1 /*- 2 * Copyright (c) 2006 John Baldwin <jhb@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27 /* 28 * This module holds the global variables and functions used to maintain 29 * lock_object structures. 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "opt_ddb.h" 36 #include "opt_mprof.h" 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/kernel.h> 41 #include <sys/ktr.h> 42 #include <sys/lock.h> 43 #include <sys/lock_profile.h> 44 #include <sys/malloc.h> 45 #include <sys/mutex.h> 46 #include <sys/pcpu.h> 47 #include <sys/proc.h> 48 #include <sys/sbuf.h> 49 #include <sys/sched.h> 50 #include <sys/smp.h> 51 #include <sys/sysctl.h> 52 53 #ifdef DDB 54 #include <ddb/ddb.h> 55 #endif 56 57 #include <machine/cpufunc.h> 58 59 CTASSERT(LOCK_CLASS_MAX == 15); 60 61 struct lock_class *lock_classes[LOCK_CLASS_MAX + 1] = { 62 &lock_class_mtx_spin, 63 &lock_class_mtx_sleep, 64 &lock_class_sx, 65 &lock_class_rm, 66 &lock_class_rm_sleepable, 67 &lock_class_rw, 68 &lock_class_lockmgr, 69 }; 70 71 void 72 lock_init(struct lock_object *lock, struct lock_class *class, const char *name, 73 const char *type, int flags) 74 { 75 int i; 76 77 /* Check for double-init and zero object. */ 78 KASSERT(flags & LO_NEW || !lock_initialized(lock), 79 ("lock \"%s\" %p already initialized", name, lock)); 80 81 /* Look up lock class to find its index. */ 82 for (i = 0; i < LOCK_CLASS_MAX; i++) 83 if (lock_classes[i] == class) { 84 lock->lo_flags = i << LO_CLASSSHIFT; 85 break; 86 } 87 KASSERT(i < LOCK_CLASS_MAX, ("unknown lock class %p", class)); 88 89 /* Initialize the lock object. */ 90 lock->lo_name = name; 91 lock->lo_flags |= flags | LO_INITIALIZED; 92 LOCK_LOG_INIT(lock, 0); 93 WITNESS_INIT(lock, (type != NULL) ? type : name); 94 } 95 96 void 97 lock_destroy(struct lock_object *lock) 98 { 99 100 KASSERT(lock_initialized(lock), ("lock %p is not initialized", lock)); 101 WITNESS_DESTROY(lock); 102 LOCK_LOG_DESTROY(lock, 0); 103 lock->lo_flags &= ~LO_INITIALIZED; 104 } 105 106 #ifdef DDB 107 DB_SHOW_COMMAND(lock, db_show_lock) 108 { 109 struct lock_object *lock; 110 struct lock_class *class; 111 112 if (!have_addr) 113 return; 114 lock = (struct lock_object *)addr; 115 if (LO_CLASSINDEX(lock) > LOCK_CLASS_MAX) { 116 db_printf("Unknown lock class: %d\n", LO_CLASSINDEX(lock)); 117 return; 118 } 119 class = LOCK_CLASS(lock); 120 db_printf(" class: %s\n", class->lc_name); 121 db_printf(" name: %s\n", lock->lo_name); 122 class->lc_ddb_show(lock); 123 } 124 #endif 125 126 #ifdef LOCK_PROFILING 127 128 /* 129 * One object per-thread for each lock the thread owns. Tracks individual 130 * lock instances. 131 */ 132 struct lock_profile_object { 133 LIST_ENTRY(lock_profile_object) lpo_link; 134 struct lock_object *lpo_obj; 135 const char *lpo_file; 136 int lpo_line; 137 uint16_t lpo_ref; 138 uint16_t lpo_cnt; 139 uint64_t lpo_acqtime; 140 uint64_t lpo_waittime; 141 u_int lpo_contest_locking; 142 }; 143 144 /* 145 * One lock_prof for each (file, line, lock object) triple. 146 */ 147 struct lock_prof { 148 SLIST_ENTRY(lock_prof) link; 149 struct lock_class *class; 150 const char *file; 151 const char *name; 152 int line; 153 int ticks; 154 uintmax_t cnt_wait_max; 155 uintmax_t cnt_max; 156 uintmax_t cnt_tot; 157 uintmax_t cnt_wait; 158 uintmax_t cnt_cur; 159 uintmax_t cnt_contest_locking; 160 }; 161 162 SLIST_HEAD(lphead, lock_prof); 163 164 #define LPROF_HASH_SIZE 4096 165 #define LPROF_HASH_MASK (LPROF_HASH_SIZE - 1) 166 #define LPROF_CACHE_SIZE 4096 167 168 /* 169 * Array of objects and profs for each type of object for each cpu. Spinlocks 170 * are handled separately because a thread may be preempted and acquire a 171 * spinlock while in the lock profiling code of a non-spinlock. In this way 172 * we only need a critical section to protect the per-cpu lists. 173 */ 174 struct lock_prof_type { 175 struct lphead lpt_lpalloc; 176 struct lpohead lpt_lpoalloc; 177 struct lphead lpt_hash[LPROF_HASH_SIZE]; 178 struct lock_prof lpt_prof[LPROF_CACHE_SIZE]; 179 struct lock_profile_object lpt_objs[LPROF_CACHE_SIZE]; 180 }; 181 182 struct lock_prof_cpu { 183 struct lock_prof_type lpc_types[2]; /* One for spin one for other. */ 184 }; 185 186 struct lock_prof_cpu *lp_cpu[MAXCPU]; 187 188 volatile int lock_prof_enable = 0; 189 static volatile int lock_prof_resetting; 190 191 #define LPROF_SBUF_SIZE 256 192 193 static int lock_prof_rejected; 194 static int lock_prof_skipspin; 195 static int lock_prof_skipcount; 196 197 #ifndef USE_CPU_NANOSECONDS 198 uint64_t 199 nanoseconds(void) 200 { 201 struct bintime bt; 202 uint64_t ns; 203 204 binuptime(&bt); 205 /* From bintime2timespec */ 206 ns = bt.sec * (uint64_t)1000000000; 207 ns += ((uint64_t)1000000000 * (uint32_t)(bt.frac >> 32)) >> 32; 208 return (ns); 209 } 210 #endif 211 212 static void 213 lock_prof_init_type(struct lock_prof_type *type) 214 { 215 int i; 216 217 SLIST_INIT(&type->lpt_lpalloc); 218 LIST_INIT(&type->lpt_lpoalloc); 219 for (i = 0; i < LPROF_CACHE_SIZE; i++) { 220 SLIST_INSERT_HEAD(&type->lpt_lpalloc, &type->lpt_prof[i], 221 link); 222 LIST_INSERT_HEAD(&type->lpt_lpoalloc, &type->lpt_objs[i], 223 lpo_link); 224 } 225 } 226 227 static void 228 lock_prof_init(void *arg) 229 { 230 int cpu; 231 232 for (cpu = 0; cpu <= mp_maxid; cpu++) { 233 lp_cpu[cpu] = malloc(sizeof(*lp_cpu[cpu]), M_DEVBUF, 234 M_WAITOK | M_ZERO); 235 lock_prof_init_type(&lp_cpu[cpu]->lpc_types[0]); 236 lock_prof_init_type(&lp_cpu[cpu]->lpc_types[1]); 237 } 238 } 239 SYSINIT(lockprof, SI_SUB_SMP, SI_ORDER_ANY, lock_prof_init, NULL); 240 241 static void 242 lock_prof_reset_wait(void) 243 { 244 245 /* 246 * Spin relinquishing our cpu so that quiesce_all_cpus may 247 * complete. 248 */ 249 while (lock_prof_resetting) 250 sched_relinquish(curthread); 251 } 252 253 static void 254 lock_prof_reset(void) 255 { 256 struct lock_prof_cpu *lpc; 257 int enabled, i, cpu; 258 259 /* 260 * We not only race with acquiring and releasing locks but also 261 * thread exit. To be certain that threads exit without valid head 262 * pointers they must see resetting set before enabled is cleared. 263 * Otherwise a lock may not be removed from a per-thread list due 264 * to disabled being set but not wait for reset() to remove it below. 265 */ 266 atomic_store_rel_int(&lock_prof_resetting, 1); 267 enabled = lock_prof_enable; 268 lock_prof_enable = 0; 269 quiesce_all_cpus("profreset", 0); 270 /* 271 * Some objects may have migrated between CPUs. Clear all links 272 * before we zero the structures. Some items may still be linked 273 * into per-thread lists as well. 274 */ 275 for (cpu = 0; cpu <= mp_maxid; cpu++) { 276 lpc = lp_cpu[cpu]; 277 for (i = 0; i < LPROF_CACHE_SIZE; i++) { 278 LIST_REMOVE(&lpc->lpc_types[0].lpt_objs[i], lpo_link); 279 LIST_REMOVE(&lpc->lpc_types[1].lpt_objs[i], lpo_link); 280 } 281 } 282 for (cpu = 0; cpu <= mp_maxid; cpu++) { 283 lpc = lp_cpu[cpu]; 284 bzero(lpc, sizeof(*lpc)); 285 lock_prof_init_type(&lpc->lpc_types[0]); 286 lock_prof_init_type(&lpc->lpc_types[1]); 287 } 288 atomic_store_rel_int(&lock_prof_resetting, 0); 289 lock_prof_enable = enabled; 290 } 291 292 static void 293 lock_prof_output(struct lock_prof *lp, struct sbuf *sb) 294 { 295 const char *p; 296 297 for (p = lp->file; p != NULL && strncmp(p, "../", 3) == 0; p += 3); 298 sbuf_printf(sb, 299 "%8ju %9ju %11ju %11ju %11ju %6ju %6ju %2ju %6ju %s:%d (%s:%s)\n", 300 lp->cnt_max / 1000, lp->cnt_wait_max / 1000, lp->cnt_tot / 1000, 301 lp->cnt_wait / 1000, lp->cnt_cur, 302 lp->cnt_cur == 0 ? (uintmax_t)0 : 303 lp->cnt_tot / (lp->cnt_cur * 1000), 304 lp->cnt_cur == 0 ? (uintmax_t)0 : 305 lp->cnt_wait / (lp->cnt_cur * 1000), 306 (uintmax_t)0, lp->cnt_contest_locking, 307 p, lp->line, lp->class->lc_name, lp->name); 308 } 309 310 static void 311 lock_prof_sum(struct lock_prof *match, struct lock_prof *dst, int hash, 312 int spin, int t) 313 { 314 struct lock_prof_type *type; 315 struct lock_prof *l; 316 int cpu; 317 318 dst->file = match->file; 319 dst->line = match->line; 320 dst->class = match->class; 321 dst->name = match->name; 322 323 for (cpu = 0; cpu <= mp_maxid; cpu++) { 324 if (lp_cpu[cpu] == NULL) 325 continue; 326 type = &lp_cpu[cpu]->lpc_types[spin]; 327 SLIST_FOREACH(l, &type->lpt_hash[hash], link) { 328 if (l->ticks == t) 329 continue; 330 if (l->file != match->file || l->line != match->line || 331 l->name != match->name) 332 continue; 333 l->ticks = t; 334 if (l->cnt_max > dst->cnt_max) 335 dst->cnt_max = l->cnt_max; 336 if (l->cnt_wait_max > dst->cnt_wait_max) 337 dst->cnt_wait_max = l->cnt_wait_max; 338 dst->cnt_tot += l->cnt_tot; 339 dst->cnt_wait += l->cnt_wait; 340 dst->cnt_cur += l->cnt_cur; 341 dst->cnt_contest_locking += l->cnt_contest_locking; 342 } 343 } 344 345 } 346 347 static void 348 lock_prof_type_stats(struct lock_prof_type *type, struct sbuf *sb, int spin, 349 int t) 350 { 351 struct lock_prof *l; 352 int i; 353 354 for (i = 0; i < LPROF_HASH_SIZE; ++i) { 355 SLIST_FOREACH(l, &type->lpt_hash[i], link) { 356 struct lock_prof lp = {}; 357 358 if (l->ticks == t) 359 continue; 360 lock_prof_sum(l, &lp, i, spin, t); 361 lock_prof_output(&lp, sb); 362 } 363 } 364 } 365 366 static int 367 dump_lock_prof_stats(SYSCTL_HANDLER_ARGS) 368 { 369 struct sbuf *sb; 370 int error, cpu, t; 371 int enabled; 372 373 error = sysctl_wire_old_buffer(req, 0); 374 if (error != 0) 375 return (error); 376 sb = sbuf_new_for_sysctl(NULL, NULL, LPROF_SBUF_SIZE, req); 377 sbuf_printf(sb, "\n%8s %9s %11s %11s %11s %6s %6s %2s %6s %s\n", 378 "max", "wait_max", "total", "wait_total", "count", "avg", "wait_avg", "cnt_hold", "cnt_lock", "name"); 379 enabled = lock_prof_enable; 380 lock_prof_enable = 0; 381 quiesce_all_cpus("profstat", 0); 382 t = ticks; 383 for (cpu = 0; cpu <= mp_maxid; cpu++) { 384 if (lp_cpu[cpu] == NULL) 385 continue; 386 lock_prof_type_stats(&lp_cpu[cpu]->lpc_types[0], sb, 0, t); 387 lock_prof_type_stats(&lp_cpu[cpu]->lpc_types[1], sb, 1, t); 388 } 389 lock_prof_enable = enabled; 390 391 error = sbuf_finish(sb); 392 /* Output a trailing NUL. */ 393 if (error == 0) 394 error = SYSCTL_OUT(req, "", 1); 395 sbuf_delete(sb); 396 return (error); 397 } 398 399 static int 400 enable_lock_prof(SYSCTL_HANDLER_ARGS) 401 { 402 int error, v; 403 404 v = lock_prof_enable; 405 error = sysctl_handle_int(oidp, &v, v, req); 406 if (error) 407 return (error); 408 if (req->newptr == NULL) 409 return (error); 410 if (v == lock_prof_enable) 411 return (0); 412 if (v == 1) 413 lock_prof_reset(); 414 lock_prof_enable = !!v; 415 416 return (0); 417 } 418 419 static int 420 reset_lock_prof_stats(SYSCTL_HANDLER_ARGS) 421 { 422 int error, v; 423 424 v = 0; 425 error = sysctl_handle_int(oidp, &v, 0, req); 426 if (error) 427 return (error); 428 if (req->newptr == NULL) 429 return (error); 430 if (v == 0) 431 return (0); 432 lock_prof_reset(); 433 434 return (0); 435 } 436 437 static struct lock_prof * 438 lock_profile_lookup(struct lock_object *lo, int spin, const char *file, 439 int line) 440 { 441 const char *unknown = "(unknown)"; 442 struct lock_prof_type *type; 443 struct lock_prof *lp; 444 struct lphead *head; 445 const char *p; 446 u_int hash; 447 448 p = file; 449 if (p == NULL || *p == '\0') 450 p = unknown; 451 hash = (uintptr_t)lo->lo_name * 31 + (uintptr_t)p * 31 + line; 452 hash &= LPROF_HASH_MASK; 453 type = &lp_cpu[PCPU_GET(cpuid)]->lpc_types[spin]; 454 head = &type->lpt_hash[hash]; 455 SLIST_FOREACH(lp, head, link) { 456 if (lp->line == line && lp->file == p && 457 lp->name == lo->lo_name) 458 return (lp); 459 460 } 461 lp = SLIST_FIRST(&type->lpt_lpalloc); 462 if (lp == NULL) { 463 lock_prof_rejected++; 464 return (lp); 465 } 466 SLIST_REMOVE_HEAD(&type->lpt_lpalloc, link); 467 lp->file = p; 468 lp->line = line; 469 lp->class = LOCK_CLASS(lo); 470 lp->name = lo->lo_name; 471 SLIST_INSERT_HEAD(&type->lpt_hash[hash], lp, link); 472 return (lp); 473 } 474 475 static struct lock_profile_object * 476 lock_profile_object_lookup(struct lock_object *lo, int spin, const char *file, 477 int line) 478 { 479 struct lock_profile_object *l; 480 struct lock_prof_type *type; 481 struct lpohead *head; 482 483 head = &curthread->td_lprof[spin]; 484 LIST_FOREACH(l, head, lpo_link) 485 if (l->lpo_obj == lo && l->lpo_file == file && 486 l->lpo_line == line) 487 return (l); 488 type = &lp_cpu[PCPU_GET(cpuid)]->lpc_types[spin]; 489 l = LIST_FIRST(&type->lpt_lpoalloc); 490 if (l == NULL) { 491 lock_prof_rejected++; 492 return (NULL); 493 } 494 LIST_REMOVE(l, lpo_link); 495 l->lpo_obj = lo; 496 l->lpo_file = file; 497 l->lpo_line = line; 498 l->lpo_cnt = 0; 499 LIST_INSERT_HEAD(head, l, lpo_link); 500 501 return (l); 502 } 503 504 void 505 lock_profile_obtain_lock_success(struct lock_object *lo, int contested, 506 uint64_t waittime, const char *file, int line) 507 { 508 static int lock_prof_count; 509 struct lock_profile_object *l; 510 int spin; 511 512 if (SCHEDULER_STOPPED()) 513 return; 514 515 /* don't reset the timer when/if recursing */ 516 if (!lock_prof_enable || (lo->lo_flags & LO_NOPROFILE)) 517 return; 518 if (lock_prof_skipcount && 519 (++lock_prof_count % lock_prof_skipcount) != 0) 520 return; 521 spin = (LOCK_CLASS(lo)->lc_flags & LC_SPINLOCK) ? 1 : 0; 522 if (spin && lock_prof_skipspin == 1) 523 return; 524 critical_enter(); 525 /* Recheck enabled now that we're in a critical section. */ 526 if (lock_prof_enable == 0) 527 goto out; 528 l = lock_profile_object_lookup(lo, spin, file, line); 529 if (l == NULL) 530 goto out; 531 l->lpo_cnt++; 532 if (++l->lpo_ref > 1) 533 goto out; 534 l->lpo_contest_locking = contested; 535 l->lpo_acqtime = nanoseconds(); 536 if (waittime && (l->lpo_acqtime > waittime)) 537 l->lpo_waittime = l->lpo_acqtime - waittime; 538 else 539 l->lpo_waittime = 0; 540 out: 541 critical_exit(); 542 } 543 544 void 545 lock_profile_thread_exit(struct thread *td) 546 { 547 #ifdef INVARIANTS 548 struct lock_profile_object *l; 549 550 MPASS(curthread->td_critnest == 0); 551 #endif 552 /* 553 * If lock profiling was disabled we have to wait for reset to 554 * clear our pointers before we can exit safely. 555 */ 556 lock_prof_reset_wait(); 557 #ifdef INVARIANTS 558 LIST_FOREACH(l, &td->td_lprof[0], lpo_link) 559 printf("thread still holds lock acquired at %s:%d\n", 560 l->lpo_file, l->lpo_line); 561 LIST_FOREACH(l, &td->td_lprof[1], lpo_link) 562 printf("thread still holds lock acquired at %s:%d\n", 563 l->lpo_file, l->lpo_line); 564 #endif 565 MPASS(LIST_FIRST(&td->td_lprof[0]) == NULL); 566 MPASS(LIST_FIRST(&td->td_lprof[1]) == NULL); 567 } 568 569 void 570 lock_profile_release_lock(struct lock_object *lo) 571 { 572 struct lock_profile_object *l; 573 struct lock_prof_type *type; 574 struct lock_prof *lp; 575 uint64_t curtime, holdtime; 576 struct lpohead *head; 577 int spin; 578 579 if (SCHEDULER_STOPPED()) 580 return; 581 if (lo->lo_flags & LO_NOPROFILE) 582 return; 583 spin = (LOCK_CLASS(lo)->lc_flags & LC_SPINLOCK) ? 1 : 0; 584 head = &curthread->td_lprof[spin]; 585 if (LIST_FIRST(head) == NULL) 586 return; 587 critical_enter(); 588 /* Recheck enabled now that we're in a critical section. */ 589 if (lock_prof_enable == 0 && lock_prof_resetting == 1) 590 goto out; 591 /* 592 * If lock profiling is not enabled we still want to remove the 593 * lpo from our queue. 594 */ 595 LIST_FOREACH(l, head, lpo_link) 596 if (l->lpo_obj == lo) 597 break; 598 if (l == NULL) 599 goto out; 600 if (--l->lpo_ref > 0) 601 goto out; 602 lp = lock_profile_lookup(lo, spin, l->lpo_file, l->lpo_line); 603 if (lp == NULL) 604 goto release; 605 curtime = nanoseconds(); 606 if (curtime < l->lpo_acqtime) 607 goto release; 608 holdtime = curtime - l->lpo_acqtime; 609 610 /* 611 * Record if the lock has been held longer now than ever 612 * before. 613 */ 614 if (holdtime > lp->cnt_max) 615 lp->cnt_max = holdtime; 616 if (l->lpo_waittime > lp->cnt_wait_max) 617 lp->cnt_wait_max = l->lpo_waittime; 618 lp->cnt_tot += holdtime; 619 lp->cnt_wait += l->lpo_waittime; 620 lp->cnt_contest_locking += l->lpo_contest_locking; 621 lp->cnt_cur += l->lpo_cnt; 622 release: 623 LIST_REMOVE(l, lpo_link); 624 type = &lp_cpu[PCPU_GET(cpuid)]->lpc_types[spin]; 625 LIST_INSERT_HEAD(&type->lpt_lpoalloc, l, lpo_link); 626 out: 627 critical_exit(); 628 } 629 630 static SYSCTL_NODE(_debug, OID_AUTO, lock, CTLFLAG_RD, NULL, "lock debugging"); 631 static SYSCTL_NODE(_debug_lock, OID_AUTO, prof, CTLFLAG_RD, NULL, 632 "lock profiling"); 633 SYSCTL_INT(_debug_lock_prof, OID_AUTO, skipspin, CTLFLAG_RW, 634 &lock_prof_skipspin, 0, "Skip profiling on spinlocks."); 635 SYSCTL_INT(_debug_lock_prof, OID_AUTO, skipcount, CTLFLAG_RW, 636 &lock_prof_skipcount, 0, "Sample approximately every N lock acquisitions."); 637 SYSCTL_INT(_debug_lock_prof, OID_AUTO, rejected, CTLFLAG_RD, 638 &lock_prof_rejected, 0, "Number of rejected profiling records"); 639 SYSCTL_PROC(_debug_lock_prof, OID_AUTO, stats, CTLTYPE_STRING | CTLFLAG_RD, 640 NULL, 0, dump_lock_prof_stats, "A", "Lock profiling statistics"); 641 SYSCTL_PROC(_debug_lock_prof, OID_AUTO, reset, CTLTYPE_INT | CTLFLAG_RW, 642 NULL, 0, reset_lock_prof_stats, "I", "Reset lock profiling statistics"); 643 SYSCTL_PROC(_debug_lock_prof, OID_AUTO, enable, CTLTYPE_INT | CTLFLAG_RW, 644 NULL, 0, enable_lock_prof, "I", "Enable lock profiling"); 645 646 #endif 647