Annotation of src/sys/uvm/uvm_aobj.c, Revision 1.137
1.137 ! ad 1: /* $NetBSD: uvm_aobj.c,v 1.136 2020/02/24 12:38:57 rin 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: *
17: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27: *
1.4 mrg 28: * from: Id: uvm_aobj.c,v 1.1.2.5 1998/02/06 05:14:38 chs Exp
29: */
1.113 rmind 30:
1.7 chs 31: /*
32: * uvm_aobj.c: anonymous memory uvm_object pager
33: *
34: * author: Chuck Silvers <chuq@chuq.com>
35: * started: Jan-1998
36: *
37: * - design mostly from Chuck Cranor
38: */
1.49 lukem 39:
40: #include <sys/cdefs.h>
1.137 ! ad 41: __KERNEL_RCSID(0, "$NetBSD: uvm_aobj.c,v 1.136 2020/02/24 12:38:57 rin Exp $");
1.7 chs 42:
1.123 pooka 43: #ifdef _KERNEL_OPT
1.7 chs 44: #include "opt_uvmhist.h"
1.123 pooka 45: #endif
1.1 mrg 46:
47: #include <sys/param.h>
48: #include <sys/systm.h>
1.37 chs 49: #include <sys/kernel.h>
1.104 rmind 50: #include <sys/kmem.h>
1.12 thorpej 51: #include <sys/pool.h>
1.119 matt 52: #include <sys/atomic.h>
1.1 mrg 53:
54: #include <uvm/uvm.h>
1.132 ad 55: #include <uvm/uvm_page_array.h>
1.1 mrg 56:
57: /*
1.117 rmind 58: * An anonymous UVM object (aobj) manages anonymous-memory. In addition to
59: * keeping the list of resident pages, it may also keep a list of allocated
60: * swap blocks. Depending on the size of the object, this list is either
61: * stored in an array (small objects) or in a hash table (large objects).
62: *
63: * Lock order
64: *
1.118 rmind 65: * uao_list_lock ->
66: * uvm_object::vmobjlock
1.1 mrg 67: */
68:
69: /*
1.117 rmind 70: * Note: for hash tables, we break the address space of the aobj into blocks
71: * of UAO_SWHASH_CLUSTER_SIZE pages, which shall be a power of two.
1.1 mrg 72: */
73:
1.117 rmind 74: #define UAO_SWHASH_CLUSTER_SHIFT 4
75: #define UAO_SWHASH_CLUSTER_SIZE (1 << UAO_SWHASH_CLUSTER_SHIFT)
1.1 mrg 76:
1.117 rmind 77: /* Get the "tag" for this page index. */
78: #define UAO_SWHASH_ELT_TAG(idx) ((idx) >> UAO_SWHASH_CLUSTER_SHIFT)
79: #define UAO_SWHASH_ELT_PAGESLOT_IDX(idx) \
80: ((idx) & (UAO_SWHASH_CLUSTER_SIZE - 1))
1.1 mrg 81:
1.117 rmind 82: /* Given an ELT and a page index, find the swap slot. */
83: #define UAO_SWHASH_ELT_PAGESLOT(elt, idx) \
84: ((elt)->slots[UAO_SWHASH_ELT_PAGESLOT_IDX(idx)])
1.75 yamt 85:
1.117 rmind 86: /* Given an ELT, return its pageidx base. */
87: #define UAO_SWHASH_ELT_PAGEIDX_BASE(ELT) \
88: ((elt)->tag << UAO_SWHASH_CLUSTER_SHIFT)
1.1 mrg 89:
1.117 rmind 90: /* The hash function. */
91: #define UAO_SWHASH_HASH(aobj, idx) \
92: (&(aobj)->u_swhash[(((idx) >> UAO_SWHASH_CLUSTER_SHIFT) \
93: & (aobj)->u_swhashmask)])
1.1 mrg 94:
95: /*
1.117 rmind 96: * The threshold which determines whether we will use an array or a
1.1 mrg 97: * hash table to store the list of allocated swap blocks.
98: */
1.117 rmind 99: #define UAO_SWHASH_THRESHOLD (UAO_SWHASH_CLUSTER_SIZE * 4)
100: #define UAO_USES_SWHASH(aobj) \
101: ((aobj)->u_pages > UAO_SWHASH_THRESHOLD)
102:
103: /* The number of buckets in a hash, with an upper bound. */
104: #define UAO_SWHASH_MAXBUCKETS 256
105: #define UAO_SWHASH_BUCKETS(aobj) \
106: (MIN((aobj)->u_pages >> UAO_SWHASH_CLUSTER_SHIFT, UAO_SWHASH_MAXBUCKETS))
1.1 mrg 107:
108: /*
109: * uao_swhash_elt: when a hash table is being used, this structure defines
110: * the format of an entry in the bucket list.
111: */
112:
113: struct uao_swhash_elt {
1.5 mrg 114: LIST_ENTRY(uao_swhash_elt) list; /* the hash list */
1.28 kleink 115: voff_t tag; /* our 'tag' */
1.5 mrg 116: int count; /* our number of active slots */
117: int slots[UAO_SWHASH_CLUSTER_SIZE]; /* the slots */
1.1 mrg 118: };
119:
120: /*
121: * uao_swhash: the swap hash table structure
122: */
123:
124: LIST_HEAD(uao_swhash, uao_swhash_elt);
125:
1.12 thorpej 126: /*
1.113 rmind 127: * uao_swhash_elt_pool: pool of uao_swhash_elt structures.
128: * Note: pages for this pool must not come from a pageable kernel map.
1.12 thorpej 129: */
1.117 rmind 130: static struct pool uao_swhash_elt_pool __cacheline_aligned;
1.1 mrg 131:
132: /*
133: * uvm_aobj: the actual anon-backed uvm_object
134: *
135: * => the uvm_object is at the top of the structure, this allows
1.46 chs 136: * (struct uvm_aobj *) == (struct uvm_object *)
1.1 mrg 137: * => only one of u_swslots and u_swhash is used in any given aobj
138: */
139:
140: struct uvm_aobj {
1.132 ad 141: struct uvm_object u_obj; /* has: lock, pgops, #pages, #refs */
1.79 cherry 142: pgoff_t u_pages; /* number of pages in entire object */
1.5 mrg 143: int u_flags; /* the flags (see uvm_aobj.h) */
144: int *u_swslots; /* array of offset->swapslot mappings */
145: /*
146: * hashtable of offset->swapslot mappings
147: * (u_swhash is an array of bucket heads)
148: */
149: struct uao_swhash *u_swhash;
150: u_long u_swhashmask; /* mask for hashtable */
151: LIST_ENTRY(uvm_aobj) u_list; /* global list of aobjs */
1.121 riastrad 152: int u_freelist; /* freelist to allocate pages from */
1.1 mrg 153: };
154:
1.62 junyoung 155: static void uao_free(struct uvm_aobj *);
156: static int uao_get(struct uvm_object *, voff_t, struct vm_page **,
157: int *, int, vm_prot_t, int, int);
1.86 matt 158: static int uao_put(struct uvm_object *, voff_t, voff_t, int);
1.72 yamt 159:
160: #if defined(VMSWAP)
161: static struct uao_swhash_elt *uao_find_swhash_elt
1.85 thorpej 162: (struct uvm_aobj *, int, bool);
1.72 yamt 163:
1.85 thorpej 164: static bool uao_pagein(struct uvm_aobj *, int, int);
165: static bool uao_pagein_page(struct uvm_aobj *, int);
1.72 yamt 166: #endif /* defined(VMSWAP) */
1.1 mrg 167:
1.121 riastrad 168: static struct vm_page *uao_pagealloc(struct uvm_object *, voff_t, int);
169:
1.1 mrg 170: /*
171: * aobj_pager
1.41 chs 172: *
1.1 mrg 173: * note that some functions (e.g. put) are handled elsewhere
174: */
175:
1.95 yamt 176: const struct uvm_pagerops aobj_pager = {
1.94 yamt 177: .pgo_reference = uao_reference,
178: .pgo_detach = uao_detach,
179: .pgo_get = uao_get,
180: .pgo_put = uao_put,
1.1 mrg 181: };
182:
183: /*
184: * uao_list: global list of active aobjs, locked by uao_list_lock
185: */
186:
1.117 rmind 187: static LIST_HEAD(aobjlist, uvm_aobj) uao_list __cacheline_aligned;
188: static kmutex_t uao_list_lock __cacheline_aligned;
1.1 mrg 189:
190: /*
191: * hash table/array related functions
192: */
193:
1.72 yamt 194: #if defined(VMSWAP)
195:
1.1 mrg 196: /*
197: * uao_find_swhash_elt: find (or create) a hash table entry for a page
198: * offset.
199: *
200: * => the object should be locked by the caller
201: */
202:
1.5 mrg 203: static struct uao_swhash_elt *
1.85 thorpej 204: uao_find_swhash_elt(struct uvm_aobj *aobj, int pageidx, bool create)
1.5 mrg 205: {
206: struct uao_swhash *swhash;
207: struct uao_swhash_elt *elt;
1.28 kleink 208: voff_t page_tag;
1.1 mrg 209:
1.45 chs 210: swhash = UAO_SWHASH_HASH(aobj, pageidx);
211: page_tag = UAO_SWHASH_ELT_TAG(pageidx);
1.1 mrg 212:
1.5 mrg 213: /*
214: * now search the bucket for the requested tag
215: */
1.45 chs 216:
1.37 chs 217: LIST_FOREACH(elt, swhash, list) {
1.45 chs 218: if (elt->tag == page_tag) {
219: return elt;
220: }
1.5 mrg 221: }
1.45 chs 222: if (!create) {
1.5 mrg 223: return NULL;
1.45 chs 224: }
1.5 mrg 225:
226: /*
1.12 thorpej 227: * allocate a new entry for the bucket and init/insert it in
1.5 mrg 228: */
1.45 chs 229:
230: elt = pool_get(&uao_swhash_elt_pool, PR_NOWAIT);
231: if (elt == NULL) {
232: return NULL;
233: }
1.5 mrg 234: LIST_INSERT_HEAD(swhash, elt, list);
235: elt->tag = page_tag;
236: elt->count = 0;
1.9 perry 237: memset(elt->slots, 0, sizeof(elt->slots));
1.45 chs 238: return elt;
1.1 mrg 239: }
240:
241: /*
242: * uao_find_swslot: find the swap slot number for an aobj/pageidx
243: *
1.41 chs 244: * => object must be locked by caller
1.1 mrg 245: */
1.46 chs 246:
247: int
1.67 thorpej 248: uao_find_swslot(struct uvm_object *uobj, int pageidx)
1.1 mrg 249: {
1.46 chs 250: struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
251: struct uao_swhash_elt *elt;
1.1 mrg 252:
1.5 mrg 253: /*
254: * if noswap flag is set, then we never return a slot
255: */
1.1 mrg 256:
1.5 mrg 257: if (aobj->u_flags & UAO_FLAG_NOSWAP)
1.117 rmind 258: return 0;
1.1 mrg 259:
1.5 mrg 260: /*
261: * if hashing, look in hash table.
262: */
1.1 mrg 263:
1.5 mrg 264: if (UAO_USES_SWHASH(aobj)) {
1.87 thorpej 265: elt = uao_find_swhash_elt(aobj, pageidx, false);
1.117 rmind 266: return elt ? UAO_SWHASH_ELT_PAGESLOT(elt, pageidx) : 0;
1.5 mrg 267: }
1.1 mrg 268:
1.41 chs 269: /*
1.5 mrg 270: * otherwise, look in the array
271: */
1.46 chs 272:
1.117 rmind 273: return aobj->u_swslots[pageidx];
1.1 mrg 274: }
275:
276: /*
277: * uao_set_swslot: set the swap slot for a page in an aobj.
278: *
279: * => setting a slot to zero frees the slot
280: * => object must be locked by caller
1.45 chs 281: * => we return the old slot number, or -1 if we failed to allocate
282: * memory to record the new slot number
1.1 mrg 283: */
1.46 chs 284:
1.5 mrg 285: int
1.67 thorpej 286: uao_set_swslot(struct uvm_object *uobj, int pageidx, int slot)
1.5 mrg 287: {
288: struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
1.45 chs 289: struct uao_swhash_elt *elt;
1.5 mrg 290: int oldslot;
291: UVMHIST_FUNC("uao_set_swslot"); UVMHIST_CALLED(pdhist);
1.126 pgoyette 292: UVMHIST_LOG(pdhist, "aobj %#jx pageidx %jd slot %jd",
293: (uintptr_t)aobj, pageidx, slot, 0);
1.1 mrg 294:
1.135 ad 295: KASSERT(rw_write_held(uobj->vmobjlock) || uobj->uo_refs == 0);
1.109 rmind 296:
1.5 mrg 297: /*
1.46 chs 298: * if noswap flag is set, then we can't set a non-zero slot.
1.5 mrg 299: */
1.1 mrg 300:
1.5 mrg 301: if (aobj->u_flags & UAO_FLAG_NOSWAP) {
1.117 rmind 302: KASSERTMSG(slot == 0, "uao_set_swslot: no swap object");
303: return 0;
1.5 mrg 304: }
1.1 mrg 305:
1.5 mrg 306: /*
307: * are we using a hash table? if so, add it in the hash.
308: */
1.1 mrg 309:
1.5 mrg 310: if (UAO_USES_SWHASH(aobj)) {
1.39 chs 311:
1.12 thorpej 312: /*
313: * Avoid allocating an entry just to free it again if
314: * the page had not swap slot in the first place, and
315: * we are freeing.
316: */
1.39 chs 317:
1.46 chs 318: elt = uao_find_swhash_elt(aobj, pageidx, slot != 0);
1.12 thorpej 319: if (elt == NULL) {
1.45 chs 320: return slot ? -1 : 0;
1.12 thorpej 321: }
1.5 mrg 322:
323: oldslot = UAO_SWHASH_ELT_PAGESLOT(elt, pageidx);
324: UAO_SWHASH_ELT_PAGESLOT(elt, pageidx) = slot;
325:
326: /*
327: * now adjust the elt's reference counter and free it if we've
328: * dropped it to zero.
329: */
330:
331: if (slot) {
332: if (oldslot == 0)
333: elt->count++;
1.45 chs 334: } else {
335: if (oldslot)
1.5 mrg 336: elt->count--;
337:
338: if (elt->count == 0) {
339: LIST_REMOVE(elt, list);
1.12 thorpej 340: pool_put(&uao_swhash_elt_pool, elt);
1.5 mrg 341: }
342: }
1.41 chs 343: } else {
1.5 mrg 344: /* we are using an array */
345: oldslot = aobj->u_swslots[pageidx];
346: aobj->u_swslots[pageidx] = slot;
347: }
1.117 rmind 348: return oldslot;
1.1 mrg 349: }
350:
1.72 yamt 351: #endif /* defined(VMSWAP) */
352:
1.1 mrg 353: /*
354: * end of hash/array functions
355: */
356:
357: /*
358: * uao_free: free all resources held by an aobj, and then free the aobj
359: *
360: * => the aobj should be dead
361: */
1.46 chs 362:
1.1 mrg 363: static void
1.67 thorpej 364: uao_free(struct uvm_aobj *aobj)
1.1 mrg 365: {
1.117 rmind 366: struct uvm_object *uobj = &aobj->u_obj;
1.96 ad 367:
1.135 ad 368: KASSERT(rw_write_held(uobj->vmobjlock));
1.118 rmind 369: uao_dropswap_range(uobj, 0, 0);
1.135 ad 370: rw_exit(uobj->vmobjlock);
1.72 yamt 371:
372: #if defined(VMSWAP)
1.5 mrg 373: if (UAO_USES_SWHASH(aobj)) {
1.1 mrg 374:
1.5 mrg 375: /*
1.75 yamt 376: * free the hash table itself.
1.5 mrg 377: */
1.46 chs 378:
1.104 rmind 379: hashdone(aobj->u_swhash, HASH_LIST, aobj->u_swhashmask);
1.5 mrg 380: } else {
381:
382: /*
1.75 yamt 383: * free the array itsself.
1.5 mrg 384: */
385:
1.104 rmind 386: kmem_free(aobj->u_swslots, aobj->u_pages * sizeof(int));
1.1 mrg 387: }
1.72 yamt 388: #endif /* defined(VMSWAP) */
389:
1.5 mrg 390: /*
391: * finally free the aobj itself
392: */
1.46 chs 393:
1.117 rmind 394: uvm_obj_destroy(uobj, true);
1.113 rmind 395: kmem_free(aobj, sizeof(struct uvm_aobj));
1.1 mrg 396: }
397:
398: /*
399: * pager functions
400: */
401:
402: /*
403: * uao_create: create an aobj of the given size and return its uvm_object.
404: *
405: * => for normal use, flags are always zero
406: * => for the kernel object, the flags are:
407: * UAO_FLAG_KERNOBJ - allocate the kernel object (can only happen once)
408: * UAO_FLAG_KERNSWAP - enable swapping of kernel object (" ")
409: */
1.46 chs 410:
1.5 mrg 411: struct uvm_object *
1.127 chs 412: uao_create(voff_t size, int flags)
1.5 mrg 413: {
1.46 chs 414: static struct uvm_aobj kernel_object_store;
1.135 ad 415: static krwlock_t kernel_object_lock __cacheline_aligned;
1.120 martin 416: static int kobj_alloced __diagused = 0;
1.127 chs 417: pgoff_t pages = round_page((uint64_t)size) >> PAGE_SHIFT;
1.5 mrg 418: struct uvm_aobj *aobj;
1.66 yamt 419: int refs;
1.1 mrg 420:
1.5 mrg 421: /*
1.114 rmind 422: * Allocate a new aobj, unless kernel object is requested.
1.27 chs 423: */
1.5 mrg 424:
1.46 chs 425: if (flags & UAO_FLAG_KERNOBJ) {
426: KASSERT(!kobj_alloced);
1.5 mrg 427: aobj = &kernel_object_store;
428: aobj->u_pages = pages;
1.46 chs 429: aobj->u_flags = UAO_FLAG_NOSWAP;
1.66 yamt 430: refs = UVM_OBJ_KERN;
1.5 mrg 431: kobj_alloced = UAO_FLAG_KERNOBJ;
432: } else if (flags & UAO_FLAG_KERNSWAP) {
1.46 chs 433: KASSERT(kobj_alloced == UAO_FLAG_KERNOBJ);
1.5 mrg 434: aobj = &kernel_object_store;
435: kobj_alloced = UAO_FLAG_KERNSWAP;
1.66 yamt 436: refs = 0xdeadbeaf; /* XXX: gcc */
1.46 chs 437: } else {
1.113 rmind 438: aobj = kmem_alloc(sizeof(struct uvm_aobj), KM_SLEEP);
1.5 mrg 439: aobj->u_pages = pages;
1.46 chs 440: aobj->u_flags = 0;
1.66 yamt 441: refs = 1;
1.5 mrg 442: }
1.1 mrg 443:
1.5 mrg 444: /*
1.121 riastrad 445: * no freelist by default
446: */
447:
448: aobj->u_freelist = VM_NFREELIST;
449:
450: /*
1.5 mrg 451: * allocate hash/array if necessary
452: *
453: * note: in the KERNSWAP case no need to worry about locking since
454: * we are still booting we should be the only thread around.
455: */
1.46 chs 456:
1.5 mrg 457: if (flags == 0 || (flags & UAO_FLAG_KERNSWAP) != 0) {
1.72 yamt 458: #if defined(VMSWAP)
1.104 rmind 459: const int kernswap = (flags & UAO_FLAG_KERNSWAP) != 0;
1.5 mrg 460:
461: /* allocate hash table or array depending on object size */
1.27 chs 462: if (UAO_USES_SWHASH(aobj)) {
1.104 rmind 463: aobj->u_swhash = hashinit(UAO_SWHASH_BUCKETS(aobj),
464: HASH_LIST, kernswap ? false : true,
465: &aobj->u_swhashmask);
1.5 mrg 466: if (aobj->u_swhash == NULL)
467: panic("uao_create: hashinit swhash failed");
468: } else {
1.104 rmind 469: aobj->u_swslots = kmem_zalloc(pages * sizeof(int),
470: kernswap ? KM_NOSLEEP : KM_SLEEP);
1.5 mrg 471: if (aobj->u_swslots == NULL)
1.114 rmind 472: panic("uao_create: swslots allocation failed");
1.5 mrg 473: }
1.72 yamt 474: #endif /* defined(VMSWAP) */
1.5 mrg 475:
476: if (flags) {
477: aobj->u_flags &= ~UAO_FLAG_NOSWAP; /* clear noswap */
1.117 rmind 478: return &aobj->u_obj;
1.5 mrg 479: }
480: }
481:
482: /*
1.115 rmind 483: * Initialise UVM object.
484: */
1.46 chs 485:
1.115 rmind 486: const bool kernobj = (flags & UAO_FLAG_KERNOBJ) != 0;
487: uvm_obj_init(&aobj->u_obj, &aobj_pager, !kernobj, refs);
488: if (__predict_false(kernobj)) {
489: /* Initialisation only once, for UAO_FLAG_KERNOBJ. */
1.135 ad 490: rw_init(&kernel_object_lock);
1.115 rmind 491: uvm_obj_setlock(&aobj->u_obj, &kernel_object_lock);
492: }
1.1 mrg 493:
1.5 mrg 494: /*
495: * now that aobj is ready, add it to the global list
496: */
1.46 chs 497:
1.90 ad 498: mutex_enter(&uao_list_lock);
1.5 mrg 499: LIST_INSERT_HEAD(&uao_list, aobj, u_list);
1.90 ad 500: mutex_exit(&uao_list_lock);
1.5 mrg 501: return(&aobj->u_obj);
1.1 mrg 502: }
503:
504: /*
1.121 riastrad 505: * uao_set_pgfl: allocate pages only from the specified freelist.
506: *
507: * => must be called before any pages are allocated for the object.
1.122 riastrad 508: * => reset by setting it to VM_NFREELIST, meaning any freelist.
1.121 riastrad 509: */
510:
511: void
512: uao_set_pgfl(struct uvm_object *uobj, int freelist)
513: {
514: struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
515:
516: KASSERTMSG((0 <= freelist), "invalid freelist %d", freelist);
1.122 riastrad 517: KASSERTMSG((freelist <= VM_NFREELIST), "invalid freelist %d",
518: freelist);
1.121 riastrad 519:
520: aobj->u_freelist = freelist;
521: }
522:
523: /*
524: * uao_pagealloc: allocate a page for aobj.
525: */
526:
527: static inline struct vm_page *
528: uao_pagealloc(struct uvm_object *uobj, voff_t offset, int flags)
529: {
530: struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
531:
532: if (__predict_true(aobj->u_freelist == VM_NFREELIST))
533: return uvm_pagealloc(uobj, offset, NULL, flags);
534: else
535: return uvm_pagealloc_strat(uobj, offset, NULL, flags,
536: UVM_PGA_STRAT_ONLY, aobj->u_freelist);
537: }
538:
539: /*
1.1 mrg 540: * uao_init: set up aobj pager subsystem
541: *
542: * => called at boot time from uvm_pager_init()
543: */
1.46 chs 544:
1.27 chs 545: void
1.46 chs 546: uao_init(void)
1.5 mrg 547: {
1.12 thorpej 548: static int uao_initialized;
549:
550: if (uao_initialized)
551: return;
1.87 thorpej 552: uao_initialized = true;
1.5 mrg 553: LIST_INIT(&uao_list);
1.96 ad 554: mutex_init(&uao_list_lock, MUTEX_DEFAULT, IPL_NONE);
1.107 pooka 555: pool_init(&uao_swhash_elt_pool, sizeof(struct uao_swhash_elt),
556: 0, 0, 0, "uaoeltpl", NULL, IPL_VM);
1.1 mrg 557: }
558:
559: /*
1.118 rmind 560: * uao_reference: hold a reference to an anonymous UVM object.
1.1 mrg 561: */
1.5 mrg 562: void
1.67 thorpej 563: uao_reference(struct uvm_object *uobj)
1.1 mrg 564: {
1.118 rmind 565: /* Kernel object is persistent. */
566: if (UVM_OBJ_IS_KERN_OBJECT(uobj)) {
1.101 ad 567: return;
1.118 rmind 568: }
569: atomic_inc_uint(&uobj->uo_refs);
1.1 mrg 570: }
571:
572: /*
1.118 rmind 573: * uao_detach: drop a reference to an anonymous UVM object.
1.1 mrg 574: */
1.5 mrg 575: void
1.67 thorpej 576: uao_detach(struct uvm_object *uobj)
1.5 mrg 577: {
1.118 rmind 578: struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
1.132 ad 579: struct uvm_page_array a;
1.118 rmind 580: struct vm_page *pg;
581:
582: UVMHIST_FUNC("uao_detach"); UVMHIST_CALLED(maphist);
1.101 ad 583:
584: /*
1.118 rmind 585: * Detaching from kernel object is a NOP.
586: */
1.101 ad 587:
588: if (UVM_OBJ_IS_KERN_OBJECT(uobj))
1.102 ad 589: return;
1.101 ad 590:
1.5 mrg 591: /*
1.118 rmind 592: * Drop the reference. If it was the last one, destroy the object.
593: */
1.5 mrg 594:
1.125 chs 595: KASSERT(uobj->uo_refs > 0);
1.136 rin 596: UVMHIST_LOG(maphist," (uobj=%#jx) ref=%jd",
1.126 pgoyette 597: (uintptr_t)uobj, uobj->uo_refs, 0, 0);
1.118 rmind 598: if (atomic_dec_uint_nv(&uobj->uo_refs) > 0) {
1.5 mrg 599: UVMHIST_LOG(maphist, "<- done (rc>0)", 0,0,0,0);
600: return;
601: }
602:
603: /*
1.118 rmind 604: * Remove the aobj from the global list.
605: */
1.46 chs 606:
1.92 ad 607: mutex_enter(&uao_list_lock);
1.5 mrg 608: LIST_REMOVE(aobj, u_list);
1.92 ad 609: mutex_exit(&uao_list_lock);
1.5 mrg 610:
611: /*
1.118 rmind 612: * Free all the pages left in the aobj. For each page, when the
613: * page is no longer busy (and thus after any disk I/O that it is
614: * involved in is complete), release any swap resources and free
615: * the page itself.
616: */
1.132 ad 617: uvm_page_array_init(&a);
1.135 ad 618: rw_enter(uobj->vmobjlock, RW_WRITER);
1.132 ad 619: while ((pg = uvm_page_array_fill_and_peek(&a, uobj, 0, 0, 0))
620: != NULL) {
621: uvm_page_array_advance(&a);
1.130 ad 622: pmap_page_protect(pg, VM_PROT_NONE);
1.5 mrg 623: if (pg->flags & PG_BUSY) {
1.137 ! ad 624: uvm_pagewait(pg, uobj->vmobjlock, "uao_det");
1.132 ad 625: uvm_page_array_clear(&a);
1.135 ad 626: rw_enter(uobj->vmobjlock, RW_WRITER);
1.5 mrg 627: continue;
628: }
1.18 chs 629: uao_dropswap(&aobj->u_obj, pg->offset >> PAGE_SHIFT);
1.5 mrg 630: uvm_pagefree(pg);
631: }
1.132 ad 632: uvm_page_array_fini(&a);
1.1 mrg 633:
1.5 mrg 634: /*
1.118 rmind 635: * Finally, free the anonymous UVM object itself.
636: */
1.1 mrg 637:
1.5 mrg 638: uao_free(aobj);
639: }
1.1 mrg 640:
641: /*
1.46 chs 642: * uao_put: flush pages out of a uvm object
1.22 thorpej 643: *
644: * => object should be locked by caller. we may _unlock_ the object
645: * if (and only if) we need to clean a page (PGO_CLEANIT).
646: * XXXJRT Currently, however, we don't. In the case of cleaning
647: * XXXJRT a page, we simply just deactivate it. Should probably
648: * XXXJRT handle this better, in the future (although "flushing"
649: * XXXJRT anonymous memory isn't terribly important).
650: * => if PGO_CLEANIT is not set, then we will neither unlock the object
651: * or block.
652: * => if PGO_ALLPAGE is set, then all pages in the object are valid targets
653: * for flushing.
1.86 matt 654: * => we return 0 unless we encountered some sort of I/O error
1.22 thorpej 655: * XXXJRT currently never happens, as we never directly initiate
656: * XXXJRT I/O
1.1 mrg 657: */
1.22 thorpej 658:
1.68 thorpej 659: static int
1.67 thorpej 660: uao_put(struct uvm_object *uobj, voff_t start, voff_t stop, int flags)
1.5 mrg 661: {
1.46 chs 662: struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
1.132 ad 663: struct uvm_page_array a;
664: struct vm_page *pg;
1.28 kleink 665: voff_t curoff;
1.46 chs 666: UVMHIST_FUNC("uao_put"); UVMHIST_CALLED(maphist);
1.22 thorpej 667:
1.135 ad 668: KASSERT(rw_write_held(uobj->vmobjlock));
1.96 ad 669:
1.22 thorpej 670: if (flags & PGO_ALLPAGES) {
671: start = 0;
672: stop = aobj->u_pages << PAGE_SHIFT;
673: } else {
674: start = trunc_page(start);
1.71 yamt 675: if (stop == 0) {
676: stop = aobj->u_pages << PAGE_SHIFT;
677: } else {
678: stop = round_page(stop);
679: }
1.127 chs 680: if (stop > (uint64_t)(aobj->u_pages << PAGE_SHIFT)) {
681: printf("uao_put: strange, got an out of range "
1.136 rin 682: "flush %#jx > %#jx (fixed)\n",
1.127 chs 683: (uintmax_t)stop,
684: (uintmax_t)(aobj->u_pages << PAGE_SHIFT));
1.22 thorpej 685: stop = aobj->u_pages << PAGE_SHIFT;
686: }
687: }
688: UVMHIST_LOG(maphist,
1.136 rin 689: " flush start=%#jx, stop=%#jx, flags=%#jx",
1.132 ad 690: start, stop, flags, 0);
1.1 mrg 691:
1.5 mrg 692: /*
1.22 thorpej 693: * Don't need to do any work here if we're not freeing
694: * or deactivating pages.
695: */
1.46 chs 696:
1.22 thorpej 697: if ((flags & (PGO_DEACTIVATE|PGO_FREE)) == 0) {
1.135 ad 698: rw_exit(uobj->vmobjlock);
1.46 chs 699: return 0;
1.22 thorpej 700: }
701:
1.99 ad 702: /* locked: uobj */
1.132 ad 703: uvm_page_array_init(&a);
704: curoff = start;
705: while ((pg = uvm_page_array_fill_and_peek(&a, uobj, curoff, 0, 0)) !=
706: NULL) {
707: if (pg->offset >= stop) {
708: break;
1.22 thorpej 709: }
1.98 yamt 710:
711: /*
712: * wait and try again if the page is busy.
713: */
714:
715: if (pg->flags & PG_BUSY) {
1.137 ! ad 716: uvm_pagewait(pg, uobj->vmobjlock, "uao_put");
1.132 ad 717: uvm_page_array_clear(&a);
1.135 ad 718: rw_enter(uobj->vmobjlock, RW_WRITER);
1.98 yamt 719: continue;
720: }
1.132 ad 721: uvm_page_array_advance(&a);
722: curoff = pg->offset + PAGE_SIZE;
1.98 yamt 723:
1.46 chs 724: switch (flags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)) {
1.41 chs 725:
1.22 thorpej 726: /*
727: * XXX In these first 3 cases, we always just
728: * XXX deactivate the page. We may want to
729: * XXX handle the different cases more specifically
730: * XXX in the future.
731: */
1.46 chs 732:
1.22 thorpej 733: case PGO_CLEANIT|PGO_FREE:
734: case PGO_CLEANIT|PGO_DEACTIVATE:
735: case PGO_DEACTIVATE:
1.25 thorpej 736: deactivate_it:
1.133 ad 737: uvm_pagelock(pg);
1.131 ad 738: uvm_pagedeactivate(pg);
1.133 ad 739: uvm_pageunlock(pg);
1.98 yamt 740: break;
1.22 thorpej 741:
742: case PGO_FREE:
1.25 thorpej 743: /*
744: * If there are multiple references to
745: * the object, just deactivate the page.
746: */
1.46 chs 747:
1.25 thorpej 748: if (uobj->uo_refs > 1)
749: goto deactivate_it;
750:
1.22 thorpej 751: /*
1.98 yamt 752: * free the swap slot and the page.
1.22 thorpej 753: */
1.46 chs 754:
755: pmap_page_protect(pg, VM_PROT_NONE);
1.75 yamt 756:
757: /*
758: * freeing swapslot here is not strictly necessary.
759: * however, leaving it here doesn't save much
760: * because we need to update swap accounting anyway.
761: */
762:
1.46 chs 763: uao_dropswap(uobj, pg->offset >> PAGE_SHIFT);
764: uvm_pagefree(pg);
1.98 yamt 765: break;
766:
767: default:
768: panic("%s: impossible", __func__);
1.22 thorpej 769: }
770: }
1.135 ad 771: rw_exit(uobj->vmobjlock);
1.132 ad 772: uvm_page_array_fini(&a);
1.46 chs 773: return 0;
1.1 mrg 774: }
775:
776: /*
777: * uao_get: fetch me a page
778: *
779: * we have three cases:
780: * 1: page is resident -> just return the page.
781: * 2: page is zero-fill -> allocate a new page and zero it.
782: * 3: page is swapped out -> fetch the page from swap.
783: *
784: * cases 1 and 2 can be handled with PGO_LOCKED, case 3 cannot.
785: * so, if the "center" page hits case 3 (or any page, with PGO_ALLPAGES),
1.40 chs 786: * then we will need to return EBUSY.
1.1 mrg 787: *
788: * => prefer map unlocked (not required)
789: * => object must be locked! we will _unlock_ it before starting any I/O.
790: * => flags: PGO_ALLPAGES: get all of the pages
791: * PGO_LOCKED: fault data structures are locked
792: * => NOTE: offset is the offset of pps[0], _NOT_ pps[centeridx]
793: * => NOTE: caller must check for released pages!!
794: */
1.46 chs 795:
1.5 mrg 796: static int
1.67 thorpej 797: uao_get(struct uvm_object *uobj, voff_t offset, struct vm_page **pps,
1.82 yamt 798: int *npagesp, int centeridx, vm_prot_t access_type, int advice, int flags)
1.5 mrg 799: {
1.28 kleink 800: voff_t current_offset;
1.52 scw 801: struct vm_page *ptmp = NULL; /* Quell compiler warning */
1.72 yamt 802: int lcv, gotpages, maxpages, swslot, pageidx;
1.85 thorpej 803: bool done;
1.5 mrg 804: UVMHIST_FUNC("uao_get"); UVMHIST_CALLED(pdhist);
805:
1.126 pgoyette 806: UVMHIST_LOG(pdhist, "aobj=%#jx offset=%jd, flags=%jd",
807: (uintptr_t)uobj, offset, flags,0);
1.37 chs 808:
1.5 mrg 809: /*
810: * get number of pages
811: */
1.46 chs 812:
1.5 mrg 813: maxpages = *npagesp;
814:
815: /*
816: * step 1: handled the case where fault data structures are locked.
817: */
1.1 mrg 818:
1.5 mrg 819: if (flags & PGO_LOCKED) {
1.46 chs 820:
1.5 mrg 821: /*
822: * step 1a: get pages that are already resident. only do
823: * this if the data structures are locked (i.e. the first
824: * time through).
825: */
826:
1.87 thorpej 827: done = true; /* be optimistic */
1.5 mrg 828: gotpages = 0; /* # of pages we got so far */
829: for (lcv = 0, current_offset = offset ; lcv < maxpages ;
830: lcv++, current_offset += PAGE_SIZE) {
831: /* do we care about this page? if not, skip it */
832: if (pps[lcv] == PGO_DONTCARE)
833: continue;
834: ptmp = uvm_pagelookup(uobj, current_offset);
835:
836: /*
1.30 thorpej 837: * if page is new, attempt to allocate the page,
838: * zero-fill'd.
1.5 mrg 839: */
1.46 chs 840:
1.117 rmind 841: if (ptmp == NULL && uao_find_swslot(uobj,
1.15 chs 842: current_offset >> PAGE_SHIFT) == 0) {
1.121 riastrad 843: ptmp = uao_pagealloc(uobj, current_offset,
844: UVM_FLAG_COLORMATCH|UVM_PGA_ZERO);
1.5 mrg 845: if (ptmp) {
846: /* new page */
1.47 chs 847: ptmp->flags &= ~(PG_FAKE);
1.134 ad 848: uvm_pagemarkdirty(ptmp,
849: UVM_PAGE_STATUS_UNKNOWN);
1.47 chs 850: goto gotpage;
1.5 mrg 851: }
852: }
853:
854: /*
1.46 chs 855: * to be useful must get a non-busy page
1.5 mrg 856: */
1.46 chs 857:
858: if (ptmp == NULL || (ptmp->flags & PG_BUSY) != 0) {
1.5 mrg 859: if (lcv == centeridx ||
860: (flags & PGO_ALLPAGES) != 0)
861: /* need to do a wait or I/O! */
1.87 thorpej 862: done = false;
1.124 martin 863: continue;
1.5 mrg 864: }
865:
866: /*
867: * useful page: busy/lock it and plug it in our
868: * result array
869: */
1.134 ad 870: KASSERT(uvm_pagegetdirty(ptmp) !=
871: UVM_PAGE_STATUS_CLEAN);
1.46 chs 872:
1.5 mrg 873: /* caller must un-busy this page */
1.41 chs 874: ptmp->flags |= PG_BUSY;
1.5 mrg 875: UVM_PAGE_OWN(ptmp, "uao_get1");
1.47 chs 876: gotpage:
1.5 mrg 877: pps[lcv] = ptmp;
878: gotpages++;
1.46 chs 879: }
1.5 mrg 880:
881: /*
882: * step 1b: now we've either done everything needed or we
883: * to unlock and do some waiting or I/O.
884: */
885:
1.126 pgoyette 886: UVMHIST_LOG(pdhist, "<- done (done=%jd)", done, 0,0,0);
1.5 mrg 887: *npagesp = gotpages;
888: if (done)
1.46 chs 889: return 0;
1.5 mrg 890: else
1.46 chs 891: return EBUSY;
1.1 mrg 892: }
893:
1.5 mrg 894: /*
895: * step 2: get non-resident or busy pages.
896: * object is locked. data structures are unlocked.
897: */
898:
1.76 yamt 899: if ((flags & PGO_SYNCIO) == 0) {
900: goto done;
901: }
902:
1.5 mrg 903: for (lcv = 0, current_offset = offset ; lcv < maxpages ;
904: lcv++, current_offset += PAGE_SIZE) {
1.27 chs 905:
1.5 mrg 906: /*
907: * - skip over pages we've already gotten or don't want
908: * - skip over pages we don't _have_ to get
909: */
1.27 chs 910:
1.5 mrg 911: if (pps[lcv] != NULL ||
912: (lcv != centeridx && (flags & PGO_ALLPAGES) == 0))
913: continue;
914:
1.27 chs 915: pageidx = current_offset >> PAGE_SHIFT;
916:
1.5 mrg 917: /*
918: * we have yet to locate the current page (pps[lcv]). we
919: * first look for a page that is already at the current offset.
920: * if we find a page, we check to see if it is busy or
921: * released. if that is the case, then we sleep on the page
922: * until it is no longer busy or released and repeat the lookup.
923: * if the page we found is neither busy nor released, then we
924: * busy it (so we own it) and plug it into pps[lcv]. this
925: * 'break's the following while loop and indicates we are
926: * ready to move on to the next page in the "lcv" loop above.
927: *
928: * if we exit the while loop with pps[lcv] still set to NULL,
929: * then it means that we allocated a new busy/fake/clean page
930: * ptmp in the object and we need to do I/O to fill in the data.
931: */
932:
933: /* top of "pps" while loop */
934: while (pps[lcv] == NULL) {
935: /* look for a resident page */
936: ptmp = uvm_pagelookup(uobj, current_offset);
937:
938: /* not resident? allocate one now (if we can) */
939: if (ptmp == NULL) {
940:
1.121 riastrad 941: ptmp = uao_pagealloc(uobj, current_offset, 0);
1.5 mrg 942:
943: /* out of RAM? */
944: if (ptmp == NULL) {
1.135 ad 945: rw_exit(uobj->vmobjlock);
1.5 mrg 946: UVMHIST_LOG(pdhist,
947: "sleeping, ptmp == NULL\n",0,0,0,0);
948: uvm_wait("uao_getpage");
1.135 ad 949: rw_enter(uobj->vmobjlock, RW_WRITER);
1.41 chs 950: continue;
1.5 mrg 951: }
952:
1.41 chs 953: /*
1.5 mrg 954: * got new page ready for I/O. break pps while
955: * loop. pps[lcv] is still NULL.
956: */
1.46 chs 957:
1.5 mrg 958: break;
959: }
960:
961: /* page is there, see if we need to wait on it */
1.46 chs 962: if ((ptmp->flags & PG_BUSY) != 0) {
1.5 mrg 963: UVMHIST_LOG(pdhist,
1.136 rin 964: "sleeping, ptmp->flags %#jx\n",
1.5 mrg 965: ptmp->flags,0,0,0);
1.137 ! ad 966: uvm_pagewait(ptmp, uobj->vmobjlock, "uao_get");
1.135 ad 967: rw_enter(uobj->vmobjlock, RW_WRITER);
1.46 chs 968: continue;
1.5 mrg 969: }
1.41 chs 970:
971: /*
1.5 mrg 972: * if we get here then the page has become resident and
973: * unbusy between steps 1 and 2. we busy it now (so we
974: * own it) and set pps[lcv] (so that we exit the while
975: * loop).
976: */
1.46 chs 977:
1.134 ad 978: KASSERT(uvm_pagegetdirty(ptmp) !=
979: UVM_PAGE_STATUS_CLEAN);
1.5 mrg 980: /* we own it, caller must un-busy */
981: ptmp->flags |= PG_BUSY;
982: UVM_PAGE_OWN(ptmp, "uao_get2");
983: pps[lcv] = ptmp;
984: }
985:
986: /*
987: * if we own the valid page at the correct offset, pps[lcv] will
988: * point to it. nothing more to do except go to the next page.
989: */
1.46 chs 990:
1.5 mrg 991: if (pps[lcv])
992: continue; /* next lcv */
993:
994: /*
1.41 chs 995: * we have a "fake/busy/clean" page that we just allocated.
1.5 mrg 996: * do the needed "i/o", either reading from swap or zeroing.
997: */
1.46 chs 998:
1.117 rmind 999: swslot = uao_find_swslot(uobj, pageidx);
1.5 mrg 1000:
1001: /*
1002: * just zero the page if there's nothing in swap.
1003: */
1.46 chs 1004:
1005: if (swslot == 0) {
1006:
1.5 mrg 1007: /*
1008: * page hasn't existed before, just zero it.
1009: */
1.46 chs 1010:
1.5 mrg 1011: uvm_pagezero(ptmp);
1.27 chs 1012: } else {
1.72 yamt 1013: #if defined(VMSWAP)
1014: int error;
1015:
1.126 pgoyette 1016: UVMHIST_LOG(pdhist, "pagein from swslot %jd",
1.5 mrg 1017: swslot, 0,0,0);
1018:
1019: /*
1020: * page in the swapped-out page.
1021: * unlock object for i/o, relock when done.
1022: */
1.46 chs 1023:
1.135 ad 1024: rw_exit(uobj->vmobjlock);
1.46 chs 1025: error = uvm_swap_get(ptmp, swslot, PGO_SYNCIO);
1.135 ad 1026: rw_enter(uobj->vmobjlock, RW_WRITER);
1.5 mrg 1027:
1028: /*
1029: * I/O done. check for errors.
1030: */
1.46 chs 1031:
1032: if (error != 0) {
1.126 pgoyette 1033: UVMHIST_LOG(pdhist, "<- done (error=%jd)",
1.46 chs 1034: error,0,0,0);
1.27 chs 1035:
1036: /*
1037: * remove the swap slot from the aobj
1038: * and mark the aobj as having no real slot.
1039: * don't free the swap slot, thus preventing
1040: * it from being used again.
1041: */
1.46 chs 1042:
1.118 rmind 1043: swslot = uao_set_swslot(uobj, pageidx,
1044: SWSLOT_BAD);
1.57 pk 1045: if (swslot > 0) {
1.45 chs 1046: uvm_swap_markbad(swslot, 1);
1047: }
1.27 chs 1048:
1.5 mrg 1049: uvm_pagefree(ptmp);
1.135 ad 1050: rw_exit(uobj->vmobjlock);
1.46 chs 1051: return error;
1.5 mrg 1052: }
1.72 yamt 1053: #else /* defined(VMSWAP) */
1054: panic("%s: pagein", __func__);
1055: #endif /* defined(VMSWAP) */
1.5 mrg 1056: }
1057:
1.134 ad 1058: /*
1059: * note that we will allow the page being writably-mapped
1060: * (!PG_RDONLY) regardless of access_type.
1061: */
1062: uvm_pagemarkdirty(ptmp, UVM_PAGE_STATUS_UNKNOWN);
1.78 yamt 1063:
1.41 chs 1064: /*
1.5 mrg 1065: * we got the page! clear the fake flag (indicates valid
1066: * data now in page) and plug into our result array. note
1.41 chs 1067: * that page is still busy.
1.5 mrg 1068: *
1069: * it is the callers job to:
1070: * => check if the page is released
1071: * => unbusy the page
1072: * => activate the page
1073: */
1.134 ad 1074: KASSERT(uvm_pagegetdirty(ptmp) != UVM_PAGE_STATUS_CLEAN);
1075: KASSERT((ptmp->flags & PG_FAKE) != 0);
1.46 chs 1076: ptmp->flags &= ~PG_FAKE;
1.5 mrg 1077: pps[lcv] = ptmp;
1.46 chs 1078: }
1.1 mrg 1079:
1080: /*
1.5 mrg 1081: * finally, unlock object and return.
1082: */
1.1 mrg 1083:
1.76 yamt 1084: done:
1.135 ad 1085: rw_exit(uobj->vmobjlock);
1.5 mrg 1086: UVMHIST_LOG(pdhist, "<- done (OK)",0,0,0,0);
1.46 chs 1087: return 0;
1.1 mrg 1088: }
1089:
1.72 yamt 1090: #if defined(VMSWAP)
1091:
1.1 mrg 1092: /*
1.18 chs 1093: * uao_dropswap: release any swap resources from this aobj page.
1.41 chs 1094: *
1.18 chs 1095: * => aobj must be locked or have a reference count of 0.
1096: */
1097:
1098: void
1.67 thorpej 1099: uao_dropswap(struct uvm_object *uobj, int pageidx)
1.18 chs 1100: {
1101: int slot;
1102:
1103: slot = uao_set_swslot(uobj, pageidx, 0);
1104: if (slot) {
1105: uvm_swap_free(slot, 1);
1106: }
1.27 chs 1107: }
1108:
1109: /*
1110: * page in every page in every aobj that is paged-out to a range of swslots.
1.41 chs 1111: *
1.27 chs 1112: * => nothing should be locked.
1.87 thorpej 1113: * => returns true if pagein was aborted due to lack of memory.
1.27 chs 1114: */
1.46 chs 1115:
1.85 thorpej 1116: bool
1.67 thorpej 1117: uao_swap_off(int startslot, int endslot)
1.27 chs 1118: {
1.118 rmind 1119: struct uvm_aobj *aobj;
1.27 chs 1120:
1121: /*
1.118 rmind 1122: * Walk the list of all anonymous UVM objects. Grab the first.
1.27 chs 1123: */
1.118 rmind 1124: mutex_enter(&uao_list_lock);
1125: if ((aobj = LIST_FIRST(&uao_list)) == NULL) {
1126: mutex_exit(&uao_list_lock);
1127: return false;
1128: }
1129: uao_reference(&aobj->u_obj);
1.27 chs 1130:
1.118 rmind 1131: do {
1132: struct uvm_aobj *nextaobj;
1133: bool rv;
1.27 chs 1134:
1135: /*
1.118 rmind 1136: * Prefetch the next object and immediately hold a reference
1137: * on it, so neither the current nor the next entry could
1138: * disappear while we are iterating.
1.27 chs 1139: */
1.118 rmind 1140: if ((nextaobj = LIST_NEXT(aobj, u_list)) != NULL) {
1141: uao_reference(&nextaobj->u_obj);
1.27 chs 1142: }
1.90 ad 1143: mutex_exit(&uao_list_lock);
1.27 chs 1144:
1145: /*
1.118 rmind 1146: * Page in all pages in the swap slot range.
1.27 chs 1147: */
1.135 ad 1148: rw_enter(aobj->u_obj.vmobjlock, RW_WRITER);
1.118 rmind 1149: rv = uao_pagein(aobj, startslot, endslot);
1.135 ad 1150: rw_exit(aobj->u_obj.vmobjlock);
1.46 chs 1151:
1.118 rmind 1152: /* Drop the reference of the current object. */
1153: uao_detach(&aobj->u_obj);
1.27 chs 1154: if (rv) {
1.118 rmind 1155: if (nextaobj) {
1156: uao_detach(&nextaobj->u_obj);
1157: }
1.27 chs 1158: return rv;
1159: }
1160:
1.118 rmind 1161: aobj = nextaobj;
1.90 ad 1162: mutex_enter(&uao_list_lock);
1.118 rmind 1163: } while (aobj);
1.27 chs 1164:
1.90 ad 1165: mutex_exit(&uao_list_lock);
1.87 thorpej 1166: return false;
1.27 chs 1167: }
1168:
1169: /*
1170: * page in any pages from aobj in the given range.
1171: *
1172: * => aobj must be locked and is returned locked.
1.87 thorpej 1173: * => returns true if pagein was aborted due to lack of memory.
1.27 chs 1174: */
1.85 thorpej 1175: static bool
1.67 thorpej 1176: uao_pagein(struct uvm_aobj *aobj, int startslot, int endslot)
1.27 chs 1177: {
1.85 thorpej 1178: bool rv;
1.27 chs 1179:
1180: if (UAO_USES_SWHASH(aobj)) {
1181: struct uao_swhash_elt *elt;
1.65 christos 1182: int buck;
1.27 chs 1183:
1184: restart:
1.65 christos 1185: for (buck = aobj->u_swhashmask; buck >= 0; buck--) {
1186: for (elt = LIST_FIRST(&aobj->u_swhash[buck]);
1.27 chs 1187: elt != NULL;
1188: elt = LIST_NEXT(elt, list)) {
1189: int i;
1190:
1191: for (i = 0; i < UAO_SWHASH_CLUSTER_SIZE; i++) {
1192: int slot = elt->slots[i];
1193:
1194: /*
1195: * if the slot isn't in range, skip it.
1196: */
1.46 chs 1197:
1.41 chs 1198: if (slot < startslot ||
1.27 chs 1199: slot >= endslot) {
1200: continue;
1201: }
1202:
1203: /*
1204: * process the page,
1205: * the start over on this object
1206: * since the swhash elt
1207: * may have been freed.
1208: */
1.46 chs 1209:
1.27 chs 1210: rv = uao_pagein_page(aobj,
1211: UAO_SWHASH_ELT_PAGEIDX_BASE(elt) + i);
1212: if (rv) {
1213: return rv;
1214: }
1215: goto restart;
1216: }
1217: }
1218: }
1219: } else {
1220: int i;
1221:
1222: for (i = 0; i < aobj->u_pages; i++) {
1223: int slot = aobj->u_swslots[i];
1224:
1225: /*
1226: * if the slot isn't in range, skip it
1227: */
1.46 chs 1228:
1.27 chs 1229: if (slot < startslot || slot >= endslot) {
1230: continue;
1231: }
1232:
1233: /*
1234: * process the page.
1235: */
1.46 chs 1236:
1.27 chs 1237: rv = uao_pagein_page(aobj, i);
1238: if (rv) {
1239: return rv;
1240: }
1241: }
1242: }
1243:
1.87 thorpej 1244: return false;
1.27 chs 1245: }
1246:
1247: /*
1.117 rmind 1248: * uao_pagein_page: page in a single page from an anonymous UVM object.
1.27 chs 1249: *
1.117 rmind 1250: * => Returns true if pagein was aborted due to lack of memory.
1251: * => Object must be locked and is returned locked.
1.27 chs 1252: */
1.46 chs 1253:
1.85 thorpej 1254: static bool
1.67 thorpej 1255: uao_pagein_page(struct uvm_aobj *aobj, int pageidx)
1.27 chs 1256: {
1.117 rmind 1257: struct uvm_object *uobj = &aobj->u_obj;
1.27 chs 1258: struct vm_page *pg;
1.57 pk 1259: int rv, npages;
1.27 chs 1260:
1261: pg = NULL;
1262: npages = 1;
1.117 rmind 1263:
1.135 ad 1264: KASSERT(rw_write_held(uobj->vmobjlock));
1.128 msaitoh 1265: rv = uao_get(uobj, (voff_t)pageidx << PAGE_SHIFT, &pg, &npages,
1.117 rmind 1266: 0, VM_PROT_READ | VM_PROT_WRITE, 0, PGO_SYNCIO);
1.27 chs 1267:
1268: /*
1269: * relock and finish up.
1270: */
1.46 chs 1271:
1.135 ad 1272: rw_enter(uobj->vmobjlock, RW_WRITER);
1.27 chs 1273: switch (rv) {
1.40 chs 1274: case 0:
1.27 chs 1275: break;
1276:
1.40 chs 1277: case EIO:
1278: case ERESTART:
1.46 chs 1279:
1.27 chs 1280: /*
1281: * nothing more to do on errors.
1.40 chs 1282: * ERESTART can only mean that the anon was freed,
1.27 chs 1283: * so again there's nothing to do.
1284: */
1.46 chs 1285:
1.87 thorpej 1286: return false;
1.59 pk 1287:
1288: default:
1.87 thorpej 1289: return true;
1.27 chs 1290: }
1291:
1292: /*
1293: * ok, we've got the page now.
1294: * mark it as dirty, clear its swslot and un-busy it.
1295: */
1.57 pk 1296: uao_dropswap(&aobj->u_obj, pageidx);
1.27 chs 1297:
1298: /*
1.80 yamt 1299: * make sure it's on a page queue.
1.27 chs 1300: */
1.133 ad 1301: uvm_pagelock(pg);
1.131 ad 1302: uvm_pageenqueue(pg);
1.137 ! ad 1303: uvm_pageunbusy(pg);
1.133 ad 1304: uvm_pageunlock(pg);
1.56 yamt 1305:
1.137 ! ad 1306: pg->flags &= ~(PG_FAKE);
1.134 ad 1307: uvm_pagemarkdirty(pg, UVM_PAGE_STATUS_DIRTY);
1.56 yamt 1308:
1.87 thorpej 1309: return false;
1.1 mrg 1310: }
1.72 yamt 1311:
1.75 yamt 1312: /*
1313: * uao_dropswap_range: drop swapslots in the range.
1314: *
1315: * => aobj must be locked and is returned locked.
1316: * => start is inclusive. end is exclusive.
1317: */
1318:
1319: void
1320: uao_dropswap_range(struct uvm_object *uobj, voff_t start, voff_t end)
1321: {
1322: struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
1.117 rmind 1323: int swpgonlydelta = 0;
1.75 yamt 1324:
1.135 ad 1325: KASSERT(rw_write_held(uobj->vmobjlock));
1.75 yamt 1326:
1327: if (end == 0) {
1328: end = INT64_MAX;
1329: }
1330:
1331: if (UAO_USES_SWHASH(aobj)) {
1332: int i, hashbuckets = aobj->u_swhashmask + 1;
1333: voff_t taghi;
1334: voff_t taglo;
1335:
1336: taglo = UAO_SWHASH_ELT_TAG(start);
1337: taghi = UAO_SWHASH_ELT_TAG(end);
1338:
1339: for (i = 0; i < hashbuckets; i++) {
1340: struct uao_swhash_elt *elt, *next;
1341:
1342: for (elt = LIST_FIRST(&aobj->u_swhash[i]);
1343: elt != NULL;
1344: elt = next) {
1345: int startidx, endidx;
1346: int j;
1347:
1348: next = LIST_NEXT(elt, list);
1349:
1350: if (elt->tag < taglo || taghi < elt->tag) {
1351: continue;
1352: }
1353:
1354: if (elt->tag == taglo) {
1355: startidx =
1356: UAO_SWHASH_ELT_PAGESLOT_IDX(start);
1357: } else {
1358: startidx = 0;
1359: }
1360:
1361: if (elt->tag == taghi) {
1362: endidx =
1363: UAO_SWHASH_ELT_PAGESLOT_IDX(end);
1364: } else {
1365: endidx = UAO_SWHASH_CLUSTER_SIZE;
1366: }
1367:
1368: for (j = startidx; j < endidx; j++) {
1369: int slot = elt->slots[j];
1370:
1371: KASSERT(uvm_pagelookup(&aobj->u_obj,
1372: (UAO_SWHASH_ELT_PAGEIDX_BASE(elt)
1373: + j) << PAGE_SHIFT) == NULL);
1374: if (slot > 0) {
1375: uvm_swap_free(slot, 1);
1376: swpgonlydelta++;
1377: KASSERT(elt->count > 0);
1378: elt->slots[j] = 0;
1379: elt->count--;
1380: }
1381: }
1382:
1383: if (elt->count == 0) {
1384: LIST_REMOVE(elt, list);
1385: pool_put(&uao_swhash_elt_pool, elt);
1386: }
1387: }
1388: }
1389: } else {
1390: int i;
1391:
1392: if (aobj->u_pages < end) {
1393: end = aobj->u_pages;
1394: }
1395: for (i = start; i < end; i++) {
1396: int slot = aobj->u_swslots[i];
1397:
1398: if (slot > 0) {
1399: uvm_swap_free(slot, 1);
1400: swpgonlydelta++;
1401: }
1402: }
1403: }
1404:
1405: /*
1406: * adjust the counter of pages only in swap for all
1407: * the swap slots we've freed.
1408: */
1409:
1410: if (swpgonlydelta > 0) {
1411: KASSERT(uvmexp.swpgonly >= swpgonlydelta);
1.129 ad 1412: atomic_add_int(&uvmexp.swpgonly, -swpgonlydelta);
1.75 yamt 1413: }
1414: }
1415:
1.72 yamt 1416: #endif /* defined(VMSWAP) */
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