1/*- 2 * Copyright (c) 1998 Berkeley Software Design, Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 3. Berkeley Software Design Inc's name may not be used to endorse or 13 * promote products derived from this software without specific prior 14 * written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * from BSDI $Id: mutex_witness.c,v 1.1.2.20 2000/04/27 03:10:27 cp Exp $ 29 * and BSDI $Id: synch_machdep.c,v 2.3.2.39 2000/04/27 03:10:25 cp Exp $ 30 */ 31 32/* 33 * Implementation of turnstiles used to hold queue of threads blocked on 34 * non-sleepable locks. Sleepable locks use condition variables to 35 * implement their queues. Turnstiles differ from a sleep queue in that 36 * turnstile queue's are assigned to a lock held by an owning thread. Thus, 37 * when one thread is enqueued onto a turnstile, it can lend its priority 38 * to the owning thread. 39 * 40 * We wish to avoid bloating locks with an embedded turnstile and we do not 41 * want to use back-pointers in the locks for the same reason. Thus, we 42 * use a similar approach to that of Solaris 7 as described in Solaris 43 * Internals by Jim Mauro and Richard McDougall. Turnstiles are looked up 44 * in a hash table based on the address of the lock. Each entry in the 45 * hash table is a linked-lists of turnstiles and is called a turnstile 46 * chain. Each chain contains a spin mutex that protects all of the 47 * turnstiles in the chain. 48 * 49 * Each time a thread is created, a turnstile is allocated from a UMA zone 50 * and attached to that thread. When a thread blocks on a lock, if it is the 51 * first thread to block, it lends its turnstile to the lock. If the lock 52 * already has a turnstile, then it gives its turnstile to the lock's 53 * turnstile's free list. When a thread is woken up, it takes a turnstile from 54 * the free list if there are any other waiters. If it is the only thread 55 * blocked on the lock, then it reclaims the turnstile associated with the lock 56 * and removes it from the hash table. 57 */ 58 59#include <sys/cdefs.h>
| 1/*- 2 * Copyright (c) 1998 Berkeley Software Design, Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 3. Berkeley Software Design Inc's name may not be used to endorse or 13 * promote products derived from this software without specific prior 14 * written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * from BSDI $Id: mutex_witness.c,v 1.1.2.20 2000/04/27 03:10:27 cp Exp $ 29 * and BSDI $Id: synch_machdep.c,v 2.3.2.39 2000/04/27 03:10:25 cp Exp $ 30 */ 31 32/* 33 * Implementation of turnstiles used to hold queue of threads blocked on 34 * non-sleepable locks. Sleepable locks use condition variables to 35 * implement their queues. Turnstiles differ from a sleep queue in that 36 * turnstile queue's are assigned to a lock held by an owning thread. Thus, 37 * when one thread is enqueued onto a turnstile, it can lend its priority 38 * to the owning thread. 39 * 40 * We wish to avoid bloating locks with an embedded turnstile and we do not 41 * want to use back-pointers in the locks for the same reason. Thus, we 42 * use a similar approach to that of Solaris 7 as described in Solaris 43 * Internals by Jim Mauro and Richard McDougall. Turnstiles are looked up 44 * in a hash table based on the address of the lock. Each entry in the 45 * hash table is a linked-lists of turnstiles and is called a turnstile 46 * chain. Each chain contains a spin mutex that protects all of the 47 * turnstiles in the chain. 48 * 49 * Each time a thread is created, a turnstile is allocated from a UMA zone 50 * and attached to that thread. When a thread blocks on a lock, if it is the 51 * first thread to block, it lends its turnstile to the lock. If the lock 52 * already has a turnstile, then it gives its turnstile to the lock's 53 * turnstile's free list. When a thread is woken up, it takes a turnstile from 54 * the free list if there are any other waiters. If it is the only thread 55 * blocked on the lock, then it reclaims the turnstile associated with the lock 56 * and removes it from the hash table. 57 */ 58 59#include <sys/cdefs.h>
|
60__FBSDID("$FreeBSD: head/sys/kern/subr_turnstile.c 169666 2007-05-18 06:32:24Z jeff $");
| 60__FBSDID("$FreeBSD: head/sys/kern/subr_turnstile.c 170295 2007-06-04 23:51:44Z jeff $");
|
61 62#include "opt_ddb.h" 63#include "opt_turnstile_profiling.h" 64 65#include <sys/param.h> 66#include <sys/systm.h> 67#include <sys/kernel.h> 68#include <sys/ktr.h> 69#include <sys/lock.h> 70#include <sys/mutex.h> 71#include <sys/proc.h> 72#include <sys/queue.h> 73#include <sys/sched.h> 74#include <sys/sysctl.h> 75#include <sys/turnstile.h> 76 77#include <vm/uma.h> 78 79#ifdef DDB 80#include <sys/kdb.h> 81#include <ddb/ddb.h> 82#include <sys/lockmgr.h> 83#include <sys/sx.h> 84#endif 85 86/* 87 * Constants for the hash table of turnstile chains. TC_SHIFT is a magic 88 * number chosen because the sleep queue's use the same value for the 89 * shift. Basically, we ignore the lower 8 bits of the address. 90 * TC_TABLESIZE must be a power of two for TC_MASK to work properly. 91 */ 92#define TC_TABLESIZE 128 /* Must be power of 2. */ 93#define TC_MASK (TC_TABLESIZE - 1) 94#define TC_SHIFT 8 95#define TC_HASH(lock) (((uintptr_t)(lock) >> TC_SHIFT) & TC_MASK) 96#define TC_LOOKUP(lock) &turnstile_chains[TC_HASH(lock)] 97 98/* 99 * There are three different lists of turnstiles as follows. The list 100 * connected by ts_link entries is a per-thread list of all the turnstiles 101 * attached to locks that we own. This is used to fixup our priority when 102 * a lock is released. The other two lists use the ts_hash entries. The 103 * first of these two is the turnstile chain list that a turnstile is on 104 * when it is attached to a lock. The second list to use ts_hash is the 105 * free list hung off of a turnstile that is attached to a lock. 106 * 107 * Each turnstile contains three lists of threads. The two ts_blocked lists 108 * are linked list of threads blocked on the turnstile's lock. One list is 109 * for exclusive waiters, and the other is for shared waiters. The 110 * ts_pending list is a linked list of threads previously awakened by 111 * turnstile_signal() or turnstile_wait() that are waiting to be put on 112 * the run queue. 113 * 114 * Locking key: 115 * c - turnstile chain lock 116 * q - td_contested lock 117 */ 118struct turnstile {
| 61 62#include "opt_ddb.h" 63#include "opt_turnstile_profiling.h" 64 65#include <sys/param.h> 66#include <sys/systm.h> 67#include <sys/kernel.h> 68#include <sys/ktr.h> 69#include <sys/lock.h> 70#include <sys/mutex.h> 71#include <sys/proc.h> 72#include <sys/queue.h> 73#include <sys/sched.h> 74#include <sys/sysctl.h> 75#include <sys/turnstile.h> 76 77#include <vm/uma.h> 78 79#ifdef DDB 80#include <sys/kdb.h> 81#include <ddb/ddb.h> 82#include <sys/lockmgr.h> 83#include <sys/sx.h> 84#endif 85 86/* 87 * Constants for the hash table of turnstile chains. TC_SHIFT is a magic 88 * number chosen because the sleep queue's use the same value for the 89 * shift. Basically, we ignore the lower 8 bits of the address. 90 * TC_TABLESIZE must be a power of two for TC_MASK to work properly. 91 */ 92#define TC_TABLESIZE 128 /* Must be power of 2. */ 93#define TC_MASK (TC_TABLESIZE - 1) 94#define TC_SHIFT 8 95#define TC_HASH(lock) (((uintptr_t)(lock) >> TC_SHIFT) & TC_MASK) 96#define TC_LOOKUP(lock) &turnstile_chains[TC_HASH(lock)] 97 98/* 99 * There are three different lists of turnstiles as follows. The list 100 * connected by ts_link entries is a per-thread list of all the turnstiles 101 * attached to locks that we own. This is used to fixup our priority when 102 * a lock is released. The other two lists use the ts_hash entries. The 103 * first of these two is the turnstile chain list that a turnstile is on 104 * when it is attached to a lock. The second list to use ts_hash is the 105 * free list hung off of a turnstile that is attached to a lock. 106 * 107 * Each turnstile contains three lists of threads. The two ts_blocked lists 108 * are linked list of threads blocked on the turnstile's lock. One list is 109 * for exclusive waiters, and the other is for shared waiters. The 110 * ts_pending list is a linked list of threads previously awakened by 111 * turnstile_signal() or turnstile_wait() that are waiting to be put on 112 * the run queue. 113 * 114 * Locking key: 115 * c - turnstile chain lock 116 * q - td_contested lock 117 */ 118struct turnstile {
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| 119 struct mtx ts_lock; /* Spin lock for self. */
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119 struct threadqueue ts_blocked[2]; /* (c + q) Blocked threads. */ 120 struct threadqueue ts_pending; /* (c) Pending threads. */ 121 LIST_ENTRY(turnstile) ts_hash; /* (c) Chain and free list. */ 122 LIST_ENTRY(turnstile) ts_link; /* (q) Contested locks. */ 123 LIST_HEAD(, turnstile) ts_free; /* (c) Free turnstiles. */ 124 struct lock_object *ts_lockobj; /* (c) Lock we reference. */ 125 struct thread *ts_owner; /* (c + q) Who owns the lock. */ 126}; 127 128struct turnstile_chain { 129 LIST_HEAD(, turnstile) tc_turnstiles; /* List of turnstiles. */ 130 struct mtx tc_lock; /* Spin lock for this chain. */ 131#ifdef TURNSTILE_PROFILING 132 u_int tc_depth; /* Length of tc_queues. */ 133 u_int tc_max_depth; /* Max length of tc_queues. */ 134#endif 135}; 136 137#ifdef TURNSTILE_PROFILING 138u_int turnstile_max_depth; 139SYSCTL_NODE(_debug, OID_AUTO, turnstile, CTLFLAG_RD, 0, "turnstile profiling"); 140SYSCTL_NODE(_debug_turnstile, OID_AUTO, chains, CTLFLAG_RD, 0, 141 "turnstile chain stats"); 142SYSCTL_UINT(_debug_turnstile, OID_AUTO, max_depth, CTLFLAG_RD, 143 &turnstile_max_depth, 0, "maxmimum depth achieved of a single chain"); 144#endif 145static struct mtx td_contested_lock; 146static struct turnstile_chain turnstile_chains[TC_TABLESIZE]; 147static uma_zone_t turnstile_zone; 148 149/* 150 * Prototypes for non-exported routines. 151 */ 152static void init_turnstile0(void *dummy); 153#ifdef TURNSTILE_PROFILING 154static void init_turnstile_profiling(void *arg); 155#endif 156static void propagate_priority(struct thread *td); 157static int turnstile_adjust_thread(struct turnstile *ts, 158 struct thread *td); 159static struct thread *turnstile_first_waiter(struct turnstile *ts); 160static void turnstile_setowner(struct turnstile *ts, struct thread *owner); 161#ifdef INVARIANTS 162static void turnstile_dtor(void *mem, int size, void *arg); 163#endif 164static int turnstile_init(void *mem, int size, int flags);
| 120 struct threadqueue ts_blocked[2]; /* (c + q) Blocked threads. */ 121 struct threadqueue ts_pending; /* (c) Pending threads. */ 122 LIST_ENTRY(turnstile) ts_hash; /* (c) Chain and free list. */ 123 LIST_ENTRY(turnstile) ts_link; /* (q) Contested locks. */ 124 LIST_HEAD(, turnstile) ts_free; /* (c) Free turnstiles. */ 125 struct lock_object *ts_lockobj; /* (c) Lock we reference. */ 126 struct thread *ts_owner; /* (c + q) Who owns the lock. */ 127}; 128 129struct turnstile_chain { 130 LIST_HEAD(, turnstile) tc_turnstiles; /* List of turnstiles. */ 131 struct mtx tc_lock; /* Spin lock for this chain. */ 132#ifdef TURNSTILE_PROFILING 133 u_int tc_depth; /* Length of tc_queues. */ 134 u_int tc_max_depth; /* Max length of tc_queues. */ 135#endif 136}; 137 138#ifdef TURNSTILE_PROFILING 139u_int turnstile_max_depth; 140SYSCTL_NODE(_debug, OID_AUTO, turnstile, CTLFLAG_RD, 0, "turnstile profiling"); 141SYSCTL_NODE(_debug_turnstile, OID_AUTO, chains, CTLFLAG_RD, 0, 142 "turnstile chain stats"); 143SYSCTL_UINT(_debug_turnstile, OID_AUTO, max_depth, CTLFLAG_RD, 144 &turnstile_max_depth, 0, "maxmimum depth achieved of a single chain"); 145#endif 146static struct mtx td_contested_lock; 147static struct turnstile_chain turnstile_chains[TC_TABLESIZE]; 148static uma_zone_t turnstile_zone; 149 150/* 151 * Prototypes for non-exported routines. 152 */ 153static void init_turnstile0(void *dummy); 154#ifdef TURNSTILE_PROFILING 155static void init_turnstile_profiling(void *arg); 156#endif 157static void propagate_priority(struct thread *td); 158static int turnstile_adjust_thread(struct turnstile *ts, 159 struct thread *td); 160static struct thread *turnstile_first_waiter(struct turnstile *ts); 161static void turnstile_setowner(struct turnstile *ts, struct thread *owner); 162#ifdef INVARIANTS 163static void turnstile_dtor(void *mem, int size, void *arg); 164#endif 165static int turnstile_init(void *mem, int size, int flags);
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| 166static void turnstile_fini(void *mem, int size);
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165 166/* 167 * Walks the chain of turnstiles and their owners to propagate the priority 168 * of the thread being blocked to all the threads holding locks that have to 169 * release their locks before this thread can run again. 170 */ 171static void 172propagate_priority(struct thread *td) 173{
| 167 168/* 169 * Walks the chain of turnstiles and their owners to propagate the priority 170 * of the thread being blocked to all the threads holding locks that have to 171 * release their locks before this thread can run again. 172 */ 173static void 174propagate_priority(struct thread *td) 175{
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174 struct turnstile_chain *tc;
| |
175 struct turnstile *ts; 176 int pri; 177
| 176 struct turnstile *ts; 177 int pri; 178
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178 mtx_assert(&sched_lock, MA_OWNED);
| 179 THREAD_LOCK_ASSERT(td, MA_OWNED);
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179 pri = td->td_priority; 180 ts = td->td_blocked;
| 180 pri = td->td_priority; 181 ts = td->td_blocked;
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| 182 MPASS(td->td_lock == &ts->ts_lock); 183 /* 184 * Grab a recursive lock on this turnstile chain so it stays locked 185 * for the whole operation. The caller expects us to return with 186 * the original lock held. We only ever lock down the chain so 187 * the lock order is constant. 188 */ 189 mtx_lock_spin(&ts->ts_lock);
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181 for (;;) { 182 td = ts->ts_owner; 183 184 if (td == NULL) { 185 /* 186 * This might be a read lock with no owner. There's 187 * not much we can do, so just bail. 188 */
| 190 for (;;) { 191 td = ts->ts_owner; 192 193 if (td == NULL) { 194 /* 195 * This might be a read lock with no owner. There's 196 * not much we can do, so just bail. 197 */
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| 198 mtx_unlock_spin(&ts->ts_lock);
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189 return; 190 } 191
| 199 return; 200 } 201
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| 202 thread_lock_flags(td, MTX_DUPOK); 203 mtx_unlock_spin(&ts->ts_lock);
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192 MPASS(td->td_proc != NULL); 193 MPASS(td->td_proc->p_magic == P_MAGIC); 194 195 /* 196 * If the thread is asleep, then we are probably about 197 * to deadlock. To make debugging this easier, just 198 * panic and tell the user which thread misbehaved so 199 * they can hopefully get a stack trace from the truly 200 * misbehaving thread. 201 */ 202 if (TD_IS_SLEEPING(td)) { 203 printf( 204 "Sleeping thread (tid %d, pid %d) owns a non-sleepable lock\n", 205 td->td_tid, td->td_proc->p_pid); 206#ifdef DDB 207 db_trace_thread(td, -1); 208#endif 209 panic("sleeping thread"); 210 } 211 212 /* 213 * If this thread already has higher priority than the 214 * thread that is being blocked, we are finished. 215 */
| 204 MPASS(td->td_proc != NULL); 205 MPASS(td->td_proc->p_magic == P_MAGIC); 206 207 /* 208 * If the thread is asleep, then we are probably about 209 * to deadlock. To make debugging this easier, just 210 * panic and tell the user which thread misbehaved so 211 * they can hopefully get a stack trace from the truly 212 * misbehaving thread. 213 */ 214 if (TD_IS_SLEEPING(td)) { 215 printf( 216 "Sleeping thread (tid %d, pid %d) owns a non-sleepable lock\n", 217 td->td_tid, td->td_proc->p_pid); 218#ifdef DDB 219 db_trace_thread(td, -1); 220#endif 221 panic("sleeping thread"); 222 } 223 224 /* 225 * If this thread already has higher priority than the 226 * thread that is being blocked, we are finished. 227 */
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216 if (td->td_priority <= pri)
| 228 if (td->td_priority <= pri) { 229 thread_unlock(td);
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217 return;
| 230 return;
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| 231 }
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218 219 /* 220 * Bump this thread's priority. 221 */ 222 sched_lend_prio(td, pri); 223 224 /* 225 * If lock holder is actually running or on the run queue 226 * then we are done. 227 */ 228 if (TD_IS_RUNNING(td) || TD_ON_RUNQ(td)) { 229 MPASS(td->td_blocked == NULL);
| 232 233 /* 234 * Bump this thread's priority. 235 */ 236 sched_lend_prio(td, pri); 237 238 /* 239 * If lock holder is actually running or on the run queue 240 * then we are done. 241 */ 242 if (TD_IS_RUNNING(td) || TD_ON_RUNQ(td)) { 243 MPASS(td->td_blocked == NULL);
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| 244 thread_unlock(td);
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230 return; 231 } 232 233#ifndef SMP 234 /* 235 * For UP, we check to see if td is curthread (this shouldn't 236 * ever happen however as it would mean we are in a deadlock.) 237 */ 238 KASSERT(td != curthread, ("Deadlock detected")); 239#endif 240 241 /* 242 * If we aren't blocked on a lock, we should be. 243 */ 244 KASSERT(TD_ON_LOCK(td), ( 245 "thread %d(%s):%d holds %s but isn't blocked on a lock\n", 246 td->td_tid, td->td_proc->p_comm, td->td_state, 247 ts->ts_lockobj->lo_name)); 248 249 /* 250 * Pick up the lock that td is blocked on. 251 */ 252 ts = td->td_blocked; 253 MPASS(ts != NULL);
| 245 return; 246 } 247 248#ifndef SMP 249 /* 250 * For UP, we check to see if td is curthread (this shouldn't 251 * ever happen however as it would mean we are in a deadlock.) 252 */ 253 KASSERT(td != curthread, ("Deadlock detected")); 254#endif 255 256 /* 257 * If we aren't blocked on a lock, we should be. 258 */ 259 KASSERT(TD_ON_LOCK(td), ( 260 "thread %d(%s):%d holds %s but isn't blocked on a lock\n", 261 td->td_tid, td->td_proc->p_comm, td->td_state, 262 ts->ts_lockobj->lo_name)); 263 264 /* 265 * Pick up the lock that td is blocked on. 266 */ 267 ts = td->td_blocked; 268 MPASS(ts != NULL);
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254 tc = TC_LOOKUP(ts->ts_lockobj); 255 mtx_lock_spin(&tc->tc_lock); 256
| 269 MPASS(td->td_lock == &ts->ts_lock);
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257 /* Resort td on the list if needed. */ 258 if (!turnstile_adjust_thread(ts, td)) {
| 270 /* Resort td on the list if needed. */ 271 if (!turnstile_adjust_thread(ts, td)) {
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259 mtx_unlock_spin(&tc->tc_lock);
| 272 mtx_unlock_spin(&ts->ts_lock);
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260 return; 261 }
| 273 return; 274 }
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262 mtx_unlock_spin(&tc->tc_lock);
| 275 /* The thread lock is released as ts lock above. */
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263 } 264} 265 266/* 267 * Adjust the thread's position on a turnstile after its priority has been 268 * changed. 269 */ 270static int 271turnstile_adjust_thread(struct turnstile *ts, struct thread *td) 272{
| 276 } 277} 278 279/* 280 * Adjust the thread's position on a turnstile after its priority has been 281 * changed. 282 */ 283static int 284turnstile_adjust_thread(struct turnstile *ts, struct thread *td) 285{
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273 struct turnstile_chain *tc;
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274 struct thread *td1, *td2; 275 int queue; 276
| 286 struct thread *td1, *td2; 287 int queue; 288
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277 mtx_assert(&sched_lock, MA_OWNED);
| 289 THREAD_LOCK_ASSERT(td, MA_OWNED);
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278 MPASS(TD_ON_LOCK(td)); 279 280 /* 281 * This thread may not be blocked on this turnstile anymore 282 * but instead might already be woken up on another CPU
| 290 MPASS(TD_ON_LOCK(td)); 291 292 /* 293 * This thread may not be blocked on this turnstile anymore 294 * but instead might already be woken up on another CPU
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283 * that is waiting on sched_lock in turnstile_unpend() to
| 295 * that is waiting on the thread lock in turnstile_unpend() to
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284 * finish waking this thread up. We can detect this case 285 * by checking to see if this thread has been given a 286 * turnstile by either turnstile_signal() or 287 * turnstile_broadcast(). In this case, treat the thread as 288 * if it was already running. 289 */ 290 if (td->td_turnstile != NULL) 291 return (0); 292 293 /* 294 * Check if the thread needs to be moved on the blocked chain. 295 * It needs to be moved if either its priority is lower than 296 * the previous thread or higher than the next thread. 297 */
| 296 * finish waking this thread up. We can detect this case 297 * by checking to see if this thread has been given a 298 * turnstile by either turnstile_signal() or 299 * turnstile_broadcast(). In this case, treat the thread as 300 * if it was already running. 301 */ 302 if (td->td_turnstile != NULL) 303 return (0); 304 305 /* 306 * Check if the thread needs to be moved on the blocked chain. 307 * It needs to be moved if either its priority is lower than 308 * the previous thread or higher than the next thread. 309 */
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298 tc = TC_LOOKUP(ts->ts_lockobj); 299 mtx_assert(&tc->tc_lock, MA_OWNED);
| 310 MPASS(td->td_lock == &ts->ts_lock);
|
300 td1 = TAILQ_PREV(td, threadqueue, td_lockq); 301 td2 = TAILQ_NEXT(td, td_lockq); 302 if ((td1 != NULL && td->td_priority < td1->td_priority) || 303 (td2 != NULL && td->td_priority > td2->td_priority)) { 304 305 /* 306 * Remove thread from blocked chain and determine where 307 * it should be moved to. 308 */ 309 queue = td->td_tsqueue; 310 MPASS(queue == TS_EXCLUSIVE_QUEUE || queue == TS_SHARED_QUEUE); 311 mtx_lock_spin(&td_contested_lock); 312 TAILQ_REMOVE(&ts->ts_blocked[queue], td, td_lockq); 313 TAILQ_FOREACH(td1, &ts->ts_blocked[queue], td_lockq) { 314 MPASS(td1->td_proc->p_magic == P_MAGIC); 315 if (td1->td_priority > td->td_priority) 316 break; 317 } 318 319 if (td1 == NULL) 320 TAILQ_INSERT_TAIL(&ts->ts_blocked[queue], td, td_lockq); 321 else 322 TAILQ_INSERT_BEFORE(td1, td, td_lockq); 323 mtx_unlock_spin(&td_contested_lock); 324 if (td1 == NULL) 325 CTR3(KTR_LOCK, 326 "turnstile_adjust_thread: td %d put at tail on [%p] %s", 327 td->td_tid, ts->ts_lockobj, ts->ts_lockobj->lo_name); 328 else 329 CTR4(KTR_LOCK, 330 "turnstile_adjust_thread: td %d moved before %d on [%p] %s", 331 td->td_tid, td1->td_tid, ts->ts_lockobj, 332 ts->ts_lockobj->lo_name); 333 } 334 return (1); 335} 336 337/* 338 * Early initialization of turnstiles. This is not done via a SYSINIT() 339 * since this needs to be initialized very early when mutexes are first 340 * initialized. 341 */ 342void 343init_turnstiles(void) 344{ 345 int i; 346 347 for (i = 0; i < TC_TABLESIZE; i++) { 348 LIST_INIT(&turnstile_chains[i].tc_turnstiles); 349 mtx_init(&turnstile_chains[i].tc_lock, "turnstile chain", 350 NULL, MTX_SPIN); 351 } 352 mtx_init(&td_contested_lock, "td_contested", NULL, MTX_SPIN); 353 LIST_INIT(&thread0.td_contested); 354 thread0.td_turnstile = NULL; 355} 356 357#ifdef TURNSTILE_PROFILING 358static void 359init_turnstile_profiling(void *arg) 360{ 361 struct sysctl_oid *chain_oid; 362 char chain_name[10]; 363 int i; 364 365 for (i = 0; i < TC_TABLESIZE; i++) { 366 snprintf(chain_name, sizeof(chain_name), "%d", i); 367 chain_oid = SYSCTL_ADD_NODE(NULL, 368 SYSCTL_STATIC_CHILDREN(_debug_turnstile_chains), OID_AUTO, 369 chain_name, CTLFLAG_RD, NULL, "turnstile chain stats"); 370 SYSCTL_ADD_UINT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO, 371 "depth", CTLFLAG_RD, &turnstile_chains[i].tc_depth, 0, 372 NULL); 373 SYSCTL_ADD_UINT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO, 374 "max_depth", CTLFLAG_RD, &turnstile_chains[i].tc_max_depth, 375 0, NULL); 376 } 377} 378SYSINIT(turnstile_profiling, SI_SUB_LOCK, SI_ORDER_ANY, 379 init_turnstile_profiling, NULL); 380#endif 381 382static void 383init_turnstile0(void *dummy) 384{ 385 386 turnstile_zone = uma_zcreate("TURNSTILE", sizeof(struct turnstile), 387#ifdef INVARIANTS
| 311 td1 = TAILQ_PREV(td, threadqueue, td_lockq); 312 td2 = TAILQ_NEXT(td, td_lockq); 313 if ((td1 != NULL && td->td_priority < td1->td_priority) || 314 (td2 != NULL && td->td_priority > td2->td_priority)) { 315 316 /* 317 * Remove thread from blocked chain and determine where 318 * it should be moved to. 319 */ 320 queue = td->td_tsqueue; 321 MPASS(queue == TS_EXCLUSIVE_QUEUE || queue == TS_SHARED_QUEUE); 322 mtx_lock_spin(&td_contested_lock); 323 TAILQ_REMOVE(&ts->ts_blocked[queue], td, td_lockq); 324 TAILQ_FOREACH(td1, &ts->ts_blocked[queue], td_lockq) { 325 MPASS(td1->td_proc->p_magic == P_MAGIC); 326 if (td1->td_priority > td->td_priority) 327 break; 328 } 329 330 if (td1 == NULL) 331 TAILQ_INSERT_TAIL(&ts->ts_blocked[queue], td, td_lockq); 332 else 333 TAILQ_INSERT_BEFORE(td1, td, td_lockq); 334 mtx_unlock_spin(&td_contested_lock); 335 if (td1 == NULL) 336 CTR3(KTR_LOCK, 337 "turnstile_adjust_thread: td %d put at tail on [%p] %s", 338 td->td_tid, ts->ts_lockobj, ts->ts_lockobj->lo_name); 339 else 340 CTR4(KTR_LOCK, 341 "turnstile_adjust_thread: td %d moved before %d on [%p] %s", 342 td->td_tid, td1->td_tid, ts->ts_lockobj, 343 ts->ts_lockobj->lo_name); 344 } 345 return (1); 346} 347 348/* 349 * Early initialization of turnstiles. This is not done via a SYSINIT() 350 * since this needs to be initialized very early when mutexes are first 351 * initialized. 352 */ 353void 354init_turnstiles(void) 355{ 356 int i; 357 358 for (i = 0; i < TC_TABLESIZE; i++) { 359 LIST_INIT(&turnstile_chains[i].tc_turnstiles); 360 mtx_init(&turnstile_chains[i].tc_lock, "turnstile chain", 361 NULL, MTX_SPIN); 362 } 363 mtx_init(&td_contested_lock, "td_contested", NULL, MTX_SPIN); 364 LIST_INIT(&thread0.td_contested); 365 thread0.td_turnstile = NULL; 366} 367 368#ifdef TURNSTILE_PROFILING 369static void 370init_turnstile_profiling(void *arg) 371{ 372 struct sysctl_oid *chain_oid; 373 char chain_name[10]; 374 int i; 375 376 for (i = 0; i < TC_TABLESIZE; i++) { 377 snprintf(chain_name, sizeof(chain_name), "%d", i); 378 chain_oid = SYSCTL_ADD_NODE(NULL, 379 SYSCTL_STATIC_CHILDREN(_debug_turnstile_chains), OID_AUTO, 380 chain_name, CTLFLAG_RD, NULL, "turnstile chain stats"); 381 SYSCTL_ADD_UINT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO, 382 "depth", CTLFLAG_RD, &turnstile_chains[i].tc_depth, 0, 383 NULL); 384 SYSCTL_ADD_UINT(NULL, SYSCTL_CHILDREN(chain_oid), OID_AUTO, 385 "max_depth", CTLFLAG_RD, &turnstile_chains[i].tc_max_depth, 386 0, NULL); 387 } 388} 389SYSINIT(turnstile_profiling, SI_SUB_LOCK, SI_ORDER_ANY, 390 init_turnstile_profiling, NULL); 391#endif 392 393static void 394init_turnstile0(void *dummy) 395{ 396 397 turnstile_zone = uma_zcreate("TURNSTILE", sizeof(struct turnstile), 398#ifdef INVARIANTS
|
388 NULL, turnstile_dtor, turnstile_init, NULL, UMA_ALIGN_CACHE, 0);
| 399 NULL, turnstile_dtor, turnstile_init, turnstile_fini, 400 UMA_ALIGN_CACHE, 0);
|
389#else
| 401#else
|
390 NULL, NULL, turnstile_init, NULL, UMA_ALIGN_CACHE, 0);
| 402 NULL, NULL, turnstile_init, turnstile_fini, UMA_ALIGN_CACHE, 0);
|
391#endif 392 thread0.td_turnstile = turnstile_alloc(); 393} 394SYSINIT(turnstile0, SI_SUB_LOCK, SI_ORDER_ANY, init_turnstile0, NULL); 395 396/* 397 * Update a thread on the turnstile list after it's priority has been changed. 398 * The old priority is passed in as an argument. 399 */ 400void 401turnstile_adjust(struct thread *td, u_char oldpri) 402{
| 403#endif 404 thread0.td_turnstile = turnstile_alloc(); 405} 406SYSINIT(turnstile0, SI_SUB_LOCK, SI_ORDER_ANY, init_turnstile0, NULL); 407 408/* 409 * Update a thread on the turnstile list after it's priority has been changed. 410 * The old priority is passed in as an argument. 411 */ 412void 413turnstile_adjust(struct thread *td, u_char oldpri) 414{
|
403 struct turnstile_chain *tc;
| |
404 struct turnstile *ts; 405
| 415 struct turnstile *ts; 416
|
406 mtx_assert(&sched_lock, MA_OWNED);
| |
407 MPASS(TD_ON_LOCK(td)); 408 409 /* 410 * Pick up the lock that td is blocked on. 411 */ 412 ts = td->td_blocked; 413 MPASS(ts != NULL);
| 417 MPASS(TD_ON_LOCK(td)); 418 419 /* 420 * Pick up the lock that td is blocked on. 421 */ 422 ts = td->td_blocked; 423 MPASS(ts != NULL);
|
414 tc = TC_LOOKUP(ts->ts_lockobj); 415 mtx_lock_spin(&tc->tc_lock);
| 424 MPASS(td->td_lock == &ts->ts_lock); 425 mtx_assert(&ts->ts_lock, MA_OWNED);
|
416 417 /* Resort the turnstile on the list. */
| 426 427 /* Resort the turnstile on the list. */
|
418 if (!turnstile_adjust_thread(ts, td)) { 419 mtx_unlock_spin(&tc->tc_lock);
| 428 if (!turnstile_adjust_thread(ts, td))
|
420 return;
| 429 return;
|
421 } 422
| |
423 /* 424 * If our priority was lowered and we are at the head of the 425 * turnstile, then propagate our new priority up the chain. 426 * Note that we currently don't try to revoke lent priorities 427 * when our priority goes up. 428 */ 429 MPASS(td->td_tsqueue == TS_EXCLUSIVE_QUEUE || 430 td->td_tsqueue == TS_SHARED_QUEUE); 431 if (td == TAILQ_FIRST(&ts->ts_blocked[td->td_tsqueue]) && 432 td->td_priority < oldpri) {
| 430 /* 431 * If our priority was lowered and we are at the head of the 432 * turnstile, then propagate our new priority up the chain. 433 * Note that we currently don't try to revoke lent priorities 434 * when our priority goes up. 435 */ 436 MPASS(td->td_tsqueue == TS_EXCLUSIVE_QUEUE || 437 td->td_tsqueue == TS_SHARED_QUEUE); 438 if (td == TAILQ_FIRST(&ts->ts_blocked[td->td_tsqueue]) && 439 td->td_priority < oldpri) {
|
433 mtx_unlock_spin(&tc->tc_lock); 434 critical_enter();
| |
435 propagate_priority(td);
| 440 propagate_priority(td);
|
436 critical_exit(); 437 } else 438 mtx_unlock_spin(&tc->tc_lock);
| 441 }
|
439} 440 441/* 442 * Set the owner of the lock this turnstile is attached to. 443 */ 444static void 445turnstile_setowner(struct turnstile *ts, struct thread *owner) 446{ 447 448 mtx_assert(&td_contested_lock, MA_OWNED); 449 MPASS(ts->ts_owner == NULL); 450 451 /* A shared lock might not have an owner. */ 452 if (owner == NULL) 453 return; 454 455 MPASS(owner->td_proc->p_magic == P_MAGIC); 456 ts->ts_owner = owner; 457 LIST_INSERT_HEAD(&owner->td_contested, ts, ts_link); 458} 459 460#ifdef INVARIANTS 461/* 462 * UMA zone item deallocator. 463 */ 464static void 465turnstile_dtor(void *mem, int size, void *arg) 466{ 467 struct turnstile *ts; 468 469 ts = mem; 470 MPASS(TAILQ_EMPTY(&ts->ts_blocked[TS_EXCLUSIVE_QUEUE])); 471 MPASS(TAILQ_EMPTY(&ts->ts_blocked[TS_SHARED_QUEUE])); 472 MPASS(TAILQ_EMPTY(&ts->ts_pending)); 473} 474#endif 475 476/* 477 * UMA zone item initializer. 478 */ 479static int 480turnstile_init(void *mem, int size, int flags) 481{ 482 struct turnstile *ts; 483 484 bzero(mem, size); 485 ts = mem; 486 TAILQ_INIT(&ts->ts_blocked[TS_EXCLUSIVE_QUEUE]); 487 TAILQ_INIT(&ts->ts_blocked[TS_SHARED_QUEUE]); 488 TAILQ_INIT(&ts->ts_pending); 489 LIST_INIT(&ts->ts_free);
| 442} 443 444/* 445 * Set the owner of the lock this turnstile is attached to. 446 */ 447static void 448turnstile_setowner(struct turnstile *ts, struct thread *owner) 449{ 450 451 mtx_assert(&td_contested_lock, MA_OWNED); 452 MPASS(ts->ts_owner == NULL); 453 454 /* A shared lock might not have an owner. */ 455 if (owner == NULL) 456 return; 457 458 MPASS(owner->td_proc->p_magic == P_MAGIC); 459 ts->ts_owner = owner; 460 LIST_INSERT_HEAD(&owner->td_contested, ts, ts_link); 461} 462 463#ifdef INVARIANTS 464/* 465 * UMA zone item deallocator. 466 */ 467static void 468turnstile_dtor(void *mem, int size, void *arg) 469{ 470 struct turnstile *ts; 471 472 ts = mem; 473 MPASS(TAILQ_EMPTY(&ts->ts_blocked[TS_EXCLUSIVE_QUEUE])); 474 MPASS(TAILQ_EMPTY(&ts->ts_blocked[TS_SHARED_QUEUE])); 475 MPASS(TAILQ_EMPTY(&ts->ts_pending)); 476} 477#endif 478 479/* 480 * UMA zone item initializer. 481 */ 482static int 483turnstile_init(void *mem, int size, int flags) 484{ 485 struct turnstile *ts; 486 487 bzero(mem, size); 488 ts = mem; 489 TAILQ_INIT(&ts->ts_blocked[TS_EXCLUSIVE_QUEUE]); 490 TAILQ_INIT(&ts->ts_blocked[TS_SHARED_QUEUE]); 491 TAILQ_INIT(&ts->ts_pending); 492 LIST_INIT(&ts->ts_free);
|
| 493 mtx_init(&ts->ts_lock, "turnstile lock", NULL, MTX_SPIN | MTX_RECURSE);
|
490 return (0); 491} 492
| 494 return (0); 495} 496
|
| 497static void 498turnstile_fini(void *mem, int size) 499{ 500 struct turnstile *ts; 501 502 ts = mem; 503 mtx_destroy(&ts->ts_lock); 504} 505
|
493/* 494 * Get a turnstile for a new thread. 495 */ 496struct turnstile * 497turnstile_alloc(void) 498{ 499 500 return (uma_zalloc(turnstile_zone, M_WAITOK)); 501} 502 503/* 504 * Free a turnstile when a thread is destroyed. 505 */ 506void 507turnstile_free(struct turnstile *ts) 508{ 509 510 uma_zfree(turnstile_zone, ts); 511} 512 513/* 514 * Lock the turnstile chain associated with the specified lock. 515 */ 516void
| 506/* 507 * Get a turnstile for a new thread. 508 */ 509struct turnstile * 510turnstile_alloc(void) 511{ 512 513 return (uma_zalloc(turnstile_zone, M_WAITOK)); 514} 515 516/* 517 * Free a turnstile when a thread is destroyed. 518 */ 519void 520turnstile_free(struct turnstile *ts) 521{ 522 523 uma_zfree(turnstile_zone, ts); 524} 525 526/* 527 * Lock the turnstile chain associated with the specified lock. 528 */ 529void
|
517turnstile_lock(struct lock_object *lock)
| 530turnstile_chain_lock(struct lock_object *lock)
|
518{ 519 struct turnstile_chain *tc; 520 521 tc = TC_LOOKUP(lock); 522 mtx_lock_spin(&tc->tc_lock); 523} 524
| 531{ 532 struct turnstile_chain *tc; 533 534 tc = TC_LOOKUP(lock); 535 mtx_lock_spin(&tc->tc_lock); 536} 537
|
| 538struct turnstile * 539turnstile_trywait(struct lock_object *lock) 540{ 541 struct turnstile_chain *tc; 542 struct turnstile *ts; 543 544 tc = TC_LOOKUP(lock); 545 mtx_lock_spin(&tc->tc_lock); 546 LIST_FOREACH(ts, &tc->tc_turnstiles, ts_hash) 547 if (ts->ts_lockobj == lock) { 548 mtx_lock_spin(&ts->ts_lock); 549 return (ts); 550 } 551 552 ts = curthread->td_turnstile; 553 MPASS(ts != NULL); 554 mtx_lock_spin(&ts->ts_lock); 555 KASSERT(ts->ts_lockobj == NULL, ("stale ts_lockobj pointer")); 556 ts->ts_lockobj = lock; 557 558 return (ts); 559} 560 561void 562turnstile_cancel(struct turnstile *ts) 563{ 564 struct turnstile_chain *tc; 565 struct lock_object *lock; 566 567 mtx_assert(&ts->ts_lock, MA_OWNED); 568 569 mtx_unlock_spin(&ts->ts_lock); 570 lock = ts->ts_lockobj; 571 if (ts == curthread->td_turnstile) 572 ts->ts_lockobj = NULL; 573 tc = TC_LOOKUP(lock); 574 mtx_unlock_spin(&tc->tc_lock); 575} 576
|
525/* 526 * Look up the turnstile for a lock in the hash table locking the associated 527 * turnstile chain along the way. If no turnstile is found in the hash 528 * table, NULL is returned. 529 */ 530struct turnstile * 531turnstile_lookup(struct lock_object *lock) 532{ 533 struct turnstile_chain *tc; 534 struct turnstile *ts; 535 536 tc = TC_LOOKUP(lock); 537 mtx_assert(&tc->tc_lock, MA_OWNED); 538 LIST_FOREACH(ts, &tc->tc_turnstiles, ts_hash)
| 577/* 578 * Look up the turnstile for a lock in the hash table locking the associated 579 * turnstile chain along the way. If no turnstile is found in the hash 580 * table, NULL is returned. 581 */ 582struct turnstile * 583turnstile_lookup(struct lock_object *lock) 584{ 585 struct turnstile_chain *tc; 586 struct turnstile *ts; 587 588 tc = TC_LOOKUP(lock); 589 mtx_assert(&tc->tc_lock, MA_OWNED); 590 LIST_FOREACH(ts, &tc->tc_turnstiles, ts_hash)
|
539 if (ts->ts_lockobj == lock)
| 591 if (ts->ts_lockobj == lock) { 592 mtx_lock_spin(&ts->ts_lock);
|
540 return (ts);
| 593 return (ts);
|
| 594 }
|
541 return (NULL); 542} 543 544/* 545 * Unlock the turnstile chain associated with a given lock. 546 */ 547void
| 595 return (NULL); 596} 597 598/* 599 * Unlock the turnstile chain associated with a given lock. 600 */ 601void
|
548turnstile_release(struct lock_object *lock)
| 602turnstile_chain_unlock(struct lock_object *lock)
|
549{ 550 struct turnstile_chain *tc; 551 552 tc = TC_LOOKUP(lock); 553 mtx_unlock_spin(&tc->tc_lock); 554} 555 556/* 557 * Return a pointer to the thread waiting on this turnstile with the 558 * most important priority or NULL if the turnstile has no waiters. 559 */ 560static struct thread * 561turnstile_first_waiter(struct turnstile *ts) 562{ 563 struct thread *std, *xtd; 564 565 std = TAILQ_FIRST(&ts->ts_blocked[TS_SHARED_QUEUE]); 566 xtd = TAILQ_FIRST(&ts->ts_blocked[TS_EXCLUSIVE_QUEUE]); 567 if (xtd == NULL || (std != NULL && std->td_priority < xtd->td_priority)) 568 return (std); 569 return (xtd); 570} 571 572/* 573 * Take ownership of a turnstile and adjust the priority of the new 574 * owner appropriately. 575 */ 576void
| 603{ 604 struct turnstile_chain *tc; 605 606 tc = TC_LOOKUP(lock); 607 mtx_unlock_spin(&tc->tc_lock); 608} 609 610/* 611 * Return a pointer to the thread waiting on this turnstile with the 612 * most important priority or NULL if the turnstile has no waiters. 613 */ 614static struct thread * 615turnstile_first_waiter(struct turnstile *ts) 616{ 617 struct thread *std, *xtd; 618 619 std = TAILQ_FIRST(&ts->ts_blocked[TS_SHARED_QUEUE]); 620 xtd = TAILQ_FIRST(&ts->ts_blocked[TS_EXCLUSIVE_QUEUE]); 621 if (xtd == NULL || (std != NULL && std->td_priority < xtd->td_priority)) 622 return (std); 623 return (xtd); 624} 625 626/* 627 * Take ownership of a turnstile and adjust the priority of the new 628 * owner appropriately. 629 */ 630void
|
577turnstile_claim(struct lock_object *lock)
| 631turnstile_claim(struct turnstile *ts)
|
578{
| 632{
|
579 struct turnstile_chain *tc; 580 struct turnstile *ts;
| |
581 struct thread *td, *owner;
| 633 struct thread *td, *owner;
|
| 634 struct turnstile_chain *tc;
|
582
| 635
|
583 tc = TC_LOOKUP(lock); 584 mtx_assert(&tc->tc_lock, MA_OWNED); 585 ts = turnstile_lookup(lock); 586 MPASS(ts != NULL);
| 636 mtx_assert(&ts->ts_lock, MA_OWNED); 637 MPASS(ts != curthread->td_turnstile);
|
587 588 owner = curthread; 589 mtx_lock_spin(&td_contested_lock); 590 turnstile_setowner(ts, owner); 591 mtx_unlock_spin(&td_contested_lock); 592 593 td = turnstile_first_waiter(ts); 594 MPASS(td != NULL); 595 MPASS(td->td_proc->p_magic == P_MAGIC);
| 638 639 owner = curthread; 640 mtx_lock_spin(&td_contested_lock); 641 turnstile_setowner(ts, owner); 642 mtx_unlock_spin(&td_contested_lock); 643 644 td = turnstile_first_waiter(ts); 645 MPASS(td != NULL); 646 MPASS(td->td_proc->p_magic == P_MAGIC);
|
596 mtx_unlock_spin(&tc->tc_lock);
| 647 MPASS(td->td_lock == &ts->ts_lock);
|
597 598 /* 599 * Update the priority of the new owner if needed. 600 */
| 648 649 /* 650 * Update the priority of the new owner if needed. 651 */
|
601 mtx_lock_spin(&sched_lock);
| 652 thread_lock(owner);
|
602 if (td->td_priority < owner->td_priority) 603 sched_lend_prio(owner, td->td_priority);
| 653 if (td->td_priority < owner->td_priority) 654 sched_lend_prio(owner, td->td_priority);
|
604 mtx_unlock_spin(&sched_lock);
| 655 thread_unlock(owner); 656 tc = TC_LOOKUP(ts->ts_lockobj); 657 mtx_unlock_spin(&ts->ts_lock); 658 mtx_unlock_spin(&tc->tc_lock);
|
605} 606 607/* 608 * Block the current thread on the turnstile assicated with 'lock'. This 609 * function will context switch and not return until this thread has been 610 * woken back up. This function must be called with the appropriate 611 * turnstile chain locked and will return with it unlocked. 612 */ 613void
| 659} 660 661/* 662 * Block the current thread on the turnstile assicated with 'lock'. This 663 * function will context switch and not return until this thread has been 664 * woken back up. This function must be called with the appropriate 665 * turnstile chain locked and will return with it unlocked. 666 */ 667void
|
614turnstile_wait(struct lock_object *lock, struct thread *owner, int queue)
| 668turnstile_wait(struct turnstile *ts, struct thread *owner, int queue)
|
615{ 616 struct turnstile_chain *tc;
| 669{ 670 struct turnstile_chain *tc;
|
617 struct turnstile *ts;
| |
618 struct thread *td, *td1;
| 671 struct thread *td, *td1;
|
| 672 struct lock_object *lock;
|
619 620 td = curthread;
| 673 674 td = curthread;
|
621 tc = TC_LOOKUP(lock); 622 mtx_assert(&tc->tc_lock, MA_OWNED); 623 MPASS(td->td_turnstile != NULL);
| 675 mtx_assert(&ts->ts_lock, MA_OWNED);
|
624 if (queue == TS_SHARED_QUEUE) 625 MPASS(owner != NULL); 626 if (owner) 627 MPASS(owner->td_proc->p_magic == P_MAGIC); 628 MPASS(queue == TS_SHARED_QUEUE || queue == TS_EXCLUSIVE_QUEUE); 629
| 676 if (queue == TS_SHARED_QUEUE) 677 MPASS(owner != NULL); 678 if (owner) 679 MPASS(owner->td_proc->p_magic == P_MAGIC); 680 MPASS(queue == TS_SHARED_QUEUE || queue == TS_EXCLUSIVE_QUEUE); 681
|
630 /* Look up the turnstile associated with the lock 'lock'. */ 631 ts = turnstile_lookup(lock); 632
| |
633 /* 634 * If the lock does not already have a turnstile, use this thread's 635 * turnstile. Otherwise insert the current thread into the 636 * turnstile already in use by this lock. 637 */
| 682 /* 683 * If the lock does not already have a turnstile, use this thread's 684 * turnstile. Otherwise insert the current thread into the 685 * turnstile already in use by this lock. 686 */
|
638 if (ts == NULL) {
| 687 tc = TC_LOOKUP(ts->ts_lockobj); 688 if (ts == td->td_turnstile) { 689 mtx_assert(&tc->tc_lock, MA_OWNED);
|
639#ifdef TURNSTILE_PROFILING 640 tc->tc_depth++; 641 if (tc->tc_depth > tc->tc_max_depth) { 642 tc->tc_max_depth = tc->tc_depth; 643 if (tc->tc_max_depth > turnstile_max_depth) 644 turnstile_max_depth = tc->tc_max_depth; 645 } 646#endif
| 690#ifdef TURNSTILE_PROFILING 691 tc->tc_depth++; 692 if (tc->tc_depth > tc->tc_max_depth) { 693 tc->tc_max_depth = tc->tc_depth; 694 if (tc->tc_max_depth > turnstile_max_depth) 695 turnstile_max_depth = tc->tc_max_depth; 696 } 697#endif
|
647 ts = td->td_turnstile;
| 698 tc = TC_LOOKUP(ts->ts_lockobj);
|
648 LIST_INSERT_HEAD(&tc->tc_turnstiles, ts, ts_hash); 649 KASSERT(TAILQ_EMPTY(&ts->ts_pending), 650 ("thread's turnstile has pending threads")); 651 KASSERT(TAILQ_EMPTY(&ts->ts_blocked[TS_EXCLUSIVE_QUEUE]), 652 ("thread's turnstile has exclusive waiters")); 653 KASSERT(TAILQ_EMPTY(&ts->ts_blocked[TS_SHARED_QUEUE]), 654 ("thread's turnstile has shared waiters")); 655 KASSERT(LIST_EMPTY(&ts->ts_free), 656 ("thread's turnstile has a non-empty free list"));
| 699 LIST_INSERT_HEAD(&tc->tc_turnstiles, ts, ts_hash); 700 KASSERT(TAILQ_EMPTY(&ts->ts_pending), 701 ("thread's turnstile has pending threads")); 702 KASSERT(TAILQ_EMPTY(&ts->ts_blocked[TS_EXCLUSIVE_QUEUE]), 703 ("thread's turnstile has exclusive waiters")); 704 KASSERT(TAILQ_EMPTY(&ts->ts_blocked[TS_SHARED_QUEUE]), 705 ("thread's turnstile has shared waiters")); 706 KASSERT(LIST_EMPTY(&ts->ts_free), 707 ("thread's turnstile has a non-empty free list"));
|
657 KASSERT(ts->ts_lockobj == NULL, ("stale ts_lockobj pointer")); 658 ts->ts_lockobj = lock;
| 708 MPASS(ts->ts_lockobj != NULL);
|
659 mtx_lock_spin(&td_contested_lock); 660 TAILQ_INSERT_TAIL(&ts->ts_blocked[queue], td, td_lockq); 661 turnstile_setowner(ts, owner); 662 mtx_unlock_spin(&td_contested_lock); 663 } else { 664 TAILQ_FOREACH(td1, &ts->ts_blocked[queue], td_lockq) 665 if (td1->td_priority > td->td_priority) 666 break; 667 mtx_lock_spin(&td_contested_lock); 668 if (td1 != NULL) 669 TAILQ_INSERT_BEFORE(td1, td, td_lockq); 670 else 671 TAILQ_INSERT_TAIL(&ts->ts_blocked[queue], td, td_lockq); 672 MPASS(owner == ts->ts_owner); 673 mtx_unlock_spin(&td_contested_lock); 674 MPASS(td->td_turnstile != NULL); 675 LIST_INSERT_HEAD(&ts->ts_free, td->td_turnstile, ts_hash); 676 }
| 709 mtx_lock_spin(&td_contested_lock); 710 TAILQ_INSERT_TAIL(&ts->ts_blocked[queue], td, td_lockq); 711 turnstile_setowner(ts, owner); 712 mtx_unlock_spin(&td_contested_lock); 713 } else { 714 TAILQ_FOREACH(td1, &ts->ts_blocked[queue], td_lockq) 715 if (td1->td_priority > td->td_priority) 716 break; 717 mtx_lock_spin(&td_contested_lock); 718 if (td1 != NULL) 719 TAILQ_INSERT_BEFORE(td1, td, td_lockq); 720 else 721 TAILQ_INSERT_TAIL(&ts->ts_blocked[queue], td, td_lockq); 722 MPASS(owner == ts->ts_owner); 723 mtx_unlock_spin(&td_contested_lock); 724 MPASS(td->td_turnstile != NULL); 725 LIST_INSERT_HEAD(&ts->ts_free, td->td_turnstile, ts_hash); 726 }
|
| 727 thread_lock(td); 728 thread_lock_set(td, &ts->ts_lock);
|
677 td->td_turnstile = NULL;
| 729 td->td_turnstile = NULL;
|
678 mtx_unlock_spin(&tc->tc_lock);
| |
679
| 730
|
680 mtx_lock_spin(&sched_lock); 681 /* 682 * Handle race condition where a thread on another CPU that owns 683 * lock 'lock' could have woken us in between us dropping the 684 * turnstile chain lock and acquiring the sched_lock. 685 */ 686 if (td->td_flags & TDF_TSNOBLOCK) { 687 td->td_flags &= ~TDF_TSNOBLOCK; 688 mtx_unlock_spin(&sched_lock); 689 return; 690 } 691 692#ifdef notyet 693 /* 694 * If we're borrowing an interrupted thread's VM context, we 695 * must clean up before going to sleep. 696 */ 697 if (td->td_ithd != NULL) { 698 struct ithd *it = td->td_ithd; 699 700 if (it->it_interrupted) { 701 if (LOCK_LOG_TEST(lock, 0)) 702 CTR3(KTR_LOCK, "%s: %p interrupted %p", 703 __func__, it, it->it_interrupted); 704 intr_thd_fixup(it); 705 } 706 } 707#endif 708
| |
709 /* Save who we are blocked on and switch. */
| 731 /* Save who we are blocked on and switch. */
|
| 732 lock = ts->ts_lockobj;
|
710 td->td_tsqueue = queue; 711 td->td_blocked = ts; 712 td->td_lockname = lock->lo_name; 713 TD_SET_LOCK(td);
| 733 td->td_tsqueue = queue; 734 td->td_blocked = ts; 735 td->td_lockname = lock->lo_name; 736 TD_SET_LOCK(td);
|
714 critical_enter();
| 737 mtx_unlock_spin(&tc->tc_lock);
|
715 propagate_priority(td);
| 738 propagate_priority(td);
|
716 critical_exit();
| |
717 718 if (LOCK_LOG_TEST(lock, 0)) 719 CTR4(KTR_LOCK, "%s: td %d blocked on [%p] %s", __func__, 720 td->td_tid, lock, lock->lo_name); 721
| 739 740 if (LOCK_LOG_TEST(lock, 0)) 741 CTR4(KTR_LOCK, "%s: td %d blocked on [%p] %s", __func__, 742 td->td_tid, lock, lock->lo_name); 743
|
| 744 MPASS(td->td_lock == &ts->ts_lock); 745 SCHED_STAT_INC(switch_turnstile);
|
722 mi_switch(SW_VOL, NULL); 723 724 if (LOCK_LOG_TEST(lock, 0)) 725 CTR4(KTR_LOCK, "%s: td %d free from blocked on [%p] %s", 726 __func__, td->td_tid, lock, lock->lo_name);
| 746 mi_switch(SW_VOL, NULL); 747 748 if (LOCK_LOG_TEST(lock, 0)) 749 CTR4(KTR_LOCK, "%s: td %d free from blocked on [%p] %s", 750 __func__, td->td_tid, lock, lock->lo_name);
|
727 728 mtx_unlock_spin(&sched_lock);
| 751 thread_unlock(td);
|
729} 730 731/* 732 * Pick the highest priority thread on this turnstile and put it on the 733 * pending list. This must be called with the turnstile chain locked. 734 */ 735int 736turnstile_signal(struct turnstile *ts, int queue) 737{ 738 struct turnstile_chain *tc; 739 struct thread *td; 740 int empty; 741 742 MPASS(ts != NULL);
| 752} 753 754/* 755 * Pick the highest priority thread on this turnstile and put it on the 756 * pending list. This must be called with the turnstile chain locked. 757 */ 758int 759turnstile_signal(struct turnstile *ts, int queue) 760{ 761 struct turnstile_chain *tc; 762 struct thread *td; 763 int empty; 764 765 MPASS(ts != NULL);
|
| 766 mtx_assert(&ts->ts_lock, MA_OWNED);
|
743 MPASS(curthread->td_proc->p_magic == P_MAGIC); 744 MPASS(ts->ts_owner == curthread || 745 (queue == TS_EXCLUSIVE_QUEUE && ts->ts_owner == NULL));
| 767 MPASS(curthread->td_proc->p_magic == P_MAGIC); 768 MPASS(ts->ts_owner == curthread || 769 (queue == TS_EXCLUSIVE_QUEUE && ts->ts_owner == NULL));
|
746 tc = TC_LOOKUP(ts->ts_lockobj); 747 mtx_assert(&tc->tc_lock, MA_OWNED);
| |
748 MPASS(queue == TS_SHARED_QUEUE || queue == TS_EXCLUSIVE_QUEUE); 749 750 /* 751 * Pick the highest priority thread blocked on this lock and 752 * move it to the pending list. 753 */ 754 td = TAILQ_FIRST(&ts->ts_blocked[queue]); 755 MPASS(td->td_proc->p_magic == P_MAGIC); 756 mtx_lock_spin(&td_contested_lock); 757 TAILQ_REMOVE(&ts->ts_blocked[queue], td, td_lockq); 758 mtx_unlock_spin(&td_contested_lock); 759 TAILQ_INSERT_TAIL(&ts->ts_pending, td, td_lockq); 760 761 /* 762 * If the turnstile is now empty, remove it from its chain and 763 * give it to the about-to-be-woken thread. Otherwise take a 764 * turnstile from the free list and give it to the thread. 765 */ 766 empty = TAILQ_EMPTY(&ts->ts_blocked[TS_EXCLUSIVE_QUEUE]) && 767 TAILQ_EMPTY(&ts->ts_blocked[TS_SHARED_QUEUE]); 768 if (empty) {
| 770 MPASS(queue == TS_SHARED_QUEUE || queue == TS_EXCLUSIVE_QUEUE); 771 772 /* 773 * Pick the highest priority thread blocked on this lock and 774 * move it to the pending list. 775 */ 776 td = TAILQ_FIRST(&ts->ts_blocked[queue]); 777 MPASS(td->td_proc->p_magic == P_MAGIC); 778 mtx_lock_spin(&td_contested_lock); 779 TAILQ_REMOVE(&ts->ts_blocked[queue], td, td_lockq); 780 mtx_unlock_spin(&td_contested_lock); 781 TAILQ_INSERT_TAIL(&ts->ts_pending, td, td_lockq); 782 783 /* 784 * If the turnstile is now empty, remove it from its chain and 785 * give it to the about-to-be-woken thread. Otherwise take a 786 * turnstile from the free list and give it to the thread. 787 */ 788 empty = TAILQ_EMPTY(&ts->ts_blocked[TS_EXCLUSIVE_QUEUE]) && 789 TAILQ_EMPTY(&ts->ts_blocked[TS_SHARED_QUEUE]); 790 if (empty) {
|
| 791 tc = TC_LOOKUP(ts->ts_lockobj); 792 mtx_assert(&tc->tc_lock, MA_OWNED);
|
769 MPASS(LIST_EMPTY(&ts->ts_free)); 770#ifdef TURNSTILE_PROFILING 771 tc->tc_depth--; 772#endif 773 } else 774 ts = LIST_FIRST(&ts->ts_free); 775 MPASS(ts != NULL); 776 LIST_REMOVE(ts, ts_hash); 777 td->td_turnstile = ts; 778 779 return (empty); 780} 781 782/* 783 * Put all blocked threads on the pending list. This must be called with 784 * the turnstile chain locked. 785 */ 786void 787turnstile_broadcast(struct turnstile *ts, int queue) 788{ 789 struct turnstile_chain *tc; 790 struct turnstile *ts1; 791 struct thread *td; 792 793 MPASS(ts != NULL);
| 793 MPASS(LIST_EMPTY(&ts->ts_free)); 794#ifdef TURNSTILE_PROFILING 795 tc->tc_depth--; 796#endif 797 } else 798 ts = LIST_FIRST(&ts->ts_free); 799 MPASS(ts != NULL); 800 LIST_REMOVE(ts, ts_hash); 801 td->td_turnstile = ts; 802 803 return (empty); 804} 805 806/* 807 * Put all blocked threads on the pending list. This must be called with 808 * the turnstile chain locked. 809 */ 810void 811turnstile_broadcast(struct turnstile *ts, int queue) 812{ 813 struct turnstile_chain *tc; 814 struct turnstile *ts1; 815 struct thread *td; 816 817 MPASS(ts != NULL);
|
| 818 mtx_assert(&ts->ts_lock, MA_OWNED);
|
794 MPASS(curthread->td_proc->p_magic == P_MAGIC); 795 MPASS(ts->ts_owner == curthread || 796 (queue == TS_EXCLUSIVE_QUEUE && ts->ts_owner == NULL));
| 819 MPASS(curthread->td_proc->p_magic == P_MAGIC); 820 MPASS(ts->ts_owner == curthread || 821 (queue == TS_EXCLUSIVE_QUEUE && ts->ts_owner == NULL));
|
| 822 /* 823 * We must have the chain locked so that we can remove the empty 824 * turnstile from the hash queue. 825 */
|
797 tc = TC_LOOKUP(ts->ts_lockobj); 798 mtx_assert(&tc->tc_lock, MA_OWNED); 799 MPASS(queue == TS_SHARED_QUEUE || queue == TS_EXCLUSIVE_QUEUE); 800 801 /* 802 * Transfer the blocked list to the pending list. 803 */ 804 mtx_lock_spin(&td_contested_lock); 805 TAILQ_CONCAT(&ts->ts_pending, &ts->ts_blocked[queue], td_lockq); 806 mtx_unlock_spin(&td_contested_lock); 807 808 /* 809 * Give a turnstile to each thread. The last thread gets 810 * this turnstile if the turnstile is empty. 811 */ 812 TAILQ_FOREACH(td, &ts->ts_pending, td_lockq) { 813 if (LIST_EMPTY(&ts->ts_free)) { 814 MPASS(TAILQ_NEXT(td, td_lockq) == NULL); 815 ts1 = ts; 816#ifdef TURNSTILE_PROFILING 817 tc->tc_depth--; 818#endif 819 } else 820 ts1 = LIST_FIRST(&ts->ts_free); 821 MPASS(ts1 != NULL); 822 LIST_REMOVE(ts1, ts_hash); 823 td->td_turnstile = ts1; 824 } 825} 826 827/* 828 * Wakeup all threads on the pending list and adjust the priority of the 829 * current thread appropriately. This must be called with the turnstile 830 * chain locked. 831 */ 832void 833turnstile_unpend(struct turnstile *ts, int owner_type) 834{ 835 TAILQ_HEAD( ,thread) pending_threads;
| 826 tc = TC_LOOKUP(ts->ts_lockobj); 827 mtx_assert(&tc->tc_lock, MA_OWNED); 828 MPASS(queue == TS_SHARED_QUEUE || queue == TS_EXCLUSIVE_QUEUE); 829 830 /* 831 * Transfer the blocked list to the pending list. 832 */ 833 mtx_lock_spin(&td_contested_lock); 834 TAILQ_CONCAT(&ts->ts_pending, &ts->ts_blocked[queue], td_lockq); 835 mtx_unlock_spin(&td_contested_lock); 836 837 /* 838 * Give a turnstile to each thread. The last thread gets 839 * this turnstile if the turnstile is empty. 840 */ 841 TAILQ_FOREACH(td, &ts->ts_pending, td_lockq) { 842 if (LIST_EMPTY(&ts->ts_free)) { 843 MPASS(TAILQ_NEXT(td, td_lockq) == NULL); 844 ts1 = ts; 845#ifdef TURNSTILE_PROFILING 846 tc->tc_depth--; 847#endif 848 } else 849 ts1 = LIST_FIRST(&ts->ts_free); 850 MPASS(ts1 != NULL); 851 LIST_REMOVE(ts1, ts_hash); 852 td->td_turnstile = ts1; 853 } 854} 855 856/* 857 * Wakeup all threads on the pending list and adjust the priority of the 858 * current thread appropriately. This must be called with the turnstile 859 * chain locked. 860 */ 861void 862turnstile_unpend(struct turnstile *ts, int owner_type) 863{ 864 TAILQ_HEAD( ,thread) pending_threads;
|
836 struct turnstile_chain *tc;
| 865 struct turnstile *nts;
|
837 struct thread *td; 838 u_char cp, pri; 839 840 MPASS(ts != NULL);
| 866 struct thread *td; 867 u_char cp, pri; 868 869 MPASS(ts != NULL);
|
| 870 mtx_assert(&ts->ts_lock, MA_OWNED);
|
841 MPASS(ts->ts_owner == curthread || 842 (owner_type == TS_SHARED_LOCK && ts->ts_owner == NULL));
| 871 MPASS(ts->ts_owner == curthread || 872 (owner_type == TS_SHARED_LOCK && ts->ts_owner == NULL));
|
843 tc = TC_LOOKUP(ts->ts_lockobj); 844 mtx_assert(&tc->tc_lock, MA_OWNED);
| |
845 MPASS(!TAILQ_EMPTY(&ts->ts_pending)); 846 847 /* 848 * Move the list of pending threads out of the turnstile and 849 * into a local variable. 850 */ 851 TAILQ_INIT(&pending_threads); 852 TAILQ_CONCAT(&pending_threads, &ts->ts_pending, td_lockq); 853#ifdef INVARIANTS 854 if (TAILQ_EMPTY(&ts->ts_blocked[TS_EXCLUSIVE_QUEUE]) && 855 TAILQ_EMPTY(&ts->ts_blocked[TS_SHARED_QUEUE])) 856 ts->ts_lockobj = NULL; 857#endif
| 873 MPASS(!TAILQ_EMPTY(&ts->ts_pending)); 874 875 /* 876 * Move the list of pending threads out of the turnstile and 877 * into a local variable. 878 */ 879 TAILQ_INIT(&pending_threads); 880 TAILQ_CONCAT(&pending_threads, &ts->ts_pending, td_lockq); 881#ifdef INVARIANTS 882 if (TAILQ_EMPTY(&ts->ts_blocked[TS_EXCLUSIVE_QUEUE]) && 883 TAILQ_EMPTY(&ts->ts_blocked[TS_SHARED_QUEUE])) 884 ts->ts_lockobj = NULL; 885#endif
|
858
| |
859 /*
| 886 /*
|
| 887 * Adjust the priority of curthread based on other contested 888 * locks it owns. Don't lower the priority below the base 889 * priority however. 890 */ 891 td = curthread; 892 pri = PRI_MAX; 893 thread_lock(td); 894 mtx_lock_spin(&td_contested_lock); 895 /*
|
860 * Remove the turnstile from this thread's list of contested locks 861 * since this thread doesn't own it anymore. New threads will 862 * not be blocking on the turnstile until it is claimed by a new 863 * owner. There might not be a current owner if this is a shared 864 * lock. 865 */ 866 if (ts->ts_owner != NULL) {
| 896 * Remove the turnstile from this thread's list of contested locks 897 * since this thread doesn't own it anymore. New threads will 898 * not be blocking on the turnstile until it is claimed by a new 899 * owner. There might not be a current owner if this is a shared 900 * lock. 901 */ 902 if (ts->ts_owner != NULL) {
|
867 mtx_lock_spin(&td_contested_lock);
| |
868 ts->ts_owner = NULL; 869 LIST_REMOVE(ts, ts_link);
| 903 ts->ts_owner = NULL; 904 LIST_REMOVE(ts, ts_link);
|
870 mtx_unlock_spin(&td_contested_lock);
| |
871 }
| 905 }
|
872 critical_enter(); 873 mtx_unlock_spin(&tc->tc_lock); 874 875 /* 876 * Adjust the priority of curthread based on other contested 877 * locks it owns. Don't lower the priority below the base 878 * priority however. 879 */ 880 td = curthread; 881 pri = PRI_MAX; 882 mtx_lock_spin(&sched_lock); 883 mtx_lock_spin(&td_contested_lock); 884 LIST_FOREACH(ts, &td->td_contested, ts_link) { 885 cp = turnstile_first_waiter(ts)->td_priority;
| 906 LIST_FOREACH(nts, &td->td_contested, ts_link) { 907 cp = turnstile_first_waiter(nts)->td_priority;
|
886 if (cp < pri) 887 pri = cp; 888 } 889 mtx_unlock_spin(&td_contested_lock); 890 sched_unlend_prio(td, pri);
| 908 if (cp < pri) 909 pri = cp; 910 } 911 mtx_unlock_spin(&td_contested_lock); 912 sched_unlend_prio(td, pri);
|
891
| 913 thread_unlock(td);
|
892 /* 893 * Wake up all the pending threads. If a thread is not blocked 894 * on a lock, then it is currently executing on another CPU in 895 * turnstile_wait() or sitting on a run queue waiting to resume 896 * in turnstile_wait(). Set a flag to force it to try to acquire 897 * the lock again instead of blocking. 898 */ 899 while (!TAILQ_EMPTY(&pending_threads)) { 900 td = TAILQ_FIRST(&pending_threads); 901 TAILQ_REMOVE(&pending_threads, td, td_lockq);
| 914 /* 915 * Wake up all the pending threads. If a thread is not blocked 916 * on a lock, then it is currently executing on another CPU in 917 * turnstile_wait() or sitting on a run queue waiting to resume 918 * in turnstile_wait(). Set a flag to force it to try to acquire 919 * the lock again instead of blocking. 920 */ 921 while (!TAILQ_EMPTY(&pending_threads)) { 922 td = TAILQ_FIRST(&pending_threads); 923 TAILQ_REMOVE(&pending_threads, td, td_lockq);
|
| 924 thread_lock(td); 925 MPASS(td->td_lock == &ts->ts_lock);
|
902 MPASS(td->td_proc->p_magic == P_MAGIC);
| 926 MPASS(td->td_proc->p_magic == P_MAGIC);
|
903 if (TD_ON_LOCK(td)) { 904 td->td_blocked = NULL; 905 td->td_lockname = NULL;
| 927 MPASS(TD_ON_LOCK(td)); 928 TD_CLR_LOCK(td); 929 MPASS(TD_CAN_RUN(td)); 930 td->td_blocked = NULL; 931 td->td_lockname = NULL;
|
906#ifdef INVARIANTS
| 932#ifdef INVARIANTS
|
907 td->td_tsqueue = 0xff;
| 933 td->td_tsqueue = 0xff;
|
908#endif
| 934#endif
|
909 TD_CLR_LOCK(td); 910 MPASS(TD_CAN_RUN(td)); 911 sched_add(td, SRQ_BORING); 912 } else { 913 td->td_flags |= TDF_TSNOBLOCK; 914 MPASS(TD_IS_RUNNING(td) || TD_ON_RUNQ(td)); 915 }
| 935 sched_add(td, SRQ_BORING); 936 thread_unlock(td);
|
916 }
| 937 }
|
917 critical_exit(); 918 mtx_unlock_spin(&sched_lock);
| 938 mtx_unlock_spin(&ts->ts_lock);
|
919} 920 921/* 922 * Give up ownership of a turnstile. This must be called with the 923 * turnstile chain locked. 924 */ 925void 926turnstile_disown(struct turnstile *ts) 927{
| 939} 940 941/* 942 * Give up ownership of a turnstile. This must be called with the 943 * turnstile chain locked. 944 */ 945void 946turnstile_disown(struct turnstile *ts) 947{
|
928 struct turnstile_chain *tc;
| |
929 struct thread *td; 930 u_char cp, pri; 931 932 MPASS(ts != NULL);
| 948 struct thread *td; 949 u_char cp, pri; 950 951 MPASS(ts != NULL);
|
| 952 mtx_assert(&ts->ts_lock, MA_OWNED);
|
933 MPASS(ts->ts_owner == curthread);
| 953 MPASS(ts->ts_owner == curthread);
|
934 tc = TC_LOOKUP(ts->ts_lockobj); 935 mtx_assert(&tc->tc_lock, MA_OWNED);
| |
936 MPASS(TAILQ_EMPTY(&ts->ts_pending)); 937 MPASS(!TAILQ_EMPTY(&ts->ts_blocked[TS_EXCLUSIVE_QUEUE]) || 938 !TAILQ_EMPTY(&ts->ts_blocked[TS_SHARED_QUEUE])); 939 940 /* 941 * Remove the turnstile from this thread's list of contested locks 942 * since this thread doesn't own it anymore. New threads will 943 * not be blocking on the turnstile until it is claimed by a new 944 * owner. 945 */ 946 mtx_lock_spin(&td_contested_lock); 947 ts->ts_owner = NULL; 948 LIST_REMOVE(ts, ts_link); 949 mtx_unlock_spin(&td_contested_lock);
| 954 MPASS(TAILQ_EMPTY(&ts->ts_pending)); 955 MPASS(!TAILQ_EMPTY(&ts->ts_blocked[TS_EXCLUSIVE_QUEUE]) || 956 !TAILQ_EMPTY(&ts->ts_blocked[TS_SHARED_QUEUE])); 957 958 /* 959 * Remove the turnstile from this thread's list of contested locks 960 * since this thread doesn't own it anymore. New threads will 961 * not be blocking on the turnstile until it is claimed by a new 962 * owner. 963 */ 964 mtx_lock_spin(&td_contested_lock); 965 ts->ts_owner = NULL; 966 LIST_REMOVE(ts, ts_link); 967 mtx_unlock_spin(&td_contested_lock);
|
950 mtx_unlock_spin(&tc->tc_lock);
| |
951 952 /* 953 * Adjust the priority of curthread based on other contested 954 * locks it owns. Don't lower the priority below the base 955 * priority however. 956 */ 957 td = curthread; 958 pri = PRI_MAX;
| 968 969 /* 970 * Adjust the priority of curthread based on other contested 971 * locks it owns. Don't lower the priority below the base 972 * priority however. 973 */ 974 td = curthread; 975 pri = PRI_MAX;
|
959 mtx_lock_spin(&sched_lock);
| 976 thread_lock(td); 977 mtx_unlock_spin(&ts->ts_lock);
|
960 mtx_lock_spin(&td_contested_lock); 961 LIST_FOREACH(ts, &td->td_contested, ts_link) { 962 cp = turnstile_first_waiter(ts)->td_priority; 963 if (cp < pri) 964 pri = cp; 965 } 966 mtx_unlock_spin(&td_contested_lock); 967 sched_unlend_prio(td, pri);
| 978 mtx_lock_spin(&td_contested_lock); 979 LIST_FOREACH(ts, &td->td_contested, ts_link) { 980 cp = turnstile_first_waiter(ts)->td_priority; 981 if (cp < pri) 982 pri = cp; 983 } 984 mtx_unlock_spin(&td_contested_lock); 985 sched_unlend_prio(td, pri);
|
968 mtx_unlock_spin(&sched_lock);
| 986 thread_unlock(td);
|
969} 970 971/* 972 * Return the first thread in a turnstile. 973 */ 974struct thread * 975turnstile_head(struct turnstile *ts, int queue) 976{ 977#ifdef INVARIANTS
| 987} 988 989/* 990 * Return the first thread in a turnstile. 991 */ 992struct thread * 993turnstile_head(struct turnstile *ts, int queue) 994{ 995#ifdef INVARIANTS
|
978 struct turnstile_chain *tc;
| |
979 980 MPASS(ts != NULL); 981 MPASS(queue == TS_SHARED_QUEUE || queue == TS_EXCLUSIVE_QUEUE);
| 996 997 MPASS(ts != NULL); 998 MPASS(queue == TS_SHARED_QUEUE || queue == TS_EXCLUSIVE_QUEUE);
|
982 tc = TC_LOOKUP(ts->ts_lockobj); 983 mtx_assert(&tc->tc_lock, MA_OWNED);
| 999 mtx_assert(&ts->ts_lock, MA_OWNED);
|
984#endif 985 return (TAILQ_FIRST(&ts->ts_blocked[queue])); 986} 987 988/* 989 * Returns true if a sub-queue of a turnstile is empty. 990 */ 991int 992turnstile_empty(struct turnstile *ts, int queue) 993{ 994#ifdef INVARIANTS
| 1000#endif 1001 return (TAILQ_FIRST(&ts->ts_blocked[queue])); 1002} 1003 1004/* 1005 * Returns true if a sub-queue of a turnstile is empty. 1006 */ 1007int 1008turnstile_empty(struct turnstile *ts, int queue) 1009{ 1010#ifdef INVARIANTS
|
995 struct turnstile_chain *tc;
| |
996 997 MPASS(ts != NULL); 998 MPASS(queue == TS_SHARED_QUEUE || queue == TS_EXCLUSIVE_QUEUE);
| 1011 1012 MPASS(ts != NULL); 1013 MPASS(queue == TS_SHARED_QUEUE || queue == TS_EXCLUSIVE_QUEUE);
|
999 tc = TC_LOOKUP(ts->ts_lockobj); 1000 mtx_assert(&tc->tc_lock, MA_OWNED);
| 1014 mtx_assert(&ts->ts_lock, MA_OWNED);
|
1001#endif 1002 return (TAILQ_EMPTY(&ts->ts_blocked[queue])); 1003} 1004 1005#ifdef DDB 1006static void 1007print_thread(struct thread *td, const char *prefix) 1008{ 1009 1010 db_printf("%s%p (tid %d, pid %d, \"%s\")\n", prefix, td, td->td_tid, 1011 td->td_proc->p_pid, td->td_name[0] != '\0' ? td->td_name : 1012 td->td_proc->p_comm); 1013} 1014 1015static void 1016print_queue(struct threadqueue *queue, const char *header, const char *prefix) 1017{ 1018 struct thread *td; 1019 1020 db_printf("%s:\n", header); 1021 if (TAILQ_EMPTY(queue)) { 1022 db_printf("%sempty\n", prefix); 1023 return; 1024 } 1025 TAILQ_FOREACH(td, queue, td_lockq) { 1026 print_thread(td, prefix); 1027 } 1028} 1029 1030DB_SHOW_COMMAND(turnstile, db_show_turnstile) 1031{ 1032 struct turnstile_chain *tc; 1033 struct turnstile *ts; 1034 struct lock_object *lock; 1035 int i; 1036 1037 if (!have_addr) 1038 return; 1039 1040 /* 1041 * First, see if there is an active turnstile for the lock indicated 1042 * by the address. 1043 */ 1044 lock = (struct lock_object *)addr; 1045 tc = TC_LOOKUP(lock); 1046 LIST_FOREACH(ts, &tc->tc_turnstiles, ts_hash) 1047 if (ts->ts_lockobj == lock) 1048 goto found; 1049 1050 /* 1051 * Second, see if there is an active turnstile at the address 1052 * indicated. 1053 */ 1054 for (i = 0; i < TC_TABLESIZE; i++) 1055 LIST_FOREACH(ts, &turnstile_chains[i].tc_turnstiles, ts_hash) { 1056 if (ts == (struct turnstile *)addr) 1057 goto found; 1058 } 1059 1060 db_printf("Unable to locate a turnstile via %p\n", (void *)addr); 1061 return; 1062found: 1063 lock = ts->ts_lockobj; 1064 db_printf("Lock: %p - (%s) %s\n", lock, LOCK_CLASS(lock)->lc_name, 1065 lock->lo_name); 1066 if (ts->ts_owner) 1067 print_thread(ts->ts_owner, "Lock Owner: "); 1068 else 1069 db_printf("Lock Owner: none\n"); 1070 print_queue(&ts->ts_blocked[TS_SHARED_QUEUE], "Shared Waiters", "\t"); 1071 print_queue(&ts->ts_blocked[TS_EXCLUSIVE_QUEUE], "Exclusive Waiters", 1072 "\t"); 1073 print_queue(&ts->ts_pending, "Pending Threads", "\t"); 1074 1075} 1076 1077/* 1078 * Show all the threads a particular thread is waiting on based on 1079 * non-sleepable and non-spin locks. 1080 */ 1081static void 1082print_lockchain(struct thread *td, const char *prefix) 1083{ 1084 struct lock_object *lock; 1085 struct lock_class *class; 1086 struct turnstile *ts; 1087 1088 /* 1089 * Follow the chain. We keep walking as long as the thread is 1090 * blocked on a turnstile that has an owner. 1091 */ 1092 while (!db_pager_quit) { 1093 db_printf("%sthread %d (pid %d, %s) ", prefix, td->td_tid, 1094 td->td_proc->p_pid, td->td_name[0] != '\0' ? td->td_name : 1095 td->td_proc->p_comm); 1096 switch (td->td_state) { 1097 case TDS_INACTIVE: 1098 db_printf("is inactive\n"); 1099 return; 1100 case TDS_CAN_RUN: 1101 db_printf("can run\n"); 1102 return; 1103 case TDS_RUNQ: 1104 db_printf("is on a run queue\n"); 1105 return; 1106 case TDS_RUNNING: 1107 db_printf("running on CPU %d\n", td->td_oncpu); 1108 return; 1109 case TDS_INHIBITED: 1110 if (TD_ON_LOCK(td)) { 1111 ts = td->td_blocked; 1112 lock = ts->ts_lockobj; 1113 class = LOCK_CLASS(lock); 1114 db_printf("blocked on lock %p (%s) \"%s\"\n", 1115 lock, class->lc_name, lock->lo_name); 1116 if (ts->ts_owner == NULL) 1117 return; 1118 td = ts->ts_owner; 1119 break; 1120 } 1121 db_printf("inhibited\n"); 1122 return; 1123 default: 1124 db_printf("??? (%#x)\n", td->td_state); 1125 return; 1126 } 1127 } 1128} 1129 1130DB_SHOW_COMMAND(lockchain, db_show_lockchain) 1131{ 1132 struct thread *td; 1133 1134 /* Figure out which thread to start with. */ 1135 if (have_addr) 1136 td = db_lookup_thread(addr, TRUE); 1137 else 1138 td = kdb_thread; 1139 1140 print_lockchain(td, ""); 1141} 1142 1143DB_SHOW_COMMAND(allchains, db_show_allchains) 1144{ 1145 struct thread *td; 1146 struct proc *p; 1147 int i; 1148 1149 i = 1; 1150 FOREACH_PROC_IN_SYSTEM(p) { 1151 FOREACH_THREAD_IN_PROC(p, td) { 1152 if (TD_ON_LOCK(td) && LIST_EMPTY(&td->td_contested)) { 1153 db_printf("chain %d:\n", i++); 1154 print_lockchain(td, " "); 1155 } 1156 if (db_pager_quit) 1157 return; 1158 } 1159 } 1160} 1161 1162/* 1163 * Show all the threads a particular thread is waiting on based on 1164 * sleepable locks. 1165 */ 1166static void 1167print_sleepchain(struct thread *td, const char *prefix) 1168{ 1169 struct thread *owner; 1170 1171 /* 1172 * Follow the chain. We keep walking as long as the thread is 1173 * blocked on a sleep lock that has an owner. 1174 */ 1175 while (!db_pager_quit) { 1176 db_printf("%sthread %d (pid %d, %s) ", prefix, td->td_tid, 1177 td->td_proc->p_pid, td->td_name[0] != '\0' ? td->td_name : 1178 td->td_proc->p_comm); 1179 switch (td->td_state) { 1180 case TDS_INACTIVE: 1181 db_printf("is inactive\n"); 1182 return; 1183 case TDS_CAN_RUN: 1184 db_printf("can run\n"); 1185 return; 1186 case TDS_RUNQ: 1187 db_printf("is on a run queue\n"); 1188 return; 1189 case TDS_RUNNING: 1190 db_printf("running on CPU %d\n", td->td_oncpu); 1191 return; 1192 case TDS_INHIBITED: 1193 if (TD_ON_SLEEPQ(td)) { 1194 if (lockmgr_chain(td, &owner) || 1195 sx_chain(td, &owner)) { 1196 if (owner == NULL) 1197 return; 1198 td = owner; 1199 break; 1200 } 1201 db_printf("sleeping on %p \"%s\"\n", 1202 td->td_wchan, td->td_wmesg); 1203 return; 1204 } 1205 db_printf("inhibited\n"); 1206 return; 1207 default: 1208 db_printf("??? (%#x)\n", td->td_state); 1209 return; 1210 } 1211 } 1212} 1213 1214DB_SHOW_COMMAND(sleepchain, db_show_sleepchain) 1215{ 1216 struct thread *td; 1217 1218 /* Figure out which thread to start with. */ 1219 if (have_addr) 1220 td = db_lookup_thread(addr, TRUE); 1221 else 1222 td = kdb_thread; 1223 1224 print_sleepchain(td, ""); 1225} 1226 1227static void print_waiters(struct turnstile *ts, int indent); 1228 1229static void 1230print_waiter(struct thread *td, int indent) 1231{ 1232 struct turnstile *ts; 1233 int i; 1234 1235 if (db_pager_quit) 1236 return; 1237 for (i = 0; i < indent; i++) 1238 db_printf(" "); 1239 print_thread(td, "thread "); 1240 LIST_FOREACH(ts, &td->td_contested, ts_link) 1241 print_waiters(ts, indent + 1); 1242} 1243 1244static void 1245print_waiters(struct turnstile *ts, int indent) 1246{ 1247 struct lock_object *lock; 1248 struct lock_class *class; 1249 struct thread *td; 1250 int i; 1251 1252 if (db_pager_quit) 1253 return; 1254 lock = ts->ts_lockobj; 1255 class = LOCK_CLASS(lock); 1256 for (i = 0; i < indent; i++) 1257 db_printf(" "); 1258 db_printf("lock %p (%s) \"%s\"\n", lock, class->lc_name, lock->lo_name); 1259 TAILQ_FOREACH(td, &ts->ts_blocked[TS_EXCLUSIVE_QUEUE], td_lockq) 1260 print_waiter(td, indent + 1); 1261 TAILQ_FOREACH(td, &ts->ts_blocked[TS_SHARED_QUEUE], td_lockq) 1262 print_waiter(td, indent + 1); 1263 TAILQ_FOREACH(td, &ts->ts_pending, td_lockq) 1264 print_waiter(td, indent + 1); 1265} 1266 1267DB_SHOW_COMMAND(locktree, db_show_locktree) 1268{ 1269 struct lock_object *lock; 1270 struct lock_class *class; 1271 struct turnstile_chain *tc; 1272 struct turnstile *ts; 1273 1274 if (!have_addr) 1275 return; 1276 lock = (struct lock_object *)addr; 1277 tc = TC_LOOKUP(lock); 1278 LIST_FOREACH(ts, &tc->tc_turnstiles, ts_hash) 1279 if (ts->ts_lockobj == lock) 1280 break; 1281 if (ts == NULL) { 1282 class = LOCK_CLASS(lock); 1283 db_printf("lock %p (%s) \"%s\"\n", lock, class->lc_name, 1284 lock->lo_name); 1285 } else 1286 print_waiters(ts, 0); 1287} 1288#endif
| 1015#endif 1016 return (TAILQ_EMPTY(&ts->ts_blocked[queue])); 1017} 1018 1019#ifdef DDB 1020static void 1021print_thread(struct thread *td, const char *prefix) 1022{ 1023 1024 db_printf("%s%p (tid %d, pid %d, \"%s\")\n", prefix, td, td->td_tid, 1025 td->td_proc->p_pid, td->td_name[0] != '\0' ? td->td_name : 1026 td->td_proc->p_comm); 1027} 1028 1029static void 1030print_queue(struct threadqueue *queue, const char *header, const char *prefix) 1031{ 1032 struct thread *td; 1033 1034 db_printf("%s:\n", header); 1035 if (TAILQ_EMPTY(queue)) { 1036 db_printf("%sempty\n", prefix); 1037 return; 1038 } 1039 TAILQ_FOREACH(td, queue, td_lockq) { 1040 print_thread(td, prefix); 1041 } 1042} 1043 1044DB_SHOW_COMMAND(turnstile, db_show_turnstile) 1045{ 1046 struct turnstile_chain *tc; 1047 struct turnstile *ts; 1048 struct lock_object *lock; 1049 int i; 1050 1051 if (!have_addr) 1052 return; 1053 1054 /* 1055 * First, see if there is an active turnstile for the lock indicated 1056 * by the address. 1057 */ 1058 lock = (struct lock_object *)addr; 1059 tc = TC_LOOKUP(lock); 1060 LIST_FOREACH(ts, &tc->tc_turnstiles, ts_hash) 1061 if (ts->ts_lockobj == lock) 1062 goto found; 1063 1064 /* 1065 * Second, see if there is an active turnstile at the address 1066 * indicated. 1067 */ 1068 for (i = 0; i < TC_TABLESIZE; i++) 1069 LIST_FOREACH(ts, &turnstile_chains[i].tc_turnstiles, ts_hash) { 1070 if (ts == (struct turnstile *)addr) 1071 goto found; 1072 } 1073 1074 db_printf("Unable to locate a turnstile via %p\n", (void *)addr); 1075 return; 1076found: 1077 lock = ts->ts_lockobj; 1078 db_printf("Lock: %p - (%s) %s\n", lock, LOCK_CLASS(lock)->lc_name, 1079 lock->lo_name); 1080 if (ts->ts_owner) 1081 print_thread(ts->ts_owner, "Lock Owner: "); 1082 else 1083 db_printf("Lock Owner: none\n"); 1084 print_queue(&ts->ts_blocked[TS_SHARED_QUEUE], "Shared Waiters", "\t"); 1085 print_queue(&ts->ts_blocked[TS_EXCLUSIVE_QUEUE], "Exclusive Waiters", 1086 "\t"); 1087 print_queue(&ts->ts_pending, "Pending Threads", "\t"); 1088 1089} 1090 1091/* 1092 * Show all the threads a particular thread is waiting on based on 1093 * non-sleepable and non-spin locks. 1094 */ 1095static void 1096print_lockchain(struct thread *td, const char *prefix) 1097{ 1098 struct lock_object *lock; 1099 struct lock_class *class; 1100 struct turnstile *ts; 1101 1102 /* 1103 * Follow the chain. We keep walking as long as the thread is 1104 * blocked on a turnstile that has an owner. 1105 */ 1106 while (!db_pager_quit) { 1107 db_printf("%sthread %d (pid %d, %s) ", prefix, td->td_tid, 1108 td->td_proc->p_pid, td->td_name[0] != '\0' ? td->td_name : 1109 td->td_proc->p_comm); 1110 switch (td->td_state) { 1111 case TDS_INACTIVE: 1112 db_printf("is inactive\n"); 1113 return; 1114 case TDS_CAN_RUN: 1115 db_printf("can run\n"); 1116 return; 1117 case TDS_RUNQ: 1118 db_printf("is on a run queue\n"); 1119 return; 1120 case TDS_RUNNING: 1121 db_printf("running on CPU %d\n", td->td_oncpu); 1122 return; 1123 case TDS_INHIBITED: 1124 if (TD_ON_LOCK(td)) { 1125 ts = td->td_blocked; 1126 lock = ts->ts_lockobj; 1127 class = LOCK_CLASS(lock); 1128 db_printf("blocked on lock %p (%s) \"%s\"\n", 1129 lock, class->lc_name, lock->lo_name); 1130 if (ts->ts_owner == NULL) 1131 return; 1132 td = ts->ts_owner; 1133 break; 1134 } 1135 db_printf("inhibited\n"); 1136 return; 1137 default: 1138 db_printf("??? (%#x)\n", td->td_state); 1139 return; 1140 } 1141 } 1142} 1143 1144DB_SHOW_COMMAND(lockchain, db_show_lockchain) 1145{ 1146 struct thread *td; 1147 1148 /* Figure out which thread to start with. */ 1149 if (have_addr) 1150 td = db_lookup_thread(addr, TRUE); 1151 else 1152 td = kdb_thread; 1153 1154 print_lockchain(td, ""); 1155} 1156 1157DB_SHOW_COMMAND(allchains, db_show_allchains) 1158{ 1159 struct thread *td; 1160 struct proc *p; 1161 int i; 1162 1163 i = 1; 1164 FOREACH_PROC_IN_SYSTEM(p) { 1165 FOREACH_THREAD_IN_PROC(p, td) { 1166 if (TD_ON_LOCK(td) && LIST_EMPTY(&td->td_contested)) { 1167 db_printf("chain %d:\n", i++); 1168 print_lockchain(td, " "); 1169 } 1170 if (db_pager_quit) 1171 return; 1172 } 1173 } 1174} 1175 1176/* 1177 * Show all the threads a particular thread is waiting on based on 1178 * sleepable locks. 1179 */ 1180static void 1181print_sleepchain(struct thread *td, const char *prefix) 1182{ 1183 struct thread *owner; 1184 1185 /* 1186 * Follow the chain. We keep walking as long as the thread is 1187 * blocked on a sleep lock that has an owner. 1188 */ 1189 while (!db_pager_quit) { 1190 db_printf("%sthread %d (pid %d, %s) ", prefix, td->td_tid, 1191 td->td_proc->p_pid, td->td_name[0] != '\0' ? td->td_name : 1192 td->td_proc->p_comm); 1193 switch (td->td_state) { 1194 case TDS_INACTIVE: 1195 db_printf("is inactive\n"); 1196 return; 1197 case TDS_CAN_RUN: 1198 db_printf("can run\n"); 1199 return; 1200 case TDS_RUNQ: 1201 db_printf("is on a run queue\n"); 1202 return; 1203 case TDS_RUNNING: 1204 db_printf("running on CPU %d\n", td->td_oncpu); 1205 return; 1206 case TDS_INHIBITED: 1207 if (TD_ON_SLEEPQ(td)) { 1208 if (lockmgr_chain(td, &owner) || 1209 sx_chain(td, &owner)) { 1210 if (owner == NULL) 1211 return; 1212 td = owner; 1213 break; 1214 } 1215 db_printf("sleeping on %p \"%s\"\n", 1216 td->td_wchan, td->td_wmesg); 1217 return; 1218 } 1219 db_printf("inhibited\n"); 1220 return; 1221 default: 1222 db_printf("??? (%#x)\n", td->td_state); 1223 return; 1224 } 1225 } 1226} 1227 1228DB_SHOW_COMMAND(sleepchain, db_show_sleepchain) 1229{ 1230 struct thread *td; 1231 1232 /* Figure out which thread to start with. */ 1233 if (have_addr) 1234 td = db_lookup_thread(addr, TRUE); 1235 else 1236 td = kdb_thread; 1237 1238 print_sleepchain(td, ""); 1239} 1240 1241static void print_waiters(struct turnstile *ts, int indent); 1242 1243static void 1244print_waiter(struct thread *td, int indent) 1245{ 1246 struct turnstile *ts; 1247 int i; 1248 1249 if (db_pager_quit) 1250 return; 1251 for (i = 0; i < indent; i++) 1252 db_printf(" "); 1253 print_thread(td, "thread "); 1254 LIST_FOREACH(ts, &td->td_contested, ts_link) 1255 print_waiters(ts, indent + 1); 1256} 1257 1258static void 1259print_waiters(struct turnstile *ts, int indent) 1260{ 1261 struct lock_object *lock; 1262 struct lock_class *class; 1263 struct thread *td; 1264 int i; 1265 1266 if (db_pager_quit) 1267 return; 1268 lock = ts->ts_lockobj; 1269 class = LOCK_CLASS(lock); 1270 for (i = 0; i < indent; i++) 1271 db_printf(" "); 1272 db_printf("lock %p (%s) \"%s\"\n", lock, class->lc_name, lock->lo_name); 1273 TAILQ_FOREACH(td, &ts->ts_blocked[TS_EXCLUSIVE_QUEUE], td_lockq) 1274 print_waiter(td, indent + 1); 1275 TAILQ_FOREACH(td, &ts->ts_blocked[TS_SHARED_QUEUE], td_lockq) 1276 print_waiter(td, indent + 1); 1277 TAILQ_FOREACH(td, &ts->ts_pending, td_lockq) 1278 print_waiter(td, indent + 1); 1279} 1280 1281DB_SHOW_COMMAND(locktree, db_show_locktree) 1282{ 1283 struct lock_object *lock; 1284 struct lock_class *class; 1285 struct turnstile_chain *tc; 1286 struct turnstile *ts; 1287 1288 if (!have_addr) 1289 return; 1290 lock = (struct lock_object *)addr; 1291 tc = TC_LOOKUP(lock); 1292 LIST_FOREACH(ts, &tc->tc_turnstiles, ts_hash) 1293 if (ts->ts_lockobj == lock) 1294 break; 1295 if (ts == NULL) { 1296 class = LOCK_CLASS(lock); 1297 db_printf("lock %p (%s) \"%s\"\n", lock, class->lc_name, 1298 lock->lo_name); 1299 } else 1300 print_waiters(ts, 0); 1301} 1302#endif
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