FreeBSD/Linux Kernel Cross Reference
sys/uvm/uvm_page.c
1 /* $NetBSD: uvm_page.c,v 1.114 2006/09/27 17:18:50 thorpej Exp $ */
2
3 /*
4 * Copyright (c) 1997 Charles D. Cranor and Washington University.
5 * Copyright (c) 1991, 1993, The Regents of the University of California.
6 *
7 * All rights reserved.
8 *
9 * This code is derived from software contributed to Berkeley by
10 * The Mach Operating System project at Carnegie-Mellon University.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 * must display the following acknowledgement:
22 * This product includes software developed by Charles D. Cranor,
23 * Washington University, the University of California, Berkeley and
24 * its contributors.
25 * 4. Neither the name of the University nor the names of its contributors
26 * may be used to endorse or promote products derived from this software
27 * without specific prior written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * SUCH DAMAGE.
40 *
41 * @(#)vm_page.c 8.3 (Berkeley) 3/21/94
42 * from: Id: uvm_page.c,v 1.1.2.18 1998/02/06 05:24:42 chs Exp
43 *
44 *
45 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
46 * All rights reserved.
47 *
48 * Permission to use, copy, modify and distribute this software and
49 * its documentation is hereby granted, provided that both the copyright
50 * notice and this permission notice appear in all copies of the
51 * software, derivative works or modified versions, and any portions
52 * thereof, and that both notices appear in supporting documentation.
53 *
54 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
55 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
56 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
57 *
58 * Carnegie Mellon requests users of this software to return to
59 *
60 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
61 * School of Computer Science
62 * Carnegie Mellon University
63 * Pittsburgh PA 15213-3890
64 *
65 * any improvements or extensions that they make and grant Carnegie the
66 * rights to redistribute these changes.
67 */
68
69 /*
70 * uvm_page.c: page ops.
71 */
72
73 #include <sys/cdefs.h>
74 __KERNEL_RCSID(0, "$NetBSD: uvm_page.c,v 1.114 2006/09/27 17:18:50 thorpej Exp $");
75
76 #include "opt_uvmhist.h"
77 #include "opt_readahead.h"
78
79 #include <sys/param.h>
80 #include <sys/systm.h>
81 #include <sys/malloc.h>
82 #include <sys/sched.h>
83 #include <sys/kernel.h>
84 #include <sys/vnode.h>
85 #include <sys/proc.h>
86
87 #include <uvm/uvm.h>
88 #include <uvm/uvm_pdpolicy.h>
89
90 /*
91 * global vars... XXXCDC: move to uvm. structure.
92 */
93
94 /*
95 * physical memory config is stored in vm_physmem.
96 */
97
98 struct vm_physseg vm_physmem[VM_PHYSSEG_MAX]; /* XXXCDC: uvm.physmem */
99 int vm_nphysseg = 0; /* XXXCDC: uvm.nphysseg */
100
101 /*
102 * Some supported CPUs in a given architecture don't support all
103 * of the things necessary to do idle page zero'ing efficiently.
104 * We therefore provide a way to disable it from machdep code here.
105 */
106 /*
107 * XXX disabled until we can find a way to do this without causing
108 * problems for either CPU caches or DMA latency.
109 */
110 boolean_t vm_page_zero_enable = FALSE;
111
112 /*
113 * local variables
114 */
115
116 /*
117 * these variables record the values returned by vm_page_bootstrap,
118 * for debugging purposes. The implementation of uvm_pageboot_alloc
119 * and pmap_startup here also uses them internally.
120 */
121
122 static vaddr_t virtual_space_start;
123 static vaddr_t virtual_space_end;
124
125 /*
126 * we use a hash table with only one bucket during bootup. we will
127 * later rehash (resize) the hash table once the allocator is ready.
128 * we static allocate the one bootstrap bucket below...
129 */
130
131 static struct pglist uvm_bootbucket;
132
133 /*
134 * we allocate an initial number of page colors in uvm_page_init(),
135 * and remember them. We may re-color pages as cache sizes are
136 * discovered during the autoconfiguration phase. But we can never
137 * free the initial set of buckets, since they are allocated using
138 * uvm_pageboot_alloc().
139 */
140
141 static boolean_t have_recolored_pages /* = FALSE */;
142
143 MALLOC_DEFINE(M_VMPAGE, "VM page", "VM page");
144
145 #ifdef DEBUG
146 vaddr_t uvm_zerocheckkva;
147 #endif /* DEBUG */
148
149 /*
150 * local prototypes
151 */
152
153 static void uvm_pageinsert(struct vm_page *);
154 static void uvm_pageinsert_after(struct vm_page *, struct vm_page *);
155 static void uvm_pageremove(struct vm_page *);
156
157 /*
158 * inline functions
159 */
160
161 /*
162 * uvm_pageinsert: insert a page in the object and the hash table
163 * uvm_pageinsert_after: insert a page into the specified place in listq
164 *
165 * => caller must lock object
166 * => caller must lock page queues
167 * => call should have already set pg's object and offset pointers
168 * and bumped the version counter
169 */
170
171 inline static void
172 uvm_pageinsert_after(struct vm_page *pg, struct vm_page *where)
173 {
174 struct pglist *buck;
175 struct uvm_object *uobj = pg->uobject;
176
177 KASSERT((pg->flags & PG_TABLED) == 0);
178 KASSERT(where == NULL || (where->flags & PG_TABLED));
179 KASSERT(where == NULL || (where->uobject == uobj));
180 buck = &uvm.page_hash[uvm_pagehash(uobj, pg->offset)];
181 simple_lock(&uvm.hashlock);
182 TAILQ_INSERT_TAIL(buck, pg, hashq);
183 simple_unlock(&uvm.hashlock);
184
185 if (UVM_OBJ_IS_VNODE(uobj)) {
186 if (uobj->uo_npages == 0) {
187 struct vnode *vp = (struct vnode *)uobj;
188
189 vholdl(vp);
190 }
191 if (UVM_OBJ_IS_VTEXT(uobj)) {
192 uvmexp.execpages++;
193 } else {
194 uvmexp.filepages++;
195 }
196 } else if (UVM_OBJ_IS_AOBJ(uobj)) {
197 uvmexp.anonpages++;
198 }
199
200 if (where)
201 TAILQ_INSERT_AFTER(&uobj->memq, where, pg, listq);
202 else
203 TAILQ_INSERT_TAIL(&uobj->memq, pg, listq);
204 pg->flags |= PG_TABLED;
205 uobj->uo_npages++;
206 }
207
208 inline static void
209 uvm_pageinsert(struct vm_page *pg)
210 {
211
212 uvm_pageinsert_after(pg, NULL);
213 }
214
215 /*
216 * uvm_page_remove: remove page from object and hash
217 *
218 * => caller must lock object
219 * => caller must lock page queues
220 */
221
222 static inline void
223 uvm_pageremove(struct vm_page *pg)
224 {
225 struct pglist *buck;
226 struct uvm_object *uobj = pg->uobject;
227
228 KASSERT(pg->flags & PG_TABLED);
229 buck = &uvm.page_hash[uvm_pagehash(uobj, pg->offset)];
230 simple_lock(&uvm.hashlock);
231 TAILQ_REMOVE(buck, pg, hashq);
232 simple_unlock(&uvm.hashlock);
233
234 if (UVM_OBJ_IS_VNODE(uobj)) {
235 if (uobj->uo_npages == 1) {
236 struct vnode *vp = (struct vnode *)uobj;
237
238 holdrelel(vp);
239 }
240 if (UVM_OBJ_IS_VTEXT(uobj)) {
241 uvmexp.execpages--;
242 } else {
243 uvmexp.filepages--;
244 }
245 } else if (UVM_OBJ_IS_AOBJ(uobj)) {
246 uvmexp.anonpages--;
247 }
248
249 /* object should be locked */
250 uobj->uo_npages--;
251 TAILQ_REMOVE(&uobj->memq, pg, listq);
252 pg->flags &= ~PG_TABLED;
253 pg->uobject = NULL;
254 }
255
256 static void
257 uvm_page_init_buckets(struct pgfreelist *pgfl)
258 {
259 int color, i;
260
261 for (color = 0; color < uvmexp.ncolors; color++) {
262 for (i = 0; i < PGFL_NQUEUES; i++) {
263 TAILQ_INIT(&pgfl->pgfl_buckets[color].pgfl_queues[i]);
264 }
265 }
266 }
267
268 /*
269 * uvm_page_init: init the page system. called from uvm_init().
270 *
271 * => we return the range of kernel virtual memory in kvm_startp/kvm_endp
272 */
273
274 void
275 uvm_page_init(vaddr_t *kvm_startp, vaddr_t *kvm_endp)
276 {
277 vsize_t freepages, pagecount, bucketcount, n;
278 struct pgflbucket *bucketarray;
279 struct vm_page *pagearray;
280 int lcv;
281 u_int i;
282 paddr_t paddr;
283
284 /*
285 * init the page queues and page queue locks, except the free
286 * list; we allocate that later (with the initial vm_page
287 * structures).
288 */
289
290 uvmpdpol_init();
291 simple_lock_init(&uvm.pageqlock);
292 simple_lock_init(&uvm.fpageqlock);
293
294 /*
295 * init the <obj,offset> => <page> hash table. for now
296 * we just have one bucket (the bootstrap bucket). later on we
297 * will allocate new buckets as we dynamically resize the hash table.
298 */
299
300 uvm.page_nhash = 1; /* 1 bucket */
301 uvm.page_hashmask = 0; /* mask for hash function */
302 uvm.page_hash = &uvm_bootbucket; /* install bootstrap bucket */
303 TAILQ_INIT(uvm.page_hash); /* init hash table */
304 simple_lock_init(&uvm.hashlock); /* init hash table lock */
305
306 /*
307 * allocate vm_page structures.
308 */
309
310 /*
311 * sanity check:
312 * before calling this function the MD code is expected to register
313 * some free RAM with the uvm_page_physload() function. our job
314 * now is to allocate vm_page structures for this memory.
315 */
316
317 if (vm_nphysseg == 0)
318 panic("uvm_page_bootstrap: no memory pre-allocated");
319
320 /*
321 * first calculate the number of free pages...
322 *
323 * note that we use start/end rather than avail_start/avail_end.
324 * this allows us to allocate extra vm_page structures in case we
325 * want to return some memory to the pool after booting.
326 */
327
328 freepages = 0;
329 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++)
330 freepages += (vm_physmem[lcv].end - vm_physmem[lcv].start);
331
332 /*
333 * Let MD code initialize the number of colors, or default
334 * to 1 color if MD code doesn't care.
335 */
336 if (uvmexp.ncolors == 0)
337 uvmexp.ncolors = 1;
338 uvmexp.colormask = uvmexp.ncolors - 1;
339
340 /*
341 * we now know we have (PAGE_SIZE * freepages) bytes of memory we can
342 * use. for each page of memory we use we need a vm_page structure.
343 * thus, the total number of pages we can use is the total size of
344 * the memory divided by the PAGE_SIZE plus the size of the vm_page
345 * structure. we add one to freepages as a fudge factor to avoid
346 * truncation errors (since we can only allocate in terms of whole
347 * pages).
348 */
349
350 bucketcount = uvmexp.ncolors * VM_NFREELIST;
351 pagecount = ((freepages + 1) << PAGE_SHIFT) /
352 (PAGE_SIZE + sizeof(struct vm_page));
353
354 bucketarray = (void *)uvm_pageboot_alloc((bucketcount *
355 sizeof(struct pgflbucket)) + (pagecount *
356 sizeof(struct vm_page)));
357 pagearray = (struct vm_page *)(bucketarray + bucketcount);
358
359 for (lcv = 0; lcv < VM_NFREELIST; lcv++) {
360 uvm.page_free[lcv].pgfl_buckets =
361 (bucketarray + (lcv * uvmexp.ncolors));
362 uvm_page_init_buckets(&uvm.page_free[lcv]);
363 }
364 memset(pagearray, 0, pagecount * sizeof(struct vm_page));
365
366 /*
367 * init the vm_page structures and put them in the correct place.
368 */
369
370 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) {
371 n = vm_physmem[lcv].end - vm_physmem[lcv].start;
372
373 /* set up page array pointers */
374 vm_physmem[lcv].pgs = pagearray;
375 pagearray += n;
376 pagecount -= n;
377 vm_physmem[lcv].lastpg = vm_physmem[lcv].pgs + (n - 1);
378
379 /* init and free vm_pages (we've already zeroed them) */
380 paddr = ptoa(vm_physmem[lcv].start);
381 for (i = 0 ; i < n ; i++, paddr += PAGE_SIZE) {
382 vm_physmem[lcv].pgs[i].phys_addr = paddr;
383 #ifdef __HAVE_VM_PAGE_MD
384 VM_MDPAGE_INIT(&vm_physmem[lcv].pgs[i]);
385 #endif
386 if (atop(paddr) >= vm_physmem[lcv].avail_start &&
387 atop(paddr) <= vm_physmem[lcv].avail_end) {
388 uvmexp.npages++;
389 /* add page to free pool */
390 uvm_pagefree(&vm_physmem[lcv].pgs[i]);
391 }
392 }
393 }
394
395 /*
396 * pass up the values of virtual_space_start and
397 * virtual_space_end (obtained by uvm_pageboot_alloc) to the upper
398 * layers of the VM.
399 */
400
401 *kvm_startp = round_page(virtual_space_start);
402 *kvm_endp = trunc_page(virtual_space_end);
403 #ifdef DEBUG
404 /*
405 * steal kva for uvm_pagezerocheck().
406 */
407 uvm_zerocheckkva = *kvm_startp;
408 *kvm_startp += PAGE_SIZE;
409 #endif /* DEBUG */
410
411 /*
412 * init locks for kernel threads
413 */
414
415 simple_lock_init(&uvm.pagedaemon_lock);
416 simple_lock_init(&uvm.aiodoned_lock);
417
418 /*
419 * init various thresholds.
420 */
421
422 uvmexp.reserve_pagedaemon = 1;
423 uvmexp.reserve_kernel = 5;
424
425 /*
426 * determine if we should zero pages in the idle loop.
427 */
428
429 uvm.page_idle_zero = vm_page_zero_enable;
430
431 /*
432 * done!
433 */
434
435 uvm.page_init_done = TRUE;
436 }
437
438 /*
439 * uvm_setpagesize: set the page size
440 *
441 * => sets page_shift and page_mask from uvmexp.pagesize.
442 */
443
444 void
445 uvm_setpagesize(void)
446 {
447
448 /*
449 * If uvmexp.pagesize is 0 at this point, we expect PAGE_SIZE
450 * to be a constant (indicated by being a non-zero value).
451 */
452 if (uvmexp.pagesize == 0) {
453 if (PAGE_SIZE == 0)
454 panic("uvm_setpagesize: uvmexp.pagesize not set");
455 uvmexp.pagesize = PAGE_SIZE;
456 }
457 uvmexp.pagemask = uvmexp.pagesize - 1;
458 if ((uvmexp.pagemask & uvmexp.pagesize) != 0)
459 panic("uvm_setpagesize: page size not a power of two");
460 for (uvmexp.pageshift = 0; ; uvmexp.pageshift++)
461 if ((1 << uvmexp.pageshift) == uvmexp.pagesize)
462 break;
463 }
464
465 /*
466 * uvm_pageboot_alloc: steal memory from physmem for bootstrapping
467 */
468
469 vaddr_t
470 uvm_pageboot_alloc(vsize_t size)
471 {
472 static boolean_t initialized = FALSE;
473 vaddr_t addr;
474 #if !defined(PMAP_STEAL_MEMORY)
475 vaddr_t vaddr;
476 paddr_t paddr;
477 #endif
478
479 /*
480 * on first call to this function, initialize ourselves.
481 */
482 if (initialized == FALSE) {
483 pmap_virtual_space(&virtual_space_start, &virtual_space_end);
484
485 /* round it the way we like it */
486 virtual_space_start = round_page(virtual_space_start);
487 virtual_space_end = trunc_page(virtual_space_end);
488
489 initialized = TRUE;
490 }
491
492 /* round to page size */
493 size = round_page(size);
494
495 #if defined(PMAP_STEAL_MEMORY)
496
497 /*
498 * defer bootstrap allocation to MD code (it may want to allocate
499 * from a direct-mapped segment). pmap_steal_memory should adjust
500 * virtual_space_start/virtual_space_end if necessary.
501 */
502
503 addr = pmap_steal_memory(size, &virtual_space_start,
504 &virtual_space_end);
505
506 return(addr);
507
508 #else /* !PMAP_STEAL_MEMORY */
509
510 /*
511 * allocate virtual memory for this request
512 */
513 if (virtual_space_start == virtual_space_end ||
514 (virtual_space_end - virtual_space_start) < size)
515 panic("uvm_pageboot_alloc: out of virtual space");
516
517 addr = virtual_space_start;
518
519 #ifdef PMAP_GROWKERNEL
520 /*
521 * If the kernel pmap can't map the requested space,
522 * then allocate more resources for it.
523 */
524 if (uvm_maxkaddr < (addr + size)) {
525 uvm_maxkaddr = pmap_growkernel(addr + size);
526 if (uvm_maxkaddr < (addr + size))
527 panic("uvm_pageboot_alloc: pmap_growkernel() failed");
528 }
529 #endif
530
531 virtual_space_start += size;
532
533 /*
534 * allocate and mapin physical pages to back new virtual pages
535 */
536
537 for (vaddr = round_page(addr) ; vaddr < addr + size ;
538 vaddr += PAGE_SIZE) {
539
540 if (!uvm_page_physget(&paddr))
541 panic("uvm_pageboot_alloc: out of memory");
542
543 /*
544 * Note this memory is no longer managed, so using
545 * pmap_kenter is safe.
546 */
547 pmap_kenter_pa(vaddr, paddr, VM_PROT_READ|VM_PROT_WRITE);
548 }
549 pmap_update(pmap_kernel());
550 return(addr);
551 #endif /* PMAP_STEAL_MEMORY */
552 }
553
554 #if !defined(PMAP_STEAL_MEMORY)
555 /*
556 * uvm_page_physget: "steal" one page from the vm_physmem structure.
557 *
558 * => attempt to allocate it off the end of a segment in which the "avail"
559 * values match the start/end values. if we can't do that, then we
560 * will advance both values (making them equal, and removing some
561 * vm_page structures from the non-avail area).
562 * => return false if out of memory.
563 */
564
565 /* subroutine: try to allocate from memory chunks on the specified freelist */
566 static boolean_t uvm_page_physget_freelist(paddr_t *, int);
567
568 static boolean_t
569 uvm_page_physget_freelist(paddr_t *paddrp, int freelist)
570 {
571 int lcv, x;
572
573 /* pass 1: try allocating from a matching end */
574 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST)
575 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--)
576 #else
577 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++)
578 #endif
579 {
580
581 if (uvm.page_init_done == TRUE)
582 panic("uvm_page_physget: called _after_ bootstrap");
583
584 if (vm_physmem[lcv].free_list != freelist)
585 continue;
586
587 /* try from front */
588 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].start &&
589 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) {
590 *paddrp = ptoa(vm_physmem[lcv].avail_start);
591 vm_physmem[lcv].avail_start++;
592 vm_physmem[lcv].start++;
593 /* nothing left? nuke it */
594 if (vm_physmem[lcv].avail_start ==
595 vm_physmem[lcv].end) {
596 if (vm_nphysseg == 1)
597 panic("uvm_page_physget: out of memory!");
598 vm_nphysseg--;
599 for (x = lcv ; x < vm_nphysseg ; x++)
600 /* structure copy */
601 vm_physmem[x] = vm_physmem[x+1];
602 }
603 return (TRUE);
604 }
605
606 /* try from rear */
607 if (vm_physmem[lcv].avail_end == vm_physmem[lcv].end &&
608 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) {
609 *paddrp = ptoa(vm_physmem[lcv].avail_end - 1);
610 vm_physmem[lcv].avail_end--;
611 vm_physmem[lcv].end--;
612 /* nothing left? nuke it */
613 if (vm_physmem[lcv].avail_end ==
614 vm_physmem[lcv].start) {
615 if (vm_nphysseg == 1)
616 panic("uvm_page_physget: out of memory!");
617 vm_nphysseg--;
618 for (x = lcv ; x < vm_nphysseg ; x++)
619 /* structure copy */
620 vm_physmem[x] = vm_physmem[x+1];
621 }
622 return (TRUE);
623 }
624 }
625
626 /* pass2: forget about matching ends, just allocate something */
627 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST)
628 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--)
629 #else
630 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++)
631 #endif
632 {
633
634 /* any room in this bank? */
635 if (vm_physmem[lcv].avail_start >= vm_physmem[lcv].avail_end)
636 continue; /* nope */
637
638 *paddrp = ptoa(vm_physmem[lcv].avail_start);
639 vm_physmem[lcv].avail_start++;
640 /* truncate! */
641 vm_physmem[lcv].start = vm_physmem[lcv].avail_start;
642
643 /* nothing left? nuke it */
644 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].end) {
645 if (vm_nphysseg == 1)
646 panic("uvm_page_physget: out of memory!");
647 vm_nphysseg--;
648 for (x = lcv ; x < vm_nphysseg ; x++)
649 /* structure copy */
650 vm_physmem[x] = vm_physmem[x+1];
651 }
652 return (TRUE);
653 }
654
655 return (FALSE); /* whoops! */
656 }
657
658 boolean_t
659 uvm_page_physget(paddr_t *paddrp)
660 {
661 int i;
662
663 /* try in the order of freelist preference */
664 for (i = 0; i < VM_NFREELIST; i++)
665 if (uvm_page_physget_freelist(paddrp, i) == TRUE)
666 return (TRUE);
667 return (FALSE);
668 }
669 #endif /* PMAP_STEAL_MEMORY */
670
671 /*
672 * uvm_page_physload: load physical memory into VM system
673 *
674 * => all args are PFs
675 * => all pages in start/end get vm_page structures
676 * => areas marked by avail_start/avail_end get added to the free page pool
677 * => we are limited to VM_PHYSSEG_MAX physical memory segments
678 */
679
680 void
681 uvm_page_physload(paddr_t start, paddr_t end, paddr_t avail_start,
682 paddr_t avail_end, int free_list)
683 {
684 int preload, lcv;
685 psize_t npages;
686 struct vm_page *pgs;
687 struct vm_physseg *ps;
688
689 if (uvmexp.pagesize == 0)
690 panic("uvm_page_physload: page size not set!");
691 if (free_list >= VM_NFREELIST || free_list < VM_FREELIST_DEFAULT)
692 panic("uvm_page_physload: bad free list %d", free_list);
693 if (start >= end)
694 panic("uvm_page_physload: start >= end");
695
696 /*
697 * do we have room?
698 */
699
700 if (vm_nphysseg == VM_PHYSSEG_MAX) {
701 printf("uvm_page_physload: unable to load physical memory "
702 "segment\n");
703 printf("\t%d segments allocated, ignoring 0x%llx -> 0x%llx\n",
704 VM_PHYSSEG_MAX, (long long)start, (long long)end);
705 printf("\tincrease VM_PHYSSEG_MAX\n");
706 return;
707 }
708
709 /*
710 * check to see if this is a "preload" (i.e. uvm_mem_init hasn't been
711 * called yet, so malloc is not available).
712 */
713
714 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) {
715 if (vm_physmem[lcv].pgs)
716 break;
717 }
718 preload = (lcv == vm_nphysseg);
719
720 /*
721 * if VM is already running, attempt to malloc() vm_page structures
722 */
723
724 if (!preload) {
725 #if defined(VM_PHYSSEG_NOADD)
726 panic("uvm_page_physload: tried to add RAM after vm_mem_init");
727 #else
728 /* XXXCDC: need some sort of lockout for this case */
729 paddr_t paddr;
730 npages = end - start; /* # of pages */
731 pgs = malloc(sizeof(struct vm_page) * npages,
732 M_VMPAGE, M_NOWAIT);
733 if (pgs == NULL) {
734 printf("uvm_page_physload: can not malloc vm_page "
735 "structs for segment\n");
736 printf("\tignoring 0x%lx -> 0x%lx\n", start, end);
737 return;
738 }
739 /* zero data, init phys_addr and free_list, and free pages */
740 memset(pgs, 0, sizeof(struct vm_page) * npages);
741 for (lcv = 0, paddr = ptoa(start) ;
742 lcv < npages ; lcv++, paddr += PAGE_SIZE) {
743 pgs[lcv].phys_addr = paddr;
744 pgs[lcv].free_list = free_list;
745 if (atop(paddr) >= avail_start &&
746 atop(paddr) <= avail_end)
747 uvm_pagefree(&pgs[lcv]);
748 }
749 /* XXXCDC: incomplete: need to update uvmexp.free, what else? */
750 /* XXXCDC: need hook to tell pmap to rebuild pv_list, etc... */
751 #endif
752 } else {
753 pgs = NULL;
754 npages = 0;
755 }
756
757 /*
758 * now insert us in the proper place in vm_physmem[]
759 */
760
761 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_RANDOM)
762 /* random: put it at the end (easy!) */
763 ps = &vm_physmem[vm_nphysseg];
764 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH)
765 {
766 int x;
767 /* sort by address for binary search */
768 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++)
769 if (start < vm_physmem[lcv].start)
770 break;
771 ps = &vm_physmem[lcv];
772 /* move back other entries, if necessary ... */
773 for (x = vm_nphysseg ; x > lcv ; x--)
774 /* structure copy */
775 vm_physmem[x] = vm_physmem[x - 1];
776 }
777 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST)
778 {
779 int x;
780 /* sort by largest segment first */
781 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++)
782 if ((end - start) >
783 (vm_physmem[lcv].end - vm_physmem[lcv].start))
784 break;
785 ps = &vm_physmem[lcv];
786 /* move back other entries, if necessary ... */
787 for (x = vm_nphysseg ; x > lcv ; x--)
788 /* structure copy */
789 vm_physmem[x] = vm_physmem[x - 1];
790 }
791 #else
792 panic("uvm_page_physload: unknown physseg strategy selected!");
793 #endif
794
795 ps->start = start;
796 ps->end = end;
797 ps->avail_start = avail_start;
798 ps->avail_end = avail_end;
799 if (preload) {
800 ps->pgs = NULL;
801 } else {
802 ps->pgs = pgs;
803 ps->lastpg = pgs + npages - 1;
804 }
805 ps->free_list = free_list;
806 vm_nphysseg++;
807
808 if (!preload) {
809 uvm_page_rehash();
810 uvmpdpol_reinit();
811 }
812 }
813
814 /*
815 * uvm_page_rehash: reallocate hash table based on number of free pages.
816 */
817
818 void
819 uvm_page_rehash(void)
820 {
821 int freepages, lcv, bucketcount, oldcount;
822 struct pglist *newbuckets, *oldbuckets;
823 struct vm_page *pg;
824 size_t newsize, oldsize;
825
826 /*
827 * compute number of pages that can go in the free pool
828 */
829
830 freepages = 0;
831 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++)
832 freepages +=
833 (vm_physmem[lcv].avail_end - vm_physmem[lcv].avail_start);
834
835 /*
836 * compute number of buckets needed for this number of pages
837 */
838
839 bucketcount = 1;
840 while (bucketcount < freepages)
841 bucketcount = bucketcount * 2;
842
843 /*
844 * compute the size of the current table and new table.
845 */
846
847 oldbuckets = uvm.page_hash;
848 oldcount = uvm.page_nhash;
849 oldsize = round_page(sizeof(struct pglist) * oldcount);
850 newsize = round_page(sizeof(struct pglist) * bucketcount);
851
852 /*
853 * allocate the new buckets
854 */
855
856 newbuckets = (struct pglist *) uvm_km_alloc(kernel_map, newsize,
857 0, UVM_KMF_WIRED);
858 if (newbuckets == NULL) {
859 printf("uvm_page_physrehash: WARNING: could not grow page "
860 "hash table\n");
861 return;
862 }
863 for (lcv = 0 ; lcv < bucketcount ; lcv++)
864 TAILQ_INIT(&newbuckets[lcv]);
865
866 /*
867 * now replace the old buckets with the new ones and rehash everything
868 */
869
870 simple_lock(&uvm.hashlock);
871 uvm.page_hash = newbuckets;
872 uvm.page_nhash = bucketcount;
873 uvm.page_hashmask = bucketcount - 1; /* power of 2 */
874
875 /* ... and rehash */
876 for (lcv = 0 ; lcv < oldcount ; lcv++) {
877 while ((pg = oldbuckets[lcv].tqh_first) != NULL) {
878 TAILQ_REMOVE(&oldbuckets[lcv], pg, hashq);
879 TAILQ_INSERT_TAIL(
880 &uvm.page_hash[uvm_pagehash(pg->uobject, pg->offset)],
881 pg, hashq);
882 }
883 }
884 simple_unlock(&uvm.hashlock);
885
886 /*
887 * free old bucket array if is not the boot-time table
888 */
889
890 if (oldbuckets != &uvm_bootbucket)
891 uvm_km_free(kernel_map, (vaddr_t) oldbuckets, oldsize,
892 UVM_KMF_WIRED);
893 }
894
895 /*
896 * uvm_page_recolor: Recolor the pages if the new bucket count is
897 * larger than the old one.
898 */
899
900 void
901 uvm_page_recolor(int newncolors)
902 {
903 struct pgflbucket *bucketarray, *oldbucketarray;
904 struct pgfreelist pgfl;
905 struct vm_page *pg;
906 vsize_t bucketcount;
907 int s, lcv, color, i, ocolors;
908
909 if (newncolors <= uvmexp.ncolors)
910 return;
911
912 if (uvm.page_init_done == FALSE) {
913 uvmexp.ncolors = newncolors;
914 return;
915 }
916
917 bucketcount = newncolors * VM_NFREELIST;
918 bucketarray = malloc(bucketcount * sizeof(struct pgflbucket),
919 M_VMPAGE, M_NOWAIT);
920 if (bucketarray == NULL) {
921 printf("WARNING: unable to allocate %ld page color buckets\n",
922 (long) bucketcount);
923 return;
924 }
925
926 s = uvm_lock_fpageq();
927
928 /* Make sure we should still do this. */
929 if (newncolors <= uvmexp.ncolors) {
930 uvm_unlock_fpageq(s);
931 free(bucketarray, M_VMPAGE);
932 return;
933 }
934
935 oldbucketarray = uvm.page_free[0].pgfl_buckets;
936 ocolors = uvmexp.ncolors;
937
938 uvmexp.ncolors = newncolors;
939 uvmexp.colormask = uvmexp.ncolors - 1;
940
941 for (lcv = 0; lcv < VM_NFREELIST; lcv++) {
942 pgfl.pgfl_buckets = (bucketarray + (lcv * newncolors));
943 uvm_page_init_buckets(&pgfl);
944 for (color = 0; color < ocolors; color++) {
945 for (i = 0; i < PGFL_NQUEUES; i++) {
946 while ((pg = TAILQ_FIRST(&uvm.page_free[
947 lcv].pgfl_buckets[color].pgfl_queues[i]))
948 != NULL) {
949 TAILQ_REMOVE(&uvm.page_free[
950 lcv].pgfl_buckets[
951 color].pgfl_queues[i], pg, pageq);
952 TAILQ_INSERT_TAIL(&pgfl.pgfl_buckets[
953 VM_PGCOLOR_BUCKET(pg)].pgfl_queues[
954 i], pg, pageq);
955 }
956 }
957 }
958 uvm.page_free[lcv].pgfl_buckets = pgfl.pgfl_buckets;
959 }
960
961 if (have_recolored_pages) {
962 uvm_unlock_fpageq(s);
963 free(oldbucketarray, M_VMPAGE);
964 return;
965 }
966
967 have_recolored_pages = TRUE;
968 uvm_unlock_fpageq(s);
969 }
970
971 /*
972 * uvm_pagealloc_pgfl: helper routine for uvm_pagealloc_strat
973 */
974
975 static struct vm_page *
976 uvm_pagealloc_pgfl(struct pgfreelist *pgfl, int try1, int try2,
977 int *trycolorp)
978 {
979 struct pglist *freeq;
980 struct vm_page *pg;
981 int color, trycolor = *trycolorp;
982
983 color = trycolor;
984 do {
985 if ((pg = TAILQ_FIRST((freeq =
986 &pgfl->pgfl_buckets[color].pgfl_queues[try1]))) != NULL)
987 goto gotit;
988 if ((pg = TAILQ_FIRST((freeq =
989 &pgfl->pgfl_buckets[color].pgfl_queues[try2]))) != NULL)
990 goto gotit;
991 color = (color + 1) & uvmexp.colormask;
992 } while (color != trycolor);
993
994 return (NULL);
995
996 gotit:
997 TAILQ_REMOVE(freeq, pg, pageq);
998 uvmexp.free--;
999
1000 /* update zero'd page count */
1001 if (pg->flags & PG_ZERO)
1002 uvmexp.zeropages--;
1003
1004 if (color == trycolor)
1005 uvmexp.colorhit++;
1006 else {
1007 uvmexp.colormiss++;
1008 *trycolorp = color;
1009 }
1010
1011 return (pg);
1012 }
1013
1014 /*
1015 * uvm_pagealloc_strat: allocate vm_page from a particular free list.
1016 *
1017 * => return null if no pages free
1018 * => wake up pagedaemon if number of free pages drops below low water mark
1019 * => if obj != NULL, obj must be locked (to put in hash)
1020 * => if anon != NULL, anon must be locked (to put in anon)
1021 * => only one of obj or anon can be non-null
1022 * => caller must activate/deactivate page if it is not wired.
1023 * => free_list is ignored if strat == UVM_PGA_STRAT_NORMAL.
1024 * => policy decision: it is more important to pull a page off of the
1025 * appropriate priority free list than it is to get a zero'd or
1026 * unknown contents page. This is because we live with the
1027 * consequences of a bad free list decision for the entire
1028 * lifetime of the page, e.g. if the page comes from memory that
1029 * is slower to access.
1030 */
1031
1032 struct vm_page *
1033 uvm_pagealloc_strat(struct uvm_object *obj, voff_t off, struct vm_anon *anon,
1034 int flags, int strat, int free_list)
1035 {
1036 int lcv, try1, try2, s, zeroit = 0, color;
1037 struct vm_page *pg;
1038 boolean_t use_reserve;
1039
1040 KASSERT(obj == NULL || anon == NULL);
1041 KASSERT(anon == NULL || off == 0);
1042 KASSERT(off == trunc_page(off));
1043 LOCK_ASSERT(obj == NULL || simple_lock_held(&obj->vmobjlock));
1044 LOCK_ASSERT(anon == NULL || simple_lock_held(&anon->an_lock));
1045
1046 s = uvm_lock_fpageq();
1047
1048 /*
1049 * This implements a global round-robin page coloring
1050 * algorithm.
1051 *
1052 * XXXJRT: Should we make the `nextcolor' per-CPU?
1053 * XXXJRT: What about virtually-indexed caches?
1054 */
1055
1056 color = uvm.page_free_nextcolor;
1057
1058 /*
1059 * check to see if we need to generate some free pages waking
1060 * the pagedaemon.
1061 */
1062
1063 uvm_kick_pdaemon();
1064
1065 /*
1066 * fail if any of these conditions is true:
1067 * [1] there really are no free pages, or
1068 * [2] only kernel "reserved" pages remain and
1069 * the page isn't being allocated to a kernel object.
1070 * [3] only pagedaemon "reserved" pages remain and
1071 * the requestor isn't the pagedaemon.
1072 */
1073
1074 use_reserve = (flags & UVM_PGA_USERESERVE) ||
1075 (obj && UVM_OBJ_IS_KERN_OBJECT(obj));
1076 if ((uvmexp.free <= uvmexp.reserve_kernel && !use_reserve) ||
1077 (uvmexp.free <= uvmexp.reserve_pagedaemon &&
1078 !(use_reserve && curproc == uvm.pagedaemon_proc)))
1079 goto fail;
1080
1081 #if PGFL_NQUEUES != 2
1082 #error uvm_pagealloc_strat needs to be updated
1083 #endif
1084
1085 /*
1086 * If we want a zero'd page, try the ZEROS queue first, otherwise
1087 * we try the UNKNOWN queue first.
1088 */
1089 if (flags & UVM_PGA_ZERO) {
1090 try1 = PGFL_ZEROS;
1091 try2 = PGFL_UNKNOWN;
1092 } else {
1093 try1 = PGFL_UNKNOWN;
1094 try2 = PGFL_ZEROS;
1095 }
1096
1097 again:
1098 switch (strat) {
1099 case UVM_PGA_STRAT_NORMAL:
1100 /* Check all freelists in descending priority order. */
1101 for (lcv = 0; lcv < VM_NFREELIST; lcv++) {
1102 pg = uvm_pagealloc_pgfl(&uvm.page_free[lcv],
1103 try1, try2, &color);
1104 if (pg != NULL)
1105 goto gotit;
1106 }
1107
1108 /* No pages free! */
1109 goto fail;
1110
1111 case UVM_PGA_STRAT_ONLY:
1112 case UVM_PGA_STRAT_FALLBACK:
1113 /* Attempt to allocate from the specified free list. */
1114 KASSERT(free_list >= 0 && free_list < VM_NFREELIST);
1115 pg = uvm_pagealloc_pgfl(&uvm.page_free[free_list],
1116 try1, try2, &color);
1117 if (pg != NULL)
1118 goto gotit;
1119
1120 /* Fall back, if possible. */
1121 if (strat == UVM_PGA_STRAT_FALLBACK) {
1122 strat = UVM_PGA_STRAT_NORMAL;
1123 goto again;
1124 }
1125
1126 /* No pages free! */
1127 goto fail;
1128
1129 default:
1130 panic("uvm_pagealloc_strat: bad strat %d", strat);
1131 /* NOTREACHED */
1132 }
1133
1134 gotit:
1135 /*
1136 * We now know which color we actually allocated from; set
1137 * the next color accordingly.
1138 */
1139
1140 uvm.page_free_nextcolor = (color + 1) & uvmexp.colormask;
1141
1142 /*
1143 * update allocation statistics and remember if we have to
1144 * zero the page
1145 */
1146
1147 if (flags & UVM_PGA_ZERO) {
1148 if (pg->flags & PG_ZERO) {
1149 uvmexp.pga_zerohit++;
1150 zeroit = 0;
1151 } else {
1152 uvmexp.pga_zeromiss++;
1153 zeroit = 1;
1154 }
1155 }
1156 uvm_unlock_fpageq(s);
1157
1158 pg->offset = off;
1159 pg->uobject = obj;
1160 pg->uanon = anon;
1161 pg->flags = PG_BUSY|PG_CLEAN|PG_FAKE;
1162 if (anon) {
1163 anon->an_page = pg;
1164 pg->pqflags = PQ_ANON;
1165 uvmexp.anonpages++;
1166 } else {
1167 if (obj) {
1168 uvm_pageinsert(pg);
1169 }
1170 pg->pqflags = 0;
1171 }
1172 #if defined(UVM_PAGE_TRKOWN)
1173 pg->owner_tag = NULL;
1174 #endif
1175 UVM_PAGE_OWN(pg, "new alloc");
1176
1177 if (flags & UVM_PGA_ZERO) {
1178 /*
1179 * A zero'd page is not clean. If we got a page not already
1180 * zero'd, then we have to zero it ourselves.
1181 */
1182 pg->flags &= ~PG_CLEAN;
1183 if (zeroit)
1184 pmap_zero_page(VM_PAGE_TO_PHYS(pg));
1185 }
1186
1187 return(pg);
1188
1189 fail:
1190 uvm_unlock_fpageq(s);
1191 return (NULL);
1192 }
1193
1194 /*
1195 * uvm_pagereplace: replace a page with another
1196 *
1197 * => object must be locked
1198 */
1199
1200 void
1201 uvm_pagereplace(struct vm_page *oldpg, struct vm_page *newpg)
1202 {
1203
1204 KASSERT((oldpg->flags & PG_TABLED) != 0);
1205 KASSERT(oldpg->uobject != NULL);
1206 KASSERT((newpg->flags & PG_TABLED) == 0);
1207 KASSERT(newpg->uobject == NULL);
1208 LOCK_ASSERT(simple_lock_held(&oldpg->uobject->vmobjlock));
1209
1210 newpg->uobject = oldpg->uobject;
1211 newpg->offset = oldpg->offset;
1212
1213 uvm_pageinsert_after(newpg, oldpg);
1214 uvm_pageremove(oldpg);
1215 }
1216
1217 /*
1218 * uvm_pagerealloc: reallocate a page from one object to another
1219 *
1220 * => both objects must be locked
1221 */
1222
1223 void
1224 uvm_pagerealloc(struct vm_page *pg, struct uvm_object *newobj, voff_t newoff)
1225 {
1226 /*
1227 * remove it from the old object
1228 */
1229
1230 if (pg->uobject) {
1231 uvm_pageremove(pg);
1232 }
1233
1234 /*
1235 * put it in the new object
1236 */
1237
1238 if (newobj) {
1239 pg->uobject = newobj;
1240 pg->offset = newoff;
1241 uvm_pageinsert(pg);
1242 }
1243 }
1244
1245 #ifdef DEBUG
1246 /*
1247 * check if page is zero-filled
1248 *
1249 * - called with free page queue lock held.
1250 */
1251 void
1252 uvm_pagezerocheck(struct vm_page *pg)
1253 {
1254 int *p, *ep;
1255
1256 KASSERT(uvm_zerocheckkva != 0);
1257 LOCK_ASSERT(simple_lock_held(&uvm.fpageqlock));
1258
1259 /*
1260 * XXX assuming pmap_kenter_pa and pmap_kremove never call
1261 * uvm page allocator.
1262 *
1263 * it might be better to have "CPU-local temporary map" pmap interface.
1264 */
1265 pmap_kenter_pa(uvm_zerocheckkva, VM_PAGE_TO_PHYS(pg), VM_PROT_READ);
1266 p = (int *)uvm_zerocheckkva;
1267 ep = (int *)((char *)p + PAGE_SIZE);
1268 pmap_update(pmap_kernel());
1269 while (p < ep) {
1270 if (*p != 0)
1271 panic("PG_ZERO page isn't zero-filled");
1272 p++;
1273 }
1274 pmap_kremove(uvm_zerocheckkva, PAGE_SIZE);
1275 }
1276 #endif /* DEBUG */
1277
1278 /*
1279 * uvm_pagefree: free page
1280 *
1281 * => erase page's identity (i.e. remove from hash/object)
1282 * => put page on free list
1283 * => caller must lock owning object (either anon or uvm_object)
1284 * => caller must lock page queues
1285 * => assumes all valid mappings of pg are gone
1286 */
1287
1288 void
1289 uvm_pagefree(struct vm_page *pg)
1290 {
1291 int s;
1292 struct pglist *pgfl;
1293 boolean_t iszero;
1294
1295 KASSERT((pg->flags & PG_PAGEOUT) == 0);
1296 LOCK_ASSERT(simple_lock_held(&uvm.pageqlock) ||
1297 !uvmpdpol_pageisqueued_p(pg));
1298 LOCK_ASSERT(pg->uobject == NULL ||
1299 simple_lock_held(&pg->uobject->vmobjlock));
1300 LOCK_ASSERT(pg->uobject != NULL || pg->uanon == NULL ||
1301 simple_lock_held(&pg->uanon->an_lock));
1302
1303 #ifdef DEBUG
1304 if (pg->uobject == (void *)0xdeadbeef &&
1305 pg->uanon == (void *)0xdeadbeef) {
1306 panic("uvm_pagefree: freeing free page %p", pg);
1307 }
1308 #endif /* DEBUG */
1309
1310 /*
1311 * if the page is loaned, resolve the loan instead of freeing.
1312 */
1313
1314 if (pg->loan_count) {
1315 KASSERT(pg->wire_count == 0);
1316
1317 /*
1318 * if the page is owned by an anon then we just want to
1319 * drop anon ownership. the kernel will free the page when
1320 * it is done with it. if the page is owned by an object,
1321 * remove it from the object and mark it dirty for the benefit
1322 * of possible anon owners.
1323 *
1324 * regardless of previous ownership, wakeup any waiters,
1325 * unbusy the page, and we're done.
1326 */
1327
1328 if (pg->uobject != NULL) {
1329 uvm_pageremove(pg);
1330 pg->flags &= ~PG_CLEAN;
1331 } else if (pg->uanon != NULL) {
1332 if ((pg->pqflags & PQ_ANON) == 0) {
1333 pg->loan_count--;
1334 } else {
1335 pg->pqflags &= ~PQ_ANON;
1336 uvmexp.anonpages--;
1337 }
1338 pg->uanon->an_page = NULL;
1339 pg->uanon = NULL;
1340 }
1341 if (pg->flags & PG_WANTED) {
1342 wakeup(pg);
1343 }
1344 pg->flags &= ~(PG_WANTED|PG_BUSY|PG_RELEASED|PG_PAGER1);
1345 #ifdef UVM_PAGE_TRKOWN
1346 pg->owner_tag = NULL;
1347 #endif
1348 if (pg->loan_count) {
1349 uvm_pagedequeue(pg);
1350 return;
1351 }
1352 }
1353
1354 /*
1355 * remove page from its object or anon.
1356 */
1357
1358 if (pg->uobject != NULL) {
1359 uvm_pageremove(pg);
1360 } else if (pg->uanon != NULL) {
1361 pg->uanon->an_page = NULL;
1362 uvmexp.anonpages--;
1363 }
1364
1365 /*
1366 * now remove the page from the queues.
1367 */
1368
1369 uvm_pagedequeue(pg);
1370
1371 /*
1372 * if the page was wired, unwire it now.
1373 */
1374
1375 if (pg->wire_count) {
1376 pg->wire_count = 0;
1377 uvmexp.wired--;
1378 }
1379
1380 /*
1381 * and put on free queue
1382 */
1383
1384 iszero = (pg->flags & PG_ZERO);
1385 pgfl = &uvm.page_free[uvm_page_lookup_freelist(pg)].
1386 pgfl_buckets[VM_PGCOLOR_BUCKET(pg)].
1387 pgfl_queues[iszero ? PGFL_ZEROS : PGFL_UNKNOWN];
1388
1389 pg->pqflags = PQ_FREE;
1390 #ifdef DEBUG
1391 pg->uobject = (void *)0xdeadbeef;
1392 pg->offset = 0xdeadbeef;
1393 pg->uanon = (void *)0xdeadbeef;
1394 #endif
1395
1396 s = uvm_lock_fpageq();
1397
1398 #ifdef DEBUG
1399 if (iszero)
1400 uvm_pagezerocheck(pg);
1401 #endif /* DEBUG */
1402
1403 TAILQ_INSERT_HEAD(pgfl, pg, pageq);
1404 uvmexp.free++;
1405 if (iszero)
1406 uvmexp.zeropages++;
1407
1408 if (uvmexp.zeropages < UVM_PAGEZERO_TARGET)
1409 uvm.page_idle_zero = vm_page_zero_enable;
1410
1411 uvm_unlock_fpageq(s);
1412 }
1413
1414 /*
1415 * uvm_page_unbusy: unbusy an array of pages.
1416 *
1417 * => pages must either all belong to the same object, or all belong to anons.
1418 * => if pages are object-owned, object must be locked.
1419 * => if pages are anon-owned, anons must be locked.
1420 * => caller must lock page queues if pages may be released.
1421 * => caller must make sure that anon-owned pages are not PG_RELEASED.
1422 */
1423
1424 void
1425 uvm_page_unbusy(struct vm_page **pgs, int npgs)
1426 {
1427 struct vm_page *pg;
1428 int i;
1429 UVMHIST_FUNC("uvm_page_unbusy"); UVMHIST_CALLED(ubchist);
1430
1431 for (i = 0; i < npgs; i++) {
1432 pg = pgs[i];
1433 if (pg == NULL || pg == PGO_DONTCARE) {
1434 continue;
1435 }
1436
1437 LOCK_ASSERT(pg->uobject == NULL ||
1438 simple_lock_held(&pg->uobject->vmobjlock));
1439 LOCK_ASSERT(pg->uobject != NULL ||
1440 (pg->uanon != NULL &&
1441 simple_lock_held(&pg->uanon->an_lock)));
1442
1443 KASSERT(pg->flags & PG_BUSY);
1444 KASSERT((pg->flags & PG_PAGEOUT) == 0);
1445 if (pg->flags & PG_WANTED) {
1446 wakeup(pg);
1447 }
1448 if (pg->flags & PG_RELEASED) {
1449 UVMHIST_LOG(ubchist, "releasing pg %p", pg,0,0,0);
1450 KASSERT(pg->uobject != NULL ||
1451 (pg->uanon != NULL && pg->uanon->an_ref > 0));
1452 pg->flags &= ~PG_RELEASED;
1453 uvm_pagefree(pg);
1454 } else {
1455 UVMHIST_LOG(ubchist, "unbusying pg %p", pg,0,0,0);
1456 pg->flags &= ~(PG_WANTED|PG_BUSY);
1457 UVM_PAGE_OWN(pg, NULL);
1458 }
1459 }
1460 }
1461
1462 #if defined(UVM_PAGE_TRKOWN)
1463 /*
1464 * uvm_page_own: set or release page ownership
1465 *
1466 * => this is a debugging function that keeps track of who sets PG_BUSY
1467 * and where they do it. it can be used to track down problems
1468 * such a process setting "PG_BUSY" and never releasing it.
1469 * => page's object [if any] must be locked
1470 * => if "tag" is NULL then we are releasing page ownership
1471 */
1472 void
1473 uvm_page_own(struct vm_page *pg, const char *tag)
1474 {
1475 struct uvm_object *uobj;
1476 struct vm_anon *anon;
1477
1478 KASSERT((pg->flags & (PG_PAGEOUT|PG_RELEASED)) == 0);
1479
1480 uobj = pg->uobject;
1481 anon = pg->uanon;
1482 if (uobj != NULL) {
1483 LOCK_ASSERT(simple_lock_held(&uobj->vmobjlock));
1484 } else if (anon != NULL) {
1485 LOCK_ASSERT(simple_lock_held(&anon->an_lock));
1486 }
1487
1488 KASSERT((pg->flags & PG_WANTED) == 0);
1489
1490 /* gain ownership? */
1491 if (tag) {
1492 KASSERT((pg->flags & PG_BUSY) != 0);
1493 if (pg->owner_tag) {
1494 printf("uvm_page_own: page %p already owned "
1495 "by proc %d [%s]\n", pg,
1496 pg->owner, pg->owner_tag);
1497 panic("uvm_page_own");
1498 }
1499 pg->owner = (curproc) ? curproc->p_pid : (pid_t) -1;
1500 pg->owner_tag = tag;
1501 return;
1502 }
1503
1504 /* drop ownership */
1505 KASSERT((pg->flags & PG_BUSY) == 0);
1506 if (pg->owner_tag == NULL) {
1507 printf("uvm_page_own: dropping ownership of an non-owned "
1508 "page (%p)\n", pg);
1509 panic("uvm_page_own");
1510 }
1511 KASSERT(uvmpdpol_pageisqueued_p(pg) ||
1512 (pg->uanon == NULL && pg->uobject == NULL) ||
1513 pg->uobject == uvm.kernel_object ||
1514 pg->wire_count > 0 ||
1515 (pg->loan_count == 1 && pg->uanon == NULL) ||
1516 pg->loan_count > 1);
1517 pg->owner_tag = NULL;
1518 }
1519 #endif
1520
1521 /*
1522 * uvm_pageidlezero: zero free pages while the system is idle.
1523 *
1524 * => try to complete one color bucket at a time, to reduce our impact
1525 * on the CPU cache.
1526 * => we loop until we either reach the target or whichqs indicates that
1527 * there is a process ready to run.
1528 */
1529 void
1530 uvm_pageidlezero(void)
1531 {
1532 struct vm_page *pg;
1533 struct pgfreelist *pgfl;
1534 int free_list, s, firstbucket;
1535 static int nextbucket;
1536
1537 KERNEL_LOCK(LK_EXCLUSIVE | LK_CANRECURSE);
1538 s = uvm_lock_fpageq();
1539 firstbucket = nextbucket;
1540 do {
1541 if (sched_whichqs != 0)
1542 goto quit;
1543 if (uvmexp.zeropages >= UVM_PAGEZERO_TARGET) {
1544 uvm.page_idle_zero = FALSE;
1545 goto quit;
1546 }
1547 for (free_list = 0; free_list < VM_NFREELIST; free_list++) {
1548 pgfl = &uvm.page_free[free_list];
1549 while ((pg = TAILQ_FIRST(&pgfl->pgfl_buckets[
1550 nextbucket].pgfl_queues[PGFL_UNKNOWN])) != NULL) {
1551 if (sched_whichqs != 0)
1552 goto quit;
1553
1554 TAILQ_REMOVE(&pgfl->pgfl_buckets[
1555 nextbucket].pgfl_queues[PGFL_UNKNOWN],
1556 pg, pageq);
1557 uvmexp.free--;
1558 uvm_unlock_fpageq(s);
1559 KERNEL_UNLOCK();
1560 #ifdef PMAP_PAGEIDLEZERO
1561 if (!PMAP_PAGEIDLEZERO(VM_PAGE_TO_PHYS(pg))) {
1562
1563 /*
1564 * The machine-dependent code detected
1565 * some reason for us to abort zeroing
1566 * pages, probably because there is a
1567 * process now ready to run.
1568 */
1569
1570 KERNEL_LOCK(
1571 LK_EXCLUSIVE | LK_CANRECURSE);
1572 s = uvm_lock_fpageq();
1573 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[
1574 nextbucket].pgfl_queues[
1575 PGFL_UNKNOWN], pg, pageq);
1576 uvmexp.free++;
1577 uvmexp.zeroaborts++;
1578 goto quit;
1579 }
1580 #else
1581 pmap_zero_page(VM_PAGE_TO_PHYS(pg));
1582 #endif /* PMAP_PAGEIDLEZERO */
1583 pg->flags |= PG_ZERO;
1584
1585 KERNEL_LOCK(LK_EXCLUSIVE | LK_CANRECURSE);
1586 s = uvm_lock_fpageq();
1587 TAILQ_INSERT_HEAD(&pgfl->pgfl_buckets[
1588 nextbucket].pgfl_queues[PGFL_ZEROS],
1589 pg, pageq);
1590 uvmexp.free++;
1591 uvmexp.zeropages++;
1592 }
1593 }
1594 nextbucket = (nextbucket + 1) & uvmexp.colormask;
1595 } while (nextbucket != firstbucket);
1596 quit:
1597 uvm_unlock_fpageq(s);
1598 KERNEL_UNLOCK();
1599 }
1600
1601 /*
1602 * uvm_lock_fpageq: lock the free page queue
1603 *
1604 * => free page queue can be accessed in interrupt context, so this
1605 * blocks all interrupts that can cause memory allocation, and
1606 * returns the previous interrupt level.
1607 */
1608
1609 int
1610 uvm_lock_fpageq(void)
1611 {
1612 int s;
1613
1614 s = splvm();
1615 simple_lock(&uvm.fpageqlock);
1616 return (s);
1617 }
1618
1619 /*
1620 * uvm_unlock_fpageq: unlock the free page queue
1621 *
1622 * => caller must supply interrupt level returned by uvm_lock_fpageq()
1623 * so that it may be restored.
1624 */
1625
1626 void
1627 uvm_unlock_fpageq(int s)
1628 {
1629
1630 simple_unlock(&uvm.fpageqlock);
1631 splx(s);
1632 }
1633
1634 /*
1635 * uvm_pagelookup: look up a page
1636 *
1637 * => caller should lock object to keep someone from pulling the page
1638 * out from under it
1639 */
1640
1641 struct vm_page *
1642 uvm_pagelookup(struct uvm_object *obj, voff_t off)
1643 {
1644 struct vm_page *pg;
1645 struct pglist *buck;
1646
1647 buck = &uvm.page_hash[uvm_pagehash(obj,off)];
1648 simple_lock(&uvm.hashlock);
1649 TAILQ_FOREACH(pg, buck, hashq) {
1650 if (pg->uobject == obj && pg->offset == off) {
1651 break;
1652 }
1653 }
1654 simple_unlock(&uvm.hashlock);
1655 KASSERT(pg == NULL || obj->uo_npages != 0);
1656 KASSERT(pg == NULL || (pg->flags & (PG_RELEASED|PG_PAGEOUT)) == 0 ||
1657 (pg->flags & PG_BUSY) != 0);
1658 return(pg);
1659 }
1660
1661 /*
1662 * uvm_pagewire: wire the page, thus removing it from the daemon's grasp
1663 *
1664 * => caller must lock page queues
1665 */
1666
1667 void
1668 uvm_pagewire(struct vm_page *pg)
1669 {
1670 UVM_LOCK_ASSERT_PAGEQ();
1671 #if defined(READAHEAD_STATS)
1672 if ((pg->pqflags & PQ_READAHEAD) != 0) {
1673 uvm_ra_hit.ev_count++;
1674 pg->pqflags &= ~PQ_READAHEAD;
1675 }
1676 #endif /* defined(READAHEAD_STATS) */
1677 if (pg->wire_count == 0) {
1678 uvm_pagedequeue(pg);
1679 uvmexp.wired++;
1680 }
1681 pg->wire_count++;
1682 }
1683
1684 /*
1685 * uvm_pageunwire: unwire the page.
1686 *
1687 * => activate if wire count goes to zero.
1688 * => caller must lock page queues
1689 */
1690
1691 void
1692 uvm_pageunwire(struct vm_page *pg)
1693 {
1694 UVM_LOCK_ASSERT_PAGEQ();
1695 pg->wire_count--;
1696 if (pg->wire_count == 0) {
1697 uvm_pageactivate(pg);
1698 uvmexp.wired--;
1699 }
1700 }
1701
1702 /*
1703 * uvm_pagedeactivate: deactivate page
1704 *
1705 * => caller must lock page queues
1706 * => caller must check to make sure page is not wired
1707 * => object that page belongs to must be locked (so we can adjust pg->flags)
1708 * => caller must clear the reference on the page before calling
1709 */
1710
1711 void
1712 uvm_pagedeactivate(struct vm_page *pg)
1713 {
1714
1715 UVM_LOCK_ASSERT_PAGEQ();
1716 KASSERT(pg->wire_count != 0 || uvmpdpol_pageisqueued_p(pg));
1717 uvmpdpol_pagedeactivate(pg);
1718 }
1719
1720 /*
1721 * uvm_pageactivate: activate page
1722 *
1723 * => caller must lock page queues
1724 */
1725
1726 void
1727 uvm_pageactivate(struct vm_page *pg)
1728 {
1729
1730 UVM_LOCK_ASSERT_PAGEQ();
1731 #if defined(READAHEAD_STATS)
1732 if ((pg->pqflags & PQ_READAHEAD) != 0) {
1733 uvm_ra_hit.ev_count++;
1734 pg->pqflags &= ~PQ_READAHEAD;
1735 }
1736 #endif /* defined(READAHEAD_STATS) */
1737 if (pg->wire_count != 0) {
1738 return;
1739 }
1740 uvmpdpol_pageactivate(pg);
1741 }
1742
1743 /*
1744 * uvm_pagedequeue: remove a page from any paging queue
1745 */
1746
1747 void
1748 uvm_pagedequeue(struct vm_page *pg)
1749 {
1750
1751 #if defined(LOCKDEBUG)
1752 if (uvmpdpol_pageisqueued_p(pg)) {
1753 UVM_LOCK_ASSERT_PAGEQ();
1754 }
1755 #endif /* defined(LOCKDEBUG) */
1756 uvmpdpol_pagedequeue(pg);
1757 }
1758
1759 /*
1760 * uvm_pageenqueue: add a page to a paging queue without activating.
1761 * used where a page is not really demanded (yet). eg. read-ahead
1762 */
1763
1764 void
1765 uvm_pageenqueue(struct vm_page *pg)
1766 {
1767
1768 UVM_LOCK_ASSERT_PAGEQ();
1769 if (pg->wire_count != 0) {
1770 return;
1771 }
1772 uvmpdpol_pageenqueue(pg);
1773 }
1774
1775 /*
1776 * uvm_pagezero: zero fill a page
1777 *
1778 * => if page is part of an object then the object should be locked
1779 * to protect pg->flags.
1780 */
1781
1782 void
1783 uvm_pagezero(struct vm_page *pg)
1784 {
1785 pg->flags &= ~PG_CLEAN;
1786 pmap_zero_page(VM_PAGE_TO_PHYS(pg));
1787 }
1788
1789 /*
1790 * uvm_pagecopy: copy a page
1791 *
1792 * => if page is part of an object then the object should be locked
1793 * to protect pg->flags.
1794 */
1795
1796 void
1797 uvm_pagecopy(struct vm_page *src, struct vm_page *dst)
1798 {
1799
1800 dst->flags &= ~PG_CLEAN;
1801 pmap_copy_page(VM_PAGE_TO_PHYS(src), VM_PAGE_TO_PHYS(dst));
1802 }
1803
1804 /*
1805 * uvm_page_lookup_freelist: look up the free list for the specified page
1806 */
1807
1808 int
1809 uvm_page_lookup_freelist(struct vm_page *pg)
1810 {
1811 int lcv;
1812
1813 lcv = vm_physseg_find(atop(VM_PAGE_TO_PHYS(pg)), NULL);
1814 KASSERT(lcv != -1);
1815 return (vm_physmem[lcv].free_list);
1816 }
Cache object: 23cf27e23d9dc97338939a89f076f387
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