Annotation of src/sys/uvm/uvm_aobj.c, Revision 1.33
1.33 ! mrg 1: /* $NetBSD: uvm_aobj.c,v 1.32 2000/06/26 14:21:17 mrg Exp $ */
1.6 mrg 2:
1.7 chs 3: /*
4: * Copyright (c) 1998 Chuck Silvers, Charles D. Cranor and
5: * Washington University.
6: * All rights reserved.
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 Charles D. Cranor and
19: * Washington University.
20: * 4. The name of the author may not be used to endorse or promote products
21: * derived from this software without specific prior written permission.
22: *
23: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33: *
1.4 mrg 34: * from: Id: uvm_aobj.c,v 1.1.2.5 1998/02/06 05:14:38 chs Exp
35: */
1.7 chs 36: /*
37: * uvm_aobj.c: anonymous memory uvm_object pager
38: *
39: * author: Chuck Silvers <chuq@chuq.com>
40: * started: Jan-1998
41: *
42: * - design mostly from Chuck Cranor
43: */
44:
45:
46:
47: #include "opt_uvmhist.h"
1.1 mrg 48:
49: #include <sys/param.h>
50: #include <sys/systm.h>
51: #include <sys/proc.h>
52: #include <sys/malloc.h>
1.12 thorpej 53: #include <sys/pool.h>
1.27 chs 54: #include <sys/kernel.h>
1.1 mrg 55:
56: #include <uvm/uvm.h>
57:
58: /*
59: * an aobj manages anonymous-memory backed uvm_objects. in addition
60: * to keeping the list of resident pages, it also keeps a list of
61: * allocated swap blocks. depending on the size of the aobj this list
62: * of allocated swap blocks is either stored in an array (small objects)
63: * or in a hash table (large objects).
64: */
65:
66: /*
67: * local structures
68: */
69:
70: /*
71: * for hash tables, we break the address space of the aobj into blocks
72: * of UAO_SWHASH_CLUSTER_SIZE pages. we require the cluster size to
73: * be a power of two.
74: */
75:
76: #define UAO_SWHASH_CLUSTER_SHIFT 4
77: #define UAO_SWHASH_CLUSTER_SIZE (1 << UAO_SWHASH_CLUSTER_SHIFT)
78:
79: /* get the "tag" for this page index */
80: #define UAO_SWHASH_ELT_TAG(PAGEIDX) \
81: ((PAGEIDX) >> UAO_SWHASH_CLUSTER_SHIFT)
82:
83: /* given an ELT and a page index, find the swap slot */
84: #define UAO_SWHASH_ELT_PAGESLOT(ELT, PAGEIDX) \
85: ((ELT)->slots[(PAGEIDX) & (UAO_SWHASH_CLUSTER_SIZE - 1)])
86:
87: /* given an ELT, return its pageidx base */
88: #define UAO_SWHASH_ELT_PAGEIDX_BASE(ELT) \
89: ((ELT)->tag << UAO_SWHASH_CLUSTER_SHIFT)
90:
91: /*
92: * the swhash hash function
93: */
94: #define UAO_SWHASH_HASH(AOBJ, PAGEIDX) \
95: (&(AOBJ)->u_swhash[(((PAGEIDX) >> UAO_SWHASH_CLUSTER_SHIFT) \
96: & (AOBJ)->u_swhashmask)])
97:
98: /*
99: * the swhash threshhold determines if we will use an array or a
100: * hash table to store the list of allocated swap blocks.
101: */
102:
103: #define UAO_SWHASH_THRESHOLD (UAO_SWHASH_CLUSTER_SIZE * 4)
104: #define UAO_USES_SWHASH(AOBJ) \
105: ((AOBJ)->u_pages > UAO_SWHASH_THRESHOLD) /* use hash? */
106:
107: /*
1.3 chs 108: * the number of buckets in a swhash, with an upper bound
1.1 mrg 109: */
110: #define UAO_SWHASH_MAXBUCKETS 256
111: #define UAO_SWHASH_BUCKETS(AOBJ) \
112: (min((AOBJ)->u_pages >> UAO_SWHASH_CLUSTER_SHIFT, \
113: UAO_SWHASH_MAXBUCKETS))
114:
115:
116: /*
117: * uao_swhash_elt: when a hash table is being used, this structure defines
118: * the format of an entry in the bucket list.
119: */
120:
121: struct uao_swhash_elt {
1.5 mrg 122: LIST_ENTRY(uao_swhash_elt) list; /* the hash list */
1.28 kleink 123: voff_t tag; /* our 'tag' */
1.5 mrg 124: int count; /* our number of active slots */
125: int slots[UAO_SWHASH_CLUSTER_SIZE]; /* the slots */
1.1 mrg 126: };
127:
128: /*
129: * uao_swhash: the swap hash table structure
130: */
131:
132: LIST_HEAD(uao_swhash, uao_swhash_elt);
133:
1.12 thorpej 134: /*
135: * uao_swhash_elt_pool: pool of uao_swhash_elt structures
136: */
137:
138: struct pool uao_swhash_elt_pool;
1.1 mrg 139:
140: /*
141: * uvm_aobj: the actual anon-backed uvm_object
142: *
143: * => the uvm_object is at the top of the structure, this allows
144: * (struct uvm_device *) == (struct uvm_object *)
145: * => only one of u_swslots and u_swhash is used in any given aobj
146: */
147:
148: struct uvm_aobj {
1.5 mrg 149: struct uvm_object u_obj; /* has: lock, pgops, memq, #pages, #refs */
1.11 drochner 150: int u_pages; /* number of pages in entire object */
1.5 mrg 151: int u_flags; /* the flags (see uvm_aobj.h) */
152: int *u_swslots; /* array of offset->swapslot mappings */
153: /*
154: * hashtable of offset->swapslot mappings
155: * (u_swhash is an array of bucket heads)
156: */
157: struct uao_swhash *u_swhash;
158: u_long u_swhashmask; /* mask for hashtable */
159: LIST_ENTRY(uvm_aobj) u_list; /* global list of aobjs */
1.1 mrg 160: };
161:
162: /*
1.12 thorpej 163: * uvm_aobj_pool: pool of uvm_aobj structures
164: */
165:
166: struct pool uvm_aobj_pool;
167:
168: /*
1.1 mrg 169: * local functions
170: */
171:
172: static struct uao_swhash_elt *uao_find_swhash_elt __P((struct uvm_aobj *,
173: int, boolean_t));
1.28 kleink 174: static int uao_find_swslot __P((struct uvm_aobj *, int));
175: static boolean_t uao_flush __P((struct uvm_object *,
176: voff_t, voff_t, int));
1.1 mrg 177: static void uao_free __P((struct uvm_aobj *));
1.28 kleink 178: static int uao_get __P((struct uvm_object *, voff_t,
179: vm_page_t *, int *, int,
1.1 mrg 180: vm_prot_t, int, int));
1.28 kleink 181: static boolean_t uao_releasepg __P((struct vm_page *,
1.1 mrg 182: struct vm_page **));
1.27 chs 183: static boolean_t uao_pagein __P((struct uvm_aobj *, int, int));
184: static boolean_t uao_pagein_page __P((struct uvm_aobj *, int));
1.1 mrg 185:
186:
187:
188: /*
189: * aobj_pager
190: *
191: * note that some functions (e.g. put) are handled elsewhere
192: */
193:
194: struct uvm_pagerops aobj_pager = {
1.27 chs 195: NULL, /* init */
1.5 mrg 196: uao_reference, /* reference */
197: uao_detach, /* detach */
198: NULL, /* fault */
199: uao_flush, /* flush */
200: uao_get, /* get */
201: NULL, /* asyncget */
202: NULL, /* put (done by pagedaemon) */
203: NULL, /* cluster */
204: NULL, /* mk_pcluster */
205: NULL, /* aiodone */
206: uao_releasepg /* releasepg */
1.1 mrg 207: };
208:
209: /*
210: * uao_list: global list of active aobjs, locked by uao_list_lock
211: */
212:
213: static LIST_HEAD(aobjlist, uvm_aobj) uao_list;
214: static simple_lock_data_t uao_list_lock;
215:
216:
217: /*
218: * functions
219: */
220:
221: /*
222: * hash table/array related functions
223: */
224:
225: /*
226: * uao_find_swhash_elt: find (or create) a hash table entry for a page
227: * offset.
228: *
229: * => the object should be locked by the caller
230: */
231:
1.5 mrg 232: static struct uao_swhash_elt *
233: uao_find_swhash_elt(aobj, pageidx, create)
234: struct uvm_aobj *aobj;
235: int pageidx;
236: boolean_t create;
237: {
238: struct uao_swhash *swhash;
239: struct uao_swhash_elt *elt;
1.28 kleink 240: voff_t page_tag;
1.1 mrg 241:
1.5 mrg 242: swhash = UAO_SWHASH_HASH(aobj, pageidx); /* first hash to get bucket */
243: page_tag = UAO_SWHASH_ELT_TAG(pageidx); /* tag to search for */
1.1 mrg 244:
1.5 mrg 245: /*
246: * now search the bucket for the requested tag
247: */
248: for (elt = swhash->lh_first; elt != NULL; elt = elt->list.le_next) {
249: if (elt->tag == page_tag)
250: return(elt);
251: }
252:
253: /* fail now if we are not allowed to create a new entry in the bucket */
254: if (!create)
255: return NULL;
256:
257:
258: /*
1.12 thorpej 259: * allocate a new entry for the bucket and init/insert it in
1.5 mrg 260: */
1.12 thorpej 261: elt = pool_get(&uao_swhash_elt_pool, PR_WAITOK);
1.5 mrg 262: LIST_INSERT_HEAD(swhash, elt, list);
263: elt->tag = page_tag;
264: elt->count = 0;
1.9 perry 265: memset(elt->slots, 0, sizeof(elt->slots));
1.5 mrg 266:
267: return(elt);
1.1 mrg 268: }
269:
270: /*
271: * uao_find_swslot: find the swap slot number for an aobj/pageidx
272: *
273: * => object must be locked by caller
274: */
1.5 mrg 275: __inline static int
276: uao_find_swslot(aobj, pageidx)
277: struct uvm_aobj *aobj;
1.11 drochner 278: int pageidx;
1.1 mrg 279: {
280:
1.5 mrg 281: /*
282: * if noswap flag is set, then we never return a slot
283: */
1.1 mrg 284:
1.5 mrg 285: if (aobj->u_flags & UAO_FLAG_NOSWAP)
286: return(0);
1.1 mrg 287:
1.5 mrg 288: /*
289: * if hashing, look in hash table.
290: */
1.1 mrg 291:
1.5 mrg 292: if (UAO_USES_SWHASH(aobj)) {
293: struct uao_swhash_elt *elt =
294: uao_find_swhash_elt(aobj, pageidx, FALSE);
295:
296: if (elt)
297: return(UAO_SWHASH_ELT_PAGESLOT(elt, pageidx));
298: else
1.31 thorpej 299: return(0);
1.5 mrg 300: }
1.1 mrg 301:
1.5 mrg 302: /*
303: * otherwise, look in the array
304: */
305: return(aobj->u_swslots[pageidx]);
1.1 mrg 306: }
307:
308: /*
309: * uao_set_swslot: set the swap slot for a page in an aobj.
310: *
311: * => setting a slot to zero frees the slot
312: * => object must be locked by caller
313: */
1.5 mrg 314: int
315: uao_set_swslot(uobj, pageidx, slot)
316: struct uvm_object *uobj;
317: int pageidx, slot;
318: {
319: struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
320: int oldslot;
321: UVMHIST_FUNC("uao_set_swslot"); UVMHIST_CALLED(pdhist);
322: UVMHIST_LOG(pdhist, "aobj %p pageidx %d slot %d",
323: aobj, pageidx, slot, 0);
1.1 mrg 324:
1.5 mrg 325: /*
326: * if noswap flag is set, then we can't set a slot
327: */
1.1 mrg 328:
1.5 mrg 329: if (aobj->u_flags & UAO_FLAG_NOSWAP) {
1.1 mrg 330:
1.5 mrg 331: if (slot == 0)
332: return(0); /* a clear is ok */
1.1 mrg 333:
1.5 mrg 334: /* but a set is not */
335: printf("uao_set_swslot: uobj = %p\n", uobj);
336: panic("uao_set_swslot: attempt to set a slot on a NOSWAP object");
337: }
1.1 mrg 338:
1.5 mrg 339: /*
340: * are we using a hash table? if so, add it in the hash.
341: */
1.1 mrg 342:
1.5 mrg 343: if (UAO_USES_SWHASH(aobj)) {
1.12 thorpej 344: /*
345: * Avoid allocating an entry just to free it again if
346: * the page had not swap slot in the first place, and
347: * we are freeing.
348: */
1.5 mrg 349: struct uao_swhash_elt *elt =
1.12 thorpej 350: uao_find_swhash_elt(aobj, pageidx, slot ? TRUE : FALSE);
351: if (elt == NULL) {
352: #ifdef DIAGNOSTIC
353: if (slot)
354: panic("uao_set_swslot: didn't create elt");
355: #endif
356: return (0);
357: }
1.5 mrg 358:
359: oldslot = UAO_SWHASH_ELT_PAGESLOT(elt, pageidx);
360: UAO_SWHASH_ELT_PAGESLOT(elt, pageidx) = slot;
361:
362: /*
363: * now adjust the elt's reference counter and free it if we've
364: * dropped it to zero.
365: */
366:
367: /* an allocation? */
368: if (slot) {
369: if (oldslot == 0)
370: elt->count++;
371: } else { /* freeing slot ... */
372: if (oldslot) /* to be safe */
373: elt->count--;
374:
375: if (elt->count == 0) {
376: LIST_REMOVE(elt, list);
1.12 thorpej 377: pool_put(&uao_swhash_elt_pool, elt);
1.5 mrg 378: }
379: }
380:
381: } else {
382: /* we are using an array */
383: oldslot = aobj->u_swslots[pageidx];
384: aobj->u_swslots[pageidx] = slot;
385: }
386: return (oldslot);
1.1 mrg 387: }
388:
389: /*
390: * end of hash/array functions
391: */
392:
393: /*
394: * uao_free: free all resources held by an aobj, and then free the aobj
395: *
396: * => the aobj should be dead
397: */
398: static void
399: uao_free(aobj)
1.5 mrg 400: struct uvm_aobj *aobj;
1.1 mrg 401: {
402:
1.27 chs 403: simple_unlock(&aobj->u_obj.vmobjlock);
404:
1.5 mrg 405: if (UAO_USES_SWHASH(aobj)) {
406: int i, hashbuckets = aobj->u_swhashmask + 1;
1.1 mrg 407:
1.5 mrg 408: /*
409: * free the swslots from each hash bucket,
410: * then the hash bucket, and finally the hash table itself.
411: */
412: for (i = 0; i < hashbuckets; i++) {
413: struct uao_swhash_elt *elt, *next;
414:
1.27 chs 415: for (elt = LIST_FIRST(&aobj->u_swhash[i]);
416: elt != NULL;
417: elt = next) {
1.5 mrg 418: int j;
419:
1.27 chs 420: for (j = 0; j < UAO_SWHASH_CLUSTER_SIZE; j++) {
1.5 mrg 421: int slot = elt->slots[j];
422:
1.18 chs 423: if (slot) {
1.5 mrg 424: uvm_swap_free(slot, 1);
1.18 chs 425:
426: /*
427: * this page is no longer
428: * only in swap.
429: */
430: simple_lock(&uvm.swap_data_lock);
431: uvmexp.swpgonly--;
432: simple_unlock(&uvm.swap_data_lock);
433: }
1.5 mrg 434: }
435:
1.27 chs 436: next = LIST_NEXT(elt, list);
1.12 thorpej 437: pool_put(&uao_swhash_elt_pool, elt);
1.5 mrg 438: }
439: }
440: FREE(aobj->u_swhash, M_UVMAOBJ);
441: } else {
442: int i;
443:
444: /*
445: * free the array
446: */
447:
1.27 chs 448: for (i = 0; i < aobj->u_pages; i++) {
1.5 mrg 449: int slot = aobj->u_swslots[i];
450:
1.18 chs 451: if (slot) {
1.5 mrg 452: uvm_swap_free(slot, 1);
1.18 chs 453:
454: /* this page is no longer only in swap. */
455: simple_lock(&uvm.swap_data_lock);
456: uvmexp.swpgonly--;
457: simple_unlock(&uvm.swap_data_lock);
458: }
1.5 mrg 459: }
460: FREE(aobj->u_swslots, M_UVMAOBJ);
1.1 mrg 461: }
462:
1.5 mrg 463: /*
464: * finally free the aobj itself
465: */
1.12 thorpej 466: pool_put(&uvm_aobj_pool, aobj);
1.1 mrg 467: }
468:
469: /*
470: * pager functions
471: */
472:
473: /*
474: * uao_create: create an aobj of the given size and return its uvm_object.
475: *
476: * => for normal use, flags are always zero
477: * => for the kernel object, the flags are:
478: * UAO_FLAG_KERNOBJ - allocate the kernel object (can only happen once)
479: * UAO_FLAG_KERNSWAP - enable swapping of kernel object (" ")
480: */
1.5 mrg 481: struct uvm_object *
482: uao_create(size, flags)
1.10 eeh 483: vsize_t size;
1.5 mrg 484: int flags;
485: {
1.27 chs 486: static struct uvm_aobj kernel_object_store; /* home of kernel_object */
1.5 mrg 487: static int kobj_alloced = 0; /* not allocated yet */
1.15 chs 488: int pages = round_page(size) >> PAGE_SHIFT;
1.5 mrg 489: struct uvm_aobj *aobj;
1.1 mrg 490:
1.5 mrg 491: /*
1.27 chs 492: * malloc a new aobj unless we are asked for the kernel object
493: */
1.5 mrg 494: if (flags & UAO_FLAG_KERNOBJ) { /* want kernel object? */
495: if (kobj_alloced)
496: panic("uao_create: kernel object already allocated");
497:
498: aobj = &kernel_object_store;
499: aobj->u_pages = pages;
500: aobj->u_flags = UAO_FLAG_NOSWAP; /* no swap to start */
501: /* we are special, we never die */
502: aobj->u_obj.uo_refs = UVM_OBJ_KERN;
503: kobj_alloced = UAO_FLAG_KERNOBJ;
504: } else if (flags & UAO_FLAG_KERNSWAP) {
505: aobj = &kernel_object_store;
506: if (kobj_alloced != UAO_FLAG_KERNOBJ)
507: panic("uao_create: asked to enable swap on kernel object");
508: kobj_alloced = UAO_FLAG_KERNSWAP;
509: } else { /* normal object */
1.12 thorpej 510: aobj = pool_get(&uvm_aobj_pool, PR_WAITOK);
1.5 mrg 511: aobj->u_pages = pages;
512: aobj->u_flags = 0; /* normal object */
513: aobj->u_obj.uo_refs = 1; /* start with 1 reference */
514: }
1.1 mrg 515:
1.5 mrg 516: /*
517: * allocate hash/array if necessary
518: *
519: * note: in the KERNSWAP case no need to worry about locking since
520: * we are still booting we should be the only thread around.
521: */
522: if (flags == 0 || (flags & UAO_FLAG_KERNSWAP) != 0) {
523: int mflags = (flags & UAO_FLAG_KERNSWAP) != 0 ?
524: M_NOWAIT : M_WAITOK;
525:
526: /* allocate hash table or array depending on object size */
1.27 chs 527: if (UAO_USES_SWHASH(aobj)) {
1.5 mrg 528: aobj->u_swhash = hashinit(UAO_SWHASH_BUCKETS(aobj),
529: M_UVMAOBJ, mflags, &aobj->u_swhashmask);
530: if (aobj->u_swhash == NULL)
531: panic("uao_create: hashinit swhash failed");
532: } else {
533: MALLOC(aobj->u_swslots, int *, pages * sizeof(int),
534: M_UVMAOBJ, mflags);
535: if (aobj->u_swslots == NULL)
536: panic("uao_create: malloc swslots failed");
1.9 perry 537: memset(aobj->u_swslots, 0, pages * sizeof(int));
1.5 mrg 538: }
539:
540: if (flags) {
541: aobj->u_flags &= ~UAO_FLAG_NOSWAP; /* clear noswap */
542: return(&aobj->u_obj);
543: /* done! */
544: }
545: }
546:
547: /*
548: * init aobj fields
549: */
550: simple_lock_init(&aobj->u_obj.vmobjlock);
551: aobj->u_obj.pgops = &aobj_pager;
552: TAILQ_INIT(&aobj->u_obj.memq);
553: aobj->u_obj.uo_npages = 0;
1.1 mrg 554:
1.5 mrg 555: /*
556: * now that aobj is ready, add it to the global list
557: */
558: simple_lock(&uao_list_lock);
559: LIST_INSERT_HEAD(&uao_list, aobj, u_list);
560: simple_unlock(&uao_list_lock);
561:
562: /*
563: * done!
564: */
565: return(&aobj->u_obj);
1.1 mrg 566: }
567:
568:
569:
570: /*
571: * uao_init: set up aobj pager subsystem
572: *
573: * => called at boot time from uvm_pager_init()
574: */
1.27 chs 575: void
1.5 mrg 576: uao_init()
577: {
1.12 thorpej 578: static int uao_initialized;
579:
580: if (uao_initialized)
581: return;
582: uao_initialized = TRUE;
1.1 mrg 583:
1.5 mrg 584: LIST_INIT(&uao_list);
585: simple_lock_init(&uao_list_lock);
1.12 thorpej 586:
1.14 thorpej 587: /*
588: * NOTE: Pages fror this pool must not come from a pageable
589: * kernel map!
590: */
1.12 thorpej 591: pool_init(&uao_swhash_elt_pool, sizeof(struct uao_swhash_elt),
1.13 thorpej 592: 0, 0, 0, "uaoeltpl", 0, NULL, NULL, M_UVMAOBJ);
1.12 thorpej 593:
594: pool_init(&uvm_aobj_pool, sizeof(struct uvm_aobj), 0, 0, 0,
595: "aobjpl", 0,
596: pool_page_alloc_nointr, pool_page_free_nointr, M_UVMAOBJ);
1.1 mrg 597: }
598:
599: /*
600: * uao_reference: add a ref to an aobj
601: *
1.27 chs 602: * => aobj must be unlocked
603: * => just lock it and call the locked version
1.1 mrg 604: */
1.5 mrg 605: void
606: uao_reference(uobj)
607: struct uvm_object *uobj;
1.1 mrg 608: {
1.27 chs 609: simple_lock(&uobj->vmobjlock);
610: uao_reference_locked(uobj);
611: simple_unlock(&uobj->vmobjlock);
612: }
613:
614: /*
615: * uao_reference_locked: add a ref to an aobj that is already locked
616: *
617: * => aobj must be locked
618: * this needs to be separate from the normal routine
619: * since sometimes we need to add a reference to an aobj when
620: * it's already locked.
621: */
622: void
623: uao_reference_locked(uobj)
624: struct uvm_object *uobj;
625: {
1.5 mrg 626: UVMHIST_FUNC("uao_reference"); UVMHIST_CALLED(maphist);
1.1 mrg 627:
1.5 mrg 628: /*
629: * kernel_object already has plenty of references, leave it alone.
630: */
1.1 mrg 631:
1.20 thorpej 632: if (UVM_OBJ_IS_KERN_OBJECT(uobj))
1.5 mrg 633: return;
1.1 mrg 634:
1.5 mrg 635: uobj->uo_refs++; /* bump! */
636: UVMHIST_LOG(maphist, "<- done (uobj=0x%x, ref = %d)",
1.27 chs 637: uobj, uobj->uo_refs,0,0);
1.1 mrg 638: }
639:
1.27 chs 640:
1.1 mrg 641: /*
642: * uao_detach: drop a reference to an aobj
643: *
1.27 chs 644: * => aobj must be unlocked
645: * => just lock it and call the locked version
1.1 mrg 646: */
1.5 mrg 647: void
648: uao_detach(uobj)
649: struct uvm_object *uobj;
650: {
1.27 chs 651: simple_lock(&uobj->vmobjlock);
652: uao_detach_locked(uobj);
653: }
654:
655:
656: /*
657: * uao_detach_locked: drop a reference to an aobj
658: *
659: * => aobj must be locked, and is unlocked (or freed) upon return.
660: * this needs to be separate from the normal routine
661: * since sometimes we need to detach from an aobj when
662: * it's already locked.
663: */
664: void
665: uao_detach_locked(uobj)
666: struct uvm_object *uobj;
667: {
1.5 mrg 668: struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
669: struct vm_page *pg;
670: boolean_t busybody;
671: UVMHIST_FUNC("uao_detach"); UVMHIST_CALLED(maphist);
1.1 mrg 672:
1.5 mrg 673: /*
674: * detaching from kernel_object is a noop.
675: */
1.27 chs 676: if (UVM_OBJ_IS_KERN_OBJECT(uobj)) {
677: simple_unlock(&uobj->vmobjlock);
1.5 mrg 678: return;
1.27 chs 679: }
1.5 mrg 680:
681: UVMHIST_LOG(maphist," (uobj=0x%x) ref=%d", uobj,uobj->uo_refs,0,0);
682: uobj->uo_refs--; /* drop ref! */
683: if (uobj->uo_refs) { /* still more refs? */
684: simple_unlock(&uobj->vmobjlock);
685: UVMHIST_LOG(maphist, "<- done (rc>0)", 0,0,0,0);
686: return;
687: }
688:
689: /*
690: * remove the aobj from the global list.
691: */
692: simple_lock(&uao_list_lock);
693: LIST_REMOVE(aobj, u_list);
694: simple_unlock(&uao_list_lock);
695:
696: /*
1.27 chs 697: * free all the pages that aren't PG_BUSY,
698: * mark for release any that are.
1.5 mrg 699: */
700: busybody = FALSE;
1.27 chs 701: for (pg = TAILQ_FIRST(&uobj->memq);
702: pg != NULL;
703: pg = TAILQ_NEXT(pg, listq)) {
1.5 mrg 704: if (pg->flags & PG_BUSY) {
705: pg->flags |= PG_RELEASED;
706: busybody = TRUE;
707: continue;
708: }
709:
710: /* zap the mappings, free the swap slot, free the page */
1.26 chs 711: pmap_page_protect(pg, VM_PROT_NONE);
1.18 chs 712: uao_dropswap(&aobj->u_obj, pg->offset >> PAGE_SHIFT);
1.5 mrg 713: uvm_lock_pageq();
714: uvm_pagefree(pg);
715: uvm_unlock_pageq();
716: }
1.1 mrg 717:
1.5 mrg 718: /*
719: * if we found any busy pages, we're done for now.
720: * mark the aobj for death, releasepg will finish up for us.
721: */
722: if (busybody) {
723: aobj->u_flags |= UAO_FLAG_KILLME;
724: simple_unlock(&aobj->u_obj.vmobjlock);
725: return;
726: }
1.1 mrg 727:
1.5 mrg 728: /*
729: * finally, free the rest.
730: */
731: uao_free(aobj);
732: }
1.1 mrg 733:
734: /*
1.22 thorpej 735: * uao_flush: "flush" pages out of a uvm object
736: *
737: * => object should be locked by caller. we may _unlock_ the object
738: * if (and only if) we need to clean a page (PGO_CLEANIT).
739: * XXXJRT Currently, however, we don't. In the case of cleaning
740: * XXXJRT a page, we simply just deactivate it. Should probably
741: * XXXJRT handle this better, in the future (although "flushing"
742: * XXXJRT anonymous memory isn't terribly important).
743: * => if PGO_CLEANIT is not set, then we will neither unlock the object
744: * or block.
745: * => if PGO_ALLPAGE is set, then all pages in the object are valid targets
746: * for flushing.
747: * => NOTE: we rely on the fact that the object's memq is a TAILQ and
748: * that new pages are inserted on the tail end of the list. thus,
749: * we can make a complete pass through the object in one go by starting
750: * at the head and working towards the tail (new pages are put in
751: * front of us).
752: * => NOTE: we are allowed to lock the page queues, so the caller
753: * must not be holding the lock on them [e.g. pagedaemon had
754: * better not call us with the queues locked]
755: * => we return TRUE unless we encountered some sort of I/O error
756: * XXXJRT currently never happens, as we never directly initiate
757: * XXXJRT I/O
758: *
759: * comment on "cleaning" object and PG_BUSY pages:
760: * this routine is holding the lock on the object. the only time
761: * that is can run into a PG_BUSY page that it does not own is if
762: * some other process has started I/O on the page (e.g. either
763: * a pagein or a pageout). if the PG_BUSY page is being paged
764: * in, then it can not be dirty (!PG_CLEAN) because no one has
765: * had a change to modify it yet. if the PG_BUSY page is being
766: * paged out then it means that someone else has already started
767: * cleaning the page for us (how nice!). in this case, if we
768: * have syncio specified, then after we make our pass through the
769: * object we need to wait for the other PG_BUSY pages to clear
770: * off (i.e. we need to do an iosync). also note that once a
771: * page is PG_BUSY is must stary in its object until it is un-busyed.
772: * XXXJRT We never actually do this, as we are "flushing" anonymous
773: * XXXJRT memory, which doesn't have persistent backing store.
774: *
775: * note on page traversal:
776: * we can traverse the pages in an object either by going down the
777: * linked list in "uobj->memq", or we can go over the address range
778: * by page doing hash table lookups for each address. depending
779: * on how many pages are in the object it may be cheaper to do one
780: * or the other. we set "by_list" to true if we are using memq.
781: * if the cost of a hash lookup was equal to the cost of the list
782: * traversal we could compare the number of pages in the start->stop
783: * range to the total number of pages in the object. however, it
784: * seems that a hash table lookup is more expensive than the linked
785: * list traversal, so we multiply the number of pages in the
786: * start->stop range by a penalty which we define below.
1.1 mrg 787: */
1.22 thorpej 788:
789: #define UAO_HASH_PENALTY 4 /* XXX: a guess */
790:
1.5 mrg 791: boolean_t
1.22 thorpej 792: uao_flush(uobj, start, stop, flags)
1.5 mrg 793: struct uvm_object *uobj;
1.28 kleink 794: voff_t start, stop;
1.5 mrg 795: int flags;
796: {
1.22 thorpej 797: struct uvm_aobj *aobj = (struct uvm_aobj *) uobj;
798: struct vm_page *pp, *ppnext;
799: boolean_t retval, by_list;
1.28 kleink 800: voff_t curoff;
1.22 thorpej 801: UVMHIST_FUNC("uao_flush"); UVMHIST_CALLED(maphist);
802:
803: curoff = 0; /* XXX: shut up gcc */
804:
805: retval = TRUE; /* default to success */
806:
807: if (flags & PGO_ALLPAGES) {
808: start = 0;
809: stop = aobj->u_pages << PAGE_SHIFT;
810: by_list = TRUE; /* always go by the list */
811: } else {
812: start = trunc_page(start);
813: stop = round_page(stop);
814: if (stop > (aobj->u_pages << PAGE_SHIFT)) {
815: printf("uao_flush: strange, got an out of range "
816: "flush (fixed)\n");
817: stop = aobj->u_pages << PAGE_SHIFT;
818: }
819: by_list = (uobj->uo_npages <=
820: ((stop - start) >> PAGE_SHIFT) * UAO_HASH_PENALTY);
821: }
822:
823: UVMHIST_LOG(maphist,
824: " flush start=0x%lx, stop=0x%x, by_list=%d, flags=0x%x",
825: start, stop, by_list, flags);
1.1 mrg 826:
1.5 mrg 827: /*
1.22 thorpej 828: * Don't need to do any work here if we're not freeing
829: * or deactivating pages.
830: */
831: if ((flags & (PGO_DEACTIVATE|PGO_FREE)) == 0) {
832: UVMHIST_LOG(maphist,
833: "<- done (no work to do)",0,0,0,0);
834: return (retval);
835: }
836:
1.5 mrg 837: /*
1.22 thorpej 838: * now do it. note: we must update ppnext in the body of loop or we
839: * will get stuck. we need to use ppnext because we may free "pp"
840: * before doing the next loop.
1.21 thorpej 841: */
1.22 thorpej 842:
843: if (by_list) {
844: pp = uobj->memq.tqh_first;
845: } else {
846: curoff = start;
847: pp = uvm_pagelookup(uobj, curoff);
848: }
849:
850: ppnext = NULL; /* XXX: shut up gcc */
851: uvm_lock_pageq(); /* page queues locked */
852:
853: /* locked: both page queues and uobj */
854: for ( ; (by_list && pp != NULL) ||
855: (!by_list && curoff < stop) ; pp = ppnext) {
856: if (by_list) {
857: ppnext = pp->listq.tqe_next;
858:
859: /* range check */
860: if (pp->offset < start || pp->offset >= stop)
861: continue;
862: } else {
863: curoff += PAGE_SIZE;
864: if (curoff < stop)
865: ppnext = uvm_pagelookup(uobj, curoff);
866:
867: /* null check */
868: if (pp == NULL)
869: continue;
870: }
871:
872: switch (flags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)) {
873: /*
874: * XXX In these first 3 cases, we always just
875: * XXX deactivate the page. We may want to
876: * XXX handle the different cases more specifically
877: * XXX in the future.
878: */
879: case PGO_CLEANIT|PGO_FREE:
880: case PGO_CLEANIT|PGO_DEACTIVATE:
881: case PGO_DEACTIVATE:
1.25 thorpej 882: deactivate_it:
1.22 thorpej 883: /* skip the page if it's loaned or wired */
884: if (pp->loan_count != 0 ||
885: pp->wire_count != 0)
886: continue;
887:
888: /* zap all mappings for the page. */
1.26 chs 889: pmap_page_protect(pp, VM_PROT_NONE);
1.22 thorpej 890:
891: /* ...and deactivate the page. */
892: uvm_pagedeactivate(pp);
893:
894: continue;
895:
896: case PGO_FREE:
1.25 thorpej 897: /*
898: * If there are multiple references to
899: * the object, just deactivate the page.
900: */
901: if (uobj->uo_refs > 1)
902: goto deactivate_it;
903:
1.22 thorpej 904: /* XXX skip the page if it's loaned or wired */
905: if (pp->loan_count != 0 ||
906: pp->wire_count != 0)
907: continue;
908:
909: /*
910: * mark the page as released if its busy.
911: */
912: if (pp->flags & PG_BUSY) {
913: pp->flags |= PG_RELEASED;
914: continue;
915: }
916:
917: /* zap all mappings for the page. */
1.26 chs 918: pmap_page_protect(pp, VM_PROT_NONE);
1.22 thorpej 919:
920: uao_dropswap(uobj, pp->offset >> PAGE_SHIFT);
921: uvm_pagefree(pp);
922:
923: continue;
924:
925: default:
926: panic("uao_flush: weird flags");
927: }
928: #ifdef DIAGNOSTIC
929: panic("uao_flush: unreachable code");
930: #endif
931: }
932:
933: uvm_unlock_pageq();
934:
935: UVMHIST_LOG(maphist,
936: "<- done, rv=%d",retval,0,0,0);
937: return (retval);
1.1 mrg 938: }
939:
940: /*
941: * uao_get: fetch me a page
942: *
943: * we have three cases:
944: * 1: page is resident -> just return the page.
945: * 2: page is zero-fill -> allocate a new page and zero it.
946: * 3: page is swapped out -> fetch the page from swap.
947: *
948: * cases 1 and 2 can be handled with PGO_LOCKED, case 3 cannot.
949: * so, if the "center" page hits case 3 (or any page, with PGO_ALLPAGES),
950: * then we will need to return VM_PAGER_UNLOCK.
951: *
952: * => prefer map unlocked (not required)
953: * => object must be locked! we will _unlock_ it before starting any I/O.
954: * => flags: PGO_ALLPAGES: get all of the pages
955: * PGO_LOCKED: fault data structures are locked
956: * => NOTE: offset is the offset of pps[0], _NOT_ pps[centeridx]
957: * => NOTE: caller must check for released pages!!
958: */
1.5 mrg 959: static int
960: uao_get(uobj, offset, pps, npagesp, centeridx, access_type, advice, flags)
961: struct uvm_object *uobj;
1.28 kleink 962: voff_t offset;
1.5 mrg 963: struct vm_page **pps;
964: int *npagesp;
965: int centeridx, advice, flags;
966: vm_prot_t access_type;
967: {
968: struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
1.28 kleink 969: voff_t current_offset;
1.5 mrg 970: vm_page_t ptmp;
1.27 chs 971: int lcv, gotpages, maxpages, swslot, rv, pageidx;
1.5 mrg 972: boolean_t done;
973: UVMHIST_FUNC("uao_get"); UVMHIST_CALLED(pdhist);
974:
1.27 chs 975: UVMHIST_LOG(pdhist, "aobj=%p offset=%d, flags=%d",
976: aobj, offset, flags,0);
1.5 mrg 977:
978: /*
979: * get number of pages
980: */
981: maxpages = *npagesp;
982:
983: /*
984: * step 1: handled the case where fault data structures are locked.
985: */
1.1 mrg 986:
1.5 mrg 987: if (flags & PGO_LOCKED) {
988: /*
989: * step 1a: get pages that are already resident. only do
990: * this if the data structures are locked (i.e. the first
991: * time through).
992: */
993:
994: done = TRUE; /* be optimistic */
995: gotpages = 0; /* # of pages we got so far */
996:
997: for (lcv = 0, current_offset = offset ; lcv < maxpages ;
998: lcv++, current_offset += PAGE_SIZE) {
999: /* do we care about this page? if not, skip it */
1000: if (pps[lcv] == PGO_DONTCARE)
1001: continue;
1002:
1003: ptmp = uvm_pagelookup(uobj, current_offset);
1004:
1005: /*
1.30 thorpej 1006: * if page is new, attempt to allocate the page,
1007: * zero-fill'd.
1.5 mrg 1008: */
1009: if (ptmp == NULL && uao_find_swslot(aobj,
1.15 chs 1010: current_offset >> PAGE_SHIFT) == 0) {
1.5 mrg 1011: ptmp = uvm_pagealloc(uobj, current_offset,
1.30 thorpej 1012: NULL, UVM_PGA_ZERO);
1.5 mrg 1013: if (ptmp) {
1014: /* new page */
1015: ptmp->flags &= ~(PG_BUSY|PG_FAKE);
1016: ptmp->pqflags |= PQ_AOBJ;
1017: UVM_PAGE_OWN(ptmp, NULL);
1018: }
1019: }
1020:
1021: /*
1022: * to be useful must get a non-busy, non-released page
1023: */
1024: if (ptmp == NULL ||
1025: (ptmp->flags & (PG_BUSY|PG_RELEASED)) != 0) {
1026: if (lcv == centeridx ||
1027: (flags & PGO_ALLPAGES) != 0)
1028: /* need to do a wait or I/O! */
1029: done = FALSE;
1030: continue;
1031: }
1032:
1033: /*
1034: * useful page: busy/lock it and plug it in our
1035: * result array
1036: */
1037: /* caller must un-busy this page */
1038: ptmp->flags |= PG_BUSY;
1039: UVM_PAGE_OWN(ptmp, "uao_get1");
1040: pps[lcv] = ptmp;
1041: gotpages++;
1042:
1043: } /* "for" lcv loop */
1044:
1045: /*
1046: * step 1b: now we've either done everything needed or we
1047: * to unlock and do some waiting or I/O.
1048: */
1049:
1050: UVMHIST_LOG(pdhist, "<- done (done=%d)", done, 0,0,0);
1051:
1052: *npagesp = gotpages;
1053: if (done)
1054: /* bingo! */
1055: return(VM_PAGER_OK);
1056: else
1057: /* EEK! Need to unlock and I/O */
1058: return(VM_PAGER_UNLOCK);
1.1 mrg 1059: }
1060:
1.5 mrg 1061: /*
1062: * step 2: get non-resident or busy pages.
1063: * object is locked. data structures are unlocked.
1064: */
1065:
1066: for (lcv = 0, current_offset = offset ; lcv < maxpages ;
1067: lcv++, current_offset += PAGE_SIZE) {
1.27 chs 1068:
1.5 mrg 1069: /*
1070: * - skip over pages we've already gotten or don't want
1071: * - skip over pages we don't _have_ to get
1072: */
1.27 chs 1073:
1.5 mrg 1074: if (pps[lcv] != NULL ||
1075: (lcv != centeridx && (flags & PGO_ALLPAGES) == 0))
1076: continue;
1077:
1.27 chs 1078: pageidx = current_offset >> PAGE_SHIFT;
1079:
1.5 mrg 1080: /*
1081: * we have yet to locate the current page (pps[lcv]). we
1082: * first look for a page that is already at the current offset.
1083: * if we find a page, we check to see if it is busy or
1084: * released. if that is the case, then we sleep on the page
1085: * until it is no longer busy or released and repeat the lookup.
1086: * if the page we found is neither busy nor released, then we
1087: * busy it (so we own it) and plug it into pps[lcv]. this
1088: * 'break's the following while loop and indicates we are
1089: * ready to move on to the next page in the "lcv" loop above.
1090: *
1091: * if we exit the while loop with pps[lcv] still set to NULL,
1092: * then it means that we allocated a new busy/fake/clean page
1093: * ptmp in the object and we need to do I/O to fill in the data.
1094: */
1095:
1096: /* top of "pps" while loop */
1097: while (pps[lcv] == NULL) {
1098: /* look for a resident page */
1099: ptmp = uvm_pagelookup(uobj, current_offset);
1100:
1101: /* not resident? allocate one now (if we can) */
1102: if (ptmp == NULL) {
1103:
1104: ptmp = uvm_pagealloc(uobj, current_offset,
1.19 chs 1105: NULL, 0);
1.5 mrg 1106:
1107: /* out of RAM? */
1108: if (ptmp == NULL) {
1109: simple_unlock(&uobj->vmobjlock);
1110: UVMHIST_LOG(pdhist,
1111: "sleeping, ptmp == NULL\n",0,0,0,0);
1112: uvm_wait("uao_getpage");
1113: simple_lock(&uobj->vmobjlock);
1114: /* goto top of pps while loop */
1115: continue;
1116: }
1117:
1118: /*
1119: * safe with PQ's unlocked: because we just
1120: * alloc'd the page
1121: */
1122: ptmp->pqflags |= PQ_AOBJ;
1123:
1124: /*
1125: * got new page ready for I/O. break pps while
1126: * loop. pps[lcv] is still NULL.
1127: */
1128: break;
1129: }
1130:
1131: /* page is there, see if we need to wait on it */
1132: if ((ptmp->flags & (PG_BUSY|PG_RELEASED)) != 0) {
1133: ptmp->flags |= PG_WANTED;
1134: UVMHIST_LOG(pdhist,
1135: "sleeping, ptmp->flags 0x%x\n",
1136: ptmp->flags,0,0,0);
1.23 thorpej 1137: UVM_UNLOCK_AND_WAIT(ptmp, &uobj->vmobjlock,
1138: FALSE, "uao_get", 0);
1.5 mrg 1139: simple_lock(&uobj->vmobjlock);
1140: continue; /* goto top of pps while loop */
1141: }
1142:
1143: /*
1144: * if we get here then the page has become resident and
1145: * unbusy between steps 1 and 2. we busy it now (so we
1146: * own it) and set pps[lcv] (so that we exit the while
1147: * loop).
1148: */
1149: /* we own it, caller must un-busy */
1150: ptmp->flags |= PG_BUSY;
1151: UVM_PAGE_OWN(ptmp, "uao_get2");
1152: pps[lcv] = ptmp;
1153: }
1154:
1155: /*
1156: * if we own the valid page at the correct offset, pps[lcv] will
1157: * point to it. nothing more to do except go to the next page.
1158: */
1159: if (pps[lcv])
1160: continue; /* next lcv */
1161:
1162: /*
1163: * we have a "fake/busy/clean" page that we just allocated.
1164: * do the needed "i/o", either reading from swap or zeroing.
1165: */
1.27 chs 1166: swslot = uao_find_swslot(aobj, pageidx);
1.5 mrg 1167:
1168: /*
1169: * just zero the page if there's nothing in swap.
1170: */
1171: if (swslot == 0)
1172: {
1173: /*
1174: * page hasn't existed before, just zero it.
1175: */
1176: uvm_pagezero(ptmp);
1.27 chs 1177: } else {
1.5 mrg 1178: UVMHIST_LOG(pdhist, "pagein from swslot %d",
1179: swslot, 0,0,0);
1180:
1181: /*
1182: * page in the swapped-out page.
1183: * unlock object for i/o, relock when done.
1184: */
1185: simple_unlock(&uobj->vmobjlock);
1186: rv = uvm_swap_get(ptmp, swslot, PGO_SYNCIO);
1187: simple_lock(&uobj->vmobjlock);
1188:
1189: /*
1190: * I/O done. check for errors.
1191: */
1192: if (rv != VM_PAGER_OK)
1193: {
1194: UVMHIST_LOG(pdhist, "<- done (error=%d)",
1195: rv,0,0,0);
1196: if (ptmp->flags & PG_WANTED)
1.24 thorpej 1197: wakeup(ptmp);
1.27 chs 1198:
1199: /*
1200: * remove the swap slot from the aobj
1201: * and mark the aobj as having no real slot.
1202: * don't free the swap slot, thus preventing
1203: * it from being used again.
1204: */
1205: swslot = uao_set_swslot(&aobj->u_obj, pageidx,
1206: SWSLOT_BAD);
1207: uvm_swap_markbad(swslot, 1);
1208:
1.5 mrg 1209: ptmp->flags &= ~(PG_WANTED|PG_BUSY);
1210: UVM_PAGE_OWN(ptmp, NULL);
1211: uvm_lock_pageq();
1212: uvm_pagefree(ptmp);
1213: uvm_unlock_pageq();
1.27 chs 1214:
1.5 mrg 1215: simple_unlock(&uobj->vmobjlock);
1216: return (rv);
1217: }
1218: }
1219:
1220: /*
1221: * we got the page! clear the fake flag (indicates valid
1222: * data now in page) and plug into our result array. note
1223: * that page is still busy.
1224: *
1225: * it is the callers job to:
1226: * => check if the page is released
1227: * => unbusy the page
1228: * => activate the page
1229: */
1230:
1231: ptmp->flags &= ~PG_FAKE; /* data is valid ... */
1.26 chs 1232: pmap_clear_modify(ptmp); /* ... and clean */
1.5 mrg 1233: pps[lcv] = ptmp;
1.1 mrg 1234:
1.5 mrg 1235: } /* lcv loop */
1.1 mrg 1236:
1237: /*
1.5 mrg 1238: * finally, unlock object and return.
1239: */
1.1 mrg 1240:
1241: simple_unlock(&uobj->vmobjlock);
1.5 mrg 1242: UVMHIST_LOG(pdhist, "<- done (OK)",0,0,0,0);
1243: return(VM_PAGER_OK);
1.1 mrg 1244: }
1245:
1246: /*
1247: * uao_releasepg: handle released page in an aobj
1248: *
1249: * => "pg" is a PG_BUSY [caller owns it], PG_RELEASED page that we need
1250: * to dispose of.
1251: * => caller must handle PG_WANTED case
1252: * => called with page's object locked, pageq's unlocked
1253: * => returns TRUE if page's object is still alive, FALSE if we
1254: * killed the page's object. if we return TRUE, then we
1255: * return with the object locked.
1256: * => if (nextpgp != NULL) => we return pageq.tqe_next here, and return
1257: * with the page queues locked [for pagedaemon]
1258: * => if (nextpgp == NULL) => we return with page queues unlocked [normal case]
1259: * => we kill the aobj if it is not referenced and we are suppose to
1260: * kill it ("KILLME").
1261: */
1.27 chs 1262: static boolean_t
1263: uao_releasepg(pg, nextpgp)
1.5 mrg 1264: struct vm_page *pg;
1265: struct vm_page **nextpgp; /* OUT */
1.1 mrg 1266: {
1.5 mrg 1267: struct uvm_aobj *aobj = (struct uvm_aobj *) pg->uobject;
1.1 mrg 1268:
1269: #ifdef DIAGNOSTIC
1.5 mrg 1270: if ((pg->flags & PG_RELEASED) == 0)
1271: panic("uao_releasepg: page not released!");
1.1 mrg 1272: #endif
1.27 chs 1273:
1.5 mrg 1274: /*
1275: * dispose of the page [caller handles PG_WANTED] and swap slot.
1276: */
1.26 chs 1277: pmap_page_protect(pg, VM_PROT_NONE);
1.18 chs 1278: uao_dropswap(&aobj->u_obj, pg->offset >> PAGE_SHIFT);
1.5 mrg 1279: uvm_lock_pageq();
1280: if (nextpgp)
1281: *nextpgp = pg->pageq.tqe_next; /* next page for daemon */
1282: uvm_pagefree(pg);
1283: if (!nextpgp)
1.27 chs 1284: uvm_unlock_pageq(); /* keep locked for daemon */
1.5 mrg 1285:
1286: /*
1287: * if we're not killing the object, we're done.
1288: */
1289: if ((aobj->u_flags & UAO_FLAG_KILLME) == 0)
1290: return TRUE;
1.1 mrg 1291:
1292: #ifdef DIAGNOSTIC
1.5 mrg 1293: if (aobj->u_obj.uo_refs)
1294: panic("uvm_km_releasepg: kill flag set on referenced object!");
1.1 mrg 1295: #endif
1296:
1.5 mrg 1297: /*
1298: * if there are still pages in the object, we're done for now.
1299: */
1300: if (aobj->u_obj.uo_npages != 0)
1301: return TRUE;
1.1 mrg 1302:
1303: #ifdef DIAGNOSTIC
1.27 chs 1304: if (TAILQ_FIRST(&aobj->u_obj.memq))
1.5 mrg 1305: panic("uvn_releasepg: pages in object with npages == 0");
1.1 mrg 1306: #endif
1307:
1.5 mrg 1308: /*
1309: * finally, free the rest.
1310: */
1311: uao_free(aobj);
1.1 mrg 1312:
1.5 mrg 1313: return FALSE;
1.18 chs 1314: }
1315:
1.27 chs 1316:
1.18 chs 1317: /*
1318: * uao_dropswap: release any swap resources from this aobj page.
1319: *
1320: * => aobj must be locked or have a reference count of 0.
1321: */
1322:
1323: void
1324: uao_dropswap(uobj, pageidx)
1325: struct uvm_object *uobj;
1326: int pageidx;
1327: {
1328: int slot;
1329:
1330: slot = uao_set_swslot(uobj, pageidx, 0);
1331: if (slot) {
1332: uvm_swap_free(slot, 1);
1333: }
1.27 chs 1334: }
1335:
1336:
1337: /*
1338: * page in every page in every aobj that is paged-out to a range of swslots.
1339: *
1340: * => nothing should be locked.
1341: * => returns TRUE if pagein was aborted due to lack of memory.
1342: */
1343: boolean_t
1344: uao_swap_off(startslot, endslot)
1345: int startslot, endslot;
1346: {
1347: struct uvm_aobj *aobj, *nextaobj;
1348:
1349: /*
1350: * walk the list of all aobjs.
1351: */
1352:
1353: restart:
1354: simple_lock(&uao_list_lock);
1355:
1356: for (aobj = LIST_FIRST(&uao_list);
1357: aobj != NULL;
1358: aobj = nextaobj) {
1359: boolean_t rv;
1360:
1361: /*
1362: * try to get the object lock,
1363: * start all over if we fail.
1364: * most of the time we'll get the aobj lock,
1365: * so this should be a rare case.
1366: */
1367: if (!simple_lock_try(&aobj->u_obj.vmobjlock)) {
1368: simple_unlock(&uao_list_lock);
1369: goto restart;
1370: }
1371:
1372: /*
1373: * add a ref to the aobj so it doesn't disappear
1374: * while we're working.
1375: */
1376: uao_reference_locked(&aobj->u_obj);
1377:
1378: /*
1379: * now it's safe to unlock the uao list.
1380: */
1381: simple_unlock(&uao_list_lock);
1382:
1383: /*
1384: * page in any pages in the swslot range.
1385: * if there's an error, abort and return the error.
1386: */
1387: rv = uao_pagein(aobj, startslot, endslot);
1388: if (rv) {
1389: uao_detach_locked(&aobj->u_obj);
1390: return rv;
1391: }
1392:
1393: /*
1394: * we're done with this aobj.
1395: * relock the list and drop our ref on the aobj.
1396: */
1397: simple_lock(&uao_list_lock);
1398: nextaobj = LIST_NEXT(aobj, u_list);
1399: uao_detach_locked(&aobj->u_obj);
1400: }
1401:
1402: /*
1403: * done with traversal, unlock the list
1404: */
1405: simple_unlock(&uao_list_lock);
1406: return FALSE;
1407: }
1408:
1409:
1410: /*
1411: * page in any pages from aobj in the given range.
1412: *
1413: * => aobj must be locked and is returned locked.
1414: * => returns TRUE if pagein was aborted due to lack of memory.
1415: */
1416: static boolean_t
1417: uao_pagein(aobj, startslot, endslot)
1418: struct uvm_aobj *aobj;
1419: int startslot, endslot;
1420: {
1421: boolean_t rv;
1422:
1423: if (UAO_USES_SWHASH(aobj)) {
1424: struct uao_swhash_elt *elt;
1425: int bucket;
1426:
1427: restart:
1428: for (bucket = aobj->u_swhashmask; bucket >= 0; bucket--) {
1429: for (elt = LIST_FIRST(&aobj->u_swhash[bucket]);
1430: elt != NULL;
1431: elt = LIST_NEXT(elt, list)) {
1432: int i;
1433:
1434: for (i = 0; i < UAO_SWHASH_CLUSTER_SIZE; i++) {
1435: int slot = elt->slots[i];
1436:
1437: /*
1438: * if the slot isn't in range, skip it.
1439: */
1440: if (slot < startslot ||
1441: slot >= endslot) {
1442: continue;
1443: }
1444:
1445: /*
1446: * process the page,
1447: * the start over on this object
1448: * since the swhash elt
1449: * may have been freed.
1450: */
1451: rv = uao_pagein_page(aobj,
1452: UAO_SWHASH_ELT_PAGEIDX_BASE(elt) + i);
1453: if (rv) {
1454: return rv;
1455: }
1456: goto restart;
1457: }
1458: }
1459: }
1460: } else {
1461: int i;
1462:
1463: for (i = 0; i < aobj->u_pages; i++) {
1464: int slot = aobj->u_swslots[i];
1465:
1466: /*
1467: * if the slot isn't in range, skip it
1468: */
1469: if (slot < startslot || slot >= endslot) {
1470: continue;
1471: }
1472:
1473: /*
1474: * process the page.
1475: */
1476: rv = uao_pagein_page(aobj, i);
1477: if (rv) {
1478: return rv;
1479: }
1480: }
1481: }
1482:
1483: return FALSE;
1484: }
1485:
1486: /*
1487: * page in a page from an aobj. used for swap_off.
1488: * returns TRUE if pagein was aborted due to lack of memory.
1489: *
1490: * => aobj must be locked and is returned locked.
1491: */
1492: static boolean_t
1493: uao_pagein_page(aobj, pageidx)
1494: struct uvm_aobj *aobj;
1495: int pageidx;
1496: {
1497: struct vm_page *pg;
1498: int rv, slot, npages;
1499: UVMHIST_FUNC("uao_pagein_page"); UVMHIST_CALLED(pdhist);
1500:
1501: pg = NULL;
1502: npages = 1;
1503: /* locked: aobj */
1504: rv = uao_get(&aobj->u_obj, pageidx << PAGE_SHIFT,
1505: &pg, &npages, 0, VM_PROT_READ|VM_PROT_WRITE, 0, 0);
1506: /* unlocked: aobj */
1507:
1508: /*
1509: * relock and finish up.
1510: */
1511: simple_lock(&aobj->u_obj.vmobjlock);
1512:
1513: switch (rv) {
1514: case VM_PAGER_OK:
1515: break;
1516:
1517: case VM_PAGER_ERROR:
1518: case VM_PAGER_REFAULT:
1519: /*
1520: * nothing more to do on errors.
1521: * VM_PAGER_REFAULT can only mean that the anon was freed,
1522: * so again there's nothing to do.
1523: */
1524: return FALSE;
1525:
1526: #ifdef DIAGNOSTIC
1527: default:
1528: panic("uao_pagein_page: uao_get -> %d\n", rv);
1529: #endif
1530: }
1531:
1532: #ifdef DIAGNOSTIC
1533: /*
1534: * this should never happen, since we have a reference on the aobj.
1535: */
1536: if (pg->flags & PG_RELEASED) {
1537: panic("uao_pagein_page: found PG_RELEASED page?\n");
1538: }
1539: #endif
1540:
1541: /*
1542: * ok, we've got the page now.
1543: * mark it as dirty, clear its swslot and un-busy it.
1544: */
1545: slot = uao_set_swslot(&aobj->u_obj, pageidx, 0);
1546: uvm_swap_free(slot, 1);
1547: pg->flags &= ~(PG_BUSY|PG_CLEAN|PG_FAKE);
1548: UVM_PAGE_OWN(pg, NULL);
1549:
1550: /*
1551: * deactivate the page (to put it on a page queue).
1552: */
1553: pmap_clear_reference(pg);
1554: pmap_page_protect(pg, VM_PROT_NONE);
1555: uvm_lock_pageq();
1556: uvm_pagedeactivate(pg);
1557: uvm_unlock_pageq();
1558:
1559: return FALSE;
1.1 mrg 1560: }
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