1 /* 2 * Copyright (C) 2001 Julian Elischer <julian@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(s), this list of conditions and the following disclaimer as 10 * the first lines of this file unmodified other than the possible 11 * addition of one or more copyright notices. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice(s), this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY 17 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 19 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY 20 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 22 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 23 * 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 SUCH 26 * DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/kernel.h> 35 #include <sys/lock.h> 36 #include <sys/malloc.h> 37 #include <sys/mutex.h> 38 #include <sys/proc.h> 39 #include <sys/smp.h> 40 #include <sys/sysctl.h> 41 #include <sys/sysproto.h> 42 #include <sys/filedesc.h> 43 #include <sys/sched.h> 44 #include <sys/signalvar.h> 45 #include <sys/sleepqueue.h> 46 #include <sys/sx.h> 47 #include <sys/tty.h> 48 #include <sys/turnstile.h> 49 #include <sys/user.h> 50 #include <sys/kse.h> 51 #include <sys/ktr.h> 52 #include <sys/ucontext.h> 53 54 #include <vm/vm.h> 55 #include <vm/vm_extern.h> 56 #include <vm/vm_object.h> 57 #include <vm/pmap.h> 58 #include <vm/uma.h> 59 #include <vm/vm_map.h> 60 61 #include <machine/frame.h> 62 63 /* 64 * KSEGRP related storage. 65 */ 66 static uma_zone_t ksegrp_zone; 67 static uma_zone_t kse_zone; 68 static uma_zone_t thread_zone; 69 static uma_zone_t upcall_zone; 70 71 /* DEBUG ONLY */ 72 SYSCTL_NODE(_kern, OID_AUTO, threads, CTLFLAG_RW, 0, "thread allocation"); 73 static int thread_debug = 0; 74 SYSCTL_INT(_kern_threads, OID_AUTO, debug, CTLFLAG_RW, 75 &thread_debug, 0, "thread debug"); 76 77 static int max_threads_per_proc = 1500; 78 SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_per_proc, CTLFLAG_RW, 79 &max_threads_per_proc, 0, "Limit on threads per proc"); 80 81 static int max_groups_per_proc = 500; 82 SYSCTL_INT(_kern_threads, OID_AUTO, max_groups_per_proc, CTLFLAG_RW, 83 &max_groups_per_proc, 0, "Limit on thread groups per proc"); 84 85 static int max_threads_hits; 86 SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_hits, CTLFLAG_RD, 87 &max_threads_hits, 0, ""); 88 89 static int virtual_cpu; 90 91 #define RANGEOF(type, start, end) (offsetof(type, end) - offsetof(type, start)) 92 93 TAILQ_HEAD(, thread) zombie_threads = TAILQ_HEAD_INITIALIZER(zombie_threads); 94 TAILQ_HEAD(, kse) zombie_kses = TAILQ_HEAD_INITIALIZER(zombie_kses); 95 TAILQ_HEAD(, ksegrp) zombie_ksegrps = TAILQ_HEAD_INITIALIZER(zombie_ksegrps); 96 TAILQ_HEAD(, kse_upcall) zombie_upcalls = 97 TAILQ_HEAD_INITIALIZER(zombie_upcalls); 98 struct mtx kse_zombie_lock; 99 MTX_SYSINIT(kse_zombie_lock, &kse_zombie_lock, "kse zombie lock", MTX_SPIN); 100 101 static void kse_purge(struct proc *p, struct thread *td); 102 static void kse_purge_group(struct thread *td); 103 static int thread_update_usr_ticks(struct thread *td, int user); 104 static void thread_alloc_spare(struct thread *td, struct thread *spare); 105 106 static int 107 sysctl_kse_virtual_cpu(SYSCTL_HANDLER_ARGS) 108 { 109 int error, new_val; 110 int def_val; 111 112 #ifdef SMP 113 def_val = mp_ncpus; 114 #else 115 def_val = 1; 116 #endif 117 if (virtual_cpu == 0) 118 new_val = def_val; 119 else 120 new_val = virtual_cpu; 121 error = sysctl_handle_int(oidp, &new_val, 0, req); 122 if (error != 0 || req->newptr == NULL) 123 return (error); 124 if (new_val < 0) 125 return (EINVAL); 126 virtual_cpu = new_val; 127 return (0); 128 } 129 130 /* DEBUG ONLY */ 131 SYSCTL_PROC(_kern_threads, OID_AUTO, virtual_cpu, CTLTYPE_INT|CTLFLAG_RW, 132 0, sizeof(virtual_cpu), sysctl_kse_virtual_cpu, "I", 133 "debug virtual cpus"); 134 135 /* 136 * Thread ID allocator. The allocator keeps track of assigned IDs by 137 * using a bitmap. The bitmap is created in parts. The parts are linked 138 * together. 139 */ 140 typedef u_long tid_bitmap_word; 141 142 #define TID_IDS_PER_PART 1024 143 #define TID_IDS_PER_IDX (sizeof(tid_bitmap_word) << 3) 144 #define TID_BITMAP_SIZE (TID_IDS_PER_PART / TID_IDS_PER_IDX) 145 #define TID_MIN (PID_MAX + 1) 146 147 struct tid_bitmap_part { 148 STAILQ_ENTRY(tid_bitmap_part) bmp_next; 149 tid_bitmap_word bmp_bitmap[TID_BITMAP_SIZE]; 150 int bmp_base; 151 int bmp_free; 152 }; 153 154 static STAILQ_HEAD(, tid_bitmap_part) tid_bitmap = 155 STAILQ_HEAD_INITIALIZER(tid_bitmap); 156 static uma_zone_t tid_zone; 157 158 struct mtx tid_lock; 159 MTX_SYSINIT(tid_lock, &tid_lock, "TID lock", MTX_DEF); 160 161 /* 162 * Prepare a thread for use. 163 */ 164 static void 165 thread_ctor(void *mem, int size, void *arg) 166 { 167 struct thread *td; 168 169 td = (struct thread *)mem; 170 td->td_tid = 0; 171 td->td_state = TDS_INACTIVE; 172 td->td_oncpu = NOCPU; 173 td->td_critnest = 1; 174 } 175 176 /* 177 * Reclaim a thread after use. 178 */ 179 static void 180 thread_dtor(void *mem, int size, void *arg) 181 { 182 struct thread *td; 183 struct tid_bitmap_part *bmp; 184 int bit, idx, tid; 185 186 td = (struct thread *)mem; 187 188 if (td->td_tid > PID_MAX) { 189 STAILQ_FOREACH(bmp, &tid_bitmap, bmp_next) { 190 if (td->td_tid >= bmp->bmp_base && 191 td->td_tid < bmp->bmp_base + TID_IDS_PER_PART) 192 break; 193 } 194 KASSERT(bmp != NULL, ("No TID bitmap?")); 195 mtx_lock(&tid_lock); 196 tid = td->td_tid - bmp->bmp_base; 197 idx = tid / TID_IDS_PER_IDX; 198 bit = 1UL << (tid % TID_IDS_PER_IDX); 199 bmp->bmp_bitmap[idx] |= bit; 200 bmp->bmp_free++; 201 mtx_unlock(&tid_lock); 202 } 203 204 #ifdef INVARIANTS 205 /* Verify that this thread is in a safe state to free. */ 206 switch (td->td_state) { 207 case TDS_INHIBITED: 208 case TDS_RUNNING: 209 case TDS_CAN_RUN: 210 case TDS_RUNQ: 211 /* 212 * We must never unlink a thread that is in one of 213 * these states, because it is currently active. 214 */ 215 panic("bad state for thread unlinking"); 216 /* NOTREACHED */ 217 case TDS_INACTIVE: 218 break; 219 default: 220 panic("bad thread state"); 221 /* NOTREACHED */ 222 } 223 #endif 224 } 225 226 /* 227 * Initialize type-stable parts of a thread (when newly created). 228 */ 229 static void 230 thread_init(void *mem, int size) 231 { 232 struct thread *td; 233 234 td = (struct thread *)mem; 235 vm_thread_new(td, 0); 236 cpu_thread_setup(td); 237 td->td_sleepqueue = sleepq_alloc(); 238 td->td_turnstile = turnstile_alloc(); 239 td->td_sched = (struct td_sched *)&td[1]; 240 } 241 242 /* 243 * Tear down type-stable parts of a thread (just before being discarded). 244 */ 245 static void 246 thread_fini(void *mem, int size) 247 { 248 struct thread *td; 249 250 td = (struct thread *)mem; 251 turnstile_free(td->td_turnstile); 252 sleepq_free(td->td_sleepqueue); 253 vm_thread_dispose(td); 254 } 255 256 /* 257 * Initialize type-stable parts of a kse (when newly created). 258 */ 259 static void 260 kse_init(void *mem, int size) 261 { 262 struct kse *ke; 263 264 ke = (struct kse *)mem; 265 ke->ke_sched = (struct ke_sched *)&ke[1]; 266 } 267 268 /* 269 * Initialize type-stable parts of a ksegrp (when newly created). 270 */ 271 static void 272 ksegrp_init(void *mem, int size) 273 { 274 struct ksegrp *kg; 275 276 kg = (struct ksegrp *)mem; 277 kg->kg_sched = (struct kg_sched *)&kg[1]; 278 } 279 280 /* 281 * KSE is linked into kse group. 282 */ 283 void 284 kse_link(struct kse *ke, struct ksegrp *kg) 285 { 286 struct proc *p = kg->kg_proc; 287 288 TAILQ_INSERT_HEAD(&kg->kg_kseq, ke, ke_kglist); 289 kg->kg_kses++; 290 ke->ke_state = KES_UNQUEUED; 291 ke->ke_proc = p; 292 ke->ke_ksegrp = kg; 293 ke->ke_thread = NULL; 294 ke->ke_oncpu = NOCPU; 295 ke->ke_flags = 0; 296 } 297 298 void 299 kse_unlink(struct kse *ke) 300 { 301 struct ksegrp *kg; 302 303 mtx_assert(&sched_lock, MA_OWNED); 304 kg = ke->ke_ksegrp; 305 TAILQ_REMOVE(&kg->kg_kseq, ke, ke_kglist); 306 if (ke->ke_state == KES_IDLE) { 307 TAILQ_REMOVE(&kg->kg_iq, ke, ke_kgrlist); 308 kg->kg_idle_kses--; 309 } 310 --kg->kg_kses; 311 /* 312 * Aggregate stats from the KSE 313 */ 314 kse_stash(ke); 315 } 316 317 void 318 ksegrp_link(struct ksegrp *kg, struct proc *p) 319 { 320 321 TAILQ_INIT(&kg->kg_threads); 322 TAILQ_INIT(&kg->kg_runq); /* links with td_runq */ 323 TAILQ_INIT(&kg->kg_slpq); /* links with td_runq */ 324 TAILQ_INIT(&kg->kg_kseq); /* all kses in ksegrp */ 325 TAILQ_INIT(&kg->kg_iq); /* all idle kses in ksegrp */ 326 TAILQ_INIT(&kg->kg_upcalls); /* all upcall structure in ksegrp */ 327 kg->kg_proc = p; 328 /* 329 * the following counters are in the -zero- section 330 * and may not need clearing 331 */ 332 kg->kg_numthreads = 0; 333 kg->kg_runnable = 0; 334 kg->kg_kses = 0; 335 kg->kg_runq_kses = 0; /* XXXKSE change name */ 336 kg->kg_idle_kses = 0; 337 kg->kg_numupcalls = 0; 338 /* link it in now that it's consistent */ 339 p->p_numksegrps++; 340 TAILQ_INSERT_HEAD(&p->p_ksegrps, kg, kg_ksegrp); 341 } 342 343 void 344 ksegrp_unlink(struct ksegrp *kg) 345 { 346 struct proc *p; 347 348 mtx_assert(&sched_lock, MA_OWNED); 349 KASSERT((kg->kg_numthreads == 0), ("ksegrp_unlink: residual threads")); 350 KASSERT((kg->kg_kses == 0), ("ksegrp_unlink: residual kses")); 351 KASSERT((kg->kg_numupcalls == 0), ("ksegrp_unlink: residual upcalls")); 352 353 p = kg->kg_proc; 354 TAILQ_REMOVE(&p->p_ksegrps, kg, kg_ksegrp); 355 p->p_numksegrps--; 356 /* 357 * Aggregate stats from the KSE 358 */ 359 ksegrp_stash(kg); 360 } 361 362 struct kse_upcall * 363 upcall_alloc(void) 364 { 365 struct kse_upcall *ku; 366 367 ku = uma_zalloc(upcall_zone, M_WAITOK); 368 bzero(ku, sizeof(*ku)); 369 return (ku); 370 } 371 372 void 373 upcall_free(struct kse_upcall *ku) 374 { 375 376 uma_zfree(upcall_zone, ku); 377 } 378 379 void 380 upcall_link(struct kse_upcall *ku, struct ksegrp *kg) 381 { 382 383 mtx_assert(&sched_lock, MA_OWNED); 384 TAILQ_INSERT_TAIL(&kg->kg_upcalls, ku, ku_link); 385 ku->ku_ksegrp = kg; 386 kg->kg_numupcalls++; 387 } 388 389 void 390 upcall_unlink(struct kse_upcall *ku) 391 { 392 struct ksegrp *kg = ku->ku_ksegrp; 393 394 mtx_assert(&sched_lock, MA_OWNED); 395 KASSERT(ku->ku_owner == NULL, ("%s: have owner", __func__)); 396 TAILQ_REMOVE(&kg->kg_upcalls, ku, ku_link); 397 kg->kg_numupcalls--; 398 upcall_stash(ku); 399 } 400 401 void 402 upcall_remove(struct thread *td) 403 { 404 405 if (td->td_upcall) { 406 td->td_upcall->ku_owner = NULL; 407 upcall_unlink(td->td_upcall); 408 td->td_upcall = 0; 409 } 410 } 411 412 /* 413 * For a newly created process, 414 * link up all the structures and its initial threads etc. 415 */ 416 void 417 proc_linkup(struct proc *p, struct ksegrp *kg, 418 struct kse *ke, struct thread *td) 419 { 420 421 TAILQ_INIT(&p->p_ksegrps); /* all ksegrps in proc */ 422 TAILQ_INIT(&p->p_threads); /* all threads in proc */ 423 TAILQ_INIT(&p->p_suspended); /* Threads suspended */ 424 p->p_numksegrps = 0; 425 p->p_numthreads = 0; 426 427 ksegrp_link(kg, p); 428 kse_link(ke, kg); 429 thread_link(td, kg); 430 } 431 432 #ifndef _SYS_SYSPROTO_H_ 433 struct kse_switchin_args { 434 const struct __mcontext *mcp; 435 long val; 436 long *loc; 437 }; 438 #endif 439 440 int 441 kse_switchin(struct thread *td, struct kse_switchin_args *uap) 442 { 443 mcontext_t mc; 444 int error; 445 446 error = (uap->mcp == NULL) ? EINVAL : 0; 447 if (!error) 448 error = copyin(uap->mcp, &mc, sizeof(mc)); 449 if (!error && uap->loc != NULL) 450 error = (suword(uap->loc, uap->val) != 0) ? EINVAL : 0; 451 if (!error) 452 error = set_mcontext(td, &mc); 453 return ((error == 0) ? EJUSTRETURN : error); 454 } 455 456 /* 457 struct kse_thr_interrupt_args { 458 struct kse_thr_mailbox * tmbx; 459 int cmd; 460 long data; 461 }; 462 */ 463 int 464 kse_thr_interrupt(struct thread *td, struct kse_thr_interrupt_args *uap) 465 { 466 struct proc *p; 467 struct thread *td2; 468 469 p = td->td_proc; 470 471 if (!(p->p_flag & P_SA)) 472 return (EINVAL); 473 474 switch (uap->cmd) { 475 case KSE_INTR_SENDSIG: 476 if (uap->data < 0 || uap->data > _SIG_MAXSIG) 477 return (EINVAL); 478 case KSE_INTR_INTERRUPT: 479 case KSE_INTR_RESTART: 480 PROC_LOCK(p); 481 mtx_lock_spin(&sched_lock); 482 FOREACH_THREAD_IN_PROC(p, td2) { 483 if (td2->td_mailbox == uap->tmbx) 484 break; 485 } 486 if (td2 == NULL) { 487 mtx_unlock_spin(&sched_lock); 488 PROC_UNLOCK(p); 489 return (ESRCH); 490 } 491 if (uap->cmd == KSE_INTR_SENDSIG) { 492 if (uap->data > 0) { 493 td2->td_flags &= ~TDF_INTERRUPT; 494 mtx_unlock_spin(&sched_lock); 495 tdsignal(td2, (int)uap->data, SIGTARGET_TD); 496 } else { 497 mtx_unlock_spin(&sched_lock); 498 } 499 } else { 500 td2->td_flags |= TDF_INTERRUPT | TDF_ASTPENDING; 501 if (TD_CAN_UNBIND(td2)) 502 td2->td_upcall->ku_flags |= KUF_DOUPCALL; 503 if (uap->cmd == KSE_INTR_INTERRUPT) 504 td2->td_intrval = EINTR; 505 else 506 td2->td_intrval = ERESTART; 507 if (TD_ON_SLEEPQ(td2) && (td2->td_flags & TDF_SINTR)) 508 sleepq_abort(td2); 509 mtx_unlock_spin(&sched_lock); 510 } 511 PROC_UNLOCK(p); 512 break; 513 case KSE_INTR_SIGEXIT: 514 if (uap->data < 1 || uap->data > _SIG_MAXSIG) 515 return (EINVAL); 516 PROC_LOCK(p); 517 sigexit(td, (int)uap->data); 518 break; 519 default: 520 return (EINVAL); 521 } 522 return (0); 523 } 524 525 /* 526 struct kse_exit_args { 527 register_t dummy; 528 }; 529 */ 530 int 531 kse_exit(struct thread *td, struct kse_exit_args *uap) 532 { 533 struct proc *p; 534 struct ksegrp *kg; 535 struct kse *ke; 536 struct kse_upcall *ku, *ku2; 537 int error, count; 538 539 p = td->td_proc; 540 if ((ku = td->td_upcall) == NULL || TD_CAN_UNBIND(td)) 541 return (EINVAL); 542 kg = td->td_ksegrp; 543 count = 0; 544 PROC_LOCK(p); 545 mtx_lock_spin(&sched_lock); 546 FOREACH_UPCALL_IN_GROUP(kg, ku2) { 547 if (ku2->ku_flags & KUF_EXITING) 548 count++; 549 } 550 if ((kg->kg_numupcalls - count) == 1 && 551 (kg->kg_numthreads > 1)) { 552 mtx_unlock_spin(&sched_lock); 553 PROC_UNLOCK(p); 554 return (EDEADLK); 555 } 556 ku->ku_flags |= KUF_EXITING; 557 mtx_unlock_spin(&sched_lock); 558 PROC_UNLOCK(p); 559 error = suword(&ku->ku_mailbox->km_flags, ku->ku_mflags|KMF_DONE); 560 PROC_LOCK(p); 561 if (error) 562 psignal(p, SIGSEGV); 563 mtx_lock_spin(&sched_lock); 564 upcall_remove(td); 565 ke = td->td_kse; 566 if (p->p_numthreads == 1) { 567 kse_purge(p, td); 568 p->p_flag &= ~P_SA; 569 mtx_unlock_spin(&sched_lock); 570 PROC_UNLOCK(p); 571 } else { 572 if (kg->kg_numthreads == 1) { /* Shutdown a group */ 573 kse_purge_group(td); 574 ke->ke_flags |= KEF_EXIT; 575 } 576 thread_stopped(p); 577 thread_exit(); 578 /* NOTREACHED */ 579 } 580 return (0); 581 } 582 583 /* 584 * Either becomes an upcall or waits for an awakening event and 585 * then becomes an upcall. Only error cases return. 586 */ 587 /* 588 struct kse_release_args { 589 struct timespec *timeout; 590 }; 591 */ 592 int 593 kse_release(struct thread *td, struct kse_release_args *uap) 594 { 595 struct proc *p; 596 struct ksegrp *kg; 597 struct kse_upcall *ku; 598 struct timespec timeout; 599 struct timeval tv; 600 sigset_t sigset; 601 int error; 602 603 p = td->td_proc; 604 kg = td->td_ksegrp; 605 if ((ku = td->td_upcall) == NULL || TD_CAN_UNBIND(td)) 606 return (EINVAL); 607 if (uap->timeout != NULL) { 608 if ((error = copyin(uap->timeout, &timeout, sizeof(timeout)))) 609 return (error); 610 TIMESPEC_TO_TIMEVAL(&tv, &timeout); 611 } 612 if (td->td_flags & TDF_SA) 613 td->td_pflags |= TDP_UPCALLING; 614 else { 615 ku->ku_mflags = fuword(&ku->ku_mailbox->km_flags); 616 if (ku->ku_mflags == -1) { 617 PROC_LOCK(p); 618 sigexit(td, SIGSEGV); 619 } 620 } 621 PROC_LOCK(p); 622 if (ku->ku_mflags & KMF_WAITSIGEVENT) { 623 /* UTS wants to wait for signal event */ 624 if (!(p->p_flag & P_SIGEVENT) && !(ku->ku_flags & KUF_DOUPCALL)) 625 error = msleep(&p->p_siglist, &p->p_mtx, PPAUSE|PCATCH, 626 "ksesigwait", (uap->timeout ? tvtohz(&tv) : 0)); 627 p->p_flag &= ~P_SIGEVENT; 628 sigset = p->p_siglist; 629 PROC_UNLOCK(p); 630 error = copyout(&sigset, &ku->ku_mailbox->km_sigscaught, 631 sizeof(sigset)); 632 } else { 633 if (! kg->kg_completed && !(ku->ku_flags & KUF_DOUPCALL)) { 634 kg->kg_upsleeps++; 635 error = msleep(&kg->kg_completed, &p->p_mtx, 636 PPAUSE|PCATCH, "kserel", 637 (uap->timeout ? tvtohz(&tv) : 0)); 638 kg->kg_upsleeps--; 639 } 640 PROC_UNLOCK(p); 641 } 642 if (ku->ku_flags & KUF_DOUPCALL) { 643 mtx_lock_spin(&sched_lock); 644 ku->ku_flags &= ~KUF_DOUPCALL; 645 mtx_unlock_spin(&sched_lock); 646 } 647 return (0); 648 } 649 650 /* struct kse_wakeup_args { 651 struct kse_mailbox *mbx; 652 }; */ 653 int 654 kse_wakeup(struct thread *td, struct kse_wakeup_args *uap) 655 { 656 struct proc *p; 657 struct ksegrp *kg; 658 struct kse_upcall *ku; 659 struct thread *td2; 660 661 p = td->td_proc; 662 td2 = NULL; 663 ku = NULL; 664 /* KSE-enabled processes only, please. */ 665 if (!(p->p_flag & P_SA)) 666 return (EINVAL); 667 PROC_LOCK(p); 668 mtx_lock_spin(&sched_lock); 669 if (uap->mbx) { 670 FOREACH_KSEGRP_IN_PROC(p, kg) { 671 FOREACH_UPCALL_IN_GROUP(kg, ku) { 672 if (ku->ku_mailbox == uap->mbx) 673 break; 674 } 675 if (ku) 676 break; 677 } 678 } else { 679 kg = td->td_ksegrp; 680 if (kg->kg_upsleeps) { 681 wakeup_one(&kg->kg_completed); 682 mtx_unlock_spin(&sched_lock); 683 PROC_UNLOCK(p); 684 return (0); 685 } 686 ku = TAILQ_FIRST(&kg->kg_upcalls); 687 } 688 if (ku) { 689 if ((td2 = ku->ku_owner) == NULL) { 690 panic("%s: no owner", __func__); 691 } else if (TD_ON_SLEEPQ(td2) && (td2->td_flags & TDF_SINTR) && 692 ((td2->td_wchan == &kg->kg_completed) || 693 (td2->td_wchan == &p->p_siglist && 694 (ku->ku_mflags & KMF_WAITSIGEVENT)))) { 695 sleepq_abort(td2); 696 } else { 697 ku->ku_flags |= KUF_DOUPCALL; 698 } 699 mtx_unlock_spin(&sched_lock); 700 PROC_UNLOCK(p); 701 return (0); 702 } 703 mtx_unlock_spin(&sched_lock); 704 PROC_UNLOCK(p); 705 return (ESRCH); 706 } 707 708 /* 709 * No new KSEG: first call: use current KSE, don't schedule an upcall 710 * All other situations, do allocate max new KSEs and schedule an upcall. 711 */ 712 /* struct kse_create_args { 713 struct kse_mailbox *mbx; 714 int newgroup; 715 }; */ 716 int 717 kse_create(struct thread *td, struct kse_create_args *uap) 718 { 719 struct kse *newke; 720 struct ksegrp *newkg; 721 struct ksegrp *kg; 722 struct proc *p; 723 struct kse_mailbox mbx; 724 struct kse_upcall *newku; 725 int err, ncpus, sa = 0, first = 0; 726 struct thread *newtd; 727 728 p = td->td_proc; 729 if ((err = copyin(uap->mbx, &mbx, sizeof(mbx)))) 730 return (err); 731 732 /* Too bad, why hasn't kernel always a cpu counter !? */ 733 #ifdef SMP 734 ncpus = mp_ncpus; 735 #else 736 ncpus = 1; 737 #endif 738 if (virtual_cpu != 0) 739 ncpus = virtual_cpu; 740 if (!(mbx.km_flags & KMF_BOUND)) 741 sa = TDF_SA; 742 else 743 ncpus = 1; 744 PROC_LOCK(p); 745 if (!(p->p_flag & P_SA)) { 746 first = 1; 747 p->p_flag |= P_SA; 748 } 749 PROC_UNLOCK(p); 750 if (!sa && !uap->newgroup && !first) 751 return (EINVAL); 752 kg = td->td_ksegrp; 753 if (uap->newgroup) { 754 /* Have race condition but it is cheap */ 755 if (p->p_numksegrps >= max_groups_per_proc) 756 return (EPROCLIM); 757 /* 758 * If we want a new KSEGRP it doesn't matter whether 759 * we have already fired up KSE mode before or not. 760 * We put the process in KSE mode and create a new KSEGRP. 761 */ 762 newkg = ksegrp_alloc(); 763 bzero(&newkg->kg_startzero, RANGEOF(struct ksegrp, 764 kg_startzero, kg_endzero)); 765 bcopy(&kg->kg_startcopy, &newkg->kg_startcopy, 766 RANGEOF(struct ksegrp, kg_startcopy, kg_endcopy)); 767 PROC_LOCK(p); 768 mtx_lock_spin(&sched_lock); 769 if (p->p_numksegrps >= max_groups_per_proc) { 770 mtx_unlock_spin(&sched_lock); 771 PROC_UNLOCK(p); 772 ksegrp_free(newkg); 773 return (EPROCLIM); 774 } 775 ksegrp_link(newkg, p); 776 sched_fork_ksegrp(kg, newkg); 777 mtx_unlock_spin(&sched_lock); 778 PROC_UNLOCK(p); 779 } else { 780 if (!first && ((td->td_flags & TDF_SA) ^ sa) != 0) 781 return (EINVAL); 782 newkg = kg; 783 } 784 785 /* 786 * Creating upcalls more than number of physical cpu does 787 * not help performance. 788 */ 789 if (newkg->kg_numupcalls >= ncpus) 790 return (EPROCLIM); 791 792 if (newkg->kg_numupcalls == 0) { 793 /* 794 * Initialize KSE group 795 * 796 * For multiplxed group, create KSEs as many as physical 797 * cpus. This increases concurrent even if userland 798 * is not MP safe and can only run on single CPU. 799 * In ideal world, every physical cpu should execute a thread. 800 * If there is enough KSEs, threads in kernel can be 801 * executed parallel on different cpus with full speed, 802 * Concurrent in kernel shouldn't be restricted by number of 803 * upcalls userland provides. Adding more upcall structures 804 * only increases concurrent in userland. 805 * 806 * For bound thread group, because there is only thread in the 807 * group, we only create one KSE for the group. Thread in this 808 * kind of group will never schedule an upcall when blocked, 809 * this intends to simulate pthread system scope thread. 810 */ 811 while (newkg->kg_kses < ncpus) { 812 newke = kse_alloc(); 813 bzero(&newke->ke_startzero, RANGEOF(struct kse, 814 ke_startzero, ke_endzero)); 815 #if 0 816 mtx_lock_spin(&sched_lock); 817 bcopy(&ke->ke_startcopy, &newke->ke_startcopy, 818 RANGEOF(struct kse, ke_startcopy, ke_endcopy)); 819 mtx_unlock_spin(&sched_lock); 820 #endif 821 mtx_lock_spin(&sched_lock); 822 kse_link(newke, newkg); 823 sched_fork_kse(td->td_kse, newke); 824 /* Add engine */ 825 kse_reassign(newke); 826 mtx_unlock_spin(&sched_lock); 827 } 828 } 829 newku = upcall_alloc(); 830 newku->ku_mailbox = uap->mbx; 831 newku->ku_func = mbx.km_func; 832 bcopy(&mbx.km_stack, &newku->ku_stack, sizeof(stack_t)); 833 834 /* For the first call this may not have been set */ 835 if (td->td_standin == NULL) 836 thread_alloc_spare(td, NULL); 837 838 PROC_LOCK(p); 839 if (newkg->kg_numupcalls >= ncpus) { 840 PROC_UNLOCK(p); 841 upcall_free(newku); 842 return (EPROCLIM); 843 } 844 if (first && sa) { 845 SIGSETOR(p->p_siglist, td->td_siglist); 846 SIGEMPTYSET(td->td_siglist); 847 SIGFILLSET(td->td_sigmask); 848 SIG_CANTMASK(td->td_sigmask); 849 } 850 mtx_lock_spin(&sched_lock); 851 PROC_UNLOCK(p); 852 upcall_link(newku, newkg); 853 if (mbx.km_quantum) 854 newkg->kg_upquantum = max(1, mbx.km_quantum/tick); 855 856 /* 857 * Each upcall structure has an owner thread, find which 858 * one owns it. 859 */ 860 if (uap->newgroup) { 861 /* 862 * Because new ksegrp hasn't thread, 863 * create an initial upcall thread to own it. 864 */ 865 newtd = thread_schedule_upcall(td, newku); 866 } else { 867 /* 868 * If current thread hasn't an upcall structure, 869 * just assign the upcall to it. 870 */ 871 if (td->td_upcall == NULL) { 872 newku->ku_owner = td; 873 td->td_upcall = newku; 874 newtd = td; 875 } else { 876 /* 877 * Create a new upcall thread to own it. 878 */ 879 newtd = thread_schedule_upcall(td, newku); 880 } 881 } 882 if (!sa) { 883 newtd->td_mailbox = mbx.km_curthread; 884 newtd->td_flags &= ~TDF_SA; 885 if (newtd != td) { 886 mtx_unlock_spin(&sched_lock); 887 cpu_set_upcall_kse(newtd, newku); 888 mtx_lock_spin(&sched_lock); 889 } 890 } else { 891 newtd->td_flags |= TDF_SA; 892 } 893 if (newtd != td) 894 setrunqueue(newtd); 895 mtx_unlock_spin(&sched_lock); 896 return (0); 897 } 898 899 /* 900 * Initialize global thread allocation resources. 901 */ 902 void 903 threadinit(void) 904 { 905 906 thread_zone = uma_zcreate("THREAD", sched_sizeof_thread(), 907 thread_ctor, thread_dtor, thread_init, thread_fini, 908 UMA_ALIGN_CACHE, 0); 909 tid_zone = uma_zcreate("TID", sizeof(struct tid_bitmap_part), 910 NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0); 911 ksegrp_zone = uma_zcreate("KSEGRP", sched_sizeof_ksegrp(), 912 NULL, NULL, ksegrp_init, NULL, 913 UMA_ALIGN_CACHE, 0); 914 kse_zone = uma_zcreate("KSE", sched_sizeof_kse(), 915 NULL, NULL, kse_init, NULL, 916 UMA_ALIGN_CACHE, 0); 917 upcall_zone = uma_zcreate("UPCALL", sizeof(struct kse_upcall), 918 NULL, NULL, NULL, NULL, UMA_ALIGN_CACHE, 0); 919 } 920 921 /* 922 * Stash an embarasingly extra thread into the zombie thread queue. 923 */ 924 void 925 thread_stash(struct thread *td) 926 { 927 mtx_lock_spin(&kse_zombie_lock); 928 TAILQ_INSERT_HEAD(&zombie_threads, td, td_runq); 929 mtx_unlock_spin(&kse_zombie_lock); 930 } 931 932 /* 933 * Stash an embarasingly extra kse into the zombie kse queue. 934 */ 935 void 936 kse_stash(struct kse *ke) 937 { 938 mtx_lock_spin(&kse_zombie_lock); 939 TAILQ_INSERT_HEAD(&zombie_kses, ke, ke_procq); 940 mtx_unlock_spin(&kse_zombie_lock); 941 } 942 943 /* 944 * Stash an embarasingly extra upcall into the zombie upcall queue. 945 */ 946 947 void 948 upcall_stash(struct kse_upcall *ku) 949 { 950 mtx_lock_spin(&kse_zombie_lock); 951 TAILQ_INSERT_HEAD(&zombie_upcalls, ku, ku_link); 952 mtx_unlock_spin(&kse_zombie_lock); 953 } 954 955 /* 956 * Stash an embarasingly extra ksegrp into the zombie ksegrp queue. 957 */ 958 void 959 ksegrp_stash(struct ksegrp *kg) 960 { 961 mtx_lock_spin(&kse_zombie_lock); 962 TAILQ_INSERT_HEAD(&zombie_ksegrps, kg, kg_ksegrp); 963 mtx_unlock_spin(&kse_zombie_lock); 964 } 965 966 /* 967 * Reap zombie kse resource. 968 */ 969 void 970 thread_reap(void) 971 { 972 struct thread *td_first, *td_next; 973 struct kse *ke_first, *ke_next; 974 struct ksegrp *kg_first, * kg_next; 975 struct kse_upcall *ku_first, *ku_next; 976 977 /* 978 * Don't even bother to lock if none at this instant, 979 * we really don't care about the next instant.. 980 */ 981 if ((!TAILQ_EMPTY(&zombie_threads)) 982 || (!TAILQ_EMPTY(&zombie_kses)) 983 || (!TAILQ_EMPTY(&zombie_ksegrps)) 984 || (!TAILQ_EMPTY(&zombie_upcalls))) { 985 mtx_lock_spin(&kse_zombie_lock); 986 td_first = TAILQ_FIRST(&zombie_threads); 987 ke_first = TAILQ_FIRST(&zombie_kses); 988 kg_first = TAILQ_FIRST(&zombie_ksegrps); 989 ku_first = TAILQ_FIRST(&zombie_upcalls); 990 if (td_first) 991 TAILQ_INIT(&zombie_threads); 992 if (ke_first) 993 TAILQ_INIT(&zombie_kses); 994 if (kg_first) 995 TAILQ_INIT(&zombie_ksegrps); 996 if (ku_first) 997 TAILQ_INIT(&zombie_upcalls); 998 mtx_unlock_spin(&kse_zombie_lock); 999 while (td_first) { 1000 td_next = TAILQ_NEXT(td_first, td_runq); 1001 if (td_first->td_ucred) 1002 crfree(td_first->td_ucred); 1003 thread_free(td_first); 1004 td_first = td_next; 1005 } 1006 while (ke_first) { 1007 ke_next = TAILQ_NEXT(ke_first, ke_procq); 1008 kse_free(ke_first); 1009 ke_first = ke_next; 1010 } 1011 while (kg_first) { 1012 kg_next = TAILQ_NEXT(kg_first, kg_ksegrp); 1013 ksegrp_free(kg_first); 1014 kg_first = kg_next; 1015 } 1016 while (ku_first) { 1017 ku_next = TAILQ_NEXT(ku_first, ku_link); 1018 upcall_free(ku_first); 1019 ku_first = ku_next; 1020 } 1021 } 1022 } 1023 1024 /* 1025 * Allocate a ksegrp. 1026 */ 1027 struct ksegrp * 1028 ksegrp_alloc(void) 1029 { 1030 return (uma_zalloc(ksegrp_zone, M_WAITOK)); 1031 } 1032 1033 /* 1034 * Allocate a kse. 1035 */ 1036 struct kse * 1037 kse_alloc(void) 1038 { 1039 return (uma_zalloc(kse_zone, M_WAITOK)); 1040 } 1041 1042 /* 1043 * Allocate a thread. 1044 */ 1045 struct thread * 1046 thread_alloc(void) 1047 { 1048 thread_reap(); /* check if any zombies to get */ 1049 return (uma_zalloc(thread_zone, M_WAITOK)); 1050 } 1051 1052 /* 1053 * Deallocate a ksegrp. 1054 */ 1055 void 1056 ksegrp_free(struct ksegrp *td) 1057 { 1058 uma_zfree(ksegrp_zone, td); 1059 } 1060 1061 /* 1062 * Deallocate a kse. 1063 */ 1064 void 1065 kse_free(struct kse *td) 1066 { 1067 uma_zfree(kse_zone, td); 1068 } 1069 1070 /* 1071 * Deallocate a thread. 1072 */ 1073 void 1074 thread_free(struct thread *td) 1075 { 1076 1077 cpu_thread_clean(td); 1078 uma_zfree(thread_zone, td); 1079 } 1080 1081 /* 1082 * Assign a thread ID. 1083 */ 1084 int 1085 thread_new_tid(void) 1086 { 1087 struct tid_bitmap_part *bmp, *new; 1088 int bit, idx, tid; 1089 1090 mtx_lock(&tid_lock); 1091 STAILQ_FOREACH(bmp, &tid_bitmap, bmp_next) { 1092 if (bmp->bmp_free) 1093 break; 1094 } 1095 /* Create a new bitmap if we run out of free bits. */ 1096 if (bmp == NULL) { 1097 mtx_unlock(&tid_lock); 1098 new = uma_zalloc(tid_zone, M_WAITOK); 1099 mtx_lock(&tid_lock); 1100 bmp = STAILQ_LAST(&tid_bitmap, tid_bitmap_part, bmp_next); 1101 if (bmp == NULL || bmp->bmp_free < TID_IDS_PER_PART/2) { 1102 /* 1=free, 0=assigned. This way we can use ffsl(). */ 1103 memset(new->bmp_bitmap, ~0U, sizeof(new->bmp_bitmap)); 1104 new->bmp_base = (bmp == NULL) ? TID_MIN : 1105 bmp->bmp_base + TID_IDS_PER_PART; 1106 new->bmp_free = TID_IDS_PER_PART; 1107 STAILQ_INSERT_TAIL(&tid_bitmap, new, bmp_next); 1108 bmp = new; 1109 new = NULL; 1110 } 1111 } else 1112 new = NULL; 1113 /* We have a bitmap with available IDs. */ 1114 idx = 0; 1115 while (idx < TID_BITMAP_SIZE && bmp->bmp_bitmap[idx] == 0UL) 1116 idx++; 1117 bit = ffsl(bmp->bmp_bitmap[idx]) - 1; 1118 tid = bmp->bmp_base + idx * TID_IDS_PER_IDX + bit; 1119 bmp->bmp_bitmap[idx] &= ~(1UL << bit); 1120 bmp->bmp_free--; 1121 mtx_unlock(&tid_lock); 1122 1123 if (new != NULL) 1124 uma_zfree(tid_zone, new); 1125 return (tid); 1126 } 1127 1128 /* 1129 * Store the thread context in the UTS's mailbox. 1130 * then add the mailbox at the head of a list we are building in user space. 1131 * The list is anchored in the ksegrp structure. 1132 */ 1133 int 1134 thread_export_context(struct thread *td, int willexit) 1135 { 1136 struct proc *p; 1137 struct ksegrp *kg; 1138 uintptr_t mbx; 1139 void *addr; 1140 int error = 0, temp, sig; 1141 mcontext_t mc; 1142 1143 p = td->td_proc; 1144 kg = td->td_ksegrp; 1145 1146 /* Export the user/machine context. */ 1147 get_mcontext(td, &mc, 0); 1148 addr = (void *)(&td->td_mailbox->tm_context.uc_mcontext); 1149 error = copyout(&mc, addr, sizeof(mcontext_t)); 1150 if (error) 1151 goto bad; 1152 1153 /* Exports clock ticks in kernel mode */ 1154 addr = (caddr_t)(&td->td_mailbox->tm_sticks); 1155 temp = fuword32(addr) + td->td_usticks; 1156 if (suword32(addr, temp)) { 1157 error = EFAULT; 1158 goto bad; 1159 } 1160 1161 /* 1162 * Post sync signal, or process SIGKILL and SIGSTOP. 1163 * For sync signal, it is only possible when the signal is not 1164 * caught by userland or process is being debugged. 1165 */ 1166 PROC_LOCK(p); 1167 if (td->td_flags & TDF_NEEDSIGCHK) { 1168 mtx_lock_spin(&sched_lock); 1169 td->td_flags &= ~TDF_NEEDSIGCHK; 1170 mtx_unlock_spin(&sched_lock); 1171 mtx_lock(&p->p_sigacts->ps_mtx); 1172 while ((sig = cursig(td)) != 0) 1173 postsig(sig); 1174 mtx_unlock(&p->p_sigacts->ps_mtx); 1175 } 1176 if (willexit) 1177 SIGFILLSET(td->td_sigmask); 1178 PROC_UNLOCK(p); 1179 1180 /* Get address in latest mbox of list pointer */ 1181 addr = (void *)(&td->td_mailbox->tm_next); 1182 /* 1183 * Put the saved address of the previous first 1184 * entry into this one 1185 */ 1186 for (;;) { 1187 mbx = (uintptr_t)kg->kg_completed; 1188 if (suword(addr, mbx)) { 1189 error = EFAULT; 1190 goto bad; 1191 } 1192 PROC_LOCK(p); 1193 if (mbx == (uintptr_t)kg->kg_completed) { 1194 kg->kg_completed = td->td_mailbox; 1195 /* 1196 * The thread context may be taken away by 1197 * other upcall threads when we unlock 1198 * process lock. it's no longer valid to 1199 * use it again in any other places. 1200 */ 1201 td->td_mailbox = NULL; 1202 PROC_UNLOCK(p); 1203 break; 1204 } 1205 PROC_UNLOCK(p); 1206 } 1207 td->td_usticks = 0; 1208 return (0); 1209 1210 bad: 1211 PROC_LOCK(p); 1212 sigexit(td, SIGILL); 1213 return (error); 1214 } 1215 1216 /* 1217 * Take the list of completed mailboxes for this KSEGRP and put them on this 1218 * upcall's mailbox as it's the next one going up. 1219 */ 1220 static int 1221 thread_link_mboxes(struct ksegrp *kg, struct kse_upcall *ku) 1222 { 1223 struct proc *p = kg->kg_proc; 1224 void *addr; 1225 uintptr_t mbx; 1226 1227 addr = (void *)(&ku->ku_mailbox->km_completed); 1228 for (;;) { 1229 mbx = (uintptr_t)kg->kg_completed; 1230 if (suword(addr, mbx)) { 1231 PROC_LOCK(p); 1232 psignal(p, SIGSEGV); 1233 PROC_UNLOCK(p); 1234 return (EFAULT); 1235 } 1236 PROC_LOCK(p); 1237 if (mbx == (uintptr_t)kg->kg_completed) { 1238 kg->kg_completed = NULL; 1239 PROC_UNLOCK(p); 1240 break; 1241 } 1242 PROC_UNLOCK(p); 1243 } 1244 return (0); 1245 } 1246 1247 /* 1248 * This function should be called at statclock interrupt time 1249 */ 1250 int 1251 thread_statclock(int user) 1252 { 1253 struct thread *td = curthread; 1254 struct ksegrp *kg = td->td_ksegrp; 1255 1256 if (kg->kg_numupcalls == 0 || !(td->td_flags & TDF_SA)) 1257 return (0); 1258 if (user) { 1259 /* Current always do via ast() */ 1260 mtx_lock_spin(&sched_lock); 1261 td->td_flags |= (TDF_USTATCLOCK|TDF_ASTPENDING); 1262 mtx_unlock_spin(&sched_lock); 1263 td->td_uuticks++; 1264 } else { 1265 if (td->td_mailbox != NULL) 1266 td->td_usticks++; 1267 else { 1268 /* XXXKSE 1269 * We will call thread_user_enter() for every 1270 * kernel entry in future, so if the thread mailbox 1271 * is NULL, it must be a UTS kernel, don't account 1272 * clock ticks for it. 1273 */ 1274 } 1275 } 1276 return (0); 1277 } 1278 1279 /* 1280 * Export state clock ticks for userland 1281 */ 1282 static int 1283 thread_update_usr_ticks(struct thread *td, int user) 1284 { 1285 struct proc *p = td->td_proc; 1286 struct kse_thr_mailbox *tmbx; 1287 struct kse_upcall *ku; 1288 struct ksegrp *kg; 1289 caddr_t addr; 1290 u_int uticks; 1291 1292 if ((ku = td->td_upcall) == NULL) 1293 return (-1); 1294 1295 tmbx = (void *)fuword((void *)&ku->ku_mailbox->km_curthread); 1296 if ((tmbx == NULL) || (tmbx == (void *)-1)) 1297 return (-1); 1298 if (user) { 1299 uticks = td->td_uuticks; 1300 td->td_uuticks = 0; 1301 addr = (caddr_t)&tmbx->tm_uticks; 1302 } else { 1303 uticks = td->td_usticks; 1304 td->td_usticks = 0; 1305 addr = (caddr_t)&tmbx->tm_sticks; 1306 } 1307 if (uticks) { 1308 if (suword32(addr, uticks+fuword32(addr))) { 1309 PROC_LOCK(p); 1310 psignal(p, SIGSEGV); 1311 PROC_UNLOCK(p); 1312 return (-2); 1313 } 1314 } 1315 kg = td->td_ksegrp; 1316 if (kg->kg_upquantum && ticks >= kg->kg_nextupcall) { 1317 mtx_lock_spin(&sched_lock); 1318 td->td_upcall->ku_flags |= KUF_DOUPCALL; 1319 mtx_unlock_spin(&sched_lock); 1320 } 1321 return (0); 1322 } 1323 1324 /* 1325 * Discard the current thread and exit from its context. 1326 * 1327 * Because we can't free a thread while we're operating under its context, 1328 * push the current thread into our CPU's deadthread holder. This means 1329 * we needn't worry about someone else grabbing our context before we 1330 * do a cpu_throw(). 1331 */ 1332 void 1333 thread_exit(void) 1334 { 1335 struct thread *td; 1336 struct kse *ke; 1337 struct proc *p; 1338 struct ksegrp *kg; 1339 1340 td = curthread; 1341 kg = td->td_ksegrp; 1342 p = td->td_proc; 1343 ke = td->td_kse; 1344 1345 mtx_assert(&sched_lock, MA_OWNED); 1346 KASSERT(p != NULL, ("thread exiting without a process")); 1347 KASSERT(ke != NULL, ("thread exiting without a kse")); 1348 KASSERT(kg != NULL, ("thread exiting without a kse group")); 1349 PROC_LOCK_ASSERT(p, MA_OWNED); 1350 CTR1(KTR_PROC, "thread_exit: thread %p", td); 1351 mtx_assert(&Giant, MA_NOTOWNED); 1352 1353 if (td->td_standin != NULL) { 1354 thread_stash(td->td_standin); 1355 td->td_standin = NULL; 1356 } 1357 1358 cpu_thread_exit(td); /* XXXSMP */ 1359 1360 /* 1361 * The last thread is left attached to the process 1362 * So that the whole bundle gets recycled. Skip 1363 * all this stuff. 1364 */ 1365 if (p->p_numthreads > 1) { 1366 thread_unlink(td); 1367 if (p->p_maxthrwaits) 1368 wakeup(&p->p_numthreads); 1369 /* 1370 * The test below is NOT true if we are the 1371 * sole exiting thread. P_STOPPED_SNGL is unset 1372 * in exit1() after it is the only survivor. 1373 */ 1374 if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE) { 1375 if (p->p_numthreads == p->p_suspcount) { 1376 thread_unsuspend_one(p->p_singlethread); 1377 } 1378 } 1379 1380 /* 1381 * Because each upcall structure has an owner thread, 1382 * owner thread exits only when process is in exiting 1383 * state, so upcall to userland is no longer needed, 1384 * deleting upcall structure is safe here. 1385 * So when all threads in a group is exited, all upcalls 1386 * in the group should be automatically freed. 1387 */ 1388 if (td->td_upcall) 1389 upcall_remove(td); 1390 1391 sched_exit_thread(FIRST_THREAD_IN_PROC(p), td); 1392 sched_exit_kse(FIRST_KSE_IN_PROC(p), ke); 1393 ke->ke_state = KES_UNQUEUED; 1394 ke->ke_thread = NULL; 1395 /* 1396 * Decide what to do with the KSE attached to this thread. 1397 */ 1398 if (ke->ke_flags & KEF_EXIT) { 1399 kse_unlink(ke); 1400 if (kg->kg_kses == 0) { 1401 sched_exit_ksegrp(FIRST_KSEGRP_IN_PROC(p), kg); 1402 ksegrp_unlink(kg); 1403 } 1404 } 1405 else 1406 kse_reassign(ke); 1407 PROC_UNLOCK(p); 1408 td->td_kse = NULL; 1409 td->td_state = TDS_INACTIVE; 1410 #if 0 1411 td->td_proc = NULL; 1412 #endif 1413 td->td_ksegrp = NULL; 1414 td->td_last_kse = NULL; 1415 PCPU_SET(deadthread, td); 1416 } else { 1417 PROC_UNLOCK(p); 1418 } 1419 /* XXX Shouldn't cpu_throw() here. */ 1420 mtx_assert(&sched_lock, MA_OWNED); 1421 cpu_throw(td, choosethread()); 1422 panic("I'm a teapot!"); 1423 /* NOTREACHED */ 1424 } 1425 1426 /* 1427 * Do any thread specific cleanups that may be needed in wait() 1428 * called with Giant, proc and schedlock not held. 1429 */ 1430 void 1431 thread_wait(struct proc *p) 1432 { 1433 struct thread *td; 1434 1435 mtx_assert(&Giant, MA_NOTOWNED); 1436 KASSERT((p->p_numthreads == 1), ("Multiple threads in wait1()")); 1437 KASSERT((p->p_numksegrps == 1), ("Multiple ksegrps in wait1()")); 1438 FOREACH_THREAD_IN_PROC(p, td) { 1439 if (td->td_standin != NULL) { 1440 thread_free(td->td_standin); 1441 td->td_standin = NULL; 1442 } 1443 cpu_thread_clean(td); 1444 } 1445 thread_reap(); /* check for zombie threads etc. */ 1446 } 1447 1448 /* 1449 * Link a thread to a process. 1450 * set up anything that needs to be initialized for it to 1451 * be used by the process. 1452 * 1453 * Note that we do not link to the proc's ucred here. 1454 * The thread is linked as if running but no KSE assigned. 1455 */ 1456 void 1457 thread_link(struct thread *td, struct ksegrp *kg) 1458 { 1459 struct proc *p; 1460 1461 p = kg->kg_proc; 1462 td->td_state = TDS_INACTIVE; 1463 td->td_proc = p; 1464 td->td_ksegrp = kg; 1465 td->td_last_kse = NULL; 1466 td->td_flags = 0; 1467 td->td_kse = NULL; 1468 1469 LIST_INIT(&td->td_contested); 1470 callout_init(&td->td_slpcallout, CALLOUT_MPSAFE); 1471 TAILQ_INSERT_HEAD(&p->p_threads, td, td_plist); 1472 TAILQ_INSERT_HEAD(&kg->kg_threads, td, td_kglist); 1473 p->p_numthreads++; 1474 kg->kg_numthreads++; 1475 } 1476 1477 void 1478 thread_unlink(struct thread *td) 1479 { 1480 struct proc *p = td->td_proc; 1481 struct ksegrp *kg = td->td_ksegrp; 1482 1483 mtx_assert(&sched_lock, MA_OWNED); 1484 TAILQ_REMOVE(&p->p_threads, td, td_plist); 1485 p->p_numthreads--; 1486 TAILQ_REMOVE(&kg->kg_threads, td, td_kglist); 1487 kg->kg_numthreads--; 1488 /* could clear a few other things here */ 1489 } 1490 1491 /* 1492 * Purge a ksegrp resource. When a ksegrp is preparing to 1493 * exit, it calls this function. 1494 */ 1495 static void 1496 kse_purge_group(struct thread *td) 1497 { 1498 struct ksegrp *kg; 1499 struct kse *ke; 1500 1501 kg = td->td_ksegrp; 1502 KASSERT(kg->kg_numthreads == 1, ("%s: bad thread number", __func__)); 1503 while ((ke = TAILQ_FIRST(&kg->kg_iq)) != NULL) { 1504 KASSERT(ke->ke_state == KES_IDLE, 1505 ("%s: wrong idle KSE state", __func__)); 1506 kse_unlink(ke); 1507 } 1508 KASSERT((kg->kg_kses == 1), 1509 ("%s: ksegrp still has %d KSEs", __func__, kg->kg_kses)); 1510 KASSERT((kg->kg_numupcalls == 0), 1511 ("%s: ksegrp still has %d upcall datas", 1512 __func__, kg->kg_numupcalls)); 1513 } 1514 1515 /* 1516 * Purge a process's KSE resource. When a process is preparing to 1517 * exit, it calls kse_purge to release any extra KSE resources in 1518 * the process. 1519 */ 1520 static void 1521 kse_purge(struct proc *p, struct thread *td) 1522 { 1523 struct ksegrp *kg; 1524 struct kse *ke; 1525 1526 KASSERT(p->p_numthreads == 1, ("bad thread number")); 1527 while ((kg = TAILQ_FIRST(&p->p_ksegrps)) != NULL) { 1528 TAILQ_REMOVE(&p->p_ksegrps, kg, kg_ksegrp); 1529 p->p_numksegrps--; 1530 /* 1531 * There is no ownership for KSE, after all threads 1532 * in the group exited, it is possible that some KSEs 1533 * were left in idle queue, gc them now. 1534 */ 1535 while ((ke = TAILQ_FIRST(&kg->kg_iq)) != NULL) { 1536 KASSERT(ke->ke_state == KES_IDLE, 1537 ("%s: wrong idle KSE state", __func__)); 1538 TAILQ_REMOVE(&kg->kg_iq, ke, ke_kgrlist); 1539 kg->kg_idle_kses--; 1540 TAILQ_REMOVE(&kg->kg_kseq, ke, ke_kglist); 1541 kg->kg_kses--; 1542 kse_stash(ke); 1543 } 1544 KASSERT(((kg->kg_kses == 0) && (kg != td->td_ksegrp)) || 1545 ((kg->kg_kses == 1) && (kg == td->td_ksegrp)), 1546 ("ksegrp has wrong kg_kses: %d", kg->kg_kses)); 1547 KASSERT((kg->kg_numupcalls == 0), 1548 ("%s: ksegrp still has %d upcall datas", 1549 __func__, kg->kg_numupcalls)); 1550 1551 if (kg != td->td_ksegrp) 1552 ksegrp_stash(kg); 1553 } 1554 TAILQ_INSERT_HEAD(&p->p_ksegrps, td->td_ksegrp, kg_ksegrp); 1555 p->p_numksegrps++; 1556 } 1557 1558 /* 1559 * This function is intended to be used to initialize a spare thread 1560 * for upcall. Initialize thread's large data area outside sched_lock 1561 * for thread_schedule_upcall(). 1562 */ 1563 void 1564 thread_alloc_spare(struct thread *td, struct thread *spare) 1565 { 1566 1567 if (td->td_standin) 1568 return; 1569 if (spare == NULL) { 1570 spare = thread_alloc(); 1571 spare->td_tid = thread_new_tid(); 1572 } 1573 td->td_standin = spare; 1574 bzero(&spare->td_startzero, 1575 (unsigned)RANGEOF(struct thread, td_startzero, td_endzero)); 1576 spare->td_proc = td->td_proc; 1577 spare->td_ucred = crhold(td->td_ucred); 1578 } 1579 1580 /* 1581 * Create a thread and schedule it for upcall on the KSE given. 1582 * Use our thread's standin so that we don't have to allocate one. 1583 */ 1584 struct thread * 1585 thread_schedule_upcall(struct thread *td, struct kse_upcall *ku) 1586 { 1587 struct thread *td2; 1588 1589 mtx_assert(&sched_lock, MA_OWNED); 1590 1591 /* 1592 * Schedule an upcall thread on specified kse_upcall, 1593 * the kse_upcall must be free. 1594 * td must have a spare thread. 1595 */ 1596 KASSERT(ku->ku_owner == NULL, ("%s: upcall has owner", __func__)); 1597 if ((td2 = td->td_standin) != NULL) { 1598 td->td_standin = NULL; 1599 } else { 1600 panic("no reserve thread when scheduling an upcall"); 1601 return (NULL); 1602 } 1603 CTR3(KTR_PROC, "thread_schedule_upcall: thread %p (pid %d, %s)", 1604 td2, td->td_proc->p_pid, td->td_proc->p_comm); 1605 bcopy(&td->td_startcopy, &td2->td_startcopy, 1606 (unsigned) RANGEOF(struct thread, td_startcopy, td_endcopy)); 1607 thread_link(td2, ku->ku_ksegrp); 1608 /* inherit blocked thread's context */ 1609 cpu_set_upcall(td2, td); 1610 /* Let the new thread become owner of the upcall */ 1611 ku->ku_owner = td2; 1612 td2->td_upcall = ku; 1613 td2->td_flags = TDF_SA; 1614 td2->td_pflags = TDP_UPCALLING; 1615 td2->td_kse = NULL; 1616 td2->td_state = TDS_CAN_RUN; 1617 td2->td_inhibitors = 0; 1618 SIGFILLSET(td2->td_sigmask); 1619 SIG_CANTMASK(td2->td_sigmask); 1620 sched_fork_thread(td, td2); 1621 return (td2); /* bogus.. should be a void function */ 1622 } 1623 1624 /* 1625 * It is only used when thread generated a trap and process is being 1626 * debugged. 1627 */ 1628 void 1629 thread_signal_add(struct thread *td, int sig) 1630 { 1631 struct proc *p; 1632 siginfo_t siginfo; 1633 struct sigacts *ps; 1634 int error; 1635 1636 p = td->td_proc; 1637 PROC_LOCK_ASSERT(p, MA_OWNED); 1638 ps = p->p_sigacts; 1639 mtx_assert(&ps->ps_mtx, MA_OWNED); 1640 1641 cpu_thread_siginfo(sig, 0, &siginfo); 1642 mtx_unlock(&ps->ps_mtx); 1643 PROC_UNLOCK(p); 1644 error = copyout(&siginfo, &td->td_mailbox->tm_syncsig, sizeof(siginfo)); 1645 if (error) { 1646 PROC_LOCK(p); 1647 sigexit(td, SIGILL); 1648 } 1649 PROC_LOCK(p); 1650 SIGADDSET(td->td_sigmask, sig); 1651 mtx_lock(&ps->ps_mtx); 1652 } 1653 1654 void 1655 thread_switchout(struct thread *td) 1656 { 1657 struct kse_upcall *ku; 1658 struct thread *td2; 1659 1660 mtx_assert(&sched_lock, MA_OWNED); 1661 1662 /* 1663 * If the outgoing thread is in threaded group and has never 1664 * scheduled an upcall, decide whether this is a short 1665 * or long term event and thus whether or not to schedule 1666 * an upcall. 1667 * If it is a short term event, just suspend it in 1668 * a way that takes its KSE with it. 1669 * Select the events for which we want to schedule upcalls. 1670 * For now it's just sleep. 1671 * XXXKSE eventually almost any inhibition could do. 1672 */ 1673 if (TD_CAN_UNBIND(td) && (td->td_standin) && TD_ON_SLEEPQ(td)) { 1674 /* 1675 * Release ownership of upcall, and schedule an upcall 1676 * thread, this new upcall thread becomes the owner of 1677 * the upcall structure. 1678 */ 1679 ku = td->td_upcall; 1680 ku->ku_owner = NULL; 1681 td->td_upcall = NULL; 1682 td->td_flags &= ~TDF_CAN_UNBIND; 1683 td2 = thread_schedule_upcall(td, ku); 1684 setrunqueue(td2); 1685 } 1686 } 1687 1688 /* 1689 * Setup done on the thread when it enters the kernel. 1690 * XXXKSE Presently only for syscalls but eventually all kernel entries. 1691 */ 1692 void 1693 thread_user_enter(struct proc *p, struct thread *td) 1694 { 1695 struct ksegrp *kg; 1696 struct kse_upcall *ku; 1697 struct kse_thr_mailbox *tmbx; 1698 uint32_t tflags; 1699 1700 kg = td->td_ksegrp; 1701 1702 /* 1703 * First check that we shouldn't just abort. 1704 * But check if we are the single thread first! 1705 */ 1706 if (p->p_flag & P_SINGLE_EXIT) { 1707 PROC_LOCK(p); 1708 mtx_lock_spin(&sched_lock); 1709 thread_stopped(p); 1710 thread_exit(); 1711 /* NOTREACHED */ 1712 } 1713 1714 /* 1715 * If we are doing a syscall in a KSE environment, 1716 * note where our mailbox is. There is always the 1717 * possibility that we could do this lazily (in kse_reassign()), 1718 * but for now do it every time. 1719 */ 1720 kg = td->td_ksegrp; 1721 if (td->td_flags & TDF_SA) { 1722 ku = td->td_upcall; 1723 KASSERT(ku, ("%s: no upcall owned", __func__)); 1724 KASSERT((ku->ku_owner == td), ("%s: wrong owner", __func__)); 1725 KASSERT(!TD_CAN_UNBIND(td), ("%s: can unbind", __func__)); 1726 ku->ku_mflags = fuword32((void *)&ku->ku_mailbox->km_flags); 1727 tmbx = (void *)fuword((void *)&ku->ku_mailbox->km_curthread); 1728 if ((tmbx == NULL) || (tmbx == (void *)-1L) || 1729 (ku->ku_mflags & KMF_NOUPCALL)) { 1730 td->td_mailbox = NULL; 1731 } else { 1732 if (td->td_standin == NULL) 1733 thread_alloc_spare(td, NULL); 1734 tflags = fuword32(&tmbx->tm_flags); 1735 /* 1736 * On some architectures, TP register points to thread 1737 * mailbox but not points to kse mailbox, and userland 1738 * can not atomically clear km_curthread, but can 1739 * use TP register, and set TMF_NOUPCALL in thread 1740 * flag to indicate a critical region. 1741 */ 1742 if (tflags & TMF_NOUPCALL) { 1743 td->td_mailbox = NULL; 1744 } else { 1745 td->td_mailbox = tmbx; 1746 mtx_lock_spin(&sched_lock); 1747 td->td_flags |= TDF_CAN_UNBIND; 1748 mtx_unlock_spin(&sched_lock); 1749 } 1750 } 1751 } 1752 } 1753 1754 /* 1755 * The extra work we go through if we are a threaded process when we 1756 * return to userland. 1757 * 1758 * If we are a KSE process and returning to user mode, check for 1759 * extra work to do before we return (e.g. for more syscalls 1760 * to complete first). If we were in a critical section, we should 1761 * just return to let it finish. Same if we were in the UTS (in 1762 * which case the mailbox's context's busy indicator will be set). 1763 * The only traps we suport will have set the mailbox. 1764 * We will clear it here. 1765 */ 1766 int 1767 thread_userret(struct thread *td, struct trapframe *frame) 1768 { 1769 int error = 0, upcalls, uts_crit; 1770 struct kse_upcall *ku; 1771 struct ksegrp *kg, *kg2; 1772 struct proc *p; 1773 struct timespec ts; 1774 1775 p = td->td_proc; 1776 kg = td->td_ksegrp; 1777 ku = td->td_upcall; 1778 1779 /* Nothing to do with bound thread */ 1780 if (!(td->td_flags & TDF_SA)) 1781 return (0); 1782 1783 /* 1784 * Stat clock interrupt hit in userland, it 1785 * is returning from interrupt, charge thread's 1786 * userland time for UTS. 1787 */ 1788 if (td->td_flags & TDF_USTATCLOCK) { 1789 thread_update_usr_ticks(td, 1); 1790 mtx_lock_spin(&sched_lock); 1791 td->td_flags &= ~TDF_USTATCLOCK; 1792 mtx_unlock_spin(&sched_lock); 1793 if (kg->kg_completed || 1794 (td->td_upcall->ku_flags & KUF_DOUPCALL)) 1795 thread_user_enter(p, td); 1796 } 1797 1798 uts_crit = (td->td_mailbox == NULL); 1799 /* 1800 * Optimisation: 1801 * This thread has not started any upcall. 1802 * If there is no work to report other than ourself, 1803 * then it can return direct to userland. 1804 */ 1805 if (TD_CAN_UNBIND(td)) { 1806 mtx_lock_spin(&sched_lock); 1807 td->td_flags &= ~TDF_CAN_UNBIND; 1808 if ((td->td_flags & TDF_NEEDSIGCHK) == 0 && 1809 (kg->kg_completed == NULL) && 1810 (ku->ku_flags & KUF_DOUPCALL) == 0 && 1811 (kg->kg_upquantum && ticks < kg->kg_nextupcall)) { 1812 mtx_unlock_spin(&sched_lock); 1813 thread_update_usr_ticks(td, 0); 1814 nanotime(&ts); 1815 error = copyout(&ts, 1816 (caddr_t)&ku->ku_mailbox->km_timeofday, 1817 sizeof(ts)); 1818 td->td_mailbox = 0; 1819 ku->ku_mflags = 0; 1820 if (error) 1821 goto out; 1822 return (0); 1823 } 1824 mtx_unlock_spin(&sched_lock); 1825 thread_export_context(td, 0); 1826 /* 1827 * There is something to report, and we own an upcall 1828 * strucuture, we can go to userland. 1829 * Turn ourself into an upcall thread. 1830 */ 1831 td->td_pflags |= TDP_UPCALLING; 1832 } else if (td->td_mailbox && (ku == NULL)) { 1833 thread_export_context(td, 1); 1834 PROC_LOCK(p); 1835 /* 1836 * There are upcall threads waiting for 1837 * work to do, wake one of them up. 1838 * XXXKSE Maybe wake all of them up. 1839 */ 1840 if (kg->kg_upsleeps) 1841 wakeup_one(&kg->kg_completed); 1842 mtx_lock_spin(&sched_lock); 1843 thread_stopped(p); 1844 thread_exit(); 1845 /* NOTREACHED */ 1846 } 1847 1848 KASSERT(ku != NULL, ("upcall is NULL\n")); 1849 KASSERT(TD_CAN_UNBIND(td) == 0, ("can unbind")); 1850 1851 if (p->p_numthreads > max_threads_per_proc) { 1852 max_threads_hits++; 1853 PROC_LOCK(p); 1854 mtx_lock_spin(&sched_lock); 1855 p->p_maxthrwaits++; 1856 while (p->p_numthreads > max_threads_per_proc) { 1857 upcalls = 0; 1858 FOREACH_KSEGRP_IN_PROC(p, kg2) { 1859 if (kg2->kg_numupcalls == 0) 1860 upcalls++; 1861 else 1862 upcalls += kg2->kg_numupcalls; 1863 } 1864 if (upcalls >= max_threads_per_proc) 1865 break; 1866 mtx_unlock_spin(&sched_lock); 1867 if (msleep(&p->p_numthreads, &p->p_mtx, PPAUSE|PCATCH, 1868 "maxthreads", 0)) { 1869 mtx_lock_spin(&sched_lock); 1870 break; 1871 } else { 1872 mtx_lock_spin(&sched_lock); 1873 } 1874 } 1875 p->p_maxthrwaits--; 1876 mtx_unlock_spin(&sched_lock); 1877 PROC_UNLOCK(p); 1878 } 1879 1880 if (td->td_pflags & TDP_UPCALLING) { 1881 uts_crit = 0; 1882 kg->kg_nextupcall = ticks+kg->kg_upquantum; 1883 /* 1884 * There is no more work to do and we are going to ride 1885 * this thread up to userland as an upcall. 1886 * Do the last parts of the setup needed for the upcall. 1887 */ 1888 CTR3(KTR_PROC, "userret: upcall thread %p (pid %d, %s)", 1889 td, td->td_proc->p_pid, td->td_proc->p_comm); 1890 1891 td->td_pflags &= ~TDP_UPCALLING; 1892 if (ku->ku_flags & KUF_DOUPCALL) { 1893 mtx_lock_spin(&sched_lock); 1894 ku->ku_flags &= ~KUF_DOUPCALL; 1895 mtx_unlock_spin(&sched_lock); 1896 } 1897 /* 1898 * Set user context to the UTS 1899 */ 1900 if (!(ku->ku_mflags & KMF_NOUPCALL)) { 1901 cpu_set_upcall_kse(td, ku); 1902 error = suword(&ku->ku_mailbox->km_curthread, 0); 1903 if (error) 1904 goto out; 1905 } 1906 1907 /* 1908 * Unhook the list of completed threads. 1909 * anything that completes after this gets to 1910 * come in next time. 1911 * Put the list of completed thread mailboxes on 1912 * this KSE's mailbox. 1913 */ 1914 if (!(ku->ku_mflags & KMF_NOCOMPLETED) && 1915 (error = thread_link_mboxes(kg, ku)) != 0) 1916 goto out; 1917 } 1918 if (!uts_crit) { 1919 nanotime(&ts); 1920 error = copyout(&ts, &ku->ku_mailbox->km_timeofday, sizeof(ts)); 1921 } 1922 1923 out: 1924 if (error) { 1925 /* 1926 * Things are going to be so screwed we should just kill 1927 * the process. 1928 * how do we do that? 1929 */ 1930 PROC_LOCK(td->td_proc); 1931 psignal(td->td_proc, SIGSEGV); 1932 PROC_UNLOCK(td->td_proc); 1933 } else { 1934 /* 1935 * Optimisation: 1936 * Ensure that we have a spare thread available, 1937 * for when we re-enter the kernel. 1938 */ 1939 if (td->td_standin == NULL) 1940 thread_alloc_spare(td, NULL); 1941 } 1942 1943 ku->ku_mflags = 0; 1944 /* 1945 * Clear thread mailbox first, then clear system tick count. 1946 * The order is important because thread_statclock() use 1947 * mailbox pointer to see if it is an userland thread or 1948 * an UTS kernel thread. 1949 */ 1950 td->td_mailbox = NULL; 1951 td->td_usticks = 0; 1952 return (error); /* go sync */ 1953 } 1954 1955 /* 1956 * Enforce single-threading. 1957 * 1958 * Returns 1 if the caller must abort (another thread is waiting to 1959 * exit the process or similar). Process is locked! 1960 * Returns 0 when you are successfully the only thread running. 1961 * A process has successfully single threaded in the suspend mode when 1962 * There are no threads in user mode. Threads in the kernel must be 1963 * allowed to continue until they get to the user boundary. They may even 1964 * copy out their return values and data before suspending. They may however be 1965 * accellerated in reaching the user boundary as we will wake up 1966 * any sleeping threads that are interruptable. (PCATCH). 1967 */ 1968 int 1969 thread_single(int force_exit) 1970 { 1971 struct thread *td; 1972 struct thread *td2; 1973 struct proc *p; 1974 1975 td = curthread; 1976 p = td->td_proc; 1977 mtx_assert(&Giant, MA_NOTOWNED); 1978 PROC_LOCK_ASSERT(p, MA_OWNED); 1979 KASSERT((td != NULL), ("curthread is NULL")); 1980 1981 if ((p->p_flag & P_SA) == 0 && p->p_numthreads == 1) 1982 return (0); 1983 1984 /* Is someone already single threading? */ 1985 if (p->p_singlethread) 1986 return (1); 1987 1988 if (force_exit == SINGLE_EXIT) { 1989 p->p_flag |= P_SINGLE_EXIT; 1990 } else 1991 p->p_flag &= ~P_SINGLE_EXIT; 1992 p->p_flag |= P_STOPPED_SINGLE; 1993 mtx_lock_spin(&sched_lock); 1994 p->p_singlethread = td; 1995 while ((p->p_numthreads - p->p_suspcount) != 1) { 1996 FOREACH_THREAD_IN_PROC(p, td2) { 1997 if (td2 == td) 1998 continue; 1999 td2->td_flags |= TDF_ASTPENDING; 2000 if (TD_IS_INHIBITED(td2)) { 2001 if (force_exit == SINGLE_EXIT) { 2002 if (TD_IS_SUSPENDED(td2)) { 2003 thread_unsuspend_one(td2); 2004 } 2005 if (TD_ON_SLEEPQ(td2) && 2006 (td2->td_flags & TDF_SINTR)) { 2007 sleepq_abort(td2); 2008 } 2009 } else { 2010 if (TD_IS_SUSPENDED(td2)) 2011 continue; 2012 /* 2013 * maybe other inhibitted states too? 2014 * XXXKSE Is it totally safe to 2015 * suspend a non-interruptable thread? 2016 */ 2017 if (td2->td_inhibitors & 2018 (TDI_SLEEPING | TDI_SWAPPED)) 2019 thread_suspend_one(td2); 2020 } 2021 } 2022 } 2023 /* 2024 * Maybe we suspended some threads.. was it enough? 2025 */ 2026 if ((p->p_numthreads - p->p_suspcount) == 1) 2027 break; 2028 2029 /* 2030 * Wake us up when everyone else has suspended. 2031 * In the mean time we suspend as well. 2032 */ 2033 thread_suspend_one(td); 2034 PROC_UNLOCK(p); 2035 mi_switch(SW_VOL); 2036 mtx_unlock_spin(&sched_lock); 2037 PROC_LOCK(p); 2038 mtx_lock_spin(&sched_lock); 2039 } 2040 if (force_exit == SINGLE_EXIT) { 2041 if (td->td_upcall) 2042 upcall_remove(td); 2043 kse_purge(p, td); 2044 } 2045 mtx_unlock_spin(&sched_lock); 2046 return (0); 2047 } 2048 2049 /* 2050 * Called in from locations that can safely check to see 2051 * whether we have to suspend or at least throttle for a 2052 * single-thread event (e.g. fork). 2053 * 2054 * Such locations include userret(). 2055 * If the "return_instead" argument is non zero, the thread must be able to 2056 * accept 0 (caller may continue), or 1 (caller must abort) as a result. 2057 * 2058 * The 'return_instead' argument tells the function if it may do a 2059 * thread_exit() or suspend, or whether the caller must abort and back 2060 * out instead. 2061 * 2062 * If the thread that set the single_threading request has set the 2063 * P_SINGLE_EXIT bit in the process flags then this call will never return 2064 * if 'return_instead' is false, but will exit. 2065 * 2066 * P_SINGLE_EXIT | return_instead == 0| return_instead != 0 2067 *---------------+--------------------+--------------------- 2068 * 0 | returns 0 | returns 0 or 1 2069 * | when ST ends | immediatly 2070 *---------------+--------------------+--------------------- 2071 * 1 | thread exits | returns 1 2072 * | | immediatly 2073 * 0 = thread_exit() or suspension ok, 2074 * other = return error instead of stopping the thread. 2075 * 2076 * While a full suspension is under effect, even a single threading 2077 * thread would be suspended if it made this call (but it shouldn't). 2078 * This call should only be made from places where 2079 * thread_exit() would be safe as that may be the outcome unless 2080 * return_instead is set. 2081 */ 2082 int 2083 thread_suspend_check(int return_instead) 2084 { 2085 struct thread *td; 2086 struct proc *p; 2087 2088 td = curthread; 2089 p = td->td_proc; 2090 mtx_assert(&Giant, MA_NOTOWNED); 2091 PROC_LOCK_ASSERT(p, MA_OWNED); 2092 while (P_SHOULDSTOP(p)) { 2093 if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE) { 2094 KASSERT(p->p_singlethread != NULL, 2095 ("singlethread not set")); 2096 /* 2097 * The only suspension in action is a 2098 * single-threading. Single threader need not stop. 2099 * XXX Should be safe to access unlocked 2100 * as it can only be set to be true by us. 2101 */ 2102 if (p->p_singlethread == td) 2103 return (0); /* Exempt from stopping. */ 2104 } 2105 if (return_instead) 2106 return (1); 2107 2108 mtx_lock_spin(&sched_lock); 2109 thread_stopped(p); 2110 /* 2111 * If the process is waiting for us to exit, 2112 * this thread should just suicide. 2113 * Assumes that P_SINGLE_EXIT implies P_STOPPED_SINGLE. 2114 */ 2115 if ((p->p_flag & P_SINGLE_EXIT) && (p->p_singlethread != td)) { 2116 if (p->p_flag & P_SA) 2117 thread_exit(); 2118 else 2119 thr_exit1(); 2120 } 2121 2122 /* 2123 * When a thread suspends, it just 2124 * moves to the processes's suspend queue 2125 * and stays there. 2126 */ 2127 thread_suspend_one(td); 2128 if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE) { 2129 if (p->p_numthreads == p->p_suspcount) { 2130 thread_unsuspend_one(p->p_singlethread); 2131 } 2132 } 2133 PROC_UNLOCK(p); 2134 mi_switch(SW_INVOL); 2135 mtx_unlock_spin(&sched_lock); 2136 PROC_LOCK(p); 2137 } 2138 return (0); 2139 } 2140 2141 void 2142 thread_suspend_one(struct thread *td) 2143 { 2144 struct proc *p = td->td_proc; 2145 2146 mtx_assert(&sched_lock, MA_OWNED); 2147 PROC_LOCK_ASSERT(p, MA_OWNED); 2148 KASSERT(!TD_IS_SUSPENDED(td), ("already suspended")); 2149 p->p_suspcount++; 2150 TD_SET_SUSPENDED(td); 2151 TAILQ_INSERT_TAIL(&p->p_suspended, td, td_runq); 2152 /* 2153 * Hack: If we are suspending but are on the sleep queue 2154 * then we are in msleep or the cv equivalent. We 2155 * want to look like we have two Inhibitors. 2156 * May already be set.. doesn't matter. 2157 */ 2158 if (TD_ON_SLEEPQ(td)) 2159 TD_SET_SLEEPING(td); 2160 } 2161 2162 void 2163 thread_unsuspend_one(struct thread *td) 2164 { 2165 struct proc *p = td->td_proc; 2166 2167 mtx_assert(&sched_lock, MA_OWNED); 2168 PROC_LOCK_ASSERT(p, MA_OWNED); 2169 TAILQ_REMOVE(&p->p_suspended, td, td_runq); 2170 TD_CLR_SUSPENDED(td); 2171 p->p_suspcount--; 2172 setrunnable(td); 2173 } 2174 2175 /* 2176 * Allow all threads blocked by single threading to continue running. 2177 */ 2178 void 2179 thread_unsuspend(struct proc *p) 2180 { 2181 struct thread *td; 2182 2183 mtx_assert(&sched_lock, MA_OWNED); 2184 PROC_LOCK_ASSERT(p, MA_OWNED); 2185 if (!P_SHOULDSTOP(p)) { 2186 while (( td = TAILQ_FIRST(&p->p_suspended))) { 2187 thread_unsuspend_one(td); 2188 } 2189 } else if ((P_SHOULDSTOP(p) == P_STOPPED_SINGLE) && 2190 (p->p_numthreads == p->p_suspcount)) { 2191 /* 2192 * Stopping everything also did the job for the single 2193 * threading request. Now we've downgraded to single-threaded, 2194 * let it continue. 2195 */ 2196 thread_unsuspend_one(p->p_singlethread); 2197 } 2198 } 2199 2200 void 2201 thread_single_end(void) 2202 { 2203 struct thread *td; 2204 struct proc *p; 2205 2206 td = curthread; 2207 p = td->td_proc; 2208 PROC_LOCK_ASSERT(p, MA_OWNED); 2209 p->p_flag &= ~P_STOPPED_SINGLE; 2210 mtx_lock_spin(&sched_lock); 2211 p->p_singlethread = NULL; 2212 /* 2213 * If there are other threads they mey now run, 2214 * unless of course there is a blanket 'stop order' 2215 * on the process. The single threader must be allowed 2216 * to continue however as this is a bad place to stop. 2217 */ 2218 if ((p->p_numthreads != 1) && (!P_SHOULDSTOP(p))) { 2219 while (( td = TAILQ_FIRST(&p->p_suspended))) { 2220 thread_unsuspend_one(td); 2221 } 2222 } 2223 mtx_unlock_spin(&sched_lock); 2224 } 2225