free); 1083177372Sjeff for (i = 0; i < SLEEPQ_PROF_LOCATIONS; i++) { 1084177372Sjeff sp = &sleepq_profent[i]; 1085177372Sjeff sp->sp_wmesg = NULL; 1086177372Sjeff sp->sp_count = 0; 1087177372Sjeff LIST_INSERT_HEAD(&sleepq_prof_free, sp, sp_link); 1088177372Sjeff } 1089177372Sjeff prof_enabled = enabled; 1090177372Sjeff mtx_unlock_spin(&sleepq_prof_lock); 1091177372Sjeff} 1092177372Sjeff 1093177372Sjeffstatic int 1094177372Sjeffenable_sleepq_prof(SYSCTL_HANDLER_ARGS) 1095177372Sjeff{ 1096177372Sjeff int error, v; 1097177372Sjeff 1098177372Sjeff v = prof_enabled; 1099177372Sjeff error = sysctl_handle_int(oidp, &v, v, req); 1100177372Sjeff if (error) 1101177372Sjeff return (error); 1102177372Sjeff if (req->newptr == NULL) 1103177372Sjeff return (error); 1104177372Sjeff if (v == prof_enabled) 1105177372Sjeff return (0); 1106177372Sjeff if (v == 1) 1107177372Sjeff sleepq_prof_reset(); 1108177372Sjeff mtx_lock_spin(&sleepq_prof_lock); 1109177372Sjeff prof_enabled = !!v; 1110177372Sjeff mtx_unlock_spin(&sleepq_prof_lock); 1111177372Sjeff 1112177372Sjeff return (0); 1113177372Sjeff} 1114177372Sjeff 1115177372Sjeffstatic int 1116177372Sjeffreset_sleepq_prof_stats(SYSCTL_HANDLER_ARGS) 1117177372Sjeff{ 1118177372Sjeff int error, v; 1119177372Sjeff 1120177372Sjeff v = 0; 1121177372Sjeff error = sysctl_handle_int(oidp, &v, 0, req); 1122177372Sjeff if (error) 1123177372Sjeff return (error); 1124177372Sjeff if (req->newptr == NULL) 1125177372Sjeff return (error); 1126177372Sjeff if (v == 0) 1127177372Sjeff return (0); 1128177372Sjeff sleepq_prof_reset(); 1129177372Sjeff 1130177372Sjeff return (0); 1131177372Sjeff} 1132177372Sjeff 1133177372Sjeffstatic int 1134177372Sjeffdump_sleepq_prof_stats(SYSCTL_HANDLER_ARGS) 1135177372Sjeff{ 1136177372Sjeff struct sleepq_prof *sp; 1137177372Sjeff struct sbuf *sb; 1138177372Sjeff int enabled; 1139177372Sjeff int error; 1140177372Sjeff int i; 1141177372Sjeff 1142217916Smdf error = sysctl_wire_old_buffer(req, 0); 1143217916Smdf if (error != 0) 1144217916Smdf return (error); 1145212750Smdf sb = sbuf_new_for_sysctl(NULL, NULL, SLEEPQ_SBUFSIZE, req); 1146177372Sjeff sbuf_printf(sb, "\nwmesg\tcount\n"); 1147177372Sjeff enabled = prof_enabled; 1148177372Sjeff mtx_lock_spin(&sleepq_prof_lock); 1149177372Sjeff prof_enabled = 0; 1150177372Sjeff mtx_unlock_spin(&sleepq_prof_lock); 1151177372Sjeff for (i = 0; i < SC_TABLESIZE; i++) { 1152177372Sjeff LIST_FOREACH(sp, &sleepq_hash[i], sp_link) { 1153177372Sjeff sbuf_printf(sb, "%s\t%ld\n", 1154177372Sjeff sp->sp_wmesg, sp->sp_count); 1155177372Sjeff } 1156177372Sjeff } 1157177372Sjeff mtx_lock_spin(&sleepq_prof_lock); 1158177372Sjeff prof_enabled = enabled; 1159177372Sjeff mtx_unlock_spin(&sleepq_prof_lock); 1160177372Sjeff 1161212750Smdf error = sbuf_finish(sb); 1162177372Sjeff sbuf_delete(sb); 1163177372Sjeff return (error); 1164177372Sjeff} 1165177372Sjeff 1166177372SjeffSYSCTL_PROC(_debug_sleepq, OID_AUTO, stats, CTLTYPE_STRING | CTLFLAG_RD, 1167177372Sjeff NULL, 0, dump_sleepq_prof_stats, "A", "Sleepqueue profiling statistics"); 1168177372SjeffSYSCTL_PROC(_debug_sleepq, OID_AUTO, reset, CTLTYPE_INT | CTLFLAG_RW, 1169177372Sjeff NULL, 0, reset_sleepq_prof_stats, "I", 1170177372Sjeff "Reset sleepqueue profiling statistics"); 1171177372SjeffSYSCTL_PROC(_debug_sleepq, OID_AUTO, enable, CTLTYPE_INT | CTLFLAG_RW, 1172177372Sjeff NULL, 0, enable_sleepq_prof, "I", "Enable sleepqueue profiling"); 1173177372Sjeff#endif 1174177372Sjeff 1175154936Sjhb#ifdef DDB 1176154936SjhbDB_SHOW_COMMAND(sleepq, db_show_sleepqueue) 1177154936Sjhb{ 1178154936Sjhb struct sleepqueue_chain *sc; 1179154936Sjhb struct sleepqueue *sq; 1180154944Simp#ifdef INVARIANTS 1181154936Sjhb struct lock_object *lock; 1182154944Simp#endif 1183154936Sjhb struct thread *td; 1184154936Sjhb void *wchan; 1185154936Sjhb int i; 1186154936Sjhb 1187154936Sjhb if (!have_addr) 1188154936Sjhb return; 1189154936Sjhb 1190154936Sjhb /* 1191154936Sjhb * First, see if there is an active sleep queue for the wait channel 1192154936Sjhb * indicated by the address. 1193154936Sjhb */ 1194154936Sjhb wchan = (void *)addr; 1195154936Sjhb sc = SC_LOOKUP(wchan); 1196154936Sjhb LIST_FOREACH(sq, &sc->sc_queues, sq_hash) 1197154936Sjhb if (sq->sq_wchan == wchan) 1198154936Sjhb goto found; 1199154936Sjhb 1200154936Sjhb /* 1201154936Sjhb * Second, see if there is an active sleep queue at the address 1202154936Sjhb * indicated. 1203154936Sjhb */ 1204154936Sjhb for (i = 0; i < SC_TABLESIZE; i++) 1205154936Sjhb LIST_FOREACH(sq, &sleepq_chains[i].sc_queues, sq_hash) { 1206154936Sjhb if (sq == (struct sleepqueue *)addr) 1207154936Sjhb goto found; 1208154936Sjhb } 1209154936Sjhb 1210154936Sjhb db_printf("Unable to locate a sleep queue via %p\n", (void *)addr); 1211154936Sjhb return; 1212154936Sjhbfound: 1213154936Sjhb db_printf("Wait channel: %p\n", sq->sq_wchan); 1214201879Sattilio db_printf("Queue type: %d\n", sq->sq_type); 1215154936Sjhb#ifdef INVARIANTS 1216154936Sjhb if (sq->sq_lock) { 1217164325Spjd lock = sq->sq_lock; 1218154936Sjhb db_printf("Associated Interlock: %p - (%s) %s\n", lock, 1219154936Sjhb LOCK_CLASS(lock)->lc_name, lock->lo_name); 1220154936Sjhb } 1221154936Sjhb#endif 1222154936Sjhb db_printf("Blocked threads:\n"); 1223165272Skmacy for (i = 0; i < NR_SLEEPQS; i++) { 1224165272Skmacy db_printf("\nQueue[%d]:\n", i); 1225165272Skmacy if (TAILQ_EMPTY(&sq->sq_blocked[i])) 1226165272Skmacy db_printf("\tempty\n"); 1227165272Skmacy else 1228165272Skmacy TAILQ_FOREACH(td, &sq->sq_blocked[0], 1229165272Skmacy td_slpq) { 1230165272Skmacy db_printf("\t%p (tid %d, pid %d, \"%s\")\n", td, 1231165272Skmacy td->td_tid, td->td_proc->p_pid, 1232180930Sjhb td->td_name); 1233165272Skmacy } 1234200447Sattilio db_printf("(expected: %u)\n", sq->sq_blockedcnt[i]); 1235165272Skmacy } 1236154936Sjhb} 1237157823Sjhb 1238157823Sjhb/* Alias 'show sleepqueue' to 'show sleepq'. */ 1239183054SsamDB_SHOW_ALIAS(sleepqueue, db_show_sleepqueue); 1240154936Sjhb#endif 1241