6583 remove whole-process swapping
1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright (c) 1991, 2010, Oracle and/or its affiliates. All rights reserved.
24 * Copyright (c) 2013, Joyent, Inc. All rights reserved.
25 */
26
27 #include <sys/types.h>
28 #include <sys/param.h>
29 #include <sys/sysmacros.h>
30 #include <sys/signal.h>
31 #include <sys/stack.h>
32 #include <sys/pcb.h>
33 #include <sys/user.h>
34 #include <sys/systm.h>
35 #include <sys/sysinfo.h>
36 #include <sys/errno.h>
37 #include <sys/cmn_err.h>
38 #include <sys/cred.h>
39 #include <sys/resource.h>
40 #include <sys/task.h>
41 #include <sys/project.h>
42 #include <sys/proc.h>
43 #include <sys/debug.h>
44 #include <sys/disp.h>
45 #include <sys/class.h>
46 #include <vm/seg_kmem.h>
47 #include <vm/seg_kp.h>
48 #include <sys/machlock.h>
49 #include <sys/kmem.h>
50 #include <sys/varargs.h>
51 #include <sys/turnstile.h>
52 #include <sys/poll.h>
53 #include <sys/vtrace.h>
54 #include <sys/callb.h>
55 #include <c2/audit.h>
56 #include <sys/tnf.h>
57 #include <sys/sobject.h>
58 #include <sys/cpupart.h>
59 #include <sys/pset.h>
60 #include <sys/door.h>
61 #include <sys/spl.h>
62 #include <sys/copyops.h>
63 #include <sys/rctl.h>
64 #include <sys/brand.h>
65 #include <sys/pool.h>
66 #include <sys/zone.h>
67 #include <sys/tsol/label.h>
68 #include <sys/tsol/tndb.h>
69 #include <sys/cpc_impl.h>
70 #include <sys/sdt.h>
71 #include <sys/reboot.h>
72 #include <sys/kdi.h>
73 #include <sys/schedctl.h>
74 #include <sys/waitq.h>
75 #include <sys/cpucaps.h>
76 #include <sys/kiconv.h>
77
78 struct kmem_cache *thread_cache; /* cache of free threads */
79 struct kmem_cache *lwp_cache; /* cache of free lwps */
80 struct kmem_cache *turnstile_cache; /* cache of free turnstiles */
81
82 /*
83 * allthreads is only for use by kmem_readers. All kernel loops can use
84 * the current thread as a start/end point.
85 */
86 kthread_t *allthreads = &t0; /* circular list of all threads */
87
88 static kcondvar_t reaper_cv; /* synchronization var */
89 kthread_t *thread_deathrow; /* circular list of reapable threads */
90 kthread_t *lwp_deathrow; /* circular list of reapable threads */
91 kmutex_t reaplock; /* protects lwp and thread deathrows */
92 int thread_reapcnt = 0; /* number of threads on deathrow */
93 int lwp_reapcnt = 0; /* number of lwps on deathrow */
94 int reaplimit = 16; /* delay reaping until reaplimit */
95
96 thread_free_lock_t *thread_free_lock;
97 /* protects tick thread from reaper */
98
99 extern int nthread;
100
101 /* System Scheduling classes. */
102 id_t syscid; /* system scheduling class ID */
103 id_t sysdccid = CLASS_UNUSED; /* reset when SDC loads */
104
105 void *segkp_thread; /* cookie for segkp pool */
106
107 int lwp_cache_sz = 32;
108 int t_cache_sz = 8;
109 static kt_did_t next_t_id = 1;
110
111 /* Default mode for thread binding to CPUs and processor sets */
112 int default_binding_mode = TB_ALLHARD;
113
114 /*
115 * Min/Max stack sizes for stack size parameters
116 */
117 #define MAX_STKSIZE (32 * DEFAULTSTKSZ)
118 #define MIN_STKSIZE DEFAULTSTKSZ
119
120 /*
121 * default_stksize overrides lwp_default_stksize if it is set.
122 */
123 int default_stksize;
124 int lwp_default_stksize;
125
126 static zone_key_t zone_thread_key;
127
128 unsigned int kmem_stackinfo; /* stackinfo feature on-off */
129 kmem_stkinfo_t *kmem_stkinfo_log; /* stackinfo circular log */
130 static kmutex_t kmem_stkinfo_lock; /* protects kmem_stkinfo_log */
131
132 /*
133 * forward declarations for internal thread specific data (tsd)
134 */
135 static void *tsd_realloc(void *, size_t, size_t);
136
137 void thread_reaper(void);
138
139 /* forward declarations for stackinfo feature */
140 static void stkinfo_begin(kthread_t *);
141 static void stkinfo_end(kthread_t *);
142 static size_t stkinfo_percent(caddr_t, caddr_t, caddr_t);
143
144 /*ARGSUSED*/
145 static int
146 turnstile_constructor(void *buf, void *cdrarg, int kmflags)
147 {
148 bzero(buf, sizeof (turnstile_t));
149 return (0);
150 }
151
152 /*ARGSUSED*/
153 static void
154 turnstile_destructor(void *buf, void *cdrarg)
155 {
156 turnstile_t *ts = buf;
157
158 ASSERT(ts->ts_free == NULL);
159 ASSERT(ts->ts_waiters == 0);
160 ASSERT(ts->ts_inheritor == NULL);
161 ASSERT(ts->ts_sleepq[0].sq_first == NULL);
162 ASSERT(ts->ts_sleepq[1].sq_first == NULL);
163 }
164
165 void
166 thread_init(void)
167 {
168 kthread_t *tp;
169 extern char sys_name[];
170 extern void idle();
171 struct cpu *cpu = CPU;
172 int i;
173 kmutex_t *lp;
174
175 mutex_init(&reaplock, NULL, MUTEX_SPIN, (void *)ipltospl(DISP_LEVEL));
176 thread_free_lock =
177 kmem_alloc(sizeof (thread_free_lock_t) * THREAD_FREE_NUM, KM_SLEEP);
178 for (i = 0; i < THREAD_FREE_NUM; i++) {
179 lp = &thread_free_lock[i].tf_lock;
180 mutex_init(lp, NULL, MUTEX_DEFAULT, NULL);
181 }
182
183 #if defined(__i386) || defined(__amd64)
184 thread_cache = kmem_cache_create("thread_cache", sizeof (kthread_t),
185 PTR24_ALIGN, NULL, NULL, NULL, NULL, NULL, 0);
186
187 /*
188 * "struct _klwp" includes a "struct pcb", which includes a
189 * "struct fpu", which needs to be 64-byte aligned on amd64
190 * (and even on i386) for xsave/xrstor.
191 */
192 lwp_cache = kmem_cache_create("lwp_cache", sizeof (klwp_t),
193 64, NULL, NULL, NULL, NULL, NULL, 0);
194 #else
195 /*
196 * Allocate thread structures from static_arena. This prevents
197 * issues where a thread tries to relocate its own thread
198 * structure and touches it after the mapping has been suspended.
199 */
200 thread_cache = kmem_cache_create("thread_cache", sizeof (kthread_t),
201 PTR24_ALIGN, NULL, NULL, NULL, NULL, static_arena, 0);
202
203 lwp_stk_cache_init();
204
205 lwp_cache = kmem_cache_create("lwp_cache", sizeof (klwp_t),
206 0, NULL, NULL, NULL, NULL, NULL, 0);
207 #endif
208
209 turnstile_cache = kmem_cache_create("turnstile_cache",
210 sizeof (turnstile_t), 0,
211 turnstile_constructor, turnstile_destructor, NULL, NULL, NULL, 0);
212
213 label_init();
214 cred_init();
215
216 /*
217 * Initialize various resource management facilities.
218 */
219 rctl_init();
220 cpucaps_init();
221 /*
222 * Zone_init() should be called before project_init() so that project ID
223 * for the first project is initialized correctly.
224 */
225 zone_init();
226 project_init();
227 brand_init();
228 kiconv_init();
229 task_init();
230 tcache_init();
231 pool_init();
232
233 curthread->t_ts = kmem_cache_alloc(turnstile_cache, KM_SLEEP);
234
235 /*
236 * Originally, we had two parameters to set default stack
237 * size: one for lwp's (lwp_default_stksize), and one for
238 * kernel-only threads (DEFAULTSTKSZ, a.k.a. _defaultstksz).
239 * Now we have a third parameter that overrides both if it is
240 * set to a legal stack size, called default_stksize.
241 */
242
243 if (default_stksize == 0) {
244 default_stksize = DEFAULTSTKSZ;
245 } else if (default_stksize % PAGESIZE != 0 ||
246 default_stksize > MAX_STKSIZE ||
247 default_stksize < MIN_STKSIZE) {
248 cmn_err(CE_WARN, "Illegal stack size. Using %d",
249 (int)DEFAULTSTKSZ);
250 default_stksize = DEFAULTSTKSZ;
251 } else {
252 lwp_default_stksize = default_stksize;
253 }
254
255 if (lwp_default_stksize == 0) {
256 lwp_default_stksize = default_stksize;
257 } else if (lwp_default_stksize % PAGESIZE != 0 ||
258 lwp_default_stksize > MAX_STKSIZE ||
259 lwp_default_stksize < MIN_STKSIZE) {
260 cmn_err(CE_WARN, "Illegal stack size. Using %d",
261 default_stksize);
262 lwp_default_stksize = default_stksize;
263 }
264
265 segkp_lwp = segkp_cache_init(segkp, lwp_cache_sz,
266 lwp_default_stksize,
267 (KPD_NOWAIT | KPD_HASREDZONE | KPD_LOCKED));
268
269 segkp_thread = segkp_cache_init(segkp, t_cache_sz,
270 default_stksize, KPD_HASREDZONE | KPD_LOCKED | KPD_NO_ANON);
271
272 (void) getcid(sys_name, &syscid);
273 curthread->t_cid = syscid; /* current thread is t0 */
274
275 /*
276 * Set up the first CPU's idle thread.
277 * It runs whenever the CPU has nothing worthwhile to do.
278 */
279 tp = thread_create(NULL, 0, idle, NULL, 0, &p0, TS_STOPPED, -1);
280 cpu->cpu_idle_thread = tp;
281 tp->t_preempt = 1;
282 tp->t_disp_queue = cpu->cpu_disp;
283 ASSERT(tp->t_disp_queue != NULL);
284 tp->t_bound_cpu = cpu;
285 tp->t_affinitycnt = 1;
286
287 /*
288 * Registering a thread in the callback table is usually
289 * done in the initialization code of the thread. In this
290 * case, we do it right after thread creation to avoid
291 * blocking idle thread while registering itself. It also
292 * avoids the possibility of reregistration in case a CPU
293 * restarts its idle thread.
294 */
295 CALLB_CPR_INIT_SAFE(tp, "idle");
296
297 /*
298 * Create the thread_reaper daemon. From this point on, exited
299 * threads will get reaped.
300 */
301 (void) thread_create(NULL, 0, (void (*)())thread_reaper,
302 NULL, 0, &p0, TS_RUN, minclsyspri);
303
304 /*
305 * Finish initializing the kernel memory allocator now that
306 * thread_create() is available.
307 */
308 kmem_thread_init();
309
310 if (boothowto & RB_DEBUG)
311 kdi_dvec_thravail();
312 }
313
314 /*
315 * Create a thread.
316 *
317 * thread_create() blocks for memory if necessary. It never fails.
318 *
319 * If stk is NULL, the thread is created at the base of the stack
320 * and cannot be swapped.
321 */
322 kthread_t *
323 thread_create(
324 caddr_t stk,
325 size_t stksize,
326 void (*proc)(),
327 void *arg,
328 size_t len,
329 proc_t *pp,
330 int state,
331 pri_t pri)
332 {
333 kthread_t *t;
334 extern struct classfuncs sys_classfuncs;
335 turnstile_t *ts;
336
337 /*
338 * Every thread keeps a turnstile around in case it needs to block.
339 * The only reason the turnstile is not simply part of the thread
340 * structure is that we may have to break the association whenever
341 * more than one thread blocks on a given synchronization object.
342 * From a memory-management standpoint, turnstiles are like the
343 * "attached mblks" that hang off dblks in the streams allocator.
344 */
345 ts = kmem_cache_alloc(turnstile_cache, KM_SLEEP);
346
347 if (stk == NULL) {
348 /*
349 * alloc both thread and stack in segkp chunk
350 */
351
352 if (stksize < default_stksize)
353 stksize = default_stksize;
354
355 if (stksize == default_stksize) {
356 stk = (caddr_t)segkp_cache_get(segkp_thread);
357 } else {
358 stksize = roundup(stksize, PAGESIZE);
359 stk = (caddr_t)segkp_get(segkp, stksize,
360 (KPD_HASREDZONE | KPD_NO_ANON | KPD_LOCKED));
361 }
362
363 ASSERT(stk != NULL);
364
365 /*
366 * The machine-dependent mutex code may require that
367 * thread pointers (since they may be used for mutex owner
368 * fields) have certain alignment requirements.
369 * PTR24_ALIGN is the size of the alignment quanta.
370 * XXX - assumes stack grows toward low addresses.
371 */
372 if (stksize <= sizeof (kthread_t) + PTR24_ALIGN)
373 cmn_err(CE_PANIC, "thread_create: proposed stack size"
374 " too small to hold thread.");
375 #ifdef STACK_GROWTH_DOWN
376 stksize -= SA(sizeof (kthread_t) + PTR24_ALIGN - 1);
377 stksize &= -PTR24_ALIGN; /* make thread aligned */
378 t = (kthread_t *)(stk + stksize);
379 bzero(t, sizeof (kthread_t));
380 if (audit_active)
381 audit_thread_create(t);
382 t->t_stk = stk + stksize;
383 t->t_stkbase = stk;
384 #else /* stack grows to larger addresses */
385 stksize -= SA(sizeof (kthread_t));
386 t = (kthread_t *)(stk);
387 bzero(t, sizeof (kthread_t));
388 t->t_stk = stk + sizeof (kthread_t);
389 t->t_stkbase = stk + stksize + sizeof (kthread_t);
390 #endif /* STACK_GROWTH_DOWN */
391 t->t_flag |= T_TALLOCSTK;
392 t->t_swap = stk;
393 } else {
394 t = kmem_cache_alloc(thread_cache, KM_SLEEP);
395 bzero(t, sizeof (kthread_t));
396 ASSERT(((uintptr_t)t & (PTR24_ALIGN - 1)) == 0);
397 if (audit_active)
398 audit_thread_create(t);
399 /*
400 * Initialize t_stk to the kernel stack pointer to use
401 * upon entry to the kernel
402 */
403 #ifdef STACK_GROWTH_DOWN
404 t->t_stk = stk + stksize;
405 t->t_stkbase = stk;
406 #else
407 t->t_stk = stk; /* 3b2-like */
408 t->t_stkbase = stk + stksize;
409 #endif /* STACK_GROWTH_DOWN */
410 }
411
412 if (kmem_stackinfo != 0) {
413 stkinfo_begin(t);
414 }
415
416 t->t_ts = ts;
417
418 /*
419 * p_cred could be NULL if it thread_create is called before cred_init
420 * is called in main.
421 */
422 mutex_enter(&pp->p_crlock);
423 if (pp->p_cred)
424 crhold(t->t_cred = pp->p_cred);
425 mutex_exit(&pp->p_crlock);
426 t->t_start = gethrestime_sec();
427 t->t_startpc = proc;
428 t->t_procp = pp;
429 t->t_clfuncs = &sys_classfuncs.thread;
430 t->t_cid = syscid;
431 t->t_pri = pri;
432 t->t_schedflag = 0;
433 t->t_bind_cpu = PBIND_NONE;
434 t->t_bindflag = (uchar_t)default_binding_mode;
435 t->t_bind_pset = PS_NONE;
436 t->t_plockp = &pp->p_lock;
437 t->t_copyops = NULL;
438 t->t_taskq = NULL;
439 t->t_anttime = 0;
440 t->t_hatdepth = 0;
441
442 t->t_dtrace_vtime = 1; /* assure vtimestamp is always non-zero */
443
444 CPU_STATS_ADDQ(CPU, sys, nthreads, 1);
445 #ifndef NPROBE
446 /* Kernel probe */
447 tnf_thread_create(t);
448 #endif /* NPROBE */
449 LOCK_INIT_CLEAR(&t->t_lock);
450
451 /*
452 * Callers who give us a NULL proc must do their own
453 * stack initialization. e.g. lwp_create()
454 */
455 if (proc != NULL) {
456 t->t_stk = thread_stk_init(t->t_stk);
457 thread_load(t, proc, arg, len);
458 }
459
460 /*
461 * Put a hold on project0. If this thread is actually in a
462 * different project, then t_proj will be changed later in
463 * lwp_create(). All kernel-only threads must be in project 0.
464 */
465 t->t_proj = project_hold(proj0p);
466
467 lgrp_affinity_init(&t->t_lgrp_affinity);
468
469 mutex_enter(&pidlock);
470 nthread++;
471 t->t_did = next_t_id++;
472 t->t_prev = curthread->t_prev;
473 t->t_next = curthread;
474
475 /*
476 * Add the thread to the list of all threads, and initialize
477 * its t_cpu pointer. We need to block preemption since
478 * cpu_offline walks the thread list looking for threads
479 * with t_cpu pointing to the CPU being offlined. We want
480 * to make sure that the list is consistent and that if t_cpu
481 * is set, the thread is on the list.
482 */
483 kpreempt_disable();
484 curthread->t_prev->t_next = t;
485 curthread->t_prev = t;
486
487 /*
488 * Threads should never have a NULL t_cpu pointer so assign it
489 * here. If the thread is being created with state TS_RUN a
490 * better CPU may be chosen when it is placed on the run queue.
491 *
492 * We need to keep kernel preemption disabled when setting all
493 * three fields to keep them in sync. Also, always create in
494 * the default partition since that's where kernel threads go
495 * (if this isn't a kernel thread, t_cpupart will be changed
496 * in lwp_create before setting the thread runnable).
497 */
498 t->t_cpupart = &cp_default;
499
500 /*
501 * For now, affiliate this thread with the root lgroup.
502 * Since the kernel does not (presently) allocate its memory
503 * in a locality aware fashion, the root is an appropriate home.
504 * If this thread is later associated with an lwp, it will have
505 * it's lgroup re-assigned at that time.
506 */
507 lgrp_move_thread(t, &cp_default.cp_lgrploads[LGRP_ROOTID], 1);
508
509 /*
510 * Inherit the current cpu. If this cpu isn't part of the chosen
511 * lgroup, a new cpu will be chosen by cpu_choose when the thread
512 * is ready to run.
513 */
514 if (CPU->cpu_part == &cp_default)
515 t->t_cpu = CPU;
516 else
517 t->t_cpu = disp_lowpri_cpu(cp_default.cp_cpulist, t->t_lpl,
518 t->t_pri, NULL);
519
520 t->t_disp_queue = t->t_cpu->cpu_disp;
521 kpreempt_enable();
522
523 /*
524 * Initialize thread state and the dispatcher lock pointer.
525 * Need to hold onto pidlock to block allthreads walkers until
526 * the state is set.
527 */
528 switch (state) {
529 case TS_RUN:
530 curthread->t_oldspl = splhigh(); /* get dispatcher spl */
531 THREAD_SET_STATE(t, TS_STOPPED, &transition_lock);
532 CL_SETRUN(t);
533 thread_unlock(t);
534 break;
535
536 case TS_ONPROC:
537 THREAD_ONPROC(t, t->t_cpu);
538 break;
539
540 case TS_FREE:
541 /*
542 * Free state will be used for intr threads.
543 * The interrupt routine must set the thread dispatcher
544 * lock pointer (t_lockp) if starting on a CPU
545 * other than the current one.
546 */
547 THREAD_FREEINTR(t, CPU);
548 break;
549
550 case TS_STOPPED:
551 THREAD_SET_STATE(t, TS_STOPPED, &stop_lock);
552 break;
553
554 default: /* TS_SLEEP, TS_ZOMB or TS_TRANS */
555 cmn_err(CE_PANIC, "thread_create: invalid state %d", state);
556 }
557 mutex_exit(&pidlock);
558 return (t);
559 }
560
561 /*
562 * Move thread to project0 and take care of project reference counters.
563 */
564 void
565 thread_rele(kthread_t *t)
566 {
567 kproject_t *kpj;
568
569 thread_lock(t);
570
571 ASSERT(t == curthread || t->t_state == TS_FREE || t->t_procp == &p0);
572 kpj = ttoproj(t);
573 t->t_proj = proj0p;
574
575 thread_unlock(t);
576
577 if (kpj != proj0p) {
578 project_rele(kpj);
579 (void) project_hold(proj0p);
580 }
581 }
582
583 void
584 thread_exit(void)
585 {
586 kthread_t *t = curthread;
587
588 if ((t->t_proc_flag & TP_ZTHREAD) != 0)
589 cmn_err(CE_PANIC, "thread_exit: zthread_exit() not called");
590
591 tsd_exit(); /* Clean up this thread's TSD */
592
593 kcpc_passivate(); /* clean up performance counter state */
594
595 /*
596 * No kernel thread should have called poll() without arranging
597 * calling pollcleanup() here.
598 */
599 ASSERT(t->t_pollstate == NULL);
600 ASSERT(t->t_schedctl == NULL);
601 if (t->t_door)
602 door_slam(); /* in case thread did an upcall */
603
604 #ifndef NPROBE
605 /* Kernel probe */
606 if (t->t_tnf_tpdp)
607 tnf_thread_exit();
608 #endif /* NPROBE */
609
610 thread_rele(t);
611 t->t_preempt++;
612
613 /*
614 * remove thread from the all threads list so that
615 * death-row can use the same pointers.
616 */
617 mutex_enter(&pidlock);
618 t->t_next->t_prev = t->t_prev;
619 t->t_prev->t_next = t->t_next;
620 ASSERT(allthreads != t); /* t0 never exits */
621 cv_broadcast(&t->t_joincv); /* wake up anyone in thread_join */
622 mutex_exit(&pidlock);
623
624 if (t->t_ctx != NULL)
625 exitctx(t);
626 if (t->t_procp->p_pctx != NULL)
627 exitpctx(t->t_procp);
628
629 if (kmem_stackinfo != 0) {
630 stkinfo_end(t);
631 }
632
633 t->t_state = TS_ZOMB; /* set zombie thread */
634
635 swtch_from_zombie(); /* give up the CPU */
636 /* NOTREACHED */
637 }
638
639 /*
640 * Check to see if the specified thread is active (defined as being on
641 * the thread list). This is certainly a slow way to do this; if there's
642 * ever a reason to speed it up, we could maintain a hash table of active
643 * threads indexed by their t_did.
644 */
645 static kthread_t *
646 did_to_thread(kt_did_t tid)
647 {
648 kthread_t *t;
649
650 ASSERT(MUTEX_HELD(&pidlock));
651 for (t = curthread->t_next; t != curthread; t = t->t_next) {
652 if (t->t_did == tid)
653 break;
654 }
655 if (t->t_did == tid)
656 return (t);
657 else
658 return (NULL);
659 }
660
661 /*
662 * Wait for specified thread to exit. Returns immediately if the thread
663 * could not be found, meaning that it has either already exited or never
664 * existed.
665 */
666 void
667 thread_join(kt_did_t tid)
668 {
669 kthread_t *t;
670
671 ASSERT(tid != curthread->t_did);
672 ASSERT(tid != t0.t_did);
673
674 mutex_enter(&pidlock);
675 /*
676 * Make sure we check that the thread is on the thread list
677 * before blocking on it; otherwise we could end up blocking on
678 * a cv that's already been freed. In other words, don't cache
679 * the thread pointer across calls to cv_wait.
680 *
681 * The choice of loop invariant means that whenever a thread
682 * is taken off the allthreads list, a cv_broadcast must be
683 * performed on that thread's t_joincv to wake up any waiters.
684 * The broadcast doesn't have to happen right away, but it
685 * shouldn't be postponed indefinitely (e.g., by doing it in
686 * thread_free which may only be executed when the deathrow
687 * queue is processed.
688 */
689 while (t = did_to_thread(tid))
690 cv_wait(&t->t_joincv, &pidlock);
691 mutex_exit(&pidlock);
692 }
693
694 void
695 thread_free_prevent(kthread_t *t)
696 {
697 kmutex_t *lp;
698
699 lp = &thread_free_lock[THREAD_FREE_HASH(t)].tf_lock;
700 mutex_enter(lp);
701 }
702
703 void
704 thread_free_allow(kthread_t *t)
705 {
706 kmutex_t *lp;
707
708 lp = &thread_free_lock[THREAD_FREE_HASH(t)].tf_lock;
709 mutex_exit(lp);
710 }
711
712 static void
713 thread_free_barrier(kthread_t *t)
714 {
715 kmutex_t *lp;
716
717 lp = &thread_free_lock[THREAD_FREE_HASH(t)].tf_lock;
718 mutex_enter(lp);
719 mutex_exit(lp);
720 }
721
722 void
723 thread_free(kthread_t *t)
724 {
725 boolean_t allocstk = (t->t_flag & T_TALLOCSTK);
726 klwp_t *lwp = t->t_lwp;
727 caddr_t swap = t->t_swap;
728
729 ASSERT(t != &t0 && t->t_state == TS_FREE);
730 ASSERT(t->t_door == NULL);
731 ASSERT(t->t_schedctl == NULL);
732 ASSERT(t->t_pollstate == NULL);
733
734 t->t_pri = 0;
735 t->t_pc = 0;
736 t->t_sp = 0;
737 t->t_wchan0 = NULL;
738 t->t_wchan = NULL;
739 if (t->t_cred != NULL) {
740 crfree(t->t_cred);
741 t->t_cred = 0;
742 }
743 if (t->t_pdmsg) {
744 kmem_free(t->t_pdmsg, strlen(t->t_pdmsg) + 1);
745 t->t_pdmsg = NULL;
746 }
747 if (audit_active)
748 audit_thread_free(t);
749 #ifndef NPROBE
750 if (t->t_tnf_tpdp)
751 tnf_thread_free(t);
752 #endif /* NPROBE */
753 if (t->t_cldata) {
754 CL_EXITCLASS(t->t_cid, (caddr_t *)t->t_cldata);
755 }
756 if (t->t_rprof != NULL) {
757 kmem_free(t->t_rprof, sizeof (*t->t_rprof));
758 t->t_rprof = NULL;
759 }
760 t->t_lockp = NULL; /* nothing should try to lock this thread now */
761 if (lwp)
762 lwp_freeregs(lwp, 0);
763 if (t->t_ctx)
764 freectx(t, 0);
765 t->t_stk = NULL;
766 if (lwp)
767 lwp_stk_fini(lwp);
768 lock_clear(&t->t_lock);
769
770 if (t->t_ts->ts_waiters > 0)
771 panic("thread_free: turnstile still active");
772
773 kmem_cache_free(turnstile_cache, t->t_ts);
774
775 free_afd(&t->t_activefd);
776
777 /*
778 * Barrier for the tick accounting code. The tick accounting code
779 * holds this lock to keep the thread from going away while it's
780 * looking at it.
781 */
782 thread_free_barrier(t);
783
784 ASSERT(ttoproj(t) == proj0p);
785 project_rele(ttoproj(t));
786
787 lgrp_affinity_free(&t->t_lgrp_affinity);
788
789 mutex_enter(&pidlock);
790 nthread--;
791 mutex_exit(&pidlock);
792
793 /*
794 * Free thread, lwp and stack. This needs to be done carefully, since
795 * if T_TALLOCSTK is set, the thread is part of the stack.
796 */
797 t->t_lwp = NULL;
798 t->t_swap = NULL;
799
800 if (swap) {
801 segkp_release(segkp, swap);
802 }
803 if (lwp) {
804 kmem_cache_free(lwp_cache, lwp);
805 }
806 if (!allocstk) {
807 kmem_cache_free(thread_cache, t);
808 }
809 }
810
811 /*
812 * Removes threads associated with the given zone from a deathrow queue.
813 * tp is a pointer to the head of the deathrow queue, and countp is a
814 * pointer to the current deathrow count. Returns a linked list of
815 * threads removed from the list.
816 */
817 static kthread_t *
818 thread_zone_cleanup(kthread_t **tp, int *countp, zoneid_t zoneid)
819 {
820 kthread_t *tmp, *list = NULL;
821 cred_t *cr;
822
823 ASSERT(MUTEX_HELD(&reaplock));
824 while (*tp != NULL) {
825 if ((cr = (*tp)->t_cred) != NULL && crgetzoneid(cr) == zoneid) {
826 tmp = *tp;
827 *tp = tmp->t_forw;
828 tmp->t_forw = list;
829 list = tmp;
830 (*countp)--;
831 } else {
832 tp = &(*tp)->t_forw;
833 }
834 }
835 return (list);
836 }
837
838 static void
839 thread_reap_list(kthread_t *t)
840 {
841 kthread_t *next;
842
843 while (t != NULL) {
844 next = t->t_forw;
845 thread_free(t);
846 t = next;
847 }
848 }
849
850 /* ARGSUSED */
851 static void
852 thread_zone_destroy(zoneid_t zoneid, void *unused)
853 {
854 kthread_t *t, *l;
855
856 mutex_enter(&reaplock);
857 /*
858 * Pull threads and lwps associated with zone off deathrow lists.
859 */
860 t = thread_zone_cleanup(&thread_deathrow, &thread_reapcnt, zoneid);
861 l = thread_zone_cleanup(&lwp_deathrow, &lwp_reapcnt, zoneid);
862 mutex_exit(&reaplock);
863
864 /*
865 * Guard against race condition in mutex_owner_running:
866 * thread=owner(mutex)
867 * <interrupt>
868 * thread exits mutex
869 * thread exits
870 * thread reaped
871 * thread struct freed
872 * cpu = thread->t_cpu <- BAD POINTER DEREFERENCE.
873 * A cross call to all cpus will cause the interrupt handler
874 * to reset the PC if it is in mutex_owner_running, refreshing
875 * stale thread pointers.
876 */
877 mutex_sync(); /* sync with mutex code */
878
879 /*
880 * Reap threads
881 */
882 thread_reap_list(t);
883
884 /*
885 * Reap lwps
886 */
887 thread_reap_list(l);
888 }
889
890 /*
891 * cleanup zombie threads that are on deathrow.
892 */
893 void
894 thread_reaper()
895 {
896 kthread_t *t, *l;
897 callb_cpr_t cprinfo;
898
899 /*
900 * Register callback to clean up threads when zone is destroyed.
901 */
902 zone_key_create(&zone_thread_key, NULL, NULL, thread_zone_destroy);
903
904 CALLB_CPR_INIT(&cprinfo, &reaplock, callb_generic_cpr, "t_reaper");
905 for (;;) {
906 mutex_enter(&reaplock);
907 while (thread_deathrow == NULL && lwp_deathrow == NULL) {
908 CALLB_CPR_SAFE_BEGIN(&cprinfo);
909 cv_wait(&reaper_cv, &reaplock);
910 CALLB_CPR_SAFE_END(&cprinfo, &reaplock);
911 }
912 /*
913 * mutex_sync() needs to be called when reaping, but
914 * not too often. We limit reaping rate to once
915 * per second. Reaplimit is max rate at which threads can
916 * be freed. Does not impact thread destruction/creation.
917 */
918 t = thread_deathrow;
919 l = lwp_deathrow;
920 thread_deathrow = NULL;
921 lwp_deathrow = NULL;
922 thread_reapcnt = 0;
923 lwp_reapcnt = 0;
924 mutex_exit(&reaplock);
925
926 /*
927 * Guard against race condition in mutex_owner_running:
928 * thread=owner(mutex)
929 * <interrupt>
930 * thread exits mutex
931 * thread exits
932 * thread reaped
933 * thread struct freed
934 * cpu = thread->t_cpu <- BAD POINTER DEREFERENCE.
935 * A cross call to all cpus will cause the interrupt handler
936 * to reset the PC if it is in mutex_owner_running, refreshing
937 * stale thread pointers.
938 */
939 mutex_sync(); /* sync with mutex code */
940 /*
941 * Reap threads
942 */
943 thread_reap_list(t);
944
945 /*
946 * Reap lwps
947 */
948 thread_reap_list(l);
949 delay(hz);
950 }
951 }
952
953 /*
954 * This is called by lwpcreate, etc.() to put a lwp_deathrow thread onto
955 * thread_deathrow. The thread's state is changed already TS_FREE to indicate
956 * that is reapable. The thread already holds the reaplock, and was already
957 * freed.
958 */
959 void
960 reapq_move_lq_to_tq(kthread_t *t)
961 {
962 ASSERT(t->t_state == TS_FREE);
963 ASSERT(MUTEX_HELD(&reaplock));
964 t->t_forw = thread_deathrow;
965 thread_deathrow = t;
966 thread_reapcnt++;
967 if (lwp_reapcnt + thread_reapcnt > reaplimit)
968 cv_signal(&reaper_cv); /* wake the reaper */
969 }
970
971 /*
972 * This is called by resume() to put a zombie thread onto deathrow.
973 * The thread's state is changed to TS_FREE to indicate that is reapable.
974 * This is called from the idle thread so it must not block - just spin.
975 */
976 void
977 reapq_add(kthread_t *t)
978 {
979 mutex_enter(&reaplock);
980
981 /*
982 * lwp_deathrow contains threads with lwp linkage and
983 * swappable thread stacks which have the default stacksize.
984 * These threads' lwps and stacks may be reused by lwp_create().
985 *
986 * Anything else goes on thread_deathrow(), where it will eventually
987 * be thread_free()d.
988 */
989 if (t->t_flag & T_LWPREUSE) {
990 ASSERT(ttolwp(t) != NULL);
991 t->t_forw = lwp_deathrow;
992 lwp_deathrow = t;
993 lwp_reapcnt++;
994 } else {
995 t->t_forw = thread_deathrow;
996 thread_deathrow = t;
997 thread_reapcnt++;
998 }
999 if (lwp_reapcnt + thread_reapcnt > reaplimit)
1000 cv_signal(&reaper_cv); /* wake the reaper */
1001 t->t_state = TS_FREE;
1002 lock_clear(&t->t_lock);
1003
1004 /*
1005 * Before we return, we need to grab and drop the thread lock for
1006 * the dead thread. At this point, the current thread is the idle
1007 * thread, and the dead thread's CPU lock points to the current
1008 * CPU -- and we must grab and drop the lock to synchronize with
1009 * a racing thread walking a blocking chain that the zombie thread
1010 * was recently in. By this point, that blocking chain is (by
1011 * definition) stale: the dead thread is not holding any locks, and
1012 * is therefore not in any blocking chains -- but if we do not regrab
1013 * our lock before freeing the dead thread's data structures, the
1014 * thread walking the (stale) blocking chain will die on memory
1015 * corruption when it attempts to drop the dead thread's lock. We
1016 * only need do this once because there is no way for the dead thread
1017 * to ever again be on a blocking chain: once we have grabbed and
1018 * dropped the thread lock, we are guaranteed that anyone that could
1019 * have seen this thread in a blocking chain can no longer see it.
1020 */
1021 thread_lock(t);
1022 thread_unlock(t);
1023
1024 mutex_exit(&reaplock);
1025 }
1026
1027 /*
1028 * Install thread context ops for the current thread.
1029 */
1030 void
1031 installctx(
1032 kthread_t *t,
1033 void *arg,
1034 void (*save)(void *),
1035 void (*restore)(void *),
1036 void (*fork)(void *, void *),
1037 void (*lwp_create)(void *, void *),
1038 void (*exit)(void *),
1039 void (*free)(void *, int))
1040 {
1041 struct ctxop *ctx;
1042
1043 ctx = kmem_alloc(sizeof (struct ctxop), KM_SLEEP);
1044 ctx->save_op = save;
1045 ctx->restore_op = restore;
1046 ctx->fork_op = fork;
1047 ctx->lwp_create_op = lwp_create;
1048 ctx->exit_op = exit;
1049 ctx->free_op = free;
1050 ctx->arg = arg;
1051 ctx->next = t->t_ctx;
1052 t->t_ctx = ctx;
1053 }
1054
1055 /*
1056 * Remove the thread context ops from a thread.
1057 */
1058 int
1059 removectx(
1060 kthread_t *t,
1061 void *arg,
1062 void (*save)(void *),
1063 void (*restore)(void *),
1064 void (*fork)(void *, void *),
1065 void (*lwp_create)(void *, void *),
1066 void (*exit)(void *),
1067 void (*free)(void *, int))
1068 {
1069 struct ctxop *ctx, *prev_ctx;
1070
1071 /*
1072 * The incoming kthread_t (which is the thread for which the
1073 * context ops will be removed) should be one of the following:
1074 *
1075 * a) the current thread,
1076 *
1077 * b) a thread of a process that's being forked (SIDL),
1078 *
1079 * c) a thread that belongs to the same process as the current
1080 * thread and for which the current thread is the agent thread,
1081 *
1082 * d) a thread that is TS_STOPPED which is indicative of it
1083 * being (if curthread is not an agent) a thread being created
1084 * as part of an lwp creation.
1085 */
1086 ASSERT(t == curthread || ttoproc(t)->p_stat == SIDL ||
1087 ttoproc(t)->p_agenttp == curthread || t->t_state == TS_STOPPED);
1088
1089 /*
1090 * Serialize modifications to t->t_ctx to prevent the agent thread
1091 * and the target thread from racing with each other during lwp exit.
1092 */
1093 mutex_enter(&t->t_ctx_lock);
1094 prev_ctx = NULL;
1095 kpreempt_disable();
1096 for (ctx = t->t_ctx; ctx != NULL; ctx = ctx->next) {
1097 if (ctx->save_op == save && ctx->restore_op == restore &&
1098 ctx->fork_op == fork && ctx->lwp_create_op == lwp_create &&
1099 ctx->exit_op == exit && ctx->free_op == free &&
1100 ctx->arg == arg) {
1101 if (prev_ctx)
1102 prev_ctx->next = ctx->next;
1103 else
1104 t->t_ctx = ctx->next;
1105 mutex_exit(&t->t_ctx_lock);
1106 if (ctx->free_op != NULL)
1107 (ctx->free_op)(ctx->arg, 0);
1108 kmem_free(ctx, sizeof (struct ctxop));
1109 kpreempt_enable();
1110 return (1);
1111 }
1112 prev_ctx = ctx;
1113 }
1114 mutex_exit(&t->t_ctx_lock);
1115 kpreempt_enable();
1116
1117 return (0);
1118 }
1119
1120 void
1121 savectx(kthread_t *t)
1122 {
1123 struct ctxop *ctx;
1124
1125 ASSERT(t == curthread);
1126 for (ctx = t->t_ctx; ctx != 0; ctx = ctx->next)
1127 if (ctx->save_op != NULL)
1128 (ctx->save_op)(ctx->arg);
1129 }
1130
1131 void
1132 restorectx(kthread_t *t)
1133 {
1134 struct ctxop *ctx;
1135
1136 ASSERT(t == curthread);
1137 for (ctx = t->t_ctx; ctx != 0; ctx = ctx->next)
1138 if (ctx->restore_op != NULL)
1139 (ctx->restore_op)(ctx->arg);
1140 }
1141
1142 void
1143 forkctx(kthread_t *t, kthread_t *ct)
1144 {
1145 struct ctxop *ctx;
1146
1147 for (ctx = t->t_ctx; ctx != NULL; ctx = ctx->next)
1148 if (ctx->fork_op != NULL)
1149 (ctx->fork_op)(t, ct);
1150 }
1151
1152 /*
1153 * Note that this operator is only invoked via the _lwp_create
1154 * system call. The system may have other reasons to create lwps
1155 * e.g. the agent lwp or the doors unreferenced lwp.
1156 */
1157 void
1158 lwp_createctx(kthread_t *t, kthread_t *ct)
1159 {
1160 struct ctxop *ctx;
1161
1162 for (ctx = t->t_ctx; ctx != NULL; ctx = ctx->next)
1163 if (ctx->lwp_create_op != NULL)
1164 (ctx->lwp_create_op)(t, ct);
1165 }
1166
1167 /*
1168 * exitctx is called from thread_exit() and lwp_exit() to perform any actions
1169 * needed when the thread/LWP leaves the processor for the last time. This
1170 * routine is not intended to deal with freeing memory; freectx() is used for
1171 * that purpose during thread_free(). This routine is provided to allow for
1172 * clean-up that can't wait until thread_free().
1173 */
1174 void
1175 exitctx(kthread_t *t)
1176 {
1177 struct ctxop *ctx;
1178
1179 for (ctx = t->t_ctx; ctx != NULL; ctx = ctx->next)
1180 if (ctx->exit_op != NULL)
1181 (ctx->exit_op)(t);
1182 }
1183
1184 /*
1185 * freectx is called from thread_free() and exec() to get
1186 * rid of old thread context ops.
1187 */
1188 void
1189 freectx(kthread_t *t, int isexec)
1190 {
1191 struct ctxop *ctx;
1192
1193 kpreempt_disable();
1194 while ((ctx = t->t_ctx) != NULL) {
1195 t->t_ctx = ctx->next;
1196 if (ctx->free_op != NULL)
1197 (ctx->free_op)(ctx->arg, isexec);
1198 kmem_free(ctx, sizeof (struct ctxop));
1199 }
1200 kpreempt_enable();
1201 }
1202
1203 /*
1204 * freectx_ctx is called from lwp_create() when lwp is reused from
1205 * lwp_deathrow and its thread structure is added to thread_deathrow.
1206 * The thread structure to which this ctx was attached may be already
1207 * freed by the thread reaper so free_op implementations shouldn't rely
1208 * on thread structure to which this ctx was attached still being around.
1209 */
1210 void
1211 freectx_ctx(struct ctxop *ctx)
1212 {
1213 struct ctxop *nctx;
1214
1215 ASSERT(ctx != NULL);
1216
1217 kpreempt_disable();
1218 do {
1219 nctx = ctx->next;
1220 if (ctx->free_op != NULL)
1221 (ctx->free_op)(ctx->arg, 0);
1222 kmem_free(ctx, sizeof (struct ctxop));
1223 } while ((ctx = nctx) != NULL);
1224 kpreempt_enable();
1225 }
1226
1227 /*
1228 * Set the thread running; arrange for it to be swapped in if necessary.
1229 */
1230 void
1231 setrun_locked(kthread_t *t)
1232 {
1233 ASSERT(THREAD_LOCK_HELD(t));
1234 if (t->t_state == TS_SLEEP) {
1235 /*
1236 * Take off sleep queue.
1237 */
1238 SOBJ_UNSLEEP(t->t_sobj_ops, t);
1239 } else if (t->t_state & (TS_RUN | TS_ONPROC)) {
1240 /*
1241 * Already on dispatcher queue.
1242 */
1243 return;
1244 } else if (t->t_state == TS_WAIT) {
1245 waitq_setrun(t);
1246 } else if (t->t_state == TS_STOPPED) {
1247 /*
1248 * All of the sending of SIGCONT (TC_XSTART) and /proc
1249 * (TC_PSTART) and lwp_continue() (TC_CSTART) must have
1250 * requested that the thread be run.
1251 * Just calling setrun() is not sufficient to set a stopped
1252 * thread running. TP_TXSTART is always set if the thread
1253 * is not stopped by a jobcontrol stop signal.
1254 * TP_TPSTART is always set if /proc is not controlling it.
1255 * TP_TCSTART is always set if lwp_suspend() didn't stop it.
1256 * The thread won't be stopped unless one of these
1257 * three mechanisms did it.
1258 *
1259 * These flags must be set before calling setrun_locked(t).
1260 * They can't be passed as arguments because the streams
1261 * code calls setrun() indirectly and the mechanism for
1262 * doing so admits only one argument. Note that the
1263 * thread must be locked in order to change t_schedflags.
1264 */
1265 if ((t->t_schedflag & TS_ALLSTART) != TS_ALLSTART)
1266 return;
1267 /*
1268 * Process is no longer stopped (a thread is running).
1269 */
1270 t->t_whystop = 0;
1271 t->t_whatstop = 0;
1272 /*
1273 * Strictly speaking, we do not have to clear these
1274 * flags here; they are cleared on entry to stop().
1275 * However, they are confusing when doing kernel
1276 * debugging or when they are revealed by ps(1).
1277 */
1278 t->t_schedflag &= ~TS_ALLSTART;
1279 THREAD_TRANSITION(t); /* drop stopped-thread lock */
1280 ASSERT(t->t_lockp == &transition_lock);
1281 ASSERT(t->t_wchan0 == NULL && t->t_wchan == NULL);
1282 /*
1283 * Let the class put the process on the dispatcher queue.
1284 */
1285 CL_SETRUN(t);
1286 }
1287 }
1288
1289 void
1290 setrun(kthread_t *t)
1291 {
1292 thread_lock(t);
1293 setrun_locked(t);
1294 thread_unlock(t);
1295 }
1296
1297 /*
1298 * Unpin an interrupted thread.
1299 * When an interrupt occurs, the interrupt is handled on the stack
1300 * of an interrupt thread, taken from a pool linked to the CPU structure.
1301 *
1302 * When swtch() is switching away from an interrupt thread because it
1303 * blocked or was preempted, this routine is called to complete the
1304 * saving of the interrupted thread state, and returns the interrupted
1305 * thread pointer so it may be resumed.
1306 *
1307 * Called by swtch() only at high spl.
1308 */
1309 kthread_t *
1310 thread_unpin()
1311 {
1312 kthread_t *t = curthread; /* current thread */
1313 kthread_t *itp; /* interrupted thread */
1314 int i; /* interrupt level */
1315 extern int intr_passivate();
1316
1317 ASSERT(t->t_intr != NULL);
1318
1319 itp = t->t_intr; /* interrupted thread */
1320 t->t_intr = NULL; /* clear interrupt ptr */
1321
1322 /*
1323 * Get state from interrupt thread for the one
1324 * it interrupted.
1325 */
1326
1327 i = intr_passivate(t, itp);
1328
1329 TRACE_5(TR_FAC_INTR, TR_INTR_PASSIVATE,
1330 "intr_passivate:level %d curthread %p (%T) ithread %p (%T)",
1331 i, t, t, itp, itp);
1332
1333 /*
1334 * Dissociate the current thread from the interrupted thread's LWP.
1335 */
1336 t->t_lwp = NULL;
1337
1338 /*
1339 * Interrupt handlers above the level that spinlocks block must
1340 * not block.
1341 */
1342 #if DEBUG
1343 if (i < 0 || i > LOCK_LEVEL)
1344 cmn_err(CE_PANIC, "thread_unpin: ipl out of range %x", i);
1345 #endif
1346
1347 /*
1348 * Compute the CPU's base interrupt level based on the active
1349 * interrupts.
1350 */
1351 ASSERT(CPU->cpu_intr_actv & (1 << i));
1352 set_base_spl();
1353
1354 return (itp);
1355 }
1356
1357 /*
1358 * Create and initialize an interrupt thread.
1359 * Returns non-zero on error.
1360 * Called at spl7() or better.
1361 */
1362 void
1363 thread_create_intr(struct cpu *cp)
1364 {
1365 kthread_t *tp;
1366
1367 tp = thread_create(NULL, 0,
1368 (void (*)())thread_create_intr, NULL, 0, &p0, TS_ONPROC, 0);
1369
1370 /*
1371 * Set the thread in the TS_FREE state. The state will change
1372 * to TS_ONPROC only while the interrupt is active. Think of these
1373 * as being on a private free list for the CPU. Being TS_FREE keeps
1374 * inactive interrupt threads out of debugger thread lists.
1375 *
1376 * We cannot call thread_create with TS_FREE because of the current
1377 * checks there for ONPROC. Fix this when thread_create takes flags.
1378 */
1379 THREAD_FREEINTR(tp, cp);
1380
1381 /*
1382 * Nobody should ever reference the credentials of an interrupt
1383 * thread so make it NULL to catch any such references.
1384 */
1385 tp->t_cred = NULL;
1386 tp->t_flag |= T_INTR_THREAD;
1387 tp->t_cpu = cp;
1388 tp->t_bound_cpu = cp;
1389 tp->t_disp_queue = cp->cpu_disp;
1390 tp->t_affinitycnt = 1;
1391 tp->t_preempt = 1;
1392
1393 /*
1394 * Don't make a user-requested binding on this thread so that
1395 * the processor can be offlined.
1396 */
1397 tp->t_bind_cpu = PBIND_NONE; /* no USER-requested binding */
1398 tp->t_bind_pset = PS_NONE;
1399
1400 #if defined(__i386) || defined(__amd64)
1401 tp->t_stk -= STACK_ALIGN;
1402 *(tp->t_stk) = 0; /* terminate intr thread stack */
1403 #endif
1404
1405 /*
1406 * Link onto CPU's interrupt pool.
1407 */
1408 tp->t_link = cp->cpu_intr_thread;
1409 cp->cpu_intr_thread = tp;
1410 }
1411
1412 /*
1413 * TSD -- THREAD SPECIFIC DATA
1414 */
1415 static kmutex_t tsd_mutex; /* linked list spin lock */
1416 static uint_t tsd_nkeys; /* size of destructor array */
1417 /* per-key destructor funcs */
1418 static void (**tsd_destructor)(void *);
1419 /* list of tsd_thread's */
1420 static struct tsd_thread *tsd_list;
1421
1422 /*
1423 * Default destructor
1424 * Needed because NULL destructor means that the key is unused
1425 */
1426 /* ARGSUSED */
1427 void
1428 tsd_defaultdestructor(void *value)
1429 {}
1430
1431 /*
1432 * Create a key (index into per thread array)
1433 * Locks out tsd_create, tsd_destroy, and tsd_exit
1434 * May allocate memory with lock held
1435 */
1436 void
1437 tsd_create(uint_t *keyp, void (*destructor)(void *))
1438 {
1439 int i;
1440 uint_t nkeys;
1441
1442 /*
1443 * if key is allocated, do nothing
1444 */
1445 mutex_enter(&tsd_mutex);
1446 if (*keyp) {
1447 mutex_exit(&tsd_mutex);
1448 return;
1449 }
1450 /*
1451 * find an unused key
1452 */
1453 if (destructor == NULL)
1454 destructor = tsd_defaultdestructor;
1455
1456 for (i = 0; i < tsd_nkeys; ++i)
1457 if (tsd_destructor[i] == NULL)
1458 break;
1459
1460 /*
1461 * if no unused keys, increase the size of the destructor array
1462 */
1463 if (i == tsd_nkeys) {
1464 if ((nkeys = (tsd_nkeys << 1)) == 0)
1465 nkeys = 1;
1466 tsd_destructor =
1467 (void (**)(void *))tsd_realloc((void *)tsd_destructor,
1468 (size_t)(tsd_nkeys * sizeof (void (*)(void *))),
1469 (size_t)(nkeys * sizeof (void (*)(void *))));
1470 tsd_nkeys = nkeys;
1471 }
1472
1473 /*
1474 * allocate the next available unused key
1475 */
1476 tsd_destructor[i] = destructor;
1477 *keyp = i + 1;
1478 mutex_exit(&tsd_mutex);
1479 }
1480
1481 /*
1482 * Destroy a key -- this is for unloadable modules
1483 *
1484 * Assumes that the caller is preventing tsd_set and tsd_get
1485 * Locks out tsd_create, tsd_destroy, and tsd_exit
1486 * May free memory with lock held
1487 */
1488 void
1489 tsd_destroy(uint_t *keyp)
1490 {
1491 uint_t key;
1492 struct tsd_thread *tsd;
1493
1494 /*
1495 * protect the key namespace and our destructor lists
1496 */
1497 mutex_enter(&tsd_mutex);
1498 key = *keyp;
1499 *keyp = 0;
1500
1501 ASSERT(key <= tsd_nkeys);
1502
1503 /*
1504 * if the key is valid
1505 */
1506 if (key != 0) {
1507 uint_t k = key - 1;
1508 /*
1509 * for every thread with TSD, call key's destructor
1510 */
1511 for (tsd = tsd_list; tsd; tsd = tsd->ts_next) {
1512 /*
1513 * no TSD for key in this thread
1514 */
1515 if (key > tsd->ts_nkeys)
1516 continue;
1517 /*
1518 * call destructor for key
1519 */
1520 if (tsd->ts_value[k] && tsd_destructor[k])
1521 (*tsd_destructor[k])(tsd->ts_value[k]);
1522 /*
1523 * reset value for key
1524 */
1525 tsd->ts_value[k] = NULL;
1526 }
1527 /*
1528 * actually free the key (NULL destructor == unused)
1529 */
1530 tsd_destructor[k] = NULL;
1531 }
1532
1533 mutex_exit(&tsd_mutex);
1534 }
1535
1536 /*
1537 * Quickly return the per thread value that was stored with the specified key
1538 * Assumes the caller is protecting key from tsd_create and tsd_destroy
1539 */
1540 void *
1541 tsd_get(uint_t key)
1542 {
1543 return (tsd_agent_get(curthread, key));
1544 }
1545
1546 /*
1547 * Set a per thread value indexed with the specified key
1548 */
1549 int
1550 tsd_set(uint_t key, void *value)
1551 {
1552 return (tsd_agent_set(curthread, key, value));
1553 }
1554
1555 /*
1556 * Like tsd_get(), except that the agent lwp can get the tsd of
1557 * another thread in the same process (the agent thread only runs when the
1558 * process is completely stopped by /proc), or syslwp is creating a new lwp.
1559 */
1560 void *
1561 tsd_agent_get(kthread_t *t, uint_t key)
1562 {
1563 struct tsd_thread *tsd = t->t_tsd;
1564
1565 ASSERT(t == curthread ||
1566 ttoproc(t)->p_agenttp == curthread || t->t_state == TS_STOPPED);
1567
1568 if (key && tsd != NULL && key <= tsd->ts_nkeys)
1569 return (tsd->ts_value[key - 1]);
1570 return (NULL);
1571 }
1572
1573 /*
1574 * Like tsd_set(), except that the agent lwp can set the tsd of
1575 * another thread in the same process, or syslwp can set the tsd
1576 * of a thread it's in the middle of creating.
1577 *
1578 * Assumes the caller is protecting key from tsd_create and tsd_destroy
1579 * May lock out tsd_destroy (and tsd_create), may allocate memory with
1580 * lock held
1581 */
1582 int
1583 tsd_agent_set(kthread_t *t, uint_t key, void *value)
1584 {
1585 struct tsd_thread *tsd = t->t_tsd;
1586
1587 ASSERT(t == curthread ||
1588 ttoproc(t)->p_agenttp == curthread || t->t_state == TS_STOPPED);
1589
1590 if (key == 0)
1591 return (EINVAL);
1592 if (tsd == NULL)
1593 tsd = t->t_tsd = kmem_zalloc(sizeof (*tsd), KM_SLEEP);
1594 if (key <= tsd->ts_nkeys) {
1595 tsd->ts_value[key - 1] = value;
1596 return (0);
1597 }
1598
1599 ASSERT(key <= tsd_nkeys);
1600
1601 /*
1602 * lock out tsd_destroy()
1603 */
1604 mutex_enter(&tsd_mutex);
1605 if (tsd->ts_nkeys == 0) {
1606 /*
1607 * Link onto list of threads with TSD
1608 */
1609 if ((tsd->ts_next = tsd_list) != NULL)
1610 tsd_list->ts_prev = tsd;
1611 tsd_list = tsd;
1612 }
1613
1614 /*
1615 * Allocate thread local storage and set the value for key
1616 */
1617 tsd->ts_value = tsd_realloc(tsd->ts_value,
1618 tsd->ts_nkeys * sizeof (void *),
1619 key * sizeof (void *));
1620 tsd->ts_nkeys = key;
1621 tsd->ts_value[key - 1] = value;
1622 mutex_exit(&tsd_mutex);
1623
1624 return (0);
1625 }
1626
1627
1628 /*
1629 * Return the per thread value that was stored with the specified key
1630 * If necessary, create the key and the value
1631 * Assumes the caller is protecting *keyp from tsd_destroy
1632 */
1633 void *
1634 tsd_getcreate(uint_t *keyp, void (*destroy)(void *), void *(*allocate)(void))
1635 {
1636 void *value;
1637 uint_t key = *keyp;
1638 struct tsd_thread *tsd = curthread->t_tsd;
1639
1640 if (tsd == NULL)
1641 tsd = curthread->t_tsd = kmem_zalloc(sizeof (*tsd), KM_SLEEP);
1642 if (key && key <= tsd->ts_nkeys && (value = tsd->ts_value[key - 1]))
1643 return (value);
1644 if (key == 0)
1645 tsd_create(keyp, destroy);
1646 (void) tsd_set(*keyp, value = (*allocate)());
1647
1648 return (value);
1649 }
1650
1651 /*
1652 * Called from thread_exit() to run the destructor function for each tsd
1653 * Locks out tsd_create and tsd_destroy
1654 * Assumes that the destructor *DOES NOT* use tsd
1655 */
1656 void
1657 tsd_exit(void)
1658 {
1659 int i;
1660 struct tsd_thread *tsd = curthread->t_tsd;
1661
1662 if (tsd == NULL)
1663 return;
1664
1665 if (tsd->ts_nkeys == 0) {
1666 kmem_free(tsd, sizeof (*tsd));
1667 curthread->t_tsd = NULL;
1668 return;
1669 }
1670
1671 /*
1672 * lock out tsd_create and tsd_destroy, call
1673 * the destructor, and mark the value as destroyed.
1674 */
1675 mutex_enter(&tsd_mutex);
1676
1677 for (i = 0; i < tsd->ts_nkeys; i++) {
1678 if (tsd->ts_value[i] && tsd_destructor[i])
1679 (*tsd_destructor[i])(tsd->ts_value[i]);
1680 tsd->ts_value[i] = NULL;
1681 }
1682
1683 /*
1684 * remove from linked list of threads with TSD
1685 */
1686 if (tsd->ts_next)
1687 tsd->ts_next->ts_prev = tsd->ts_prev;
1688 if (tsd->ts_prev)
1689 tsd->ts_prev->ts_next = tsd->ts_next;
1690 if (tsd_list == tsd)
1691 tsd_list = tsd->ts_next;
1692
1693 mutex_exit(&tsd_mutex);
1694
1695 /*
1696 * free up the TSD
1697 */
1698 kmem_free(tsd->ts_value, tsd->ts_nkeys * sizeof (void *));
1699 kmem_free(tsd, sizeof (struct tsd_thread));
1700 curthread->t_tsd = NULL;
1701 }
1702
1703 /*
1704 * realloc
1705 */
1706 static void *
1707 tsd_realloc(void *old, size_t osize, size_t nsize)
1708 {
1709 void *new;
1710
1711 new = kmem_zalloc(nsize, KM_SLEEP);
1712 if (old) {
1713 bcopy(old, new, osize);
1714 kmem_free(old, osize);
1715 }
1716 return (new);
1717 }
1718
1719 /*
1720 * Return non-zero if an interrupt is being serviced.
1721 */
1722 int
1723 servicing_interrupt()
1724 {
1725 int onintr = 0;
1726
1727 /* Are we an interrupt thread */
1728 if (curthread->t_flag & T_INTR_THREAD)
1729 return (1);
1730 /* Are we servicing a high level interrupt? */
1731 if (CPU_ON_INTR(CPU)) {
1732 kpreempt_disable();
1733 onintr = CPU_ON_INTR(CPU);
1734 kpreempt_enable();
1735 }
1736 return (onintr);
1737 }
1738
1739
1740 /*
1741 * Change the dispatch priority of a thread in the system.
1742 * Used when raising or lowering a thread's priority.
1743 * (E.g., priority inheritance)
1744 *
1745 * Since threads are queued according to their priority, we
1746 * we must check the thread's state to determine whether it
1747 * is on a queue somewhere. If it is, we've got to:
1748 *
1749 * o Dequeue the thread.
1750 * o Change its effective priority.
1751 * o Enqueue the thread.
1752 *
1753 * Assumptions: The thread whose priority we wish to change
1754 * must be locked before we call thread_change_(e)pri().
1755 * The thread_change(e)pri() function doesn't drop the thread
1756 * lock--that must be done by its caller.
1757 */
1758 void
1759 thread_change_epri(kthread_t *t, pri_t disp_pri)
1760 {
1761 uint_t state;
1762
1763 ASSERT(THREAD_LOCK_HELD(t));
1764
1765 /*
1766 * If the inherited priority hasn't actually changed,
1767 * just return.
1768 */
1769 if (t->t_epri == disp_pri)
1770 return;
1771
1772 state = t->t_state;
1773
1774 /*
1775 * If it's not on a queue, change the priority with impunity.
1776 */
1777 if ((state & (TS_SLEEP | TS_RUN | TS_WAIT)) == 0) {
1778 t->t_epri = disp_pri;
1779 if (state == TS_ONPROC) {
1780 cpu_t *cp = t->t_disp_queue->disp_cpu;
1781
1782 if (t == cp->cpu_dispthread)
1783 cp->cpu_dispatch_pri = DISP_PRIO(t);
1784 }
1785 } else if (state == TS_SLEEP) {
1786 /*
1787 * Take the thread out of its sleep queue.
1788 * Change the inherited priority.
1789 * Re-enqueue the thread.
1790 * Each synchronization object exports a function
1791 * to do this in an appropriate manner.
1792 */
1793 SOBJ_CHANGE_EPRI(t->t_sobj_ops, t, disp_pri);
1794 } else if (state == TS_WAIT) {
1795 /*
1796 * Re-enqueue a thread on the wait queue if its
1797 * effective priority needs to change.
1798 */
1799 if (disp_pri != t->t_epri)
1800 waitq_change_pri(t, disp_pri);
1801 } else {
1802 /*
1803 * The thread is on a run queue.
1804 * Note: setbackdq() may not put the thread
1805 * back on the same run queue where it originally
1806 * resided.
1807 */
1808 (void) dispdeq(t);
1809 t->t_epri = disp_pri;
1810 setbackdq(t);
1811 }
1812 schedctl_set_cidpri(t);
1813 }
1814
1815 /*
1816 * Function: Change the t_pri field of a thread.
1817 * Side Effects: Adjust the thread ordering on a run queue
1818 * or sleep queue, if necessary.
1819 * Returns: 1 if the thread was on a run queue, else 0.
1820 */
1821 int
1822 thread_change_pri(kthread_t *t, pri_t disp_pri, int front)
1823 {
1824 uint_t state;
1825 int on_rq = 0;
1826
1827 ASSERT(THREAD_LOCK_HELD(t));
1828
1829 state = t->t_state;
1830 THREAD_WILLCHANGE_PRI(t, disp_pri);
1831
1832 /*
1833 * If it's not on a queue, change the priority with impunity.
1834 */
1835 if ((state & (TS_SLEEP | TS_RUN | TS_WAIT)) == 0) {
1836 t->t_pri = disp_pri;
1837
1838 if (state == TS_ONPROC) {
1839 cpu_t *cp = t->t_disp_queue->disp_cpu;
1840
1841 if (t == cp->cpu_dispthread)
1842 cp->cpu_dispatch_pri = DISP_PRIO(t);
1843 }
1844 } else if (state == TS_SLEEP) {
1845 /*
1846 * If the priority has changed, take the thread out of
1847 * its sleep queue and change the priority.
1848 * Re-enqueue the thread.
1849 * Each synchronization object exports a function
1850 * to do this in an appropriate manner.
1851 */
1852 if (disp_pri != t->t_pri)
1853 SOBJ_CHANGE_PRI(t->t_sobj_ops, t, disp_pri);
1854 } else if (state == TS_WAIT) {
1855 /*
1856 * Re-enqueue a thread on the wait queue if its
1857 * priority needs to change.
1858 */
1859 if (disp_pri != t->t_pri)
1860 waitq_change_pri(t, disp_pri);
1861 } else {
1862 /*
1863 * The thread is on a run queue.
1864 * Note: setbackdq() may not put the thread
1865 * back on the same run queue where it originally
1866 * resided.
1867 *
1868 * We still requeue the thread even if the priority
1869 * is unchanged to preserve round-robin (and other)
1870 * effects between threads of the same priority.
1871 */
1872 on_rq = dispdeq(t);
1873 ASSERT(on_rq);
1874 t->t_pri = disp_pri;
1875 if (front) {
1876 setfrontdq(t);
1877 } else {
1878 setbackdq(t);
1879 }
1880 }
1881 schedctl_set_cidpri(t);
1882 return (on_rq);
1883 }
1884
1885 /*
1886 * Tunable kmem_stackinfo is set, fill the kernel thread stack with a
1887 * specific pattern.
1888 */
1889 static void
1890 stkinfo_begin(kthread_t *t)
1891 {
1892 caddr_t start; /* stack start */
1893 caddr_t end; /* stack end */
1894 uint64_t *ptr; /* pattern pointer */
1895
1896 /*
1897 * Stack grows up or down, see thread_create(),
1898 * compute stack memory area start and end (start < end).
1899 */
1900 if (t->t_stk > t->t_stkbase) {
1901 /* stack grows down */
1902 start = t->t_stkbase;
1903 end = t->t_stk;
1904 } else {
1905 /* stack grows up */
1906 start = t->t_stk;
1907 end = t->t_stkbase;
1908 }
1909
1910 /*
1911 * Stackinfo pattern size is 8 bytes. Ensure proper 8 bytes
1912 * alignement for start and end in stack area boundaries
1913 * (protection against corrupt t_stkbase/t_stk data).
1914 */
1915 if ((((uintptr_t)start) & 0x7) != 0) {
1916 start = (caddr_t)((((uintptr_t)start) & (~0x7)) + 8);
1917 }
1918 end = (caddr_t)(((uintptr_t)end) & (~0x7));
1919
1920 if ((end <= start) || (end - start) > (1024 * 1024)) {
1921 /* negative or stack size > 1 meg, assume bogus */
1922 return;
1923 }
1924
1925 /* fill stack area with a pattern (instead of zeros) */
1926 ptr = (uint64_t *)((void *)start);
1927 while (ptr < (uint64_t *)((void *)end)) {
1928 *ptr++ = KMEM_STKINFO_PATTERN;
1929 }
1930 }
1931
1932
1933 /*
1934 * Tunable kmem_stackinfo is set, create stackinfo log if doesn't already exist,
1935 * compute the percentage of kernel stack really used, and set in the log
1936 * if it's the latest highest percentage.
1937 */
1938 static void
1939 stkinfo_end(kthread_t *t)
1940 {
1941 caddr_t start; /* stack start */
1942 caddr_t end; /* stack end */
1943 uint64_t *ptr; /* pattern pointer */
1944 size_t stksz; /* stack size */
1945 size_t smallest = 0;
1946 size_t percent = 0;
1947 uint_t index = 0;
1948 uint_t i;
1949 static size_t smallest_percent = (size_t)-1;
1950 static uint_t full = 0;
1951
1952 /* create the stackinfo log, if doesn't already exist */
1953 mutex_enter(&kmem_stkinfo_lock);
1954 if (kmem_stkinfo_log == NULL) {
1955 kmem_stkinfo_log = (kmem_stkinfo_t *)
1956 kmem_zalloc(KMEM_STKINFO_LOG_SIZE *
1957 (sizeof (kmem_stkinfo_t)), KM_NOSLEEP);
1958 if (kmem_stkinfo_log == NULL) {
1959 mutex_exit(&kmem_stkinfo_lock);
1960 return;
1961 }
1962 }
1963 mutex_exit(&kmem_stkinfo_lock);
1964
1965 /*
1966 * Stack grows up or down, see thread_create(),
1967 * compute stack memory area start and end (start < end).
1968 */
1969 if (t->t_stk > t->t_stkbase) {
1970 /* stack grows down */
1971 start = t->t_stkbase;
1972 end = t->t_stk;
1973 } else {
1974 /* stack grows up */
1975 start = t->t_stk;
1976 end = t->t_stkbase;
1977 }
1978
1979 /* stack size as found in kthread_t */
1980 stksz = end - start;
1981
1982 /*
1983 * Stackinfo pattern size is 8 bytes. Ensure proper 8 bytes
1984 * alignement for start and end in stack area boundaries
1985 * (protection against corrupt t_stkbase/t_stk data).
1986 */
1987 if ((((uintptr_t)start) & 0x7) != 0) {
1988 start = (caddr_t)((((uintptr_t)start) & (~0x7)) + 8);
1989 }
1990 end = (caddr_t)(((uintptr_t)end) & (~0x7));
1991
1992 if ((end <= start) || (end - start) > (1024 * 1024)) {
1993 /* negative or stack size > 1 meg, assume bogus */
1994 return;
1995 }
1996
1997 /* search until no pattern in the stack */
1998 if (t->t_stk > t->t_stkbase) {
1999 /* stack grows down */
2000 #if defined(__i386) || defined(__amd64)
2001 /*
2002 * 6 longs are pushed on stack, see thread_load(). Skip
2003 * them, so if kthread has never run, percent is zero.
2004 * 8 bytes alignement is preserved for a 32 bit kernel,
2005 * 6 x 4 = 24, 24 is a multiple of 8.
2006 *
2007 */
2008 end -= (6 * sizeof (long));
2009 #endif
2010 ptr = (uint64_t *)((void *)start);
2011 while (ptr < (uint64_t *)((void *)end)) {
2012 if (*ptr != KMEM_STKINFO_PATTERN) {
2013 percent = stkinfo_percent(end,
2014 start, (caddr_t)ptr);
2015 break;
2016 }
2017 ptr++;
2018 }
2019 } else {
2020 /* stack grows up */
2021 ptr = (uint64_t *)((void *)end);
2022 ptr--;
2023 while (ptr >= (uint64_t *)((void *)start)) {
2024 if (*ptr != KMEM_STKINFO_PATTERN) {
2025 percent = stkinfo_percent(start,
2026 end, (caddr_t)ptr);
2027 break;
2028 }
2029 ptr--;
2030 }
2031 }
2032
2033 DTRACE_PROBE3(stack__usage, kthread_t *, t,
2034 size_t, stksz, size_t, percent);
2035
2036 if (percent == 0) {
2037 return;
2038 }
2039
2040 mutex_enter(&kmem_stkinfo_lock);
2041 if (full == KMEM_STKINFO_LOG_SIZE && percent < smallest_percent) {
2042 /*
2043 * The log is full and already contains the highest values
2044 */
2045 mutex_exit(&kmem_stkinfo_lock);
2046 return;
2047 }
2048
2049 /* keep a log of the highest used stack */
2050 for (i = 0; i < KMEM_STKINFO_LOG_SIZE; i++) {
2051 if (kmem_stkinfo_log[i].percent == 0) {
2052 index = i;
2053 full++;
2054 break;
2055 }
2056 if (smallest == 0) {
2057 smallest = kmem_stkinfo_log[i].percent;
2058 index = i;
2059 continue;
2060 }
2061 if (kmem_stkinfo_log[i].percent < smallest) {
2062 smallest = kmem_stkinfo_log[i].percent;
2063 index = i;
2064 }
2065 }
2066
2067 if (percent >= kmem_stkinfo_log[index].percent) {
2068 kmem_stkinfo_log[index].kthread = (caddr_t)t;
2069 kmem_stkinfo_log[index].t_startpc = (caddr_t)t->t_startpc;
2070 kmem_stkinfo_log[index].start = start;
2071 kmem_stkinfo_log[index].stksz = stksz;
2072 kmem_stkinfo_log[index].percent = percent;
2073 kmem_stkinfo_log[index].t_tid = t->t_tid;
2074 kmem_stkinfo_log[index].cmd[0] = '\0';
2075 if (t->t_tid != 0) {
2076 stksz = strlen((t->t_procp)->p_user.u_comm);
2077 if (stksz >= KMEM_STKINFO_STR_SIZE) {
2078 stksz = KMEM_STKINFO_STR_SIZE - 1;
2079 kmem_stkinfo_log[index].cmd[stksz] = '\0';
2080 } else {
2081 stksz += 1;
2082 }
2083 (void) memcpy(kmem_stkinfo_log[index].cmd,
2084 (t->t_procp)->p_user.u_comm, stksz);
2085 }
2086 if (percent < smallest_percent) {
2087 smallest_percent = percent;
2088 }
2089 }
2090 mutex_exit(&kmem_stkinfo_lock);
2091 }
2092
2093 /*
2094 * Tunable kmem_stackinfo is set, compute stack utilization percentage.
2095 */
2096 static size_t
2097 stkinfo_percent(caddr_t t_stk, caddr_t t_stkbase, caddr_t sp)
2098 {
2099 size_t percent;
2100 size_t s;
2101
2102 if (t_stk > t_stkbase) {
2103 /* stack grows down */
2104 if (sp > t_stk) {
2105 return (0);
2106 }
2107 if (sp < t_stkbase) {
2108 return (100);
2109 }
2110 percent = t_stk - sp + 1;
2111 s = t_stk - t_stkbase + 1;
2112 } else {
2113 /* stack grows up */
2114 if (sp < t_stk) {
2115 return (0);
2116 }
2117 if (sp > t_stkbase) {
2118 return (100);
2119 }
2120 percent = sp - t_stk + 1;
2121 s = t_stkbase - t_stk + 1;
2122 }
2123 percent = ((100 * percent) / s) + 1;
2124 if (percent > 100) {
2125 percent = 100;
2126 }
2127 return (percent);
2128 }
--- EOF ---