Annotation of src/sys/uvm/uvm_aobj.c, Revision 1.45.2.1
1.45.2.1! thorpej 1: /* $NetBSD: uvm_aobj.c,v 1.49 2001/11/10 07:36:59 lukem 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:
1.45.2.1! thorpej 45: #include <sys/cdefs.h>
! 46: __KERNEL_RCSID(0, "$NetBSD: uvm_aobj.c,v 1.49 2001/11/10 07:36:59 lukem Exp $");
1.7 chs 47:
48: #include "opt_uvmhist.h"
1.1 mrg 49:
50: #include <sys/param.h>
51: #include <sys/systm.h>
52: #include <sys/proc.h>
53: #include <sys/malloc.h>
1.37 chs 54: #include <sys/kernel.h>
1.12 thorpej 55: #include <sys/pool.h>
1.27 chs 56: #include <sys/kernel.h>
1.1 mrg 57:
58: #include <uvm/uvm.h>
59:
60: /*
61: * an aobj manages anonymous-memory backed uvm_objects. in addition
62: * to keeping the list of resident pages, it also keeps a list of
63: * allocated swap blocks. depending on the size of the aobj this list
64: * of allocated swap blocks is either stored in an array (small objects)
65: * or in a hash table (large objects).
66: */
67:
68: /*
69: * local structures
70: */
71:
72: /*
73: * for hash tables, we break the address space of the aobj into blocks
74: * of UAO_SWHASH_CLUSTER_SIZE pages. we require the cluster size to
75: * be a power of two.
76: */
77:
78: #define UAO_SWHASH_CLUSTER_SHIFT 4
79: #define UAO_SWHASH_CLUSTER_SIZE (1 << UAO_SWHASH_CLUSTER_SHIFT)
80:
81: /* get the "tag" for this page index */
82: #define UAO_SWHASH_ELT_TAG(PAGEIDX) \
83: ((PAGEIDX) >> UAO_SWHASH_CLUSTER_SHIFT)
84:
85: /* given an ELT and a page index, find the swap slot */
86: #define UAO_SWHASH_ELT_PAGESLOT(ELT, PAGEIDX) \
87: ((ELT)->slots[(PAGEIDX) & (UAO_SWHASH_CLUSTER_SIZE - 1)])
88:
89: /* given an ELT, return its pageidx base */
90: #define UAO_SWHASH_ELT_PAGEIDX_BASE(ELT) \
91: ((ELT)->tag << UAO_SWHASH_CLUSTER_SHIFT)
92:
93: /*
94: * the swhash hash function
95: */
1.45.2.1! thorpej 96:
1.1 mrg 97: #define UAO_SWHASH_HASH(AOBJ, PAGEIDX) \
98: (&(AOBJ)->u_swhash[(((PAGEIDX) >> UAO_SWHASH_CLUSTER_SHIFT) \
99: & (AOBJ)->u_swhashmask)])
100:
101: /*
102: * the swhash threshhold determines if we will use an array or a
103: * hash table to store the list of allocated swap blocks.
104: */
105:
106: #define UAO_SWHASH_THRESHOLD (UAO_SWHASH_CLUSTER_SIZE * 4)
107: #define UAO_USES_SWHASH(AOBJ) \
108: ((AOBJ)->u_pages > UAO_SWHASH_THRESHOLD) /* use hash? */
109:
110: /*
1.3 chs 111: * the number of buckets in a swhash, with an upper bound
1.1 mrg 112: */
1.45.2.1! thorpej 113:
1.1 mrg 114: #define UAO_SWHASH_MAXBUCKETS 256
115: #define UAO_SWHASH_BUCKETS(AOBJ) \
1.45.2.1! thorpej 116: (MIN((AOBJ)->u_pages >> UAO_SWHASH_CLUSTER_SHIFT, \
1.1 mrg 117: UAO_SWHASH_MAXBUCKETS))
118:
119:
120: /*
121: * uao_swhash_elt: when a hash table is being used, this structure defines
122: * the format of an entry in the bucket list.
123: */
124:
125: struct uao_swhash_elt {
1.5 mrg 126: LIST_ENTRY(uao_swhash_elt) list; /* the hash list */
1.28 kleink 127: voff_t tag; /* our 'tag' */
1.5 mrg 128: int count; /* our number of active slots */
129: int slots[UAO_SWHASH_CLUSTER_SIZE]; /* the slots */
1.1 mrg 130: };
131:
132: /*
133: * uao_swhash: the swap hash table structure
134: */
135:
136: LIST_HEAD(uao_swhash, uao_swhash_elt);
137:
1.12 thorpej 138: /*
139: * uao_swhash_elt_pool: pool of uao_swhash_elt structures
140: */
141:
142: struct pool uao_swhash_elt_pool;
1.1 mrg 143:
144: /*
145: * uvm_aobj: the actual anon-backed uvm_object
146: *
147: * => the uvm_object is at the top of the structure, this allows
1.45.2.1! thorpej 148: * (struct uvm_aobj *) == (struct uvm_object *)
1.1 mrg 149: * => only one of u_swslots and u_swhash is used in any given aobj
150: */
151:
152: struct uvm_aobj {
1.5 mrg 153: struct uvm_object u_obj; /* has: lock, pgops, memq, #pages, #refs */
1.11 drochner 154: int u_pages; /* number of pages in entire object */
1.5 mrg 155: int u_flags; /* the flags (see uvm_aobj.h) */
156: int *u_swslots; /* array of offset->swapslot mappings */
157: /*
158: * hashtable of offset->swapslot mappings
159: * (u_swhash is an array of bucket heads)
160: */
161: struct uao_swhash *u_swhash;
162: u_long u_swhashmask; /* mask for hashtable */
163: LIST_ENTRY(uvm_aobj) u_list; /* global list of aobjs */
1.1 mrg 164: };
165:
166: /*
1.12 thorpej 167: * uvm_aobj_pool: pool of uvm_aobj structures
168: */
169:
170: struct pool uvm_aobj_pool;
171:
172: /*
1.1 mrg 173: * local functions
174: */
175:
1.45.2.1! thorpej 176: static struct uao_swhash_elt *uao_find_swhash_elt
! 177: __P((struct uvm_aobj *, int, boolean_t));
! 178:
! 179: static void uao_free __P((struct uvm_aobj *));
! 180: static int uao_get __P((struct uvm_object *, voff_t, struct vm_page **,
! 181: int *, int, vm_prot_t, int, int));
! 182: static boolean_t uao_put __P((struct uvm_object *, voff_t, voff_t, int));
! 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: * aobj_pager
1.41 chs 188: *
1.1 mrg 189: * note that some functions (e.g. put) are handled elsewhere
190: */
191:
192: struct uvm_pagerops aobj_pager = {
1.27 chs 193: NULL, /* init */
1.5 mrg 194: uao_reference, /* reference */
195: uao_detach, /* detach */
196: NULL, /* fault */
197: uao_get, /* get */
1.45.2.1! thorpej 198: uao_put, /* flush */
1.1 mrg 199: };
200:
201: /*
202: * uao_list: global list of active aobjs, locked by uao_list_lock
203: */
204:
205: static LIST_HEAD(aobjlist, uvm_aobj) uao_list;
1.42 chs 206: static struct simplelock uao_list_lock;
1.1 mrg 207:
208: /*
209: * functions
210: */
211:
212: /*
213: * hash table/array related functions
214: */
215:
216: /*
217: * uao_find_swhash_elt: find (or create) a hash table entry for a page
218: * offset.
219: *
220: * => the object should be locked by the caller
221: */
222:
1.5 mrg 223: static struct uao_swhash_elt *
224: uao_find_swhash_elt(aobj, pageidx, create)
225: struct uvm_aobj *aobj;
226: int pageidx;
227: boolean_t create;
228: {
229: struct uao_swhash *swhash;
230: struct uao_swhash_elt *elt;
1.28 kleink 231: voff_t page_tag;
1.1 mrg 232:
1.45 chs 233: swhash = UAO_SWHASH_HASH(aobj, pageidx);
234: page_tag = UAO_SWHASH_ELT_TAG(pageidx);
1.1 mrg 235:
1.5 mrg 236: /*
237: * now search the bucket for the requested tag
238: */
1.45 chs 239:
1.37 chs 240: LIST_FOREACH(elt, swhash, list) {
1.45 chs 241: if (elt->tag == page_tag) {
242: return elt;
243: }
1.5 mrg 244: }
1.45 chs 245: if (!create) {
1.5 mrg 246: return NULL;
1.45 chs 247: }
1.5 mrg 248:
249: /*
1.12 thorpej 250: * allocate a new entry for the bucket and init/insert it in
1.5 mrg 251: */
1.45 chs 252:
253: elt = pool_get(&uao_swhash_elt_pool, PR_NOWAIT);
254: if (elt == NULL) {
255: return NULL;
256: }
1.5 mrg 257: LIST_INSERT_HEAD(swhash, elt, list);
258: elt->tag = page_tag;
259: elt->count = 0;
1.9 perry 260: memset(elt->slots, 0, sizeof(elt->slots));
1.45 chs 261: return elt;
1.1 mrg 262: }
263:
264: /*
265: * uao_find_swslot: find the swap slot number for an aobj/pageidx
266: *
1.41 chs 267: * => object must be locked by caller
1.1 mrg 268: */
1.45.2.1! thorpej 269:
! 270: int
! 271: uao_find_swslot(uobj, pageidx)
! 272: struct uvm_object *uobj;
1.11 drochner 273: int pageidx;
1.1 mrg 274: {
1.45.2.1! thorpej 275: struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
! 276: struct uao_swhash_elt *elt;
1.1 mrg 277:
1.5 mrg 278: /*
279: * if noswap flag is set, then we never return a slot
280: */
1.1 mrg 281:
1.5 mrg 282: if (aobj->u_flags & UAO_FLAG_NOSWAP)
283: return(0);
1.1 mrg 284:
1.5 mrg 285: /*
286: * if hashing, look in hash table.
287: */
1.1 mrg 288:
1.5 mrg 289: if (UAO_USES_SWHASH(aobj)) {
1.45.2.1! thorpej 290: elt = uao_find_swhash_elt(aobj, pageidx, FALSE);
1.5 mrg 291: if (elt)
292: return(UAO_SWHASH_ELT_PAGESLOT(elt, pageidx));
293: else
1.31 thorpej 294: return(0);
1.5 mrg 295: }
1.1 mrg 296:
1.41 chs 297: /*
1.5 mrg 298: * otherwise, look in the array
299: */
1.45.2.1! thorpej 300:
1.5 mrg 301: return(aobj->u_swslots[pageidx]);
1.1 mrg 302: }
303:
304: /*
305: * uao_set_swslot: set the swap slot for a page in an aobj.
306: *
307: * => setting a slot to zero frees the slot
308: * => object must be locked by caller
1.45 chs 309: * => we return the old slot number, or -1 if we failed to allocate
310: * memory to record the new slot number
1.1 mrg 311: */
1.45.2.1! thorpej 312:
1.5 mrg 313: int
314: uao_set_swslot(uobj, pageidx, slot)
315: struct uvm_object *uobj;
316: int pageidx, slot;
317: {
318: struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
1.45 chs 319: struct uao_swhash_elt *elt;
1.5 mrg 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: /*
1.45.2.1! thorpej 326: * if noswap flag is set, then we can't set a non-zero slot.
1.5 mrg 327: */
1.1 mrg 328:
1.5 mrg 329: if (aobj->u_flags & UAO_FLAG_NOSWAP) {
330: if (slot == 0)
1.45.2.1! thorpej 331: return(0);
1.1 mrg 332:
1.5 mrg 333: printf("uao_set_swslot: uobj = %p\n", uobj);
1.45.2.1! thorpej 334: panic("uao_set_swslot: NOSWAP object");
1.5 mrg 335: }
1.1 mrg 336:
1.5 mrg 337: /*
338: * are we using a hash table? if so, add it in the hash.
339: */
1.1 mrg 340:
1.5 mrg 341: if (UAO_USES_SWHASH(aobj)) {
1.39 chs 342:
1.12 thorpej 343: /*
344: * Avoid allocating an entry just to free it again if
345: * the page had not swap slot in the first place, and
346: * we are freeing.
347: */
1.39 chs 348:
1.45.2.1! thorpej 349: elt = uao_find_swhash_elt(aobj, pageidx, slot != 0);
1.12 thorpej 350: if (elt == NULL) {
1.45 chs 351: return slot ? -1 : 0;
1.12 thorpej 352: }
1.5 mrg 353:
354: oldslot = UAO_SWHASH_ELT_PAGESLOT(elt, pageidx);
355: UAO_SWHASH_ELT_PAGESLOT(elt, pageidx) = slot;
356:
357: /*
358: * now adjust the elt's reference counter and free it if we've
359: * dropped it to zero.
360: */
361:
362: if (slot) {
363: if (oldslot == 0)
364: elt->count++;
1.45 chs 365: } else {
366: if (oldslot)
1.5 mrg 367: elt->count--;
368:
369: if (elt->count == 0) {
370: LIST_REMOVE(elt, list);
1.12 thorpej 371: pool_put(&uao_swhash_elt_pool, elt);
1.5 mrg 372: }
373: }
1.41 chs 374: } else {
1.5 mrg 375: /* we are using an array */
376: oldslot = aobj->u_swslots[pageidx];
377: aobj->u_swslots[pageidx] = slot;
378: }
379: return (oldslot);
1.1 mrg 380: }
381:
382: /*
383: * end of hash/array functions
384: */
385:
386: /*
387: * uao_free: free all resources held by an aobj, and then free the aobj
388: *
389: * => the aobj should be dead
390: */
1.45.2.1! thorpej 391:
1.1 mrg 392: static void
393: uao_free(aobj)
1.5 mrg 394: struct uvm_aobj *aobj;
1.1 mrg 395: {
1.45.2.1! thorpej 396: int swpgonlydelta = 0;
1.1 mrg 397:
1.27 chs 398: simple_unlock(&aobj->u_obj.vmobjlock);
1.5 mrg 399: if (UAO_USES_SWHASH(aobj)) {
400: int i, hashbuckets = aobj->u_swhashmask + 1;
1.1 mrg 401:
1.5 mrg 402: /*
403: * free the swslots from each hash bucket,
404: * then the hash bucket, and finally the hash table itself.
405: */
1.45.2.1! thorpej 406:
1.5 mrg 407: for (i = 0; i < hashbuckets; i++) {
408: struct uao_swhash_elt *elt, *next;
409:
1.27 chs 410: for (elt = LIST_FIRST(&aobj->u_swhash[i]);
411: elt != NULL;
412: elt = next) {
1.5 mrg 413: int j;
414:
1.27 chs 415: for (j = 0; j < UAO_SWHASH_CLUSTER_SIZE; j++) {
1.5 mrg 416: int slot = elt->slots[j];
417:
1.37 chs 418: if (slot == 0) {
419: continue;
420: }
421: uvm_swap_free(slot, 1);
1.45.2.1! thorpej 422: swpgonlydelta++;
1.5 mrg 423: }
424:
1.27 chs 425: next = LIST_NEXT(elt, list);
1.12 thorpej 426: pool_put(&uao_swhash_elt_pool, elt);
1.5 mrg 427: }
428: }
1.34 thorpej 429: free(aobj->u_swhash, M_UVMAOBJ);
1.5 mrg 430: } else {
431: int i;
432:
433: /*
434: * free the array
435: */
436:
1.27 chs 437: for (i = 0; i < aobj->u_pages; i++) {
1.5 mrg 438: int slot = aobj->u_swslots[i];
439:
1.18 chs 440: if (slot) {
1.5 mrg 441: uvm_swap_free(slot, 1);
1.45.2.1! thorpej 442: swpgonlydelta++;
1.18 chs 443: }
1.5 mrg 444: }
1.34 thorpej 445: free(aobj->u_swslots, M_UVMAOBJ);
1.1 mrg 446: }
447:
1.5 mrg 448: /*
449: * finally free the aobj itself
450: */
1.45.2.1! thorpej 451:
1.12 thorpej 452: pool_put(&uvm_aobj_pool, aobj);
1.45.2.1! thorpej 453:
! 454: /*
! 455: * adjust the counter of pages only in swap for all
! 456: * the swap slots we've freed.
! 457: */
! 458:
! 459: if (swpgonlydelta > 0) {
! 460: simple_lock(&uvm.swap_data_lock);
! 461: KASSERT(uvmexp.swpgonly >= swpgonlydelta);
! 462: uvmexp.swpgonly -= swpgonlydelta;
! 463: simple_unlock(&uvm.swap_data_lock);
! 464: }
1.1 mrg 465: }
466:
467: /*
468: * pager functions
469: */
470:
471: /*
472: * uao_create: create an aobj of the given size and return its uvm_object.
473: *
474: * => for normal use, flags are always zero
475: * => for the kernel object, the flags are:
476: * UAO_FLAG_KERNOBJ - allocate the kernel object (can only happen once)
477: * UAO_FLAG_KERNSWAP - enable swapping of kernel object (" ")
478: */
1.45.2.1! thorpej 479:
1.5 mrg 480: struct uvm_object *
481: uao_create(size, flags)
1.10 eeh 482: vsize_t size;
1.5 mrg 483: int flags;
484: {
1.45.2.1! thorpej 485: static struct uvm_aobj kernel_object_store;
! 486: static int kobj_alloced = 0;
1.15 chs 487: int pages = round_page(size) >> PAGE_SHIFT;
1.5 mrg 488: struct uvm_aobj *aobj;
1.1 mrg 489:
1.5 mrg 490: /*
1.27 chs 491: * malloc a new aobj unless we are asked for the kernel object
492: */
1.5 mrg 493:
1.45.2.1! thorpej 494: if (flags & UAO_FLAG_KERNOBJ) {
! 495: KASSERT(!kobj_alloced);
1.5 mrg 496: aobj = &kernel_object_store;
497: aobj->u_pages = pages;
1.45.2.1! thorpej 498: aobj->u_flags = UAO_FLAG_NOSWAP;
1.5 mrg 499: aobj->u_obj.uo_refs = UVM_OBJ_KERN;
500: kobj_alloced = UAO_FLAG_KERNOBJ;
501: } else if (flags & UAO_FLAG_KERNSWAP) {
1.45.2.1! thorpej 502: KASSERT(kobj_alloced == UAO_FLAG_KERNOBJ);
1.5 mrg 503: aobj = &kernel_object_store;
504: kobj_alloced = UAO_FLAG_KERNSWAP;
1.45.2.1! thorpej 505: } else {
1.12 thorpej 506: aobj = pool_get(&uvm_aobj_pool, PR_WAITOK);
1.5 mrg 507: aobj->u_pages = pages;
1.45.2.1! thorpej 508: aobj->u_flags = 0;
! 509: aobj->u_obj.uo_refs = 1;
1.5 mrg 510: }
1.1 mrg 511:
1.5 mrg 512: /*
513: * allocate hash/array if necessary
514: *
515: * note: in the KERNSWAP case no need to worry about locking since
516: * we are still booting we should be the only thread around.
517: */
1.45.2.1! thorpej 518:
1.5 mrg 519: if (flags == 0 || (flags & UAO_FLAG_KERNSWAP) != 0) {
520: int mflags = (flags & UAO_FLAG_KERNSWAP) != 0 ?
521: M_NOWAIT : M_WAITOK;
522:
523: /* allocate hash table or array depending on object size */
1.27 chs 524: if (UAO_USES_SWHASH(aobj)) {
1.5 mrg 525: aobj->u_swhash = hashinit(UAO_SWHASH_BUCKETS(aobj),
1.35 ad 526: HASH_LIST, M_UVMAOBJ, mflags, &aobj->u_swhashmask);
1.5 mrg 527: if (aobj->u_swhash == NULL)
528: panic("uao_create: hashinit swhash failed");
529: } else {
1.34 thorpej 530: aobj->u_swslots = malloc(pages * sizeof(int),
1.5 mrg 531: M_UVMAOBJ, mflags);
532: if (aobj->u_swslots == NULL)
533: panic("uao_create: malloc swslots failed");
1.9 perry 534: memset(aobj->u_swslots, 0, pages * sizeof(int));
1.5 mrg 535: }
536:
537: if (flags) {
538: aobj->u_flags &= ~UAO_FLAG_NOSWAP; /* clear noswap */
539: return(&aobj->u_obj);
540: }
541: }
542:
543: /*
544: * init aobj fields
545: */
1.45.2.1! thorpej 546:
1.5 mrg 547: simple_lock_init(&aobj->u_obj.vmobjlock);
548: aobj->u_obj.pgops = &aobj_pager;
549: TAILQ_INIT(&aobj->u_obj.memq);
550: aobj->u_obj.uo_npages = 0;
1.1 mrg 551:
1.5 mrg 552: /*
553: * now that aobj is ready, add it to the global list
554: */
1.45.2.1! thorpej 555:
1.5 mrg 556: simple_lock(&uao_list_lock);
557: LIST_INSERT_HEAD(&uao_list, aobj, u_list);
558: simple_unlock(&uao_list_lock);
559: return(&aobj->u_obj);
1.1 mrg 560: }
561:
562:
563:
564: /*
565: * uao_init: set up aobj pager subsystem
566: *
567: * => called at boot time from uvm_pager_init()
568: */
1.45.2.1! thorpej 569:
1.27 chs 570: void
1.45.2.1! thorpej 571: uao_init(void)
1.5 mrg 572: {
1.12 thorpej 573: static int uao_initialized;
574:
575: if (uao_initialized)
576: return;
577: uao_initialized = TRUE;
1.5 mrg 578: LIST_INIT(&uao_list);
579: simple_lock_init(&uao_list_lock);
1.12 thorpej 580:
1.14 thorpej 581: /*
582: * NOTE: Pages fror this pool must not come from a pageable
583: * kernel map!
584: */
1.45.2.1! thorpej 585:
1.12 thorpej 586: pool_init(&uao_swhash_elt_pool, sizeof(struct uao_swhash_elt),
1.13 thorpej 587: 0, 0, 0, "uaoeltpl", 0, NULL, NULL, M_UVMAOBJ);
1.12 thorpej 588: pool_init(&uvm_aobj_pool, sizeof(struct uvm_aobj), 0, 0, 0,
589: "aobjpl", 0,
590: pool_page_alloc_nointr, pool_page_free_nointr, M_UVMAOBJ);
1.1 mrg 591: }
592:
593: /*
594: * uao_reference: add a ref to an aobj
595: *
1.27 chs 596: * => aobj must be unlocked
597: * => just lock it and call the locked version
1.1 mrg 598: */
1.45.2.1! thorpej 599:
1.5 mrg 600: void
601: uao_reference(uobj)
602: struct uvm_object *uobj;
1.1 mrg 603: {
1.27 chs 604: simple_lock(&uobj->vmobjlock);
605: uao_reference_locked(uobj);
606: simple_unlock(&uobj->vmobjlock);
607: }
608:
609: /*
610: * uao_reference_locked: add a ref to an aobj that is already locked
611: *
612: * => aobj must be locked
613: * this needs to be separate from the normal routine
614: * since sometimes we need to add a reference to an aobj when
615: * it's already locked.
616: */
1.45.2.1! thorpej 617:
1.27 chs 618: void
619: uao_reference_locked(uobj)
620: struct uvm_object *uobj;
621: {
1.5 mrg 622: UVMHIST_FUNC("uao_reference"); UVMHIST_CALLED(maphist);
1.1 mrg 623:
1.5 mrg 624: /*
625: * kernel_object already has plenty of references, leave it alone.
626: */
1.1 mrg 627:
1.20 thorpej 628: if (UVM_OBJ_IS_KERN_OBJECT(uobj))
1.5 mrg 629: return;
1.1 mrg 630:
1.45.2.1! thorpej 631: uobj->uo_refs++;
1.41 chs 632: UVMHIST_LOG(maphist, "<- done (uobj=0x%x, ref = %d)",
1.27 chs 633: uobj, uobj->uo_refs,0,0);
1.1 mrg 634: }
635:
636: /*
637: * uao_detach: drop a reference to an aobj
638: *
1.27 chs 639: * => aobj must be unlocked
640: * => just lock it and call the locked version
1.1 mrg 641: */
1.45.2.1! thorpej 642:
1.5 mrg 643: void
644: uao_detach(uobj)
645: struct uvm_object *uobj;
646: {
1.27 chs 647: simple_lock(&uobj->vmobjlock);
648: uao_detach_locked(uobj);
649: }
650:
651: /*
652: * uao_detach_locked: drop a reference to an aobj
653: *
654: * => aobj must be locked, and is unlocked (or freed) upon return.
655: * this needs to be separate from the normal routine
656: * since sometimes we need to detach from an aobj when
657: * it's already locked.
658: */
1.45.2.1! thorpej 659:
1.27 chs 660: void
661: uao_detach_locked(uobj)
662: struct uvm_object *uobj;
663: {
1.5 mrg 664: struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
1.45.2.1! thorpej 665: struct vm_page *pg;
1.5 mrg 666: UVMHIST_FUNC("uao_detach"); UVMHIST_CALLED(maphist);
1.1 mrg 667:
1.5 mrg 668: /*
669: * detaching from kernel_object is a noop.
670: */
1.45.2.1! thorpej 671:
1.27 chs 672: if (UVM_OBJ_IS_KERN_OBJECT(uobj)) {
673: simple_unlock(&uobj->vmobjlock);
1.5 mrg 674: return;
1.27 chs 675: }
1.5 mrg 676:
677: UVMHIST_LOG(maphist," (uobj=0x%x) ref=%d", uobj,uobj->uo_refs,0,0);
1.45.2.1! thorpej 678: uobj->uo_refs--;
! 679: if (uobj->uo_refs) {
1.5 mrg 680: simple_unlock(&uobj->vmobjlock);
681: UVMHIST_LOG(maphist, "<- done (rc>0)", 0,0,0,0);
682: return;
683: }
684:
685: /*
686: * remove the aobj from the global list.
687: */
1.45.2.1! thorpej 688:
1.5 mrg 689: simple_lock(&uao_list_lock);
690: LIST_REMOVE(aobj, u_list);
691: simple_unlock(&uao_list_lock);
692:
693: /*
1.45.2.1! thorpej 694: * free all the pages left in the aobj. for each page,
! 695: * when the page is no longer busy (and thus after any disk i/o that
! 696: * it's involved in is complete), release any swap resources and
! 697: * free the page itself.
1.5 mrg 698: */
1.45.2.1! thorpej 699:
! 700: uvm_lock_pageq();
! 701: while ((pg = TAILQ_FIRST(&uobj->memq)) != NULL) {
! 702: pmap_page_protect(pg, VM_PROT_NONE);
1.5 mrg 703: if (pg->flags & PG_BUSY) {
1.45.2.1! thorpej 704: pg->flags |= PG_WANTED;
! 705: uvm_unlock_pageq();
! 706: UVM_UNLOCK_AND_WAIT(pg, &uobj->vmobjlock, FALSE,
! 707: "uao_det", 0);
! 708: simple_lock(&uobj->vmobjlock);
! 709: uvm_lock_pageq();
1.5 mrg 710: continue;
711: }
1.18 chs 712: uao_dropswap(&aobj->u_obj, pg->offset >> PAGE_SHIFT);
1.5 mrg 713: uvm_pagefree(pg);
714: }
1.45.2.1! thorpej 715: uvm_unlock_pageq();
1.1 mrg 716:
1.5 mrg 717: /*
1.45.2.1! thorpej 718: * finally, free the aobj itself.
1.5 mrg 719: */
1.1 mrg 720:
1.5 mrg 721: uao_free(aobj);
722: }
1.1 mrg 723:
724: /*
1.45.2.1! thorpej 725: * uao_put: flush pages out of a uvm object
1.22 thorpej 726: *
727: * => object should be locked by caller. we may _unlock_ the object
728: * if (and only if) we need to clean a page (PGO_CLEANIT).
729: * XXXJRT Currently, however, we don't. In the case of cleaning
730: * XXXJRT a page, we simply just deactivate it. Should probably
731: * XXXJRT handle this better, in the future (although "flushing"
732: * XXXJRT anonymous memory isn't terribly important).
733: * => if PGO_CLEANIT is not set, then we will neither unlock the object
734: * or block.
735: * => if PGO_ALLPAGE is set, then all pages in the object are valid targets
736: * for flushing.
737: * => NOTE: we rely on the fact that the object's memq is a TAILQ and
738: * that new pages are inserted on the tail end of the list. thus,
739: * we can make a complete pass through the object in one go by starting
740: * at the head and working towards the tail (new pages are put in
741: * front of us).
742: * => NOTE: we are allowed to lock the page queues, so the caller
743: * must not be holding the lock on them [e.g. pagedaemon had
744: * better not call us with the queues locked]
745: * => we return TRUE unless we encountered some sort of I/O error
746: * XXXJRT currently never happens, as we never directly initiate
747: * XXXJRT I/O
748: *
749: * note on page traversal:
750: * we can traverse the pages in an object either by going down the
751: * linked list in "uobj->memq", or we can go over the address range
752: * by page doing hash table lookups for each address. depending
753: * on how many pages are in the object it may be cheaper to do one
754: * or the other. we set "by_list" to true if we are using memq.
755: * if the cost of a hash lookup was equal to the cost of the list
756: * traversal we could compare the number of pages in the start->stop
757: * range to the total number of pages in the object. however, it
758: * seems that a hash table lookup is more expensive than the linked
759: * list traversal, so we multiply the number of pages in the
760: * start->stop range by a penalty which we define below.
1.1 mrg 761: */
1.22 thorpej 762:
1.45.2.1! thorpej 763: int
! 764: uao_put(uobj, start, stop, flags)
1.5 mrg 765: struct uvm_object *uobj;
1.28 kleink 766: voff_t start, stop;
1.5 mrg 767: int flags;
768: {
1.45.2.1! thorpej 769: struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
! 770: struct vm_page *pg, *nextpg;
! 771: boolean_t by_list;
1.28 kleink 772: voff_t curoff;
1.45.2.1! thorpej 773: UVMHIST_FUNC("uao_put"); UVMHIST_CALLED(maphist);
1.22 thorpej 774:
1.45.2.1! thorpej 775: curoff = 0;
1.22 thorpej 776: if (flags & PGO_ALLPAGES) {
777: start = 0;
778: stop = aobj->u_pages << PAGE_SHIFT;
779: by_list = TRUE; /* always go by the list */
780: } else {
781: start = trunc_page(start);
782: stop = round_page(stop);
783: if (stop > (aobj->u_pages << PAGE_SHIFT)) {
784: printf("uao_flush: strange, got an out of range "
785: "flush (fixed)\n");
786: stop = aobj->u_pages << PAGE_SHIFT;
787: }
788: by_list = (uobj->uo_npages <=
1.45.2.1! thorpej 789: ((stop - start) >> PAGE_SHIFT) * UVM_PAGE_HASH_PENALTY);
1.22 thorpej 790: }
791: UVMHIST_LOG(maphist,
792: " flush start=0x%lx, stop=0x%x, by_list=%d, flags=0x%x",
793: start, stop, by_list, flags);
1.1 mrg 794:
1.5 mrg 795: /*
1.22 thorpej 796: * Don't need to do any work here if we're not freeing
797: * or deactivating pages.
798: */
1.45.2.1! thorpej 799:
1.22 thorpej 800: if ((flags & (PGO_DEACTIVATE|PGO_FREE)) == 0) {
1.45.2.1! thorpej 801: simple_unlock(&uobj->vmobjlock);
! 802: return 0;
1.22 thorpej 803: }
804:
1.5 mrg 805: /*
1.45.2.1! thorpej 806: * now do it. note: we must update nextpg in the body of loop or we
! 807: * will get stuck. we need to use nextpg because we may free "pg"
1.22 thorpej 808: * before doing the next loop.
1.21 thorpej 809: */
1.22 thorpej 810:
811: if (by_list) {
1.45.2.1! thorpej 812: pg = TAILQ_FIRST(&uobj->memq);
1.22 thorpej 813: } else {
814: curoff = start;
1.45.2.1! thorpej 815: pg = uvm_pagelookup(uobj, curoff);
1.22 thorpej 816: }
817:
1.45.2.1! thorpej 818: nextpg = NULL;
! 819: uvm_lock_pageq();
1.22 thorpej 820:
821: /* locked: both page queues and uobj */
1.45.2.1! thorpej 822: for ( ; (by_list && pg != NULL) ||
! 823: (!by_list && curoff < stop) ; pg = nextpg) {
1.22 thorpej 824: if (by_list) {
1.45.2.1! thorpej 825: nextpg = TAILQ_NEXT(pg, listq);
! 826: if (pg->offset < start || pg->offset >= stop)
1.22 thorpej 827: continue;
828: } else {
829: curoff += PAGE_SIZE;
830: if (curoff < stop)
1.45.2.1! thorpej 831: nextpg = uvm_pagelookup(uobj, curoff);
! 832: if (pg == NULL)
1.22 thorpej 833: continue;
834: }
835: switch (flags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)) {
1.45.2.1! thorpej 836:
1.22 thorpej 837: /*
838: * XXX In these first 3 cases, we always just
839: * XXX deactivate the page. We may want to
840: * XXX handle the different cases more specifically
841: * XXX in the future.
842: */
1.45.2.1! thorpej 843:
1.22 thorpej 844: case PGO_CLEANIT|PGO_FREE:
845: case PGO_CLEANIT|PGO_DEACTIVATE:
846: case PGO_DEACTIVATE:
1.25 thorpej 847: deactivate_it:
1.22 thorpej 848: /* skip the page if it's loaned or wired */
1.45.2.1! thorpej 849: if (pg->loan_count != 0 || pg->wire_count != 0)
1.22 thorpej 850: continue;
851:
852: /* ...and deactivate the page. */
1.45.2.1! thorpej 853: pmap_clear_reference(pg);
! 854: uvm_pagedeactivate(pg);
1.22 thorpej 855: continue;
856:
857: case PGO_FREE:
1.45.2.1! thorpej 858:
1.25 thorpej 859: /*
860: * If there are multiple references to
861: * the object, just deactivate the page.
862: */
1.45.2.1! thorpej 863:
1.25 thorpej 864: if (uobj->uo_refs > 1)
865: goto deactivate_it;
866:
1.22 thorpej 867: /* XXX skip the page if it's loaned or wired */
1.45.2.1! thorpej 868: if (pg->loan_count != 0 || pg->wire_count != 0)
1.22 thorpej 869: continue;
870:
871: /*
1.45.2.1! thorpej 872: * wait if the page is busy, then free the swap slot
! 873: * and the page.
1.22 thorpej 874: */
875:
1.45.2.1! thorpej 876: pmap_page_protect(pg, VM_PROT_NONE);
! 877: while (pg->flags & PG_BUSY) {
! 878: pg->flags |= PG_WANTED;
! 879: uvm_unlock_pageq();
! 880: UVM_UNLOCK_AND_WAIT(pg, &uobj->vmobjlock, 0,
! 881: "uao_put", 0);
! 882: simple_lock(&uobj->vmobjlock);
! 883: uvm_lock_pageq();
! 884: }
! 885: uao_dropswap(uobj, pg->offset >> PAGE_SHIFT);
! 886: uvm_pagefree(pg);
1.22 thorpej 887: continue;
888: }
889: }
890: uvm_unlock_pageq();
1.45.2.1! thorpej 891: simple_unlock(&uobj->vmobjlock);
! 892: return 0;
1.1 mrg 893: }
894:
895: /*
896: * uao_get: fetch me a page
897: *
898: * we have three cases:
899: * 1: page is resident -> just return the page.
900: * 2: page is zero-fill -> allocate a new page and zero it.
901: * 3: page is swapped out -> fetch the page from swap.
902: *
903: * cases 1 and 2 can be handled with PGO_LOCKED, case 3 cannot.
904: * so, if the "center" page hits case 3 (or any page, with PGO_ALLPAGES),
1.40 chs 905: * then we will need to return EBUSY.
1.1 mrg 906: *
907: * => prefer map unlocked (not required)
908: * => object must be locked! we will _unlock_ it before starting any I/O.
909: * => flags: PGO_ALLPAGES: get all of the pages
910: * PGO_LOCKED: fault data structures are locked
911: * => NOTE: offset is the offset of pps[0], _NOT_ pps[centeridx]
912: * => NOTE: caller must check for released pages!!
913: */
1.45.2.1! thorpej 914:
1.5 mrg 915: static int
916: uao_get(uobj, offset, pps, npagesp, centeridx, access_type, advice, flags)
917: struct uvm_object *uobj;
1.28 kleink 918: voff_t offset;
1.5 mrg 919: struct vm_page **pps;
920: int *npagesp;
921: int centeridx, advice, flags;
922: vm_prot_t access_type;
923: {
924: struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
1.28 kleink 925: voff_t current_offset;
1.43 chs 926: struct vm_page *ptmp;
1.45.2.1! thorpej 927: int lcv, gotpages, maxpages, swslot, error, pageidx;
1.5 mrg 928: boolean_t done;
929: UVMHIST_FUNC("uao_get"); UVMHIST_CALLED(pdhist);
930:
1.27 chs 931: UVMHIST_LOG(pdhist, "aobj=%p offset=%d, flags=%d",
932: aobj, offset, flags,0);
1.37 chs 933:
1.5 mrg 934: /*
935: * get number of pages
936: */
1.45.2.1! thorpej 937:
1.5 mrg 938: maxpages = *npagesp;
939:
940: /*
941: * step 1: handled the case where fault data structures are locked.
942: */
1.1 mrg 943:
1.5 mrg 944: if (flags & PGO_LOCKED) {
1.45.2.1! thorpej 945:
1.5 mrg 946: /*
947: * step 1a: get pages that are already resident. only do
948: * this if the data structures are locked (i.e. the first
949: * time through).
950: */
951:
952: done = TRUE; /* be optimistic */
953: gotpages = 0; /* # of pages we got so far */
954: for (lcv = 0, current_offset = offset ; lcv < maxpages ;
955: lcv++, current_offset += PAGE_SIZE) {
956: /* do we care about this page? if not, skip it */
957: if (pps[lcv] == PGO_DONTCARE)
958: continue;
959: ptmp = uvm_pagelookup(uobj, current_offset);
960:
961: /*
1.30 thorpej 962: * if page is new, attempt to allocate the page,
963: * zero-fill'd.
1.5 mrg 964: */
1.45.2.1! thorpej 965:
! 966: if (ptmp == NULL && uao_find_swslot(&aobj->u_obj,
1.15 chs 967: current_offset >> PAGE_SHIFT) == 0) {
1.5 mrg 968: ptmp = uvm_pagealloc(uobj, current_offset,
1.30 thorpej 969: NULL, UVM_PGA_ZERO);
1.5 mrg 970: if (ptmp) {
971: /* new page */
1.45.2.1! thorpej 972: ptmp->flags &= ~(PG_FAKE);
1.5 mrg 973: ptmp->pqflags |= PQ_AOBJ;
1.45.2.1! thorpej 974: goto gotpage;
1.5 mrg 975: }
976: }
977:
978: /*
1.45.2.1! thorpej 979: * to be useful must get a non-busy page
1.5 mrg 980: */
1.45.2.1! thorpej 981:
! 982: if (ptmp == NULL || (ptmp->flags & PG_BUSY) != 0) {
1.5 mrg 983: if (lcv == centeridx ||
984: (flags & PGO_ALLPAGES) != 0)
985: /* need to do a wait or I/O! */
1.41 chs 986: done = FALSE;
1.5 mrg 987: continue;
988: }
989:
990: /*
991: * useful page: busy/lock it and plug it in our
992: * result array
993: */
1.45.2.1! thorpej 994:
1.5 mrg 995: /* caller must un-busy this page */
1.41 chs 996: ptmp->flags |= PG_BUSY;
1.5 mrg 997: UVM_PAGE_OWN(ptmp, "uao_get1");
1.45.2.1! thorpej 998: gotpage:
1.5 mrg 999: pps[lcv] = ptmp;
1000: gotpages++;
1.45.2.1! thorpej 1001: }
1.5 mrg 1002:
1003: /*
1004: * step 1b: now we've either done everything needed or we
1005: * to unlock and do some waiting or I/O.
1006: */
1007:
1008: UVMHIST_LOG(pdhist, "<- done (done=%d)", done, 0,0,0);
1009: *npagesp = gotpages;
1010: if (done)
1.45.2.1! thorpej 1011: return 0;
1.5 mrg 1012: else
1.45.2.1! thorpej 1013: return EBUSY;
1.1 mrg 1014: }
1015:
1.5 mrg 1016: /*
1017: * step 2: get non-resident or busy pages.
1018: * object is locked. data structures are unlocked.
1019: */
1020:
1021: for (lcv = 0, current_offset = offset ; lcv < maxpages ;
1022: lcv++, current_offset += PAGE_SIZE) {
1.27 chs 1023:
1.5 mrg 1024: /*
1025: * - skip over pages we've already gotten or don't want
1026: * - skip over pages we don't _have_ to get
1027: */
1.27 chs 1028:
1.5 mrg 1029: if (pps[lcv] != NULL ||
1030: (lcv != centeridx && (flags & PGO_ALLPAGES) == 0))
1031: continue;
1032:
1.27 chs 1033: pageidx = current_offset >> PAGE_SHIFT;
1034:
1.5 mrg 1035: /*
1036: * we have yet to locate the current page (pps[lcv]). we
1037: * first look for a page that is already at the current offset.
1038: * if we find a page, we check to see if it is busy or
1039: * released. if that is the case, then we sleep on the page
1040: * until it is no longer busy or released and repeat the lookup.
1041: * if the page we found is neither busy nor released, then we
1042: * busy it (so we own it) and plug it into pps[lcv]. this
1043: * 'break's the following while loop and indicates we are
1044: * ready to move on to the next page in the "lcv" loop above.
1045: *
1046: * if we exit the while loop with pps[lcv] still set to NULL,
1047: * then it means that we allocated a new busy/fake/clean page
1048: * ptmp in the object and we need to do I/O to fill in the data.
1049: */
1050:
1051: /* top of "pps" while loop */
1052: while (pps[lcv] == NULL) {
1053: /* look for a resident page */
1054: ptmp = uvm_pagelookup(uobj, current_offset);
1055:
1056: /* not resident? allocate one now (if we can) */
1057: if (ptmp == NULL) {
1058:
1059: ptmp = uvm_pagealloc(uobj, current_offset,
1.19 chs 1060: NULL, 0);
1.5 mrg 1061:
1062: /* out of RAM? */
1063: if (ptmp == NULL) {
1064: simple_unlock(&uobj->vmobjlock);
1065: UVMHIST_LOG(pdhist,
1066: "sleeping, ptmp == NULL\n",0,0,0,0);
1067: uvm_wait("uao_getpage");
1068: simple_lock(&uobj->vmobjlock);
1.41 chs 1069: continue;
1.5 mrg 1070: }
1071:
1072: /*
1073: * safe with PQ's unlocked: because we just
1074: * alloc'd the page
1075: */
1.45.2.1! thorpej 1076:
1.5 mrg 1077: ptmp->pqflags |= PQ_AOBJ;
1078:
1.41 chs 1079: /*
1.5 mrg 1080: * got new page ready for I/O. break pps while
1081: * loop. pps[lcv] is still NULL.
1082: */
1.45.2.1! thorpej 1083:
1.5 mrg 1084: break;
1085: }
1086:
1087: /* page is there, see if we need to wait on it */
1.45.2.1! thorpej 1088: if ((ptmp->flags & PG_BUSY) != 0) {
1.5 mrg 1089: ptmp->flags |= PG_WANTED;
1090: UVMHIST_LOG(pdhist,
1091: "sleeping, ptmp->flags 0x%x\n",
1092: ptmp->flags,0,0,0);
1.23 thorpej 1093: UVM_UNLOCK_AND_WAIT(ptmp, &uobj->vmobjlock,
1094: FALSE, "uao_get", 0);
1.5 mrg 1095: simple_lock(&uobj->vmobjlock);
1.45.2.1! thorpej 1096: continue;
1.5 mrg 1097: }
1.41 chs 1098:
1099: /*
1.5 mrg 1100: * if we get here then the page has become resident and
1101: * unbusy between steps 1 and 2. we busy it now (so we
1102: * own it) and set pps[lcv] (so that we exit the while
1103: * loop).
1104: */
1.45.2.1! thorpej 1105:
1.5 mrg 1106: /* we own it, caller must un-busy */
1107: ptmp->flags |= PG_BUSY;
1108: UVM_PAGE_OWN(ptmp, "uao_get2");
1109: pps[lcv] = ptmp;
1110: }
1111:
1112: /*
1113: * if we own the valid page at the correct offset, pps[lcv] will
1114: * point to it. nothing more to do except go to the next page.
1115: */
1.45.2.1! thorpej 1116:
1.5 mrg 1117: if (pps[lcv])
1118: continue; /* next lcv */
1119:
1120: /*
1.41 chs 1121: * we have a "fake/busy/clean" page that we just allocated.
1.5 mrg 1122: * do the needed "i/o", either reading from swap or zeroing.
1123: */
1.45.2.1! thorpej 1124:
! 1125: swslot = uao_find_swslot(&aobj->u_obj, pageidx);
1.5 mrg 1126:
1127: /*
1128: * just zero the page if there's nothing in swap.
1129: */
1.45.2.1! thorpej 1130:
! 1131: if (swslot == 0) {
! 1132:
1.5 mrg 1133: /*
1134: * page hasn't existed before, just zero it.
1135: */
1.45.2.1! thorpej 1136:
1.5 mrg 1137: uvm_pagezero(ptmp);
1.27 chs 1138: } else {
1.5 mrg 1139: UVMHIST_LOG(pdhist, "pagein from swslot %d",
1140: swslot, 0,0,0);
1141:
1142: /*
1143: * page in the swapped-out page.
1144: * unlock object for i/o, relock when done.
1145: */
1.45.2.1! thorpej 1146:
1.5 mrg 1147: simple_unlock(&uobj->vmobjlock);
1.45.2.1! thorpej 1148: error = uvm_swap_get(ptmp, swslot, PGO_SYNCIO);
1.5 mrg 1149: simple_lock(&uobj->vmobjlock);
1150:
1151: /*
1152: * I/O done. check for errors.
1153: */
1.45.2.1! thorpej 1154:
! 1155: if (error != 0) {
1.5 mrg 1156: UVMHIST_LOG(pdhist, "<- done (error=%d)",
1.45.2.1! thorpej 1157: error,0,0,0);
1.5 mrg 1158: if (ptmp->flags & PG_WANTED)
1.24 thorpej 1159: wakeup(ptmp);
1.27 chs 1160:
1161: /*
1162: * remove the swap slot from the aobj
1163: * and mark the aobj as having no real slot.
1164: * don't free the swap slot, thus preventing
1165: * it from being used again.
1166: */
1.45.2.1! thorpej 1167:
1.27 chs 1168: swslot = uao_set_swslot(&aobj->u_obj, pageidx,
1169: SWSLOT_BAD);
1.45 chs 1170: if (swslot != -1) {
1171: uvm_swap_markbad(swslot, 1);
1172: }
1.27 chs 1173:
1.5 mrg 1174: uvm_lock_pageq();
1175: uvm_pagefree(ptmp);
1176: uvm_unlock_pageq();
1177: simple_unlock(&uobj->vmobjlock);
1.45.2.1! thorpej 1178: return error;
1.5 mrg 1179: }
1180: }
1181:
1.41 chs 1182: /*
1.5 mrg 1183: * we got the page! clear the fake flag (indicates valid
1184: * data now in page) and plug into our result array. note
1.41 chs 1185: * that page is still busy.
1.5 mrg 1186: *
1187: * it is the callers job to:
1188: * => check if the page is released
1189: * => unbusy the page
1190: * => activate the page
1191: */
1192:
1.45.2.1! thorpej 1193: ptmp->flags &= ~PG_FAKE;
1.5 mrg 1194: pps[lcv] = ptmp;
1.45.2.1! thorpej 1195: }
1.1 mrg 1196:
1197: /*
1.5 mrg 1198: * finally, unlock object and return.
1199: */
1.1 mrg 1200:
1201: simple_unlock(&uobj->vmobjlock);
1.5 mrg 1202: UVMHIST_LOG(pdhist, "<- done (OK)",0,0,0,0);
1.45.2.1! thorpej 1203: return 0;
1.1 mrg 1204: }
1205:
1206: /*
1.18 chs 1207: * uao_dropswap: release any swap resources from this aobj page.
1.41 chs 1208: *
1.18 chs 1209: * => aobj must be locked or have a reference count of 0.
1210: */
1211:
1212: void
1213: uao_dropswap(uobj, pageidx)
1214: struct uvm_object *uobj;
1215: int pageidx;
1216: {
1217: int slot;
1218:
1219: slot = uao_set_swslot(uobj, pageidx, 0);
1220: if (slot) {
1221: uvm_swap_free(slot, 1);
1222: }
1.27 chs 1223: }
1224:
1225: /*
1226: * page in every page in every aobj that is paged-out to a range of swslots.
1.41 chs 1227: *
1.27 chs 1228: * => nothing should be locked.
1229: * => returns TRUE if pagein was aborted due to lack of memory.
1230: */
1.45.2.1! thorpej 1231:
1.27 chs 1232: boolean_t
1233: uao_swap_off(startslot, endslot)
1234: int startslot, endslot;
1235: {
1236: struct uvm_aobj *aobj, *nextaobj;
1.45.2.1! thorpej 1237: boolean_t rv;
1.27 chs 1238:
1239: /*
1240: * walk the list of all aobjs.
1241: */
1242:
1243: restart:
1244: simple_lock(&uao_list_lock);
1245: for (aobj = LIST_FIRST(&uao_list);
1246: aobj != NULL;
1247: aobj = nextaobj) {
1248:
1249: /*
1.45.2.1! thorpej 1250: * try to get the object lock, start all over if we fail.
1.27 chs 1251: * most of the time we'll get the aobj lock,
1252: * so this should be a rare case.
1253: */
1.45.2.1! thorpej 1254:
1.27 chs 1255: if (!simple_lock_try(&aobj->u_obj.vmobjlock)) {
1256: simple_unlock(&uao_list_lock);
1257: goto restart;
1258: }
1259:
1260: /*
1261: * add a ref to the aobj so it doesn't disappear
1262: * while we're working.
1263: */
1.45.2.1! thorpej 1264:
1.27 chs 1265: uao_reference_locked(&aobj->u_obj);
1266:
1267: /*
1268: * now it's safe to unlock the uao list.
1269: */
1.45.2.1! thorpej 1270:
1.27 chs 1271: simple_unlock(&uao_list_lock);
1272:
1273: /*
1274: * page in any pages in the swslot range.
1275: * if there's an error, abort and return the error.
1276: */
1.45.2.1! thorpej 1277:
1.27 chs 1278: rv = uao_pagein(aobj, startslot, endslot);
1279: if (rv) {
1280: uao_detach_locked(&aobj->u_obj);
1281: return rv;
1282: }
1283:
1284: /*
1285: * we're done with this aobj.
1286: * relock the list and drop our ref on the aobj.
1287: */
1.45.2.1! thorpej 1288:
1.27 chs 1289: simple_lock(&uao_list_lock);
1290: nextaobj = LIST_NEXT(aobj, u_list);
1291: uao_detach_locked(&aobj->u_obj);
1292: }
1293:
1294: /*
1295: * done with traversal, unlock the list
1296: */
1297: simple_unlock(&uao_list_lock);
1298: return FALSE;
1299: }
1300:
1301:
1302: /*
1303: * page in any pages from aobj in the given range.
1304: *
1305: * => aobj must be locked and is returned locked.
1306: * => returns TRUE if pagein was aborted due to lack of memory.
1307: */
1308: static boolean_t
1309: uao_pagein(aobj, startslot, endslot)
1310: struct uvm_aobj *aobj;
1311: int startslot, endslot;
1312: {
1313: boolean_t rv;
1314:
1315: if (UAO_USES_SWHASH(aobj)) {
1316: struct uao_swhash_elt *elt;
1317: int bucket;
1318:
1319: restart:
1320: for (bucket = aobj->u_swhashmask; bucket >= 0; bucket--) {
1321: for (elt = LIST_FIRST(&aobj->u_swhash[bucket]);
1322: elt != NULL;
1323: elt = LIST_NEXT(elt, list)) {
1324: int i;
1325:
1326: for (i = 0; i < UAO_SWHASH_CLUSTER_SIZE; i++) {
1327: int slot = elt->slots[i];
1328:
1329: /*
1330: * if the slot isn't in range, skip it.
1331: */
1.45.2.1! thorpej 1332:
1.41 chs 1333: if (slot < startslot ||
1.27 chs 1334: slot >= endslot) {
1335: continue;
1336: }
1337:
1338: /*
1339: * process the page,
1340: * the start over on this object
1341: * since the swhash elt
1342: * may have been freed.
1343: */
1.45.2.1! thorpej 1344:
1.27 chs 1345: rv = uao_pagein_page(aobj,
1346: UAO_SWHASH_ELT_PAGEIDX_BASE(elt) + i);
1347: if (rv) {
1348: return rv;
1349: }
1350: goto restart;
1351: }
1352: }
1353: }
1354: } else {
1355: int i;
1356:
1357: for (i = 0; i < aobj->u_pages; i++) {
1358: int slot = aobj->u_swslots[i];
1359:
1360: /*
1361: * if the slot isn't in range, skip it
1362: */
1.45.2.1! thorpej 1363:
1.27 chs 1364: if (slot < startslot || slot >= endslot) {
1365: continue;
1366: }
1367:
1368: /*
1369: * process the page.
1370: */
1.45.2.1! thorpej 1371:
1.27 chs 1372: rv = uao_pagein_page(aobj, i);
1373: if (rv) {
1374: return rv;
1375: }
1376: }
1377: }
1378:
1379: return FALSE;
1380: }
1381:
1382: /*
1383: * page in a page from an aobj. used for swap_off.
1384: * returns TRUE if pagein was aborted due to lack of memory.
1385: *
1386: * => aobj must be locked and is returned locked.
1387: */
1.45.2.1! thorpej 1388:
1.27 chs 1389: static boolean_t
1390: uao_pagein_page(aobj, pageidx)
1391: struct uvm_aobj *aobj;
1392: int pageidx;
1393: {
1394: struct vm_page *pg;
1395: int rv, slot, npages;
1396:
1397: pg = NULL;
1398: npages = 1;
1399: /* locked: aobj */
1400: rv = uao_get(&aobj->u_obj, pageidx << PAGE_SHIFT,
1401: &pg, &npages, 0, VM_PROT_READ|VM_PROT_WRITE, 0, 0);
1402: /* unlocked: aobj */
1403:
1404: /*
1405: * relock and finish up.
1406: */
1407:
1.45.2.1! thorpej 1408: simple_lock(&aobj->u_obj.vmobjlock);
1.27 chs 1409: switch (rv) {
1.40 chs 1410: case 0:
1.27 chs 1411: break;
1412:
1.40 chs 1413: case EIO:
1414: case ERESTART:
1.45.2.1! thorpej 1415:
1.27 chs 1416: /*
1417: * nothing more to do on errors.
1.40 chs 1418: * ERESTART can only mean that the anon was freed,
1.27 chs 1419: * so again there's nothing to do.
1420: */
1421:
1.45.2.1! thorpej 1422: return FALSE;
1.27 chs 1423: }
1424:
1425: /*
1426: * ok, we've got the page now.
1427: * mark it as dirty, clear its swslot and un-busy it.
1428: */
1.45.2.1! thorpej 1429:
1.27 chs 1430: slot = uao_set_swslot(&aobj->u_obj, pageidx, 0);
1431: uvm_swap_free(slot, 1);
1432: pg->flags &= ~(PG_BUSY|PG_CLEAN|PG_FAKE);
1433: UVM_PAGE_OWN(pg, NULL);
1434:
1435: /*
1.45.2.1! thorpej 1436: * deactivate the page (to make sure it's on a page queue).
1.27 chs 1437: */
1.45.2.1! thorpej 1438:
1.27 chs 1439: uvm_lock_pageq();
1440: uvm_pagedeactivate(pg);
1441: uvm_unlock_pageq();
1442: return FALSE;
1.1 mrg 1443: }
CVSweb <webmaster@jp.NetBSD.org>
![[BACK]](/icons/back.gif){kind=icon}
Return to uvm_aobj.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [cvs.NetBSD.org] / src / sys / uvm