1/*
2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * The Mach Operating System project at Carnegie-Mellon University.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * from: @(#)vm_glue.c 8.6 (Berkeley) 1/5/94
37 *
38 *
39 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
40 * All rights reserved.
41 *
42 * Permission to use, copy, modify and distribute this software and
43 * its documentation is hereby granted, provided that both the copyright
44 * notice and this permission notice appear in all copies of the
45 * software, derivative works or modified versions, and any portions
46 * thereof, and that both notices appear in supporting documentation.
47 *
48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
51 *
52 * Carnegie Mellon requests users of this software to return to
53 *
54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
55 * School of Computer Science
56 * Carnegie Mellon University
57 * Pittsburgh PA 15213-3890
58 *
59 * any improvements or extensions that they make and grant Carnegie the
60 * rights to redistribute these changes.
61 *
| 1/*
2 * Copyright (c) 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * The Mach Operating System project at Carnegie-Mellon University.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * from: @(#)vm_glue.c 8.6 (Berkeley) 1/5/94
37 *
38 *
39 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
40 * All rights reserved.
41 *
42 * Permission to use, copy, modify and distribute this software and
43 * its documentation is hereby granted, provided that both the copyright
44 * notice and this permission notice appear in all copies of the
45 * software, derivative works or modified versions, and any portions
46 * thereof, and that both notices appear in supporting documentation.
47 *
48 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
49 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
50 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
51 *
52 * Carnegie Mellon requests users of this software to return to
53 *
54 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
55 * School of Computer Science
56 * Carnegie Mellon University
57 * Pittsburgh PA 15213-3890
58 *
59 * any improvements or extensions that they make and grant Carnegie the
60 * rights to redistribute these changes.
61 *
|
172 return (rv == TRUE);
173}
174
175/*
176 * MPSAFE
177 */
178void
179vslock(addr, len)
180 caddr_t addr;
181 u_int len;
182{
183
184 vm_map_wire(&curproc->p_vmspace->vm_map, trunc_page((vm_offset_t)addr),
185 round_page((vm_offset_t)addr + len), FALSE);
186}
187
188/*
189 * MPSAFE
190 */
191void
192vsunlock(addr, len)
193 caddr_t addr;
194 u_int len;
195{
196
197 vm_map_unwire(&curproc->p_vmspace->vm_map,
198 trunc_page((vm_offset_t)addr),
199 round_page((vm_offset_t)addr + len), FALSE);
200}
201
202/*
203 * Create the U area for a new process.
204 * This routine directly affects the fork perf for a process.
205 */
206void
207vm_proc_new(struct proc *p)
208{
209 vm_page_t ma[UAREA_PAGES];
210 vm_object_t upobj;
211 vm_offset_t up;
212 vm_page_t m;
213 u_int i;
214
215 /*
216 * Allocate object for the upage.
217 */
218 upobj = vm_object_allocate(OBJT_DEFAULT, UAREA_PAGES);
219 p->p_upages_obj = upobj;
220
221 /*
222 * Get a kernel virtual address for the U area for this process.
223 */
224 up = kmem_alloc_nofault(kernel_map, UAREA_PAGES * PAGE_SIZE);
225 if (up == 0)
226 panic("vm_proc_new: upage allocation failed");
227 p->p_uarea = (struct user *)up;
228
229 for (i = 0; i < UAREA_PAGES; i++) {
230 /*
231 * Get a uarea page.
232 */
233 m = vm_page_grab(upobj, i,
234 VM_ALLOC_NORMAL | VM_ALLOC_RETRY | VM_ALLOC_WIRED);
235 ma[i] = m;
236
237 vm_page_wakeup(m);
238 vm_page_flag_clear(m, PG_ZERO);
239 m->valid = VM_PAGE_BITS_ALL;
240 }
241
242 /*
243 * Enter the pages into the kernel address space.
244 */
245 pmap_qenter(up, ma, UAREA_PAGES);
246}
247
248/*
249 * Dispose the U area for a process that has exited.
250 * This routine directly impacts the exit perf of a process.
251 * XXX proc_zone is marked UMA_ZONE_NOFREE, so this should never be called.
252 */
253void
254vm_proc_dispose(struct proc *p)
255{
256 vm_object_t upobj;
257 vm_offset_t up;
258 vm_page_t m;
259
260 upobj = p->p_upages_obj;
261 if (upobj->resident_page_count != UAREA_PAGES)
262 panic("vm_proc_dispose: incorrect number of pages in upobj");
263 vm_page_lock_queues();
264 while ((m = TAILQ_FIRST(&upobj->memq)) != NULL) {
265 vm_page_busy(m);
266 vm_page_unwire(m, 0);
267 vm_page_free(m);
268 }
269 vm_page_unlock_queues();
270 up = (vm_offset_t)p->p_uarea;
271 pmap_qremove(up, UAREA_PAGES);
272 kmem_free(kernel_map, up, UAREA_PAGES * PAGE_SIZE);
273 vm_object_deallocate(upobj);
274}
275
276#ifndef NO_SWAPPING
277/*
278 * Allow the U area for a process to be prejudicially paged out.
279 */
280void
281vm_proc_swapout(struct proc *p)
282{
283 vm_object_t upobj;
284 vm_offset_t up;
285 vm_page_t m;
286
287 upobj = p->p_upages_obj;
288 if (upobj->resident_page_count != UAREA_PAGES)
289 panic("vm_proc_dispose: incorrect number of pages in upobj");
290 vm_page_lock_queues();
291 TAILQ_FOREACH(m, &upobj->memq, listq) {
292 vm_page_dirty(m);
293 vm_page_unwire(m, 0);
294 }
295 vm_page_unlock_queues();
296 up = (vm_offset_t)p->p_uarea;
297 pmap_qremove(up, UAREA_PAGES);
298}
299
300/*
301 * Bring the U area for a specified process back in.
302 */
303void
304vm_proc_swapin(struct proc *p)
305{
306 vm_page_t ma[UAREA_PAGES];
307 vm_object_t upobj;
308 vm_offset_t up;
309 vm_page_t m;
310 int rv;
311 int i;
312
313 upobj = p->p_upages_obj;
314 for (i = 0; i < UAREA_PAGES; i++) {
315 m = vm_page_grab(upobj, i, VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
316 if (m->valid != VM_PAGE_BITS_ALL) {
317 rv = vm_pager_get_pages(upobj, &m, 1, 0);
318 if (rv != VM_PAGER_OK)
319 panic("vm_proc_swapin: cannot get upage");
320 }
321 ma[i] = m;
322 }
323 if (upobj->resident_page_count != UAREA_PAGES)
324 panic("vm_proc_swapin: lost pages from upobj");
325 vm_page_lock_queues();
326 TAILQ_FOREACH(m, &upobj->memq, listq) {
327 m->valid = VM_PAGE_BITS_ALL;
328 vm_page_wire(m);
329 vm_page_wakeup(m);
330 }
331 vm_page_unlock_queues();
332 up = (vm_offset_t)p->p_uarea;
333 pmap_qenter(up, ma, UAREA_PAGES);
334}
335#endif
336
337/*
338 * Implement fork's actions on an address space.
339 * Here we arrange for the address space to be copied or referenced,
340 * allocate a user struct (pcb and kernel stack), then call the
341 * machine-dependent layer to fill those in and make the new process
342 * ready to run. The new process is set up so that it returns directly
343 * to user mode to avoid stack copying and relocation problems.
344 */
345void
346vm_forkproc(td, p2, td2, flags)
347 struct thread *td;
348 struct proc *p2;
349 struct thread *td2;
350 int flags;
351{
352 struct proc *p1 = td->td_proc;
353 struct user *up;
354
355 GIANT_REQUIRED;
356
357 if ((flags & RFPROC) == 0) {
358 /*
359 * Divorce the memory, if it is shared, essentially
360 * this changes shared memory amongst threads, into
361 * COW locally.
362 */
363 if ((flags & RFMEM) == 0) {
364 if (p1->p_vmspace->vm_refcnt > 1) {
365 vmspace_unshare(p1);
366 }
367 }
368 cpu_fork(td, p2, td2, flags);
369 return;
370 }
371
372 if (flags & RFMEM) {
373 p2->p_vmspace = p1->p_vmspace;
374 p1->p_vmspace->vm_refcnt++;
375 }
376
377 while (vm_page_count_severe()) {
378 VM_WAIT;
379 }
380
381 if ((flags & RFMEM) == 0) {
382 p2->p_vmspace = vmspace_fork(p1->p_vmspace);
383
384 pmap_pinit2(vmspace_pmap(p2->p_vmspace));
385
386 if (p1->p_vmspace->vm_shm)
387 shmfork(p1, p2);
388 }
389
390 /* XXXKSE this is unsatisfactory but should be adequate */
391 up = p2->p_uarea;
392
393 /*
394 * p_stats currently points at fields in the user struct
395 * but not at &u, instead at p_addr. Copy parts of
396 * p_stats; zero the rest of p_stats (statistics).
397 *
398 * If procsig->ps_refcnt is 1 and p2->p_sigacts is NULL we dont' need
399 * to share sigacts, so we use the up->u_sigacts.
400 */
401 p2->p_stats = &up->u_stats;
402 if (p2->p_sigacts == NULL) {
403 if (p2->p_procsig->ps_refcnt != 1)
404 printf ("PID:%d NULL sigacts with refcnt not 1!\n",p2->p_pid);
405 p2->p_sigacts = &up->u_sigacts;
406 up->u_sigacts = *p1->p_sigacts;
407 }
408
409 bzero(&up->u_stats.pstat_startzero,
410 (unsigned) ((caddr_t) &up->u_stats.pstat_endzero -
411 (caddr_t) &up->u_stats.pstat_startzero));
412 bcopy(&p1->p_stats->pstat_startcopy, &up->u_stats.pstat_startcopy,
413 ((caddr_t) &up->u_stats.pstat_endcopy -
414 (caddr_t) &up->u_stats.pstat_startcopy));
415
416
417 /*
418 * cpu_fork will copy and update the pcb, set up the kernel stack,
419 * and make the child ready to run.
420 */
421 cpu_fork(td, p2, td2, flags);
422}
423
424/*
425 * Called after process has been wait(2)'ed apon and is being reaped.
426 * The idea is to reclaim resources that we could not reclaim while
427 * the process was still executing.
428 */
429void
430vm_waitproc(p)
431 struct proc *p;
432{
433
434 GIANT_REQUIRED;
435 cpu_wait(p);
436 vmspace_exitfree(p); /* and clean-out the vmspace */
437}
438
439/*
440 * Set default limits for VM system.
441 * Called for proc 0, and then inherited by all others.
442 *
443 * XXX should probably act directly on proc0.
444 */
445static void
446vm_init_limits(udata)
447 void *udata;
448{
449 struct proc *p = udata;
450 int rss_limit;
451
452 /*
453 * Set up the initial limits on process VM. Set the maximum resident
454 * set size to be half of (reasonably) available memory. Since this
455 * is a soft limit, it comes into effect only when the system is out
456 * of memory - half of main memory helps to favor smaller processes,
457 * and reduces thrashing of the object cache.
458 */
459 p->p_rlimit[RLIMIT_STACK].rlim_cur = dflssiz;
460 p->p_rlimit[RLIMIT_STACK].rlim_max = maxssiz;
461 p->p_rlimit[RLIMIT_DATA].rlim_cur = dfldsiz;
462 p->p_rlimit[RLIMIT_DATA].rlim_max = maxdsiz;
463 /* limit the limit to no less than 2MB */
464 rss_limit = max(cnt.v_free_count, 512);
465 p->p_rlimit[RLIMIT_RSS].rlim_cur = ptoa(rss_limit);
466 p->p_rlimit[RLIMIT_RSS].rlim_max = RLIM_INFINITY;
467}
468
469void
470faultin(p)
471 struct proc *p;
472{
473
474 GIANT_REQUIRED;
475 PROC_LOCK_ASSERT(p, MA_OWNED);
476 mtx_assert(&sched_lock, MA_OWNED);
477#ifdef NO_SWAPPING
478 if ((p->p_sflag & PS_INMEM) == 0)
479 panic("faultin: proc swapped out with NO_SWAPPING!");
480#else
481 if ((p->p_sflag & PS_INMEM) == 0) {
482 struct thread *td;
483
484 ++p->p_lock;
485 /*
486 * If another process is swapping in this process,
487 * just wait until it finishes.
488 */
489 if (p->p_sflag & PS_SWAPPINGIN) {
490 mtx_unlock_spin(&sched_lock);
491 msleep(&p->p_sflag, &p->p_mtx, PVM, "faultin", 0);
492 mtx_lock_spin(&sched_lock);
493 --p->p_lock;
494 return;
495 }
496
497 p->p_sflag |= PS_SWAPPINGIN;
498 mtx_unlock_spin(&sched_lock);
499 PROC_UNLOCK(p);
500
501 vm_proc_swapin(p);
502 FOREACH_THREAD_IN_PROC (p, td) {
503 pmap_swapin_thread(td);
504 TD_CLR_SWAPPED(td);
505 }
506
507 PROC_LOCK(p);
508 mtx_lock_spin(&sched_lock);
509 p->p_sflag &= ~PS_SWAPPINGIN;
510 p->p_sflag |= PS_INMEM;
511 FOREACH_THREAD_IN_PROC (p, td)
512 if (TD_CAN_RUN(td))
513 setrunnable(td);
514
515 wakeup(&p->p_sflag);
516
517 /* undo the effect of setting SLOCK above */
518 --p->p_lock;
519 }
520#endif
521}
522
523/*
524 * This swapin algorithm attempts to swap-in processes only if there
525 * is enough space for them. Of course, if a process waits for a long
526 * time, it will be swapped in anyway.
527 *
528 * XXXKSE - process with the thread with highest priority counts..
529 *
530 * Giant is still held at this point, to be released in tsleep.
531 */
532/* ARGSUSED*/
533static void
534scheduler(dummy)
535 void *dummy;
536{
537 struct proc *p;
538 struct thread *td;
539 int pri;
540 struct proc *pp;
541 int ppri;
542
543 mtx_assert(&Giant, MA_OWNED | MA_NOTRECURSED);
544 /* GIANT_REQUIRED */
545
546loop:
547 if (vm_page_count_min()) {
548 VM_WAIT;
549 goto loop;
550 }
551
552 pp = NULL;
553 ppri = INT_MIN;
554 sx_slock(&allproc_lock);
555 FOREACH_PROC_IN_SYSTEM(p) {
556 struct ksegrp *kg;
557 if (p->p_sflag & (PS_INMEM | PS_SWAPPING | PS_SWAPPINGIN)) {
558 continue;
559 }
560 mtx_lock_spin(&sched_lock);
561 FOREACH_THREAD_IN_PROC(p, td) {
562 /*
563 * An otherwise runnable thread of a process
564 * swapped out has only the TDI_SWAPPED bit set.
565 *
566 */
567 if (td->td_inhibitors == TDI_SWAPPED) {
568 kg = td->td_ksegrp;
569 pri = p->p_swtime + kg->kg_slptime;
570 if ((p->p_sflag & PS_SWAPINREQ) == 0) {
571 pri -= kg->kg_nice * 8;
572 }
573
574 /*
575 * if this ksegrp is higher priority
576 * and there is enough space, then select
577 * this process instead of the previous
578 * selection.
579 */
580 if (pri > ppri) {
581 pp = p;
582 ppri = pri;
583 }
584 }
585 }
586 mtx_unlock_spin(&sched_lock);
587 }
588 sx_sunlock(&allproc_lock);
589
590 /*
591 * Nothing to do, back to sleep.
592 */
593 if ((p = pp) == NULL) {
594 tsleep(&proc0, PVM, "sched", maxslp * hz / 2);
595 goto loop;
596 }
597 PROC_LOCK(p);
598 mtx_lock_spin(&sched_lock);
599
600 /*
601 * Another process may be bringing or may have already
602 * brought this process in while we traverse all threads.
603 * Or, this process may even be being swapped out again.
604 */
605 if (p->p_sflag & (PS_INMEM|PS_SWAPPING|PS_SWAPPINGIN)) {
606 mtx_unlock_spin(&sched_lock);
607 PROC_UNLOCK(p);
608 goto loop;
609 }
610
611 p->p_sflag &= ~PS_SWAPINREQ;
612
613 /*
614 * We would like to bring someone in. (only if there is space).
615 * [What checks the space? ]
616 */
617 faultin(p);
618 PROC_UNLOCK(p);
619 p->p_swtime = 0;
620 mtx_unlock_spin(&sched_lock);
621 goto loop;
622}
623
624#ifndef NO_SWAPPING
625
626/*
627 * Swap_idle_threshold1 is the guaranteed swapped in time for a process
628 */
629static int swap_idle_threshold1 = 2;
630SYSCTL_INT(_vm, OID_AUTO, swap_idle_threshold1,
631 CTLFLAG_RW, &swap_idle_threshold1, 0, "");
632
633/*
634 * Swap_idle_threshold2 is the time that a process can be idle before
635 * it will be swapped out, if idle swapping is enabled.
636 */
637static int swap_idle_threshold2 = 10;
638SYSCTL_INT(_vm, OID_AUTO, swap_idle_threshold2,
639 CTLFLAG_RW, &swap_idle_threshold2, 0, "");
640
641/*
642 * Swapout is driven by the pageout daemon. Very simple, we find eligible
643 * procs and unwire their u-areas. We try to always "swap" at least one
644 * process in case we need the room for a swapin.
645 * If any procs have been sleeping/stopped for at least maxslp seconds,
646 * they are swapped. Else, we swap the longest-sleeping or stopped process,
647 * if any, otherwise the longest-resident process.
648 */
649void
650swapout_procs(action)
651int action;
652{
653 struct proc *p;
654 struct thread *td;
655 struct ksegrp *kg;
656 struct proc *outp, *outp2;
657 int outpri, outpri2;
658 int didswap = 0;
659
660 GIANT_REQUIRED;
661
662 outp = outp2 = NULL;
663 outpri = outpri2 = INT_MIN;
664retry:
665 sx_slock(&allproc_lock);
666 FOREACH_PROC_IN_SYSTEM(p) {
667 struct vmspace *vm;
668 int minslptime = 100000;
669
670 /*
671 * Do not swapout a process that
672 * is waiting for VM data
673 * structures there is a possible
674 * deadlock. Test this first as
675 * this may block.
676 *
677 * Lock the map until swapout
678 * finishes, or a thread of this
679 * process may attempt to alter
680 * the map.
681 *
682 * Watch out for a process in
683 * creation. It may have no
684 * address space yet.
685 *
686 * An aio daemon switches its
687 * address space while running.
688 * Perform a quick check whether
689 * a process has P_SYSTEM.
690 */
691 PROC_LOCK(p);
692 if ((p->p_flag & P_SYSTEM) != 0) {
693 PROC_UNLOCK(p);
694 continue;
695 }
696 mtx_lock_spin(&sched_lock);
697 if (p->p_state == PRS_NEW) {
698 mtx_unlock_spin(&sched_lock);
699 PROC_UNLOCK(p);
700 continue;
701 }
702 vm = p->p_vmspace;
703 KASSERT(vm != NULL,
704 ("swapout_procs: a process has no address space"));
705 ++vm->vm_refcnt;
706 mtx_unlock_spin(&sched_lock);
707 PROC_UNLOCK(p);
708 if (!vm_map_trylock(&vm->vm_map))
709 goto nextproc1;
710
711 PROC_LOCK(p);
712 if (p->p_lock != 0 ||
713 (p->p_flag & (P_STOPPED_SINGLE|P_TRACED|P_SYSTEM|P_WEXIT)
714 ) != 0) {
715 goto nextproc2;
716 }
717 /*
718 * only aiod changes vmspace, however it will be
719 * skipped because of the if statement above checking
720 * for P_SYSTEM
721 */
722 mtx_lock_spin(&sched_lock);
723 if ((p->p_sflag & (PS_INMEM|PS_SWAPPING|PS_SWAPPINGIN)) != PS_INMEM)
724 goto nextproc;
725
726 switch (p->p_state) {
727 default:
728 /* Don't swap out processes in any sort
729 * of 'special' state. */
730 goto nextproc;
731
732 case PRS_NORMAL:
733 /*
734 * do not swapout a realtime process
735 * Check all the thread groups..
736 */
737 FOREACH_KSEGRP_IN_PROC(p, kg) {
738 if (PRI_IS_REALTIME(kg->kg_pri_class))
739 goto nextproc;
740
741 /*
742 * Guarantee swap_idle_threshold1
743 * time in memory.
744 */
745 if (kg->kg_slptime < swap_idle_threshold1)
746 goto nextproc;
747
748 /*
749 * Do not swapout a process if it is
750 * waiting on a critical event of some
751 * kind or there is a thread whose
752 * pageable memory may be accessed.
753 *
754 * This could be refined to support
755 * swapping out a thread.
756 */
757 FOREACH_THREAD_IN_GROUP(kg, td) {
758 if ((td->td_priority) < PSOCK ||
759 !thread_safetoswapout(td))
760 goto nextproc;
761 }
762 /*
763 * If the system is under memory stress,
764 * or if we are swapping
765 * idle processes >= swap_idle_threshold2,
766 * then swap the process out.
767 */
768 if (((action & VM_SWAP_NORMAL) == 0) &&
769 (((action & VM_SWAP_IDLE) == 0) ||
770 (kg->kg_slptime < swap_idle_threshold2)))
771 goto nextproc;
772
773 if (minslptime > kg->kg_slptime)
774 minslptime = kg->kg_slptime;
775 }
776
777 /*
778 * If the process has been asleep for awhile and had
779 * most of its pages taken away already, swap it out.
780 */
781 if ((action & VM_SWAP_NORMAL) ||
782 ((action & VM_SWAP_IDLE) &&
783 (minslptime > swap_idle_threshold2))) {
784 swapout(p);
785 didswap++;
786
787 /*
788 * swapout() unlocks a proc lock. This is
789 * ugly, but avoids superfluous lock.
790 */
791 mtx_unlock_spin(&sched_lock);
792 vm_map_unlock(&vm->vm_map);
793 vmspace_free(vm);
794 sx_sunlock(&allproc_lock);
795 goto retry;
796 }
797 }
798nextproc:
799 mtx_unlock_spin(&sched_lock);
800nextproc2:
801 PROC_UNLOCK(p);
802 vm_map_unlock(&vm->vm_map);
803nextproc1:
804 vmspace_free(vm);
805 continue;
806 }
807 sx_sunlock(&allproc_lock);
808 /*
809 * If we swapped something out, and another process needed memory,
810 * then wakeup the sched process.
811 */
812 if (didswap)
813 wakeup(&proc0);
814}
815
816static void
817swapout(p)
818 struct proc *p;
819{
820 struct thread *td;
821
822 PROC_LOCK_ASSERT(p, MA_OWNED);
823 mtx_assert(&sched_lock, MA_OWNED | MA_NOTRECURSED);
824#if defined(SWAP_DEBUG)
825 printf("swapping out %d\n", p->p_pid);
826#endif
827
828 /*
829 * The states of this process and its threads may have changed
830 * by now. Assuming that there is only one pageout daemon thread,
831 * this process should still be in memory.
832 */
833 KASSERT((p->p_sflag & (PS_INMEM|PS_SWAPPING|PS_SWAPPINGIN)) == PS_INMEM,
834 ("swapout: lost a swapout race?"));
835
836#if defined(INVARIANTS)
837 /*
838 * Make sure that all threads are safe to be swapped out.
839 *
840 * Alternatively, we could swap out only safe threads.
841 */
842 FOREACH_THREAD_IN_PROC(p, td) {
843 KASSERT(thread_safetoswapout(td),
844 ("swapout: there is a thread not safe for swapout"));
845 }
846#endif /* INVARIANTS */
847
848 ++p->p_stats->p_ru.ru_nswap;
849 /*
850 * remember the process resident count
851 */
852 p->p_vmspace->vm_swrss = vmspace_resident_count(p->p_vmspace);
853
854 PROC_UNLOCK(p);
855 FOREACH_THREAD_IN_PROC (p, td) /* shouldn't be possible, but..... */
856 if (TD_ON_RUNQ(td)) { /* XXXKSE */
857 panic("swapping out runnable process");
858 remrunqueue(td); /* XXXKSE */
859 }
860 p->p_sflag &= ~PS_INMEM;
861 p->p_sflag |= PS_SWAPPING;
862 mtx_unlock_spin(&sched_lock);
863
864 vm_proc_swapout(p);
865 FOREACH_THREAD_IN_PROC(p, td) {
866 pmap_swapout_thread(td);
867 TD_SET_SWAPPED(td);
868 }
869 mtx_lock_spin(&sched_lock);
870 p->p_sflag &= ~PS_SWAPPING;
871 p->p_swtime = 0;
872}
873#endif /* !NO_SWAPPING */
| 164 return (rv == TRUE);
165}
166
167/*
168 * MPSAFE
169 */
170void
171vslock(addr, len)
172 caddr_t addr;
173 u_int len;
174{
175
176 vm_map_wire(&curproc->p_vmspace->vm_map, trunc_page((vm_offset_t)addr),
177 round_page((vm_offset_t)addr + len), FALSE);
178}
179
180/*
181 * MPSAFE
182 */
183void
184vsunlock(addr, len)
185 caddr_t addr;
186 u_int len;
187{
188
189 vm_map_unwire(&curproc->p_vmspace->vm_map,
190 trunc_page((vm_offset_t)addr),
191 round_page((vm_offset_t)addr + len), FALSE);
192}
193
194/*
195 * Create the U area for a new process.
196 * This routine directly affects the fork perf for a process.
197 */
198void
199vm_proc_new(struct proc *p)
200{
201 vm_page_t ma[UAREA_PAGES];
202 vm_object_t upobj;
203 vm_offset_t up;
204 vm_page_t m;
205 u_int i;
206
207 /*
208 * Allocate object for the upage.
209 */
210 upobj = vm_object_allocate(OBJT_DEFAULT, UAREA_PAGES);
211 p->p_upages_obj = upobj;
212
213 /*
214 * Get a kernel virtual address for the U area for this process.
215 */
216 up = kmem_alloc_nofault(kernel_map, UAREA_PAGES * PAGE_SIZE);
217 if (up == 0)
218 panic("vm_proc_new: upage allocation failed");
219 p->p_uarea = (struct user *)up;
220
221 for (i = 0; i < UAREA_PAGES; i++) {
222 /*
223 * Get a uarea page.
224 */
225 m = vm_page_grab(upobj, i,
226 VM_ALLOC_NORMAL | VM_ALLOC_RETRY | VM_ALLOC_WIRED);
227 ma[i] = m;
228
229 vm_page_wakeup(m);
230 vm_page_flag_clear(m, PG_ZERO);
231 m->valid = VM_PAGE_BITS_ALL;
232 }
233
234 /*
235 * Enter the pages into the kernel address space.
236 */
237 pmap_qenter(up, ma, UAREA_PAGES);
238}
239
240/*
241 * Dispose the U area for a process that has exited.
242 * This routine directly impacts the exit perf of a process.
243 * XXX proc_zone is marked UMA_ZONE_NOFREE, so this should never be called.
244 */
245void
246vm_proc_dispose(struct proc *p)
247{
248 vm_object_t upobj;
249 vm_offset_t up;
250 vm_page_t m;
251
252 upobj = p->p_upages_obj;
253 if (upobj->resident_page_count != UAREA_PAGES)
254 panic("vm_proc_dispose: incorrect number of pages in upobj");
255 vm_page_lock_queues();
256 while ((m = TAILQ_FIRST(&upobj->memq)) != NULL) {
257 vm_page_busy(m);
258 vm_page_unwire(m, 0);
259 vm_page_free(m);
260 }
261 vm_page_unlock_queues();
262 up = (vm_offset_t)p->p_uarea;
263 pmap_qremove(up, UAREA_PAGES);
264 kmem_free(kernel_map, up, UAREA_PAGES * PAGE_SIZE);
265 vm_object_deallocate(upobj);
266}
267
268#ifndef NO_SWAPPING
269/*
270 * Allow the U area for a process to be prejudicially paged out.
271 */
272void
273vm_proc_swapout(struct proc *p)
274{
275 vm_object_t upobj;
276 vm_offset_t up;
277 vm_page_t m;
278
279 upobj = p->p_upages_obj;
280 if (upobj->resident_page_count != UAREA_PAGES)
281 panic("vm_proc_dispose: incorrect number of pages in upobj");
282 vm_page_lock_queues();
283 TAILQ_FOREACH(m, &upobj->memq, listq) {
284 vm_page_dirty(m);
285 vm_page_unwire(m, 0);
286 }
287 vm_page_unlock_queues();
288 up = (vm_offset_t)p->p_uarea;
289 pmap_qremove(up, UAREA_PAGES);
290}
291
292/*
293 * Bring the U area for a specified process back in.
294 */
295void
296vm_proc_swapin(struct proc *p)
297{
298 vm_page_t ma[UAREA_PAGES];
299 vm_object_t upobj;
300 vm_offset_t up;
301 vm_page_t m;
302 int rv;
303 int i;
304
305 upobj = p->p_upages_obj;
306 for (i = 0; i < UAREA_PAGES; i++) {
307 m = vm_page_grab(upobj, i, VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
308 if (m->valid != VM_PAGE_BITS_ALL) {
309 rv = vm_pager_get_pages(upobj, &m, 1, 0);
310 if (rv != VM_PAGER_OK)
311 panic("vm_proc_swapin: cannot get upage");
312 }
313 ma[i] = m;
314 }
315 if (upobj->resident_page_count != UAREA_PAGES)
316 panic("vm_proc_swapin: lost pages from upobj");
317 vm_page_lock_queues();
318 TAILQ_FOREACH(m, &upobj->memq, listq) {
319 m->valid = VM_PAGE_BITS_ALL;
320 vm_page_wire(m);
321 vm_page_wakeup(m);
322 }
323 vm_page_unlock_queues();
324 up = (vm_offset_t)p->p_uarea;
325 pmap_qenter(up, ma, UAREA_PAGES);
326}
327#endif
328
329/*
330 * Implement fork's actions on an address space.
331 * Here we arrange for the address space to be copied or referenced,
332 * allocate a user struct (pcb and kernel stack), then call the
333 * machine-dependent layer to fill those in and make the new process
334 * ready to run. The new process is set up so that it returns directly
335 * to user mode to avoid stack copying and relocation problems.
336 */
337void
338vm_forkproc(td, p2, td2, flags)
339 struct thread *td;
340 struct proc *p2;
341 struct thread *td2;
342 int flags;
343{
344 struct proc *p1 = td->td_proc;
345 struct user *up;
346
347 GIANT_REQUIRED;
348
349 if ((flags & RFPROC) == 0) {
350 /*
351 * Divorce the memory, if it is shared, essentially
352 * this changes shared memory amongst threads, into
353 * COW locally.
354 */
355 if ((flags & RFMEM) == 0) {
356 if (p1->p_vmspace->vm_refcnt > 1) {
357 vmspace_unshare(p1);
358 }
359 }
360 cpu_fork(td, p2, td2, flags);
361 return;
362 }
363
364 if (flags & RFMEM) {
365 p2->p_vmspace = p1->p_vmspace;
366 p1->p_vmspace->vm_refcnt++;
367 }
368
369 while (vm_page_count_severe()) {
370 VM_WAIT;
371 }
372
373 if ((flags & RFMEM) == 0) {
374 p2->p_vmspace = vmspace_fork(p1->p_vmspace);
375
376 pmap_pinit2(vmspace_pmap(p2->p_vmspace));
377
378 if (p1->p_vmspace->vm_shm)
379 shmfork(p1, p2);
380 }
381
382 /* XXXKSE this is unsatisfactory but should be adequate */
383 up = p2->p_uarea;
384
385 /*
386 * p_stats currently points at fields in the user struct
387 * but not at &u, instead at p_addr. Copy parts of
388 * p_stats; zero the rest of p_stats (statistics).
389 *
390 * If procsig->ps_refcnt is 1 and p2->p_sigacts is NULL we dont' need
391 * to share sigacts, so we use the up->u_sigacts.
392 */
393 p2->p_stats = &up->u_stats;
394 if (p2->p_sigacts == NULL) {
395 if (p2->p_procsig->ps_refcnt != 1)
396 printf ("PID:%d NULL sigacts with refcnt not 1!\n",p2->p_pid);
397 p2->p_sigacts = &up->u_sigacts;
398 up->u_sigacts = *p1->p_sigacts;
399 }
400
401 bzero(&up->u_stats.pstat_startzero,
402 (unsigned) ((caddr_t) &up->u_stats.pstat_endzero -
403 (caddr_t) &up->u_stats.pstat_startzero));
404 bcopy(&p1->p_stats->pstat_startcopy, &up->u_stats.pstat_startcopy,
405 ((caddr_t) &up->u_stats.pstat_endcopy -
406 (caddr_t) &up->u_stats.pstat_startcopy));
407
408
409 /*
410 * cpu_fork will copy and update the pcb, set up the kernel stack,
411 * and make the child ready to run.
412 */
413 cpu_fork(td, p2, td2, flags);
414}
415
416/*
417 * Called after process has been wait(2)'ed apon and is being reaped.
418 * The idea is to reclaim resources that we could not reclaim while
419 * the process was still executing.
420 */
421void
422vm_waitproc(p)
423 struct proc *p;
424{
425
426 GIANT_REQUIRED;
427 cpu_wait(p);
428 vmspace_exitfree(p); /* and clean-out the vmspace */
429}
430
431/*
432 * Set default limits for VM system.
433 * Called for proc 0, and then inherited by all others.
434 *
435 * XXX should probably act directly on proc0.
436 */
437static void
438vm_init_limits(udata)
439 void *udata;
440{
441 struct proc *p = udata;
442 int rss_limit;
443
444 /*
445 * Set up the initial limits on process VM. Set the maximum resident
446 * set size to be half of (reasonably) available memory. Since this
447 * is a soft limit, it comes into effect only when the system is out
448 * of memory - half of main memory helps to favor smaller processes,
449 * and reduces thrashing of the object cache.
450 */
451 p->p_rlimit[RLIMIT_STACK].rlim_cur = dflssiz;
452 p->p_rlimit[RLIMIT_STACK].rlim_max = maxssiz;
453 p->p_rlimit[RLIMIT_DATA].rlim_cur = dfldsiz;
454 p->p_rlimit[RLIMIT_DATA].rlim_max = maxdsiz;
455 /* limit the limit to no less than 2MB */
456 rss_limit = max(cnt.v_free_count, 512);
457 p->p_rlimit[RLIMIT_RSS].rlim_cur = ptoa(rss_limit);
458 p->p_rlimit[RLIMIT_RSS].rlim_max = RLIM_INFINITY;
459}
460
461void
462faultin(p)
463 struct proc *p;
464{
465
466 GIANT_REQUIRED;
467 PROC_LOCK_ASSERT(p, MA_OWNED);
468 mtx_assert(&sched_lock, MA_OWNED);
469#ifdef NO_SWAPPING
470 if ((p->p_sflag & PS_INMEM) == 0)
471 panic("faultin: proc swapped out with NO_SWAPPING!");
472#else
473 if ((p->p_sflag & PS_INMEM) == 0) {
474 struct thread *td;
475
476 ++p->p_lock;
477 /*
478 * If another process is swapping in this process,
479 * just wait until it finishes.
480 */
481 if (p->p_sflag & PS_SWAPPINGIN) {
482 mtx_unlock_spin(&sched_lock);
483 msleep(&p->p_sflag, &p->p_mtx, PVM, "faultin", 0);
484 mtx_lock_spin(&sched_lock);
485 --p->p_lock;
486 return;
487 }
488
489 p->p_sflag |= PS_SWAPPINGIN;
490 mtx_unlock_spin(&sched_lock);
491 PROC_UNLOCK(p);
492
493 vm_proc_swapin(p);
494 FOREACH_THREAD_IN_PROC (p, td) {
495 pmap_swapin_thread(td);
496 TD_CLR_SWAPPED(td);
497 }
498
499 PROC_LOCK(p);
500 mtx_lock_spin(&sched_lock);
501 p->p_sflag &= ~PS_SWAPPINGIN;
502 p->p_sflag |= PS_INMEM;
503 FOREACH_THREAD_IN_PROC (p, td)
504 if (TD_CAN_RUN(td))
505 setrunnable(td);
506
507 wakeup(&p->p_sflag);
508
509 /* undo the effect of setting SLOCK above */
510 --p->p_lock;
511 }
512#endif
513}
514
515/*
516 * This swapin algorithm attempts to swap-in processes only if there
517 * is enough space for them. Of course, if a process waits for a long
518 * time, it will be swapped in anyway.
519 *
520 * XXXKSE - process with the thread with highest priority counts..
521 *
522 * Giant is still held at this point, to be released in tsleep.
523 */
524/* ARGSUSED*/
525static void
526scheduler(dummy)
527 void *dummy;
528{
529 struct proc *p;
530 struct thread *td;
531 int pri;
532 struct proc *pp;
533 int ppri;
534
535 mtx_assert(&Giant, MA_OWNED | MA_NOTRECURSED);
536 /* GIANT_REQUIRED */
537
538loop:
539 if (vm_page_count_min()) {
540 VM_WAIT;
541 goto loop;
542 }
543
544 pp = NULL;
545 ppri = INT_MIN;
546 sx_slock(&allproc_lock);
547 FOREACH_PROC_IN_SYSTEM(p) {
548 struct ksegrp *kg;
549 if (p->p_sflag & (PS_INMEM | PS_SWAPPING | PS_SWAPPINGIN)) {
550 continue;
551 }
552 mtx_lock_spin(&sched_lock);
553 FOREACH_THREAD_IN_PROC(p, td) {
554 /*
555 * An otherwise runnable thread of a process
556 * swapped out has only the TDI_SWAPPED bit set.
557 *
558 */
559 if (td->td_inhibitors == TDI_SWAPPED) {
560 kg = td->td_ksegrp;
561 pri = p->p_swtime + kg->kg_slptime;
562 if ((p->p_sflag & PS_SWAPINREQ) == 0) {
563 pri -= kg->kg_nice * 8;
564 }
565
566 /*
567 * if this ksegrp is higher priority
568 * and there is enough space, then select
569 * this process instead of the previous
570 * selection.
571 */
572 if (pri > ppri) {
573 pp = p;
574 ppri = pri;
575 }
576 }
577 }
578 mtx_unlock_spin(&sched_lock);
579 }
580 sx_sunlock(&allproc_lock);
581
582 /*
583 * Nothing to do, back to sleep.
584 */
585 if ((p = pp) == NULL) {
586 tsleep(&proc0, PVM, "sched", maxslp * hz / 2);
587 goto loop;
588 }
589 PROC_LOCK(p);
590 mtx_lock_spin(&sched_lock);
591
592 /*
593 * Another process may be bringing or may have already
594 * brought this process in while we traverse all threads.
595 * Or, this process may even be being swapped out again.
596 */
597 if (p->p_sflag & (PS_INMEM|PS_SWAPPING|PS_SWAPPINGIN)) {
598 mtx_unlock_spin(&sched_lock);
599 PROC_UNLOCK(p);
600 goto loop;
601 }
602
603 p->p_sflag &= ~PS_SWAPINREQ;
604
605 /*
606 * We would like to bring someone in. (only if there is space).
607 * [What checks the space? ]
608 */
609 faultin(p);
610 PROC_UNLOCK(p);
611 p->p_swtime = 0;
612 mtx_unlock_spin(&sched_lock);
613 goto loop;
614}
615
616#ifndef NO_SWAPPING
617
618/*
619 * Swap_idle_threshold1 is the guaranteed swapped in time for a process
620 */
621static int swap_idle_threshold1 = 2;
622SYSCTL_INT(_vm, OID_AUTO, swap_idle_threshold1,
623 CTLFLAG_RW, &swap_idle_threshold1, 0, "");
624
625/*
626 * Swap_idle_threshold2 is the time that a process can be idle before
627 * it will be swapped out, if idle swapping is enabled.
628 */
629static int swap_idle_threshold2 = 10;
630SYSCTL_INT(_vm, OID_AUTO, swap_idle_threshold2,
631 CTLFLAG_RW, &swap_idle_threshold2, 0, "");
632
633/*
634 * Swapout is driven by the pageout daemon. Very simple, we find eligible
635 * procs and unwire their u-areas. We try to always "swap" at least one
636 * process in case we need the room for a swapin.
637 * If any procs have been sleeping/stopped for at least maxslp seconds,
638 * they are swapped. Else, we swap the longest-sleeping or stopped process,
639 * if any, otherwise the longest-resident process.
640 */
641void
642swapout_procs(action)
643int action;
644{
645 struct proc *p;
646 struct thread *td;
647 struct ksegrp *kg;
648 struct proc *outp, *outp2;
649 int outpri, outpri2;
650 int didswap = 0;
651
652 GIANT_REQUIRED;
653
654 outp = outp2 = NULL;
655 outpri = outpri2 = INT_MIN;
656retry:
657 sx_slock(&allproc_lock);
658 FOREACH_PROC_IN_SYSTEM(p) {
659 struct vmspace *vm;
660 int minslptime = 100000;
661
662 /*
663 * Do not swapout a process that
664 * is waiting for VM data
665 * structures there is a possible
666 * deadlock. Test this first as
667 * this may block.
668 *
669 * Lock the map until swapout
670 * finishes, or a thread of this
671 * process may attempt to alter
672 * the map.
673 *
674 * Watch out for a process in
675 * creation. It may have no
676 * address space yet.
677 *
678 * An aio daemon switches its
679 * address space while running.
680 * Perform a quick check whether
681 * a process has P_SYSTEM.
682 */
683 PROC_LOCK(p);
684 if ((p->p_flag & P_SYSTEM) != 0) {
685 PROC_UNLOCK(p);
686 continue;
687 }
688 mtx_lock_spin(&sched_lock);
689 if (p->p_state == PRS_NEW) {
690 mtx_unlock_spin(&sched_lock);
691 PROC_UNLOCK(p);
692 continue;
693 }
694 vm = p->p_vmspace;
695 KASSERT(vm != NULL,
696 ("swapout_procs: a process has no address space"));
697 ++vm->vm_refcnt;
698 mtx_unlock_spin(&sched_lock);
699 PROC_UNLOCK(p);
700 if (!vm_map_trylock(&vm->vm_map))
701 goto nextproc1;
702
703 PROC_LOCK(p);
704 if (p->p_lock != 0 ||
705 (p->p_flag & (P_STOPPED_SINGLE|P_TRACED|P_SYSTEM|P_WEXIT)
706 ) != 0) {
707 goto nextproc2;
708 }
709 /*
710 * only aiod changes vmspace, however it will be
711 * skipped because of the if statement above checking
712 * for P_SYSTEM
713 */
714 mtx_lock_spin(&sched_lock);
715 if ((p->p_sflag & (PS_INMEM|PS_SWAPPING|PS_SWAPPINGIN)) != PS_INMEM)
716 goto nextproc;
717
718 switch (p->p_state) {
719 default:
720 /* Don't swap out processes in any sort
721 * of 'special' state. */
722 goto nextproc;
723
724 case PRS_NORMAL:
725 /*
726 * do not swapout a realtime process
727 * Check all the thread groups..
728 */
729 FOREACH_KSEGRP_IN_PROC(p, kg) {
730 if (PRI_IS_REALTIME(kg->kg_pri_class))
731 goto nextproc;
732
733 /*
734 * Guarantee swap_idle_threshold1
735 * time in memory.
736 */
737 if (kg->kg_slptime < swap_idle_threshold1)
738 goto nextproc;
739
740 /*
741 * Do not swapout a process if it is
742 * waiting on a critical event of some
743 * kind or there is a thread whose
744 * pageable memory may be accessed.
745 *
746 * This could be refined to support
747 * swapping out a thread.
748 */
749 FOREACH_THREAD_IN_GROUP(kg, td) {
750 if ((td->td_priority) < PSOCK ||
751 !thread_safetoswapout(td))
752 goto nextproc;
753 }
754 /*
755 * If the system is under memory stress,
756 * or if we are swapping
757 * idle processes >= swap_idle_threshold2,
758 * then swap the process out.
759 */
760 if (((action & VM_SWAP_NORMAL) == 0) &&
761 (((action & VM_SWAP_IDLE) == 0) ||
762 (kg->kg_slptime < swap_idle_threshold2)))
763 goto nextproc;
764
765 if (minslptime > kg->kg_slptime)
766 minslptime = kg->kg_slptime;
767 }
768
769 /*
770 * If the process has been asleep for awhile and had
771 * most of its pages taken away already, swap it out.
772 */
773 if ((action & VM_SWAP_NORMAL) ||
774 ((action & VM_SWAP_IDLE) &&
775 (minslptime > swap_idle_threshold2))) {
776 swapout(p);
777 didswap++;
778
779 /*
780 * swapout() unlocks a proc lock. This is
781 * ugly, but avoids superfluous lock.
782 */
783 mtx_unlock_spin(&sched_lock);
784 vm_map_unlock(&vm->vm_map);
785 vmspace_free(vm);
786 sx_sunlock(&allproc_lock);
787 goto retry;
788 }
789 }
790nextproc:
791 mtx_unlock_spin(&sched_lock);
792nextproc2:
793 PROC_UNLOCK(p);
794 vm_map_unlock(&vm->vm_map);
795nextproc1:
796 vmspace_free(vm);
797 continue;
798 }
799 sx_sunlock(&allproc_lock);
800 /*
801 * If we swapped something out, and another process needed memory,
802 * then wakeup the sched process.
803 */
804 if (didswap)
805 wakeup(&proc0);
806}
807
808static void
809swapout(p)
810 struct proc *p;
811{
812 struct thread *td;
813
814 PROC_LOCK_ASSERT(p, MA_OWNED);
815 mtx_assert(&sched_lock, MA_OWNED | MA_NOTRECURSED);
816#if defined(SWAP_DEBUG)
817 printf("swapping out %d\n", p->p_pid);
818#endif
819
820 /*
821 * The states of this process and its threads may have changed
822 * by now. Assuming that there is only one pageout daemon thread,
823 * this process should still be in memory.
824 */
825 KASSERT((p->p_sflag & (PS_INMEM|PS_SWAPPING|PS_SWAPPINGIN)) == PS_INMEM,
826 ("swapout: lost a swapout race?"));
827
828#if defined(INVARIANTS)
829 /*
830 * Make sure that all threads are safe to be swapped out.
831 *
832 * Alternatively, we could swap out only safe threads.
833 */
834 FOREACH_THREAD_IN_PROC(p, td) {
835 KASSERT(thread_safetoswapout(td),
836 ("swapout: there is a thread not safe for swapout"));
837 }
838#endif /* INVARIANTS */
839
840 ++p->p_stats->p_ru.ru_nswap;
841 /*
842 * remember the process resident count
843 */
844 p->p_vmspace->vm_swrss = vmspace_resident_count(p->p_vmspace);
845
846 PROC_UNLOCK(p);
847 FOREACH_THREAD_IN_PROC (p, td) /* shouldn't be possible, but..... */
848 if (TD_ON_RUNQ(td)) { /* XXXKSE */
849 panic("swapping out runnable process");
850 remrunqueue(td); /* XXXKSE */
851 }
852 p->p_sflag &= ~PS_INMEM;
853 p->p_sflag |= PS_SWAPPING;
854 mtx_unlock_spin(&sched_lock);
855
856 vm_proc_swapout(p);
857 FOREACH_THREAD_IN_PROC(p, td) {
858 pmap_swapout_thread(td);
859 TD_SET_SWAPPED(td);
860 }
861 mtx_lock_spin(&sched_lock);
862 p->p_sflag &= ~PS_SWAPPING;
863 p->p_swtime = 0;
864}
865#endif /* !NO_SWAPPING */
|