2 * Copyright (C) 2001 Julian Elischer <julian@freebsd.org>.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
36 #include <sys/mutex.h>
38 #include <sys/resourcevar.h>
40 #include <sys/sysctl.h>
41 #include <sys/sched.h>
42 #include <sys/sleepqueue.h>
43 #include <sys/turnstile.h>
47 #include <security/audit/audit.h>
50 #include <vm/vm_extern.h>
54 * thread related storage.
56 static uma_zone_t thread_zone;
58 SYSCTL_NODE(_kern, OID_AUTO, threads, CTLFLAG_RW, 0, "thread allocation");
60 int max_threads_per_proc = 1500;
61 SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_per_proc, CTLFLAG_RW,
62 &max_threads_per_proc, 0, "Limit on threads per proc");
65 SYSCTL_INT(_kern_threads, OID_AUTO, max_threads_hits, CTLFLAG_RD,
66 &max_threads_hits, 0, "");
72 TAILQ_HEAD(, thread) zombie_threads = TAILQ_HEAD_INITIALIZER(zombie_threads);
73 struct mtx kse_zombie_lock;
74 MTX_SYSINIT(kse_zombie_lock, &kse_zombie_lock, "kse zombie lock", MTX_SPIN);
78 sysctl_kse_virtual_cpu(SYSCTL_HANDLER_ARGS)
87 new_val = virtual_cpu;
88 error = sysctl_handle_int(oidp, &new_val, 0, req);
89 if (error != 0 || req->newptr == NULL)
93 virtual_cpu = new_val;
98 SYSCTL_PROC(_kern_threads, OID_AUTO, virtual_cpu, CTLTYPE_INT|CTLFLAG_RW,
99 0, sizeof(virtual_cpu), sysctl_kse_virtual_cpu, "I",
100 "debug virtual cpus");
104 static struct unrhdr *tid_unrhdr;
107 * Prepare a thread for use.
110 thread_ctor(void *mem, int size, void *arg, int flags)
114 td = (struct thread *)mem;
115 td->td_state = TDS_INACTIVE;
116 td->td_oncpu = NOCPU;
118 td->td_tid = alloc_unr(tid_unrhdr);
122 * Note that td_critnest begins life as 1 because the thread is not
123 * running and is thereby implicitly waiting to be on the receiving
124 * end of a context switch. A context switch must occur inside a
125 * critical section, and in fact, includes hand-off of the sched_lock.
126 * After a context switch to a newly created thread, it will release
127 * sched_lock for the first time, and its td_critnest will hit 0 for
128 * the first time. This happens on the far end of a context switch,
129 * and when it context switches away from itself, it will in fact go
130 * back into a critical section, and hand off the sched lock to the
136 audit_thread_alloc(td);
138 umtx_thread_alloc(td);
143 * Reclaim a thread after use.
146 thread_dtor(void *mem, int size, void *arg)
150 td = (struct thread *)mem;
153 /* Verify that this thread is in a safe state to free. */
154 switch (td->td_state) {
160 * We must never unlink a thread that is in one of
161 * these states, because it is currently active.
163 panic("bad state for thread unlinking");
168 panic("bad thread state");
173 audit_thread_free(td);
175 free_unr(tid_unrhdr, td->td_tid);
180 * Initialize type-stable parts of a thread (when newly created).
183 thread_init(void *mem, int size, int flags)
187 td = (struct thread *)mem;
189 vm_thread_new(td, 0);
190 cpu_thread_setup(td);
191 td->td_sleepqueue = sleepq_alloc();
192 td->td_turnstile = turnstile_alloc();
193 td->td_sched = (struct td_sched *)&td[1];
195 umtx_thread_init(td);
200 * Tear down type-stable parts of a thread (just before being discarded).
203 thread_fini(void *mem, int size)
207 td = (struct thread *)mem;
208 turnstile_free(td->td_turnstile);
209 sleepq_free(td->td_sleepqueue);
210 umtx_thread_fini(td);
211 vm_thread_dispose(td);
215 * For a newly created process,
216 * link up all the structures and its initial threads etc.
218 * {arch}/{arch}/machdep.c ia64_init(), init386() etc.
219 * proc_dtor() (should go away)
223 proc_linkup(struct proc *p, struct thread *td)
225 TAILQ_INIT(&p->p_threads); /* all threads in proc */
226 TAILQ_INIT(&p->p_upcalls); /* upcall list */
227 sigqueue_init(&p->p_sigqueue, p);
228 p->p_ksi = ksiginfo_alloc(1);
229 if (p->p_ksi != NULL) {
230 /* XXX p_ksi may be null if ksiginfo zone is not ready */
231 p->p_ksi->ksi_flags = KSI_EXT | KSI_INS;
233 LIST_INIT(&p->p_mqnotifier);
239 * Initialize global thread allocation resources.
245 mtx_init(&tid_lock, "TID lock", NULL, MTX_DEF);
246 tid_unrhdr = new_unrhdr(PID_MAX + 1, INT_MAX, &tid_lock);
248 thread_zone = uma_zcreate("THREAD", sched_sizeof_thread(),
249 thread_ctor, thread_dtor, thread_init, thread_fini,
252 kseinit(); /* set up kse specific stuff e.g. upcall zone*/
257 * Stash an embarasingly extra thread into the zombie thread queue.
258 * Use the slpq as that must be unused by now.
261 thread_stash(struct thread *td)
263 mtx_lock_spin(&kse_zombie_lock);
264 TAILQ_INSERT_HEAD(&zombie_threads, td, td_slpq);
265 mtx_unlock_spin(&kse_zombie_lock);
269 * Reap zombie kse resource.
274 struct thread *td_first, *td_next;
277 * Don't even bother to lock if none at this instant,
278 * we really don't care about the next instant..
280 if (!TAILQ_EMPTY(&zombie_threads)) {
281 mtx_lock_spin(&kse_zombie_lock);
282 td_first = TAILQ_FIRST(&zombie_threads);
284 TAILQ_INIT(&zombie_threads);
285 mtx_unlock_spin(&kse_zombie_lock);
287 td_next = TAILQ_NEXT(td_first, td_slpq);
288 if (td_first->td_ucred)
289 crfree(td_first->td_ucred);
290 thread_free(td_first);
303 thread_reap(); /* check if any zombies to get */
304 return (uma_zalloc(thread_zone, M_WAITOK));
309 * Deallocate a thread.
312 thread_free(struct thread *td)
315 cpu_thread_clean(td);
316 uma_zfree(thread_zone, td);
320 * Discard the current thread and exit from its context.
321 * Always called with scheduler locked.
323 * Because we can't free a thread while we're operating under its context,
324 * push the current thread into our CPU's deadthread holder. This means
325 * we needn't worry about someone else grabbing our context before we
326 * do a cpu_throw(). This may not be needed now as we are under schedlock.
327 * Maybe we can just do a thread_stash() as thr_exit1 does.
330 * libthr expects its thread exit to return for the last
331 * thread, meaning that the program is back to non-threaded
332 * mode I guess. Because we do this (cpu_throw) unconditionally
333 * here, they have their own version of it. (thr_exit1())
334 * that doesn't do it all if this was the last thread.
335 * It is also called from thread_suspend_check().
336 * Of course in the end, they end up coming here through exit1
337 * anyhow.. After fixing 'thr' to play by the rules we should be able
338 * to merge these two functions together.
345 * thread_user_enter()
348 * thread_suspend_check()
353 uint64_t new_switchtime;
361 mtx_assert(&sched_lock, MA_OWNED);
362 mtx_assert(&Giant, MA_NOTOWNED);
363 PROC_LOCK_ASSERT(p, MA_OWNED);
364 KASSERT(p != NULL, ("thread exiting without a process"));
365 CTR3(KTR_PROC, "thread_exit: thread %p (pid %ld, %s)", td,
366 (long)p->p_pid, p->p_comm);
367 KASSERT(TAILQ_EMPTY(&td->td_sigqueue.sq_list), ("signal pending"));
370 AUDIT_SYSCALL_EXIT(0, td);
374 if (td->td_standin != NULL) {
376 * Note that we don't need to free the cred here as it
377 * is done in thread_reap().
379 thread_stash(td->td_standin);
380 td->td_standin = NULL;
384 umtx_thread_exit(td);
387 * drop FPU & debug register state storage, or any other
388 * architecture specific resources that
389 * would not be on a new untouched process.
391 cpu_thread_exit(td); /* XXXSMP */
395 * The thread is exiting. scheduler can release its stuff
396 * and collect stats etc.
397 * XXX this is not very right, since PROC_UNLOCK may still
398 * need scheduler stuff.
400 sched_thread_exit(td);
403 /* Do the same timestamp bookkeeping that mi_switch() would do. */
404 new_switchtime = cpu_ticks();
405 p->p_rux.rux_runtime += (new_switchtime - PCPU_GET(switchtime));
406 PCPU_SET(switchtime, new_switchtime);
407 PCPU_SET(switchticks, ticks);
410 * Aggregate this thread's tick stats in the parent so they are not
411 * lost. Also add the child usage to our own when the final thread
414 ruxagg(&p->p_rux, td);
415 if (p->p_numthreads == 1)
416 ruadd(p->p_ru, &p->p_rux, &p->p_stats->p_cru, &p->p_crux);
418 * The last thread is left attached to the process
419 * So that the whole bundle gets recycled. Skip
420 * all this stuff if we never had threads.
421 * EXIT clears all sign of other threads when
422 * it goes to single threading, so the last thread always
423 * takes the short path.
425 if (p->p_flag & P_HADTHREADS) {
426 if (p->p_numthreads > 1) {
428 /* Impart our resource usage on another thread */
429 td2 = FIRST_THREAD_IN_PROC(p);
430 rucollect(&td2->td_ru, &td->td_ru);
431 sched_exit_thread(td2, td);
434 * The test below is NOT true if we are the
435 * sole exiting thread. P_STOPPED_SNGL is unset
436 * in exit1() after it is the only survivor.
438 if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE) {
439 if (p->p_numthreads == p->p_suspcount) {
440 thread_unsuspend_one(p->p_singlethread);
446 * Because each upcall structure has an owner thread,
447 * owner thread exits only when process is in exiting
448 * state, so upcall to userland is no longer needed,
449 * deleting upcall structure is safe here.
450 * So when all threads in a group is exited, all upcalls
451 * in the group should be automatically freed.
452 * XXXKSE This is a KSE thing and should be exported
459 PCPU_SET(deadthread, td);
462 * The last thread is exiting.. but not through exit()
464 * Theoretically this can't happen
465 * exit1() - clears threading flags before coming here
466 * kse_exit() - treats last thread specially
467 * thr_exit() - treats last thread specially
469 * thread_user_enter() - only if more exist
470 * thread_userret() - only if more exist
472 * thread_suspend_check() - only if more exist
474 panic ("thread_exit: Last thread exiting on its own");
478 * non threaded process comes here.
479 * This includes an EX threaded process that is coming
480 * here via exit1(). (exit1 dethreads the proc first).
484 td->td_state = TDS_INACTIVE;
485 CTR1(KTR_PROC, "thread_exit: cpu_throw() thread %p", td);
486 cpu_throw(td, choosethread());
487 panic("I'm a teapot!");
492 * Do any thread specific cleanups that may be needed in wait()
493 * called with Giant, proc and schedlock not held.
496 thread_wait(struct proc *p)
500 mtx_assert(&Giant, MA_NOTOWNED);
501 KASSERT((p->p_numthreads == 1), ("Multiple threads in wait1()"));
502 FOREACH_THREAD_IN_PROC(p, td) {
504 if (td->td_standin != NULL) {
505 if (td->td_standin->td_ucred != NULL) {
506 crfree(td->td_standin->td_ucred);
507 td->td_standin->td_ucred = NULL;
509 thread_free(td->td_standin);
510 td->td_standin = NULL;
513 cpu_thread_clean(td);
514 crfree(td->td_ucred);
516 thread_reap(); /* check for zombie threads etc. */
520 * Link a thread to a process.
521 * set up anything that needs to be initialized for it to
522 * be used by the process.
524 * Note that we do not link to the proc's ucred here.
525 * The thread is linked as if running but no KSE assigned.
528 * thread_schedule_upcall()
532 thread_link(struct thread *td, struct proc *p)
535 td->td_state = TDS_INACTIVE;
539 LIST_INIT(&td->td_contested);
540 sigqueue_init(&td->td_sigqueue, p);
541 callout_init(&td->td_slpcallout, CALLOUT_MPSAFE);
542 TAILQ_INSERT_HEAD(&p->p_threads, td, td_plist);
547 * Convert a process with one thread to an unthreaded process.
549 * thread_single(exit) (called from execve and exit)
550 * kse_exit() XXX may need cleaning up wrt KSE stuff
553 thread_unthread(struct thread *td)
555 struct proc *p = td->td_proc;
557 KASSERT((p->p_numthreads == 1), ("Unthreading with >1 threads"));
560 p->p_flag &= ~(P_SA|P_HADTHREADS);
561 td->td_mailbox = NULL;
562 td->td_pflags &= ~(TDP_SA | TDP_CAN_UNBIND);
563 if (td->td_standin != NULL) {
564 thread_stash(td->td_standin);
565 td->td_standin = NULL;
567 sched_set_concurrency(p, 1);
569 p->p_flag &= ~P_HADTHREADS;
578 thread_unlink(struct thread *td)
580 struct proc *p = td->td_proc;
582 mtx_assert(&sched_lock, MA_OWNED);
583 TAILQ_REMOVE(&p->p_threads, td, td_plist);
585 /* could clear a few other things here */
586 /* Must NOT clear links to proc! */
590 * Enforce single-threading.
592 * Returns 1 if the caller must abort (another thread is waiting to
593 * exit the process or similar). Process is locked!
594 * Returns 0 when you are successfully the only thread running.
595 * A process has successfully single threaded in the suspend mode when
596 * There are no threads in user mode. Threads in the kernel must be
597 * allowed to continue until they get to the user boundary. They may even
598 * copy out their return values and data before suspending. They may however be
599 * accelerated in reaching the user boundary as we will wake up
600 * any sleeping threads that are interruptable. (PCATCH).
603 thread_single(int mode)
612 mtx_assert(&Giant, MA_NOTOWNED);
613 PROC_LOCK_ASSERT(p, MA_OWNED);
614 KASSERT((td != NULL), ("curthread is NULL"));
616 if ((p->p_flag & P_HADTHREADS) == 0)
619 /* Is someone already single threading? */
620 if (p->p_singlethread != NULL && p->p_singlethread != td)
623 if (mode == SINGLE_EXIT) {
624 p->p_flag |= P_SINGLE_EXIT;
625 p->p_flag &= ~P_SINGLE_BOUNDARY;
627 p->p_flag &= ~P_SINGLE_EXIT;
628 if (mode == SINGLE_BOUNDARY)
629 p->p_flag |= P_SINGLE_BOUNDARY;
631 p->p_flag &= ~P_SINGLE_BOUNDARY;
633 p->p_flag |= P_STOPPED_SINGLE;
634 mtx_lock_spin(&sched_lock);
635 p->p_singlethread = td;
636 if (mode == SINGLE_EXIT)
637 remaining = p->p_numthreads;
638 else if (mode == SINGLE_BOUNDARY)
639 remaining = p->p_numthreads - p->p_boundary_count;
641 remaining = p->p_numthreads - p->p_suspcount;
642 while (remaining != 1) {
643 if (P_SHOULDSTOP(p) != P_STOPPED_SINGLE)
645 FOREACH_THREAD_IN_PROC(p, td2) {
648 td2->td_flags |= TDF_ASTPENDING;
649 if (TD_IS_INHIBITED(td2)) {
652 if (td->td_flags & TDF_DBSUSPEND)
653 td->td_flags &= ~TDF_DBSUSPEND;
654 if (TD_IS_SUSPENDED(td2))
655 thread_unsuspend_one(td2);
656 if (TD_ON_SLEEPQ(td2) &&
657 (td2->td_flags & TDF_SINTR))
658 sleepq_abort(td2, EINTR);
660 case SINGLE_BOUNDARY:
661 if (TD_IS_SUSPENDED(td2) &&
662 !(td2->td_flags & TDF_BOUNDARY))
663 thread_unsuspend_one(td2);
664 if (TD_ON_SLEEPQ(td2) &&
665 (td2->td_flags & TDF_SINTR))
666 sleepq_abort(td2, ERESTART);
669 if (TD_IS_SUSPENDED(td2))
672 * maybe other inhibited states too?
674 if ((td2->td_flags & TDF_SINTR) &&
675 (td2->td_inhibitors &
676 (TDI_SLEEPING | TDI_SWAPPED)))
677 thread_suspend_one(td2);
682 else if (TD_IS_RUNNING(td2) && td != td2) {
687 if (mode == SINGLE_EXIT)
688 remaining = p->p_numthreads;
689 else if (mode == SINGLE_BOUNDARY)
690 remaining = p->p_numthreads - p->p_boundary_count;
692 remaining = p->p_numthreads - p->p_suspcount;
695 * Maybe we suspended some threads.. was it enough?
702 * Wake us up when everyone else has suspended.
703 * In the mean time we suspend as well.
706 thread_suspend_one(td);
708 mi_switch(SW_VOL, NULL);
709 mtx_unlock_spin(&sched_lock);
711 mtx_lock_spin(&sched_lock);
712 if (mode == SINGLE_EXIT)
713 remaining = p->p_numthreads;
714 else if (mode == SINGLE_BOUNDARY)
715 remaining = p->p_numthreads - p->p_boundary_count;
717 remaining = p->p_numthreads - p->p_suspcount;
719 if (mode == SINGLE_EXIT) {
721 * We have gotten rid of all the other threads and we
722 * are about to either exit or exec. In either case,
723 * we try our utmost to revert to being a non-threaded
726 p->p_singlethread = NULL;
727 p->p_flag &= ~(P_STOPPED_SINGLE | P_SINGLE_EXIT);
730 mtx_unlock_spin(&sched_lock);
735 * Called in from locations that can safely check to see
736 * whether we have to suspend or at least throttle for a
737 * single-thread event (e.g. fork).
739 * Such locations include userret().
740 * If the "return_instead" argument is non zero, the thread must be able to
741 * accept 0 (caller may continue), or 1 (caller must abort) as a result.
743 * The 'return_instead' argument tells the function if it may do a
744 * thread_exit() or suspend, or whether the caller must abort and back
747 * If the thread that set the single_threading request has set the
748 * P_SINGLE_EXIT bit in the process flags then this call will never return
749 * if 'return_instead' is false, but will exit.
751 * P_SINGLE_EXIT | return_instead == 0| return_instead != 0
752 *---------------+--------------------+---------------------
753 * 0 | returns 0 | returns 0 or 1
754 * | when ST ends | immediatly
755 *---------------+--------------------+---------------------
756 * 1 | thread exits | returns 1
758 * 0 = thread_exit() or suspension ok,
759 * other = return error instead of stopping the thread.
761 * While a full suspension is under effect, even a single threading
762 * thread would be suspended if it made this call (but it shouldn't).
763 * This call should only be made from places where
764 * thread_exit() would be safe as that may be the outcome unless
765 * return_instead is set.
768 thread_suspend_check(int return_instead)
775 mtx_assert(&Giant, MA_NOTOWNED);
776 PROC_LOCK_ASSERT(p, MA_OWNED);
777 while (P_SHOULDSTOP(p) ||
778 ((p->p_flag & P_TRACED) && (td->td_flags & TDF_DBSUSPEND))) {
779 if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE) {
780 KASSERT(p->p_singlethread != NULL,
781 ("singlethread not set"));
783 * The only suspension in action is a
784 * single-threading. Single threader need not stop.
785 * XXX Should be safe to access unlocked
786 * as it can only be set to be true by us.
788 if (p->p_singlethread == td)
789 return (0); /* Exempt from stopping. */
791 if ((p->p_flag & P_SINGLE_EXIT) && return_instead)
794 /* Should we goto user boundary if we didn't come from there? */
795 if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE &&
796 (p->p_flag & P_SINGLE_BOUNDARY) && return_instead)
799 /* If thread will exit, flush its pending signals */
800 if ((p->p_flag & P_SINGLE_EXIT) && (p->p_singlethread != td))
801 sigqueue_flush(&td->td_sigqueue);
803 mtx_lock_spin(&sched_lock);
806 * If the process is waiting for us to exit,
807 * this thread should just suicide.
808 * Assumes that P_SINGLE_EXIT implies P_STOPPED_SINGLE.
810 if ((p->p_flag & P_SINGLE_EXIT) && (p->p_singlethread != td))
814 * When a thread suspends, it just
815 * gets taken off all queues.
817 thread_suspend_one(td);
818 if (return_instead == 0) {
819 p->p_boundary_count++;
820 td->td_flags |= TDF_BOUNDARY;
822 if (P_SHOULDSTOP(p) == P_STOPPED_SINGLE) {
823 if (p->p_numthreads == p->p_suspcount)
824 thread_unsuspend_one(p->p_singlethread);
827 mi_switch(SW_INVOL, NULL);
828 if (return_instead == 0) {
829 p->p_boundary_count--;
830 td->td_flags &= ~TDF_BOUNDARY;
832 mtx_unlock_spin(&sched_lock);
839 thread_suspend_one(struct thread *td)
841 struct proc *p = td->td_proc;
843 mtx_assert(&sched_lock, MA_OWNED);
844 PROC_LOCK_ASSERT(p, MA_OWNED);
845 KASSERT(!TD_IS_SUSPENDED(td), ("already suspended"));
847 TD_SET_SUSPENDED(td);
851 thread_unsuspend_one(struct thread *td)
853 struct proc *p = td->td_proc;
855 mtx_assert(&sched_lock, MA_OWNED);
856 PROC_LOCK_ASSERT(p, MA_OWNED);
857 KASSERT(TD_IS_SUSPENDED(td), ("Thread not suspended"));
858 TD_CLR_SUSPENDED(td);
864 * Allow all threads blocked by single threading to continue running.
867 thread_unsuspend(struct proc *p)
871 mtx_assert(&sched_lock, MA_OWNED);
872 PROC_LOCK_ASSERT(p, MA_OWNED);
873 if (!P_SHOULDSTOP(p)) {
874 FOREACH_THREAD_IN_PROC(p, td) {
875 if (TD_IS_SUSPENDED(td)) {
876 thread_unsuspend_one(td);
879 } else if ((P_SHOULDSTOP(p) == P_STOPPED_SINGLE) &&
880 (p->p_numthreads == p->p_suspcount)) {
882 * Stopping everything also did the job for the single
883 * threading request. Now we've downgraded to single-threaded,
886 thread_unsuspend_one(p->p_singlethread);
891 * End the single threading mode..
894 thread_single_end(void)
901 PROC_LOCK_ASSERT(p, MA_OWNED);
902 p->p_flag &= ~(P_STOPPED_SINGLE | P_SINGLE_EXIT | P_SINGLE_BOUNDARY);
903 mtx_lock_spin(&sched_lock);
904 p->p_singlethread = NULL;
906 * If there are other threads they mey now run,
907 * unless of course there is a blanket 'stop order'
908 * on the process. The single threader must be allowed
909 * to continue however as this is a bad place to stop.
911 if ((p->p_numthreads != 1) && (!P_SHOULDSTOP(p))) {
912 FOREACH_THREAD_IN_PROC(p, td) {
913 if (TD_IS_SUSPENDED(td)) {
914 thread_unsuspend_one(td);
918 mtx_unlock_spin(&sched_lock);
922 thread_find(struct proc *p, lwpid_t tid)
926 PROC_LOCK_ASSERT(p, MA_OWNED);
927 mtx_lock_spin(&sched_lock);
928 FOREACH_THREAD_IN_PROC(p, td) {
929 if (td->td_tid == tid)
932 mtx_unlock_spin(&sched_lock);