Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/kern/subr_vmem.c
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1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c)2006,2007,2008,2009 YAMAMOTO Takashi, 5 * Copyright (c) 2013 EMC Corp. 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 AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 /* 31 * From: 32 * $NetBSD: vmem_impl.h,v 1.2 2013/01/29 21:26:24 para Exp $ 33 * $NetBSD: subr_vmem.c,v 1.83 2013/03/06 11:20:10 yamt Exp $ 34 */ 35 36 /* 37 * reference: 38 * - Magazines and Vmem: Extending the Slab Allocator 39 * to Many CPUs and Arbitrary Resources 40 * http://www.usenix.org/event/usenix01/bonwick.html 41 */ 42 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 #include "opt_ddb.h" 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/kernel.h> 51 #include <sys/queue.h> 52 #include <sys/callout.h> 53 #include <sys/hash.h> 54 #include <sys/lock.h> 55 #include <sys/malloc.h> 56 #include <sys/mutex.h> 57 #include <sys/smp.h> 58 #include <sys/condvar.h> 59 #include <sys/sysctl.h> 60 #include <sys/taskqueue.h> 61 #include <sys/vmem.h> 62 #include <sys/vmmeter.h> 63 64 #include "opt_vm.h" 65 66 #include <vm/uma.h> 67 #include <vm/vm.h> 68 #include <vm/pmap.h> 69 #include <vm/vm_map.h> 70 #include <vm/vm_object.h> 71 #include <vm/vm_kern.h> 72 #include <vm/vm_extern.h> 73 #include <vm/vm_param.h> 74 #include <vm/vm_page.h> 75 #include <vm/vm_pageout.h> 76 #include <vm/vm_phys.h> 77 #include <vm/vm_pagequeue.h> 78 #include <vm/uma_int.h> 79 80 #define VMEM_OPTORDER 5 81 #define VMEM_OPTVALUE (1 << VMEM_OPTORDER) 82 #define VMEM_MAXORDER \ 83 (VMEM_OPTVALUE - 1 + sizeof(vmem_size_t) * NBBY - VMEM_OPTORDER) 84 85 #define VMEM_HASHSIZE_MIN 16 86 #define VMEM_HASHSIZE_MAX 131072 87 88 #define VMEM_QCACHE_IDX_MAX 16 89 90 #define VMEM_FITMASK (M_BESTFIT | M_FIRSTFIT | M_NEXTFIT) 91 92 #define VMEM_FLAGS (M_NOWAIT | M_WAITOK | M_USE_RESERVE | M_NOVM | \ 93 M_BESTFIT | M_FIRSTFIT | M_NEXTFIT) 94 95 #define BT_FLAGS (M_NOWAIT | M_WAITOK | M_USE_RESERVE | M_NOVM) 96 97 #define QC_NAME_MAX 16 98 99 /* 100 * Data structures private to vmem. 101 */ 102 MALLOC_DEFINE(M_VMEM, "vmem", "vmem internal structures"); 103 104 typedef struct vmem_btag bt_t; 105 106 TAILQ_HEAD(vmem_seglist, vmem_btag); 107 LIST_HEAD(vmem_freelist, vmem_btag); 108 LIST_HEAD(vmem_hashlist, vmem_btag); 109 110 struct qcache { 111 uma_zone_t qc_cache; 112 vmem_t *qc_vmem; 113 vmem_size_t qc_size; 114 char qc_name[QC_NAME_MAX]; 115 }; 116 typedef struct qcache qcache_t; 117 #define QC_POOL_TO_QCACHE(pool) ((qcache_t *)(pool->pr_qcache)) 118 119 #define VMEM_NAME_MAX 16 120 121 /* boundary tag */ 122 struct vmem_btag { 123 TAILQ_ENTRY(vmem_btag) bt_seglist; 124 union { 125 LIST_ENTRY(vmem_btag) u_freelist; /* BT_TYPE_FREE */ 126 LIST_ENTRY(vmem_btag) u_hashlist; /* BT_TYPE_BUSY */ 127 } bt_u; 128 #define bt_hashlist bt_u.u_hashlist 129 #define bt_freelist bt_u.u_freelist 130 vmem_addr_t bt_start; 131 vmem_size_t bt_size; 132 int bt_type; 133 }; 134 135 /* vmem arena */ 136 struct vmem { 137 struct mtx_padalign vm_lock; 138 struct cv vm_cv; 139 char vm_name[VMEM_NAME_MAX+1]; 140 LIST_ENTRY(vmem) vm_alllist; 141 struct vmem_hashlist vm_hash0[VMEM_HASHSIZE_MIN]; 142 struct vmem_freelist vm_freelist[VMEM_MAXORDER]; 143 struct vmem_seglist vm_seglist; 144 struct vmem_hashlist *vm_hashlist; 145 vmem_size_t vm_hashsize; 146 147 /* Constant after init */ 148 vmem_size_t vm_qcache_max; 149 vmem_size_t vm_quantum_mask; 150 vmem_size_t vm_import_quantum; 151 int vm_quantum_shift; 152 153 /* Written on alloc/free */ 154 LIST_HEAD(, vmem_btag) vm_freetags; 155 int vm_nfreetags; 156 int vm_nbusytag; 157 vmem_size_t vm_inuse; 158 vmem_size_t vm_size; 159 vmem_size_t vm_limit; 160 struct vmem_btag vm_cursor; 161 162 /* Used on import. */ 163 vmem_import_t *vm_importfn; 164 vmem_release_t *vm_releasefn; 165 void *vm_arg; 166 167 /* Space exhaustion callback. */ 168 vmem_reclaim_t *vm_reclaimfn; 169 170 /* quantum cache */ 171 qcache_t vm_qcache[VMEM_QCACHE_IDX_MAX]; 172 }; 173 174 #define BT_TYPE_SPAN 1 /* Allocated from importfn */ 175 #define BT_TYPE_SPAN_STATIC 2 /* vmem_add() or create. */ 176 #define BT_TYPE_FREE 3 /* Available space. */ 177 #define BT_TYPE_BUSY 4 /* Used space. */ 178 #define BT_TYPE_CURSOR 5 /* Cursor for nextfit allocations. */ 179 #define BT_ISSPAN_P(bt) ((bt)->bt_type <= BT_TYPE_SPAN_STATIC) 180 181 #define BT_END(bt) ((bt)->bt_start + (bt)->bt_size - 1) 182 183 #if defined(DIAGNOSTIC) 184 static int enable_vmem_check = 1; 185 SYSCTL_INT(_debug, OID_AUTO, vmem_check, CTLFLAG_RWTUN, 186 &enable_vmem_check, 0, "Enable vmem check"); 187 static void vmem_check(vmem_t *); 188 #endif 189 190 static struct callout vmem_periodic_ch; 191 static int vmem_periodic_interval; 192 static struct task vmem_periodic_wk; 193 194 static struct mtx_padalign __exclusive_cache_line vmem_list_lock; 195 static LIST_HEAD(, vmem) vmem_list = LIST_HEAD_INITIALIZER(vmem_list); 196 static uma_zone_t vmem_zone; 197 198 /* ---- misc */ 199 #define VMEM_CONDVAR_INIT(vm, wchan) cv_init(&vm->vm_cv, wchan) 200 #define VMEM_CONDVAR_DESTROY(vm) cv_destroy(&vm->vm_cv) 201 #define VMEM_CONDVAR_WAIT(vm) cv_wait(&vm->vm_cv, &vm->vm_lock) 202 #define VMEM_CONDVAR_BROADCAST(vm) cv_broadcast(&vm->vm_cv) 203 204 #define VMEM_LOCK(vm) mtx_lock(&vm->vm_lock) 205 #define VMEM_TRYLOCK(vm) mtx_trylock(&vm->vm_lock) 206 #define VMEM_UNLOCK(vm) mtx_unlock(&vm->vm_lock) 207 #define VMEM_LOCK_INIT(vm, name) mtx_init(&vm->vm_lock, (name), NULL, MTX_DEF) 208 #define VMEM_LOCK_DESTROY(vm) mtx_destroy(&vm->vm_lock) 209 #define VMEM_ASSERT_LOCKED(vm) mtx_assert(&vm->vm_lock, MA_OWNED); 210 211 #define VMEM_ALIGNUP(addr, align) (-(-(addr) & -(align))) 212 213 #define VMEM_CROSS_P(addr1, addr2, boundary) \ 214 ((((addr1) ^ (addr2)) & -(boundary)) != 0) 215 216 #define ORDER2SIZE(order) ((order) < VMEM_OPTVALUE ? ((order) + 1) : \ 217 (vmem_size_t)1 << ((order) - (VMEM_OPTVALUE - VMEM_OPTORDER - 1))) 218 #define SIZE2ORDER(size) ((size) <= VMEM_OPTVALUE ? ((size) - 1) : \ 219 (flsl(size) + (VMEM_OPTVALUE - VMEM_OPTORDER - 2))) 220 221 /* 222 * Maximum number of boundary tags that may be required to satisfy an 223 * allocation. Two may be required to import. Another two may be 224 * required to clip edges. 225 */ 226 #define BT_MAXALLOC 4 227 228 /* 229 * Max free limits the number of locally cached boundary tags. We 230 * just want to avoid hitting the zone allocator for every call. 231 */ 232 #define BT_MAXFREE (BT_MAXALLOC * 8) 233 234 /* Allocator for boundary tags. */ 235 static uma_zone_t vmem_bt_zone; 236 237 /* boot time arena storage. */ 238 static struct vmem kernel_arena_storage; 239 static struct vmem buffer_arena_storage; 240 static struct vmem transient_arena_storage; 241 /* kernel and kmem arenas are aliased for backwards KPI compat. */ 242 vmem_t *kernel_arena = &kernel_arena_storage; 243 vmem_t *kmem_arena = &kernel_arena_storage; 244 vmem_t *buffer_arena = &buffer_arena_storage; 245 vmem_t *transient_arena = &transient_arena_storage; 246 247 #ifdef DEBUG_MEMGUARD 248 static struct vmem memguard_arena_storage; 249 vmem_t *memguard_arena = &memguard_arena_storage; 250 #endif 251 252 static bool 253 bt_isbusy(bt_t *bt) 254 { 255 return (bt->bt_type == BT_TYPE_BUSY); 256 } 257 258 static bool 259 bt_isfree(bt_t *bt) 260 { 261 return (bt->bt_type == BT_TYPE_FREE); 262 } 263 264 /* 265 * Fill the vmem's boundary tag cache. We guarantee that boundary tag 266 * allocation will not fail once bt_fill() passes. To do so we cache 267 * at least the maximum possible tag allocations in the arena. 268 */ 269 static __noinline int 270 _bt_fill(vmem_t *vm, int flags) 271 { 272 bt_t *bt; 273 274 VMEM_ASSERT_LOCKED(vm); 275 276 /* 277 * Only allow the kernel arena and arenas derived from kernel arena to 278 * dip into reserve tags. They are where new tags come from. 279 */ 280 flags &= BT_FLAGS; 281 if (vm != kernel_arena && vm->vm_arg != kernel_arena) 282 flags &= ~M_USE_RESERVE; 283 284 /* 285 * Loop until we meet the reserve. To minimize the lock shuffle 286 * and prevent simultaneous fills we first try a NOWAIT regardless 287 * of the caller's flags. Specify M_NOVM so we don't recurse while 288 * holding a vmem lock. 289 */ 290 while (vm->vm_nfreetags < BT_MAXALLOC) { 291 bt = uma_zalloc(vmem_bt_zone, 292 (flags & M_USE_RESERVE) | M_NOWAIT | M_NOVM); 293 if (bt == NULL) { 294 VMEM_UNLOCK(vm); 295 bt = uma_zalloc(vmem_bt_zone, flags); 296 VMEM_LOCK(vm); 297 if (bt == NULL) 298 break; 299 } 300 LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist); 301 vm->vm_nfreetags++; 302 } 303 304 if (vm->vm_nfreetags < BT_MAXALLOC) 305 return ENOMEM; 306 307 return 0; 308 } 309 310 static inline int 311 bt_fill(vmem_t *vm, int flags) 312 { 313 if (vm->vm_nfreetags >= BT_MAXALLOC) 314 return (0); 315 return (_bt_fill(vm, flags)); 316 } 317 318 /* 319 * Pop a tag off of the freetag stack. 320 */ 321 static bt_t * 322 bt_alloc(vmem_t *vm) 323 { 324 bt_t *bt; 325 326 VMEM_ASSERT_LOCKED(vm); 327 bt = LIST_FIRST(&vm->vm_freetags); 328 MPASS(bt != NULL); 329 LIST_REMOVE(bt, bt_freelist); 330 vm->vm_nfreetags--; 331 332 return bt; 333 } 334 335 /* 336 * Trim the per-vmem free list. Returns with the lock released to 337 * avoid allocator recursions. 338 */ 339 static void 340 bt_freetrim(vmem_t *vm, int freelimit) 341 { 342 LIST_HEAD(, vmem_btag) freetags; 343 bt_t *bt; 344 345 LIST_INIT(&freetags); 346 VMEM_ASSERT_LOCKED(vm); 347 while (vm->vm_nfreetags > freelimit) { 348 bt = LIST_FIRST(&vm->vm_freetags); 349 LIST_REMOVE(bt, bt_freelist); 350 vm->vm_nfreetags--; 351 LIST_INSERT_HEAD(&freetags, bt, bt_freelist); 352 } 353 VMEM_UNLOCK(vm); 354 while ((bt = LIST_FIRST(&freetags)) != NULL) { 355 LIST_REMOVE(bt, bt_freelist); 356 uma_zfree(vmem_bt_zone, bt); 357 } 358 } 359 360 static inline void 361 bt_free(vmem_t *vm, bt_t *bt) 362 { 363 364 VMEM_ASSERT_LOCKED(vm); 365 MPASS(LIST_FIRST(&vm->vm_freetags) != bt); 366 LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist); 367 vm->vm_nfreetags++; 368 } 369 370 /* 371 * Hide MAXALLOC tags before dropping the arena lock to ensure that a 372 * concurrent allocation attempt does not grab them. 373 */ 374 static void 375 bt_save(vmem_t *vm) 376 { 377 KASSERT(vm->vm_nfreetags >= BT_MAXALLOC, 378 ("%s: insufficient free tags %d", __func__, vm->vm_nfreetags)); 379 vm->vm_nfreetags -= BT_MAXALLOC; 380 } 381 382 static void 383 bt_restore(vmem_t *vm) 384 { 385 vm->vm_nfreetags += BT_MAXALLOC; 386 } 387 388 /* 389 * freelist[0] ... [1, 1] 390 * freelist[1] ... [2, 2] 391 * : 392 * freelist[29] ... [30, 30] 393 * freelist[30] ... [31, 31] 394 * freelist[31] ... [32, 63] 395 * freelist[33] ... [64, 127] 396 * : 397 * freelist[n] ... [(1 << (n - 26)), (1 << (n - 25)) - 1] 398 * : 399 */ 400 401 static struct vmem_freelist * 402 bt_freehead_tofree(vmem_t *vm, vmem_size_t size) 403 { 404 const vmem_size_t qsize = size >> vm->vm_quantum_shift; 405 const int idx = SIZE2ORDER(qsize); 406 407 MPASS(size != 0 && qsize != 0); 408 MPASS((size & vm->vm_quantum_mask) == 0); 409 MPASS(idx >= 0); 410 MPASS(idx < VMEM_MAXORDER); 411 412 return &vm->vm_freelist[idx]; 413 } 414 415 /* 416 * bt_freehead_toalloc: return the freelist for the given size and allocation 417 * strategy. 418 * 419 * For M_FIRSTFIT, return the list in which any blocks are large enough 420 * for the requested size. otherwise, return the list which can have blocks 421 * large enough for the requested size. 422 */ 423 static struct vmem_freelist * 424 bt_freehead_toalloc(vmem_t *vm, vmem_size_t size, int strat) 425 { 426 const vmem_size_t qsize = size >> vm->vm_quantum_shift; 427 int idx = SIZE2ORDER(qsize); 428 429 MPASS(size != 0 && qsize != 0); 430 MPASS((size & vm->vm_quantum_mask) == 0); 431 432 if (strat == M_FIRSTFIT && ORDER2SIZE(idx) != qsize) { 433 idx++; 434 /* check too large request? */ 435 } 436 MPASS(idx >= 0); 437 MPASS(idx < VMEM_MAXORDER); 438 439 return &vm->vm_freelist[idx]; 440 } 441 442 /* ---- boundary tag hash */ 443 444 static struct vmem_hashlist * 445 bt_hashhead(vmem_t *vm, vmem_addr_t addr) 446 { 447 struct vmem_hashlist *list; 448 unsigned int hash; 449 450 hash = hash32_buf(&addr, sizeof(addr), 0); 451 list = &vm->vm_hashlist[hash % vm->vm_hashsize]; 452 453 return list; 454 } 455 456 static bt_t * 457 bt_lookupbusy(vmem_t *vm, vmem_addr_t addr) 458 { 459 struct vmem_hashlist *list; 460 bt_t *bt; 461 462 VMEM_ASSERT_LOCKED(vm); 463 list = bt_hashhead(vm, addr); 464 LIST_FOREACH(bt, list, bt_hashlist) { 465 if (bt->bt_start == addr) { 466 break; 467 } 468 } 469 470 return bt; 471 } 472 473 static void 474 bt_rembusy(vmem_t *vm, bt_t *bt) 475 { 476 477 VMEM_ASSERT_LOCKED(vm); 478 MPASS(vm->vm_nbusytag > 0); 479 vm->vm_inuse -= bt->bt_size; 480 vm->vm_nbusytag--; 481 LIST_REMOVE(bt, bt_hashlist); 482 } 483 484 static void 485 bt_insbusy(vmem_t *vm, bt_t *bt) 486 { 487 struct vmem_hashlist *list; 488 489 VMEM_ASSERT_LOCKED(vm); 490 MPASS(bt->bt_type == BT_TYPE_BUSY); 491 492 list = bt_hashhead(vm, bt->bt_start); 493 LIST_INSERT_HEAD(list, bt, bt_hashlist); 494 vm->vm_nbusytag++; 495 vm->vm_inuse += bt->bt_size; 496 } 497 498 /* ---- boundary tag list */ 499 500 static void 501 bt_remseg(vmem_t *vm, bt_t *bt) 502 { 503 504 MPASS(bt->bt_type != BT_TYPE_CURSOR); 505 TAILQ_REMOVE(&vm->vm_seglist, bt, bt_seglist); 506 bt_free(vm, bt); 507 } 508 509 static void 510 bt_insseg(vmem_t *vm, bt_t *bt, bt_t *prev) 511 { 512 513 TAILQ_INSERT_AFTER(&vm->vm_seglist, prev, bt, bt_seglist); 514 } 515 516 static void 517 bt_insseg_tail(vmem_t *vm, bt_t *bt) 518 { 519 520 TAILQ_INSERT_TAIL(&vm->vm_seglist, bt, bt_seglist); 521 } 522 523 static void 524 bt_remfree(vmem_t *vm __unused, bt_t *bt) 525 { 526 527 MPASS(bt->bt_type == BT_TYPE_FREE); 528 529 LIST_REMOVE(bt, bt_freelist); 530 } 531 532 static void 533 bt_insfree(vmem_t *vm, bt_t *bt) 534 { 535 struct vmem_freelist *list; 536 537 list = bt_freehead_tofree(vm, bt->bt_size); 538 LIST_INSERT_HEAD(list, bt, bt_freelist); 539 } 540 541 /* ---- vmem internal functions */ 542 543 /* 544 * Import from the arena into the quantum cache in UMA. 545 * 546 * We use VMEM_ADDR_QCACHE_MIN instead of 0: uma_zalloc() returns 0 to indicate 547 * failure, so UMA can't be used to cache a resource with value 0. 548 */ 549 static int 550 qc_import(void *arg, void **store, int cnt, int domain, int flags) 551 { 552 qcache_t *qc; 553 vmem_addr_t addr; 554 int i; 555 556 KASSERT((flags & M_WAITOK) == 0, ("blocking allocation")); 557 558 qc = arg; 559 for (i = 0; i < cnt; i++) { 560 if (vmem_xalloc(qc->qc_vmem, qc->qc_size, 0, 0, 0, 561 VMEM_ADDR_QCACHE_MIN, VMEM_ADDR_MAX, flags, &addr) != 0) 562 break; 563 store[i] = (void *)addr; 564 } 565 return (i); 566 } 567 568 /* 569 * Release memory from the UMA cache to the arena. 570 */ 571 static void 572 qc_release(void *arg, void **store, int cnt) 573 { 574 qcache_t *qc; 575 int i; 576 577 qc = arg; 578 for (i = 0; i < cnt; i++) 579 vmem_xfree(qc->qc_vmem, (vmem_addr_t)store[i], qc->qc_size); 580 } 581 582 static void 583 qc_init(vmem_t *vm, vmem_size_t qcache_max) 584 { 585 qcache_t *qc; 586 vmem_size_t size; 587 int qcache_idx_max; 588 int i; 589 590 MPASS((qcache_max & vm->vm_quantum_mask) == 0); 591 qcache_idx_max = MIN(qcache_max >> vm->vm_quantum_shift, 592 VMEM_QCACHE_IDX_MAX); 593 vm->vm_qcache_max = qcache_idx_max << vm->vm_quantum_shift; 594 for (i = 0; i < qcache_idx_max; i++) { 595 qc = &vm->vm_qcache[i]; 596 size = (i + 1) << vm->vm_quantum_shift; 597 snprintf(qc->qc_name, sizeof(qc->qc_name), "%s-%zu", 598 vm->vm_name, size); 599 qc->qc_vmem = vm; 600 qc->qc_size = size; 601 qc->qc_cache = uma_zcache_create(qc->qc_name, size, 602 NULL, NULL, NULL, NULL, qc_import, qc_release, qc, 0); 603 MPASS(qc->qc_cache); 604 } 605 } 606 607 static void 608 qc_destroy(vmem_t *vm) 609 { 610 int qcache_idx_max; 611 int i; 612 613 qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift; 614 for (i = 0; i < qcache_idx_max; i++) 615 uma_zdestroy(vm->vm_qcache[i].qc_cache); 616 } 617 618 static void 619 qc_drain(vmem_t *vm) 620 { 621 int qcache_idx_max; 622 int i; 623 624 qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift; 625 for (i = 0; i < qcache_idx_max; i++) 626 uma_zone_reclaim(vm->vm_qcache[i].qc_cache, UMA_RECLAIM_DRAIN); 627 } 628 629 #ifndef UMA_MD_SMALL_ALLOC 630 631 static struct mtx_padalign __exclusive_cache_line vmem_bt_lock; 632 633 /* 634 * vmem_bt_alloc: Allocate a new page of boundary tags. 635 * 636 * On architectures with uma_small_alloc there is no recursion; no address 637 * space need be allocated to allocate boundary tags. For the others, we 638 * must handle recursion. Boundary tags are necessary to allocate new 639 * boundary tags. 640 * 641 * UMA guarantees that enough tags are held in reserve to allocate a new 642 * page of kva. We dip into this reserve by specifying M_USE_RESERVE only 643 * when allocating the page to hold new boundary tags. In this way the 644 * reserve is automatically filled by the allocation that uses the reserve. 645 * 646 * We still have to guarantee that the new tags are allocated atomically since 647 * many threads may try concurrently. The bt_lock provides this guarantee. 648 * We convert WAITOK allocations to NOWAIT and then handle the blocking here 649 * on failure. It's ok to return NULL for a WAITOK allocation as UMA will 650 * loop again after checking to see if we lost the race to allocate. 651 * 652 * There is a small race between vmem_bt_alloc() returning the page and the 653 * zone lock being acquired to add the page to the zone. For WAITOK 654 * allocations we just pause briefly. NOWAIT may experience a transient 655 * failure. To alleviate this we permit a small number of simultaneous 656 * fills to proceed concurrently so NOWAIT is less likely to fail unless 657 * we are really out of KVA. 658 */ 659 static void * 660 vmem_bt_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag, 661 int wait) 662 { 663 vmem_addr_t addr; 664 665 *pflag = UMA_SLAB_KERNEL; 666 667 /* 668 * Single thread boundary tag allocation so that the address space 669 * and memory are added in one atomic operation. 670 */ 671 mtx_lock(&vmem_bt_lock); 672 if (vmem_xalloc(vm_dom[domain].vmd_kernel_arena, bytes, 0, 0, 0, 673 VMEM_ADDR_MIN, VMEM_ADDR_MAX, 674 M_NOWAIT | M_NOVM | M_USE_RESERVE | M_BESTFIT, &addr) == 0) { 675 if (kmem_back_domain(domain, kernel_object, addr, bytes, 676 M_NOWAIT | M_USE_RESERVE) == 0) { 677 mtx_unlock(&vmem_bt_lock); 678 return ((void *)addr); 679 } 680 vmem_xfree(vm_dom[domain].vmd_kernel_arena, addr, bytes); 681 mtx_unlock(&vmem_bt_lock); 682 /* 683 * Out of memory, not address space. This may not even be 684 * possible due to M_USE_RESERVE page allocation. 685 */ 686 if (wait & M_WAITOK) 687 vm_wait_domain(domain); 688 return (NULL); 689 } 690 mtx_unlock(&vmem_bt_lock); 691 /* 692 * We're either out of address space or lost a fill race. 693 */ 694 if (wait & M_WAITOK) 695 pause("btalloc", 1); 696 697 return (NULL); 698 } 699 #endif 700 701 void 702 vmem_startup(void) 703 { 704 705 mtx_init(&vmem_list_lock, "vmem list lock", NULL, MTX_DEF); 706 vmem_zone = uma_zcreate("vmem", 707 sizeof(struct vmem), NULL, NULL, NULL, NULL, 708 UMA_ALIGN_PTR, 0); 709 vmem_bt_zone = uma_zcreate("vmem btag", 710 sizeof(struct vmem_btag), NULL, NULL, NULL, NULL, 711 UMA_ALIGN_PTR, UMA_ZONE_VM); 712 #ifndef UMA_MD_SMALL_ALLOC 713 mtx_init(&vmem_bt_lock, "btag lock", NULL, MTX_DEF); 714 uma_prealloc(vmem_bt_zone, BT_MAXALLOC); 715 /* 716 * Reserve enough tags to allocate new tags. We allow multiple 717 * CPUs to attempt to allocate new tags concurrently to limit 718 * false restarts in UMA. vmem_bt_alloc() allocates from a per-domain 719 * arena, which may involve importing a range from the kernel arena, 720 * so we need to keep at least 2 * BT_MAXALLOC tags reserved. 721 */ 722 uma_zone_reserve(vmem_bt_zone, 2 * BT_MAXALLOC * mp_ncpus); 723 uma_zone_set_allocf(vmem_bt_zone, vmem_bt_alloc); 724 #endif 725 } 726 727 /* ---- rehash */ 728 729 static int 730 vmem_rehash(vmem_t *vm, vmem_size_t newhashsize) 731 { 732 bt_t *bt; 733 struct vmem_hashlist *newhashlist; 734 struct vmem_hashlist *oldhashlist; 735 vmem_size_t i, oldhashsize; 736 737 MPASS(newhashsize > 0); 738 739 newhashlist = malloc(sizeof(struct vmem_hashlist) * newhashsize, 740 M_VMEM, M_NOWAIT); 741 if (newhashlist == NULL) 742 return ENOMEM; 743 for (i = 0; i < newhashsize; i++) { 744 LIST_INIT(&newhashlist[i]); 745 } 746 747 VMEM_LOCK(vm); 748 oldhashlist = vm->vm_hashlist; 749 oldhashsize = vm->vm_hashsize; 750 vm->vm_hashlist = newhashlist; 751 vm->vm_hashsize = newhashsize; 752 if (oldhashlist == NULL) { 753 VMEM_UNLOCK(vm); 754 return 0; 755 } 756 for (i = 0; i < oldhashsize; i++) { 757 while ((bt = LIST_FIRST(&oldhashlist[i])) != NULL) { 758 bt_rembusy(vm, bt); 759 bt_insbusy(vm, bt); 760 } 761 } 762 VMEM_UNLOCK(vm); 763 764 if (oldhashlist != vm->vm_hash0) 765 free(oldhashlist, M_VMEM); 766 767 return 0; 768 } 769 770 static void 771 vmem_periodic_kick(void *dummy) 772 { 773 774 taskqueue_enqueue(taskqueue_thread, &vmem_periodic_wk); 775 } 776 777 static void 778 vmem_periodic(void *unused, int pending) 779 { 780 vmem_t *vm; 781 vmem_size_t desired; 782 vmem_size_t current; 783 784 mtx_lock(&vmem_list_lock); 785 LIST_FOREACH(vm, &vmem_list, vm_alllist) { 786 #ifdef DIAGNOSTIC 787 /* Convenient time to verify vmem state. */ 788 if (enable_vmem_check == 1) { 789 VMEM_LOCK(vm); 790 vmem_check(vm); 791 VMEM_UNLOCK(vm); 792 } 793 #endif 794 desired = 1 << flsl(vm->vm_nbusytag); 795 desired = MIN(MAX(desired, VMEM_HASHSIZE_MIN), 796 VMEM_HASHSIZE_MAX); 797 current = vm->vm_hashsize; 798 799 /* Grow in powers of two. Shrink less aggressively. */ 800 if (desired >= current * 2 || desired * 4 <= current) 801 vmem_rehash(vm, desired); 802 803 /* 804 * Periodically wake up threads waiting for resources, 805 * so they could ask for reclamation again. 806 */ 807 VMEM_CONDVAR_BROADCAST(vm); 808 } 809 mtx_unlock(&vmem_list_lock); 810 811 callout_reset(&vmem_periodic_ch, vmem_periodic_interval, 812 vmem_periodic_kick, NULL); 813 } 814 815 static void 816 vmem_start_callout(void *unused) 817 { 818 819 TASK_INIT(&vmem_periodic_wk, 0, vmem_periodic, NULL); 820 vmem_periodic_interval = hz * 10; 821 callout_init(&vmem_periodic_ch, 1); 822 callout_reset(&vmem_periodic_ch, vmem_periodic_interval, 823 vmem_periodic_kick, NULL); 824 } 825 SYSINIT(vfs, SI_SUB_CONFIGURE, SI_ORDER_ANY, vmem_start_callout, NULL); 826 827 static void 828 vmem_add1(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, int type) 829 { 830 bt_t *btfree, *btprev, *btspan; 831 832 VMEM_ASSERT_LOCKED(vm); 833 MPASS(type == BT_TYPE_SPAN || type == BT_TYPE_SPAN_STATIC); 834 MPASS((size & vm->vm_quantum_mask) == 0); 835 836 if (vm->vm_releasefn == NULL) { 837 /* 838 * The new segment will never be released, so see if it is 839 * contiguous with respect to an existing segment. In this case 840 * a span tag is not needed, and it may be possible now or in 841 * the future to coalesce the new segment with an existing free 842 * segment. 843 */ 844 btprev = TAILQ_LAST(&vm->vm_seglist, vmem_seglist); 845 if ((!bt_isbusy(btprev) && !bt_isfree(btprev)) || 846 btprev->bt_start + btprev->bt_size != addr) 847 btprev = NULL; 848 } else { 849 btprev = NULL; 850 } 851 852 if (btprev == NULL || bt_isbusy(btprev)) { 853 if (btprev == NULL) { 854 btspan = bt_alloc(vm); 855 btspan->bt_type = type; 856 btspan->bt_start = addr; 857 btspan->bt_size = size; 858 bt_insseg_tail(vm, btspan); 859 } 860 861 btfree = bt_alloc(vm); 862 btfree->bt_type = BT_TYPE_FREE; 863 btfree->bt_start = addr; 864 btfree->bt_size = size; 865 bt_insseg_tail(vm, btfree); 866 bt_insfree(vm, btfree); 867 } else { 868 bt_remfree(vm, btprev); 869 btprev->bt_size += size; 870 bt_insfree(vm, btprev); 871 } 872 873 vm->vm_size += size; 874 } 875 876 static void 877 vmem_destroy1(vmem_t *vm) 878 { 879 bt_t *bt; 880 881 /* 882 * Drain per-cpu quantum caches. 883 */ 884 qc_destroy(vm); 885 886 /* 887 * The vmem should now only contain empty segments. 888 */ 889 VMEM_LOCK(vm); 890 MPASS(vm->vm_nbusytag == 0); 891 892 TAILQ_REMOVE(&vm->vm_seglist, &vm->vm_cursor, bt_seglist); 893 while ((bt = TAILQ_FIRST(&vm->vm_seglist)) != NULL) 894 bt_remseg(vm, bt); 895 896 if (vm->vm_hashlist != NULL && vm->vm_hashlist != vm->vm_hash0) 897 free(vm->vm_hashlist, M_VMEM); 898 899 bt_freetrim(vm, 0); 900 901 VMEM_CONDVAR_DESTROY(vm); 902 VMEM_LOCK_DESTROY(vm); 903 uma_zfree(vmem_zone, vm); 904 } 905 906 static int 907 vmem_import(vmem_t *vm, vmem_size_t size, vmem_size_t align, int flags) 908 { 909 vmem_addr_t addr; 910 int error; 911 912 if (vm->vm_importfn == NULL) 913 return (EINVAL); 914 915 /* 916 * To make sure we get a span that meets the alignment we double it 917 * and add the size to the tail. This slightly overestimates. 918 */ 919 if (align != vm->vm_quantum_mask + 1) 920 size = (align * 2) + size; 921 size = roundup(size, vm->vm_import_quantum); 922 923 if (vm->vm_limit != 0 && vm->vm_limit < vm->vm_size + size) 924 return (ENOMEM); 925 926 bt_save(vm); 927 VMEM_UNLOCK(vm); 928 error = (vm->vm_importfn)(vm->vm_arg, size, flags, &addr); 929 VMEM_LOCK(vm); 930 bt_restore(vm); 931 if (error) 932 return (ENOMEM); 933 934 vmem_add1(vm, addr, size, BT_TYPE_SPAN); 935 936 return 0; 937 } 938 939 /* 940 * vmem_fit: check if a bt can satisfy the given restrictions. 941 * 942 * it's a caller's responsibility to ensure the region is big enough 943 * before calling us. 944 */ 945 static int 946 vmem_fit(const bt_t *bt, vmem_size_t size, vmem_size_t align, 947 vmem_size_t phase, vmem_size_t nocross, vmem_addr_t minaddr, 948 vmem_addr_t maxaddr, vmem_addr_t *addrp) 949 { 950 vmem_addr_t start; 951 vmem_addr_t end; 952 953 MPASS(size > 0); 954 MPASS(bt->bt_size >= size); /* caller's responsibility */ 955 956 /* 957 * XXX assumption: vmem_addr_t and vmem_size_t are 958 * unsigned integer of the same size. 959 */ 960 961 start = bt->bt_start; 962 if (start < minaddr) { 963 start = minaddr; 964 } 965 end = BT_END(bt); 966 if (end > maxaddr) 967 end = maxaddr; 968 if (start > end) 969 return (ENOMEM); 970 971 start = VMEM_ALIGNUP(start - phase, align) + phase; 972 if (start < bt->bt_start) 973 start += align; 974 if (VMEM_CROSS_P(start, start + size - 1, nocross)) { 975 MPASS(align < nocross); 976 start = VMEM_ALIGNUP(start - phase, nocross) + phase; 977 } 978 if (start <= end && end - start >= size - 1) { 979 MPASS((start & (align - 1)) == phase); 980 MPASS(!VMEM_CROSS_P(start, start + size - 1, nocross)); 981 MPASS(minaddr <= start); 982 MPASS(maxaddr == 0 || start + size - 1 <= maxaddr); 983 MPASS(bt->bt_start <= start); 984 MPASS(BT_END(bt) - start >= size - 1); 985 *addrp = start; 986 987 return (0); 988 } 989 return (ENOMEM); 990 } 991 992 /* 993 * vmem_clip: Trim the boundary tag edges to the requested start and size. 994 */ 995 static void 996 vmem_clip(vmem_t *vm, bt_t *bt, vmem_addr_t start, vmem_size_t size) 997 { 998 bt_t *btnew; 999 bt_t *btprev; 1000 1001 VMEM_ASSERT_LOCKED(vm); 1002 MPASS(bt->bt_type == BT_TYPE_FREE); 1003 MPASS(bt->bt_size >= size); 1004 bt_remfree(vm, bt); 1005 if (bt->bt_start != start) { 1006 btprev = bt_alloc(vm); 1007 btprev->bt_type = BT_TYPE_FREE; 1008 btprev->bt_start = bt->bt_start; 1009 btprev->bt_size = start - bt->bt_start; 1010 bt->bt_start = start; 1011 bt->bt_size -= btprev->bt_size; 1012 bt_insfree(vm, btprev); 1013 bt_insseg(vm, btprev, 1014 TAILQ_PREV(bt, vmem_seglist, bt_seglist)); 1015 } 1016 MPASS(bt->bt_start == start); 1017 if (bt->bt_size != size && bt->bt_size - size > vm->vm_quantum_mask) { 1018 /* split */ 1019 btnew = bt_alloc(vm); 1020 btnew->bt_type = BT_TYPE_BUSY; 1021 btnew->bt_start = bt->bt_start; 1022 btnew->bt_size = size; 1023 bt->bt_start = bt->bt_start + size; 1024 bt->bt_size -= size; 1025 bt_insfree(vm, bt); 1026 bt_insseg(vm, btnew, 1027 TAILQ_PREV(bt, vmem_seglist, bt_seglist)); 1028 bt_insbusy(vm, btnew); 1029 bt = btnew; 1030 } else { 1031 bt->bt_type = BT_TYPE_BUSY; 1032 bt_insbusy(vm, bt); 1033 } 1034 MPASS(bt->bt_size >= size); 1035 } 1036 1037 static int 1038 vmem_try_fetch(vmem_t *vm, const vmem_size_t size, vmem_size_t align, int flags) 1039 { 1040 vmem_size_t avail; 1041 1042 VMEM_ASSERT_LOCKED(vm); 1043 1044 /* 1045 * XXX it is possible to fail to meet xalloc constraints with the 1046 * imported region. It is up to the user to specify the 1047 * import quantum such that it can satisfy any allocation. 1048 */ 1049 if (vmem_import(vm, size, align, flags) == 0) 1050 return (1); 1051 1052 /* 1053 * Try to free some space from the quantum cache or reclaim 1054 * functions if available. 1055 */ 1056 if (vm->vm_qcache_max != 0 || vm->vm_reclaimfn != NULL) { 1057 avail = vm->vm_size - vm->vm_inuse; 1058 bt_save(vm); 1059 VMEM_UNLOCK(vm); 1060 if (vm->vm_qcache_max != 0) 1061 qc_drain(vm); 1062 if (vm->vm_reclaimfn != NULL) 1063 vm->vm_reclaimfn(vm, flags); 1064 VMEM_LOCK(vm); 1065 bt_restore(vm); 1066 /* If we were successful retry even NOWAIT. */ 1067 if (vm->vm_size - vm->vm_inuse > avail) 1068 return (1); 1069 } 1070 if ((flags & M_NOWAIT) != 0) 1071 return (0); 1072 bt_save(vm); 1073 VMEM_CONDVAR_WAIT(vm); 1074 bt_restore(vm); 1075 return (1); 1076 } 1077 1078 static int 1079 vmem_try_release(vmem_t *vm, struct vmem_btag *bt, const bool remfree) 1080 { 1081 struct vmem_btag *prev; 1082 1083 MPASS(bt->bt_type == BT_TYPE_FREE); 1084 1085 if (vm->vm_releasefn == NULL) 1086 return (0); 1087 1088 prev = TAILQ_PREV(bt, vmem_seglist, bt_seglist); 1089 MPASS(prev != NULL); 1090 MPASS(prev->bt_type != BT_TYPE_FREE); 1091 1092 if (prev->bt_type == BT_TYPE_SPAN && prev->bt_size == bt->bt_size) { 1093 vmem_addr_t spanaddr; 1094 vmem_size_t spansize; 1095 1096 MPASS(prev->bt_start == bt->bt_start); 1097 spanaddr = prev->bt_start; 1098 spansize = prev->bt_size; 1099 if (remfree) 1100 bt_remfree(vm, bt); 1101 bt_remseg(vm, bt); 1102 bt_remseg(vm, prev); 1103 vm->vm_size -= spansize; 1104 VMEM_CONDVAR_BROADCAST(vm); 1105 bt_freetrim(vm, BT_MAXFREE); 1106 vm->vm_releasefn(vm->vm_arg, spanaddr, spansize); 1107 return (1); 1108 } 1109 return (0); 1110 } 1111 1112 static int 1113 vmem_xalloc_nextfit(vmem_t *vm, const vmem_size_t size, vmem_size_t align, 1114 const vmem_size_t phase, const vmem_size_t nocross, int flags, 1115 vmem_addr_t *addrp) 1116 { 1117 struct vmem_btag *bt, *cursor, *next, *prev; 1118 int error; 1119 1120 error = ENOMEM; 1121 VMEM_LOCK(vm); 1122 1123 /* 1124 * Make sure we have enough tags to complete the operation. 1125 */ 1126 if (bt_fill(vm, flags) != 0) 1127 goto out; 1128 1129 retry: 1130 /* 1131 * Find the next free tag meeting our constraints. If one is found, 1132 * perform the allocation. 1133 */ 1134 for (cursor = &vm->vm_cursor, bt = TAILQ_NEXT(cursor, bt_seglist); 1135 bt != cursor; bt = TAILQ_NEXT(bt, bt_seglist)) { 1136 if (bt == NULL) 1137 bt = TAILQ_FIRST(&vm->vm_seglist); 1138 if (bt->bt_type == BT_TYPE_FREE && bt->bt_size >= size && 1139 (error = vmem_fit(bt, size, align, phase, nocross, 1140 VMEM_ADDR_MIN, VMEM_ADDR_MAX, addrp)) == 0) { 1141 vmem_clip(vm, bt, *addrp, size); 1142 break; 1143 } 1144 } 1145 1146 /* 1147 * Try to coalesce free segments around the cursor. If we succeed, and 1148 * have not yet satisfied the allocation request, try again with the 1149 * newly coalesced segment. 1150 */ 1151 if ((next = TAILQ_NEXT(cursor, bt_seglist)) != NULL && 1152 (prev = TAILQ_PREV(cursor, vmem_seglist, bt_seglist)) != NULL && 1153 next->bt_type == BT_TYPE_FREE && prev->bt_type == BT_TYPE_FREE && 1154 prev->bt_start + prev->bt_size == next->bt_start) { 1155 prev->bt_size += next->bt_size; 1156 bt_remfree(vm, next); 1157 bt_remseg(vm, next); 1158 1159 /* 1160 * The coalesced segment might be able to satisfy our request. 1161 * If not, we might need to release it from the arena. 1162 */ 1163 if (error == ENOMEM && prev->bt_size >= size && 1164 (error = vmem_fit(prev, size, align, phase, nocross, 1165 VMEM_ADDR_MIN, VMEM_ADDR_MAX, addrp)) == 0) { 1166 vmem_clip(vm, prev, *addrp, size); 1167 bt = prev; 1168 } else 1169 (void)vmem_try_release(vm, prev, true); 1170 } 1171 1172 /* 1173 * If the allocation was successful, advance the cursor. 1174 */ 1175 if (error == 0) { 1176 TAILQ_REMOVE(&vm->vm_seglist, cursor, bt_seglist); 1177 for (; bt != NULL && bt->bt_start < *addrp + size; 1178 bt = TAILQ_NEXT(bt, bt_seglist)) 1179 ; 1180 if (bt != NULL) 1181 TAILQ_INSERT_BEFORE(bt, cursor, bt_seglist); 1182 else 1183 TAILQ_INSERT_HEAD(&vm->vm_seglist, cursor, bt_seglist); 1184 } 1185 1186 /* 1187 * Attempt to bring additional resources into the arena. If that fails 1188 * and M_WAITOK is specified, sleep waiting for resources to be freed. 1189 */ 1190 if (error == ENOMEM && vmem_try_fetch(vm, size, align, flags)) 1191 goto retry; 1192 1193 out: 1194 VMEM_UNLOCK(vm); 1195 return (error); 1196 } 1197 1198 /* ---- vmem API */ 1199 1200 void 1201 vmem_set_import(vmem_t *vm, vmem_import_t *importfn, 1202 vmem_release_t *releasefn, void *arg, vmem_size_t import_quantum) 1203 { 1204 1205 VMEM_LOCK(vm); 1206 KASSERT(vm->vm_size == 0, ("%s: arena is non-empty", __func__)); 1207 vm->vm_importfn = importfn; 1208 vm->vm_releasefn = releasefn; 1209 vm->vm_arg = arg; 1210 vm->vm_import_quantum = import_quantum; 1211 VMEM_UNLOCK(vm); 1212 } 1213 1214 void 1215 vmem_set_limit(vmem_t *vm, vmem_size_t limit) 1216 { 1217 1218 VMEM_LOCK(vm); 1219 vm->vm_limit = limit; 1220 VMEM_UNLOCK(vm); 1221 } 1222 1223 void 1224 vmem_set_reclaim(vmem_t *vm, vmem_reclaim_t *reclaimfn) 1225 { 1226 1227 VMEM_LOCK(vm); 1228 vm->vm_reclaimfn = reclaimfn; 1229 VMEM_UNLOCK(vm); 1230 } 1231 1232 /* 1233 * vmem_init: Initializes vmem arena. 1234 */ 1235 vmem_t * 1236 vmem_init(vmem_t *vm, const char *name, vmem_addr_t base, vmem_size_t size, 1237 vmem_size_t quantum, vmem_size_t qcache_max, int flags) 1238 { 1239 vmem_size_t i; 1240 1241 MPASS(quantum > 0); 1242 MPASS((quantum & (quantum - 1)) == 0); 1243 1244 bzero(vm, sizeof(*vm)); 1245 1246 VMEM_CONDVAR_INIT(vm, name); 1247 VMEM_LOCK_INIT(vm, name); 1248 vm->vm_nfreetags = 0; 1249 LIST_INIT(&vm->vm_freetags); 1250 strlcpy(vm->vm_name, name, sizeof(vm->vm_name)); 1251 vm->vm_quantum_mask = quantum - 1; 1252 vm->vm_quantum_shift = flsl(quantum) - 1; 1253 vm->vm_nbusytag = 0; 1254 vm->vm_size = 0; 1255 vm->vm_limit = 0; 1256 vm->vm_inuse = 0; 1257 qc_init(vm, qcache_max); 1258 1259 TAILQ_INIT(&vm->vm_seglist); 1260 vm->vm_cursor.bt_start = vm->vm_cursor.bt_size = 0; 1261 vm->vm_cursor.bt_type = BT_TYPE_CURSOR; 1262 TAILQ_INSERT_TAIL(&vm->vm_seglist, &vm->vm_cursor, bt_seglist); 1263 1264 for (i = 0; i < VMEM_MAXORDER; i++) 1265 LIST_INIT(&vm->vm_freelist[i]); 1266 1267 memset(&vm->vm_hash0, 0, sizeof(vm->vm_hash0)); 1268 vm->vm_hashsize = VMEM_HASHSIZE_MIN; 1269 vm->vm_hashlist = vm->vm_hash0; 1270 1271 if (size != 0) { 1272 if (vmem_add(vm, base, size, flags) != 0) { 1273 vmem_destroy1(vm); 1274 return NULL; 1275 } 1276 } 1277 1278 mtx_lock(&vmem_list_lock); 1279 LIST_INSERT_HEAD(&vmem_list, vm, vm_alllist); 1280 mtx_unlock(&vmem_list_lock); 1281 1282 return vm; 1283 } 1284 1285 /* 1286 * vmem_create: create an arena. 1287 */ 1288 vmem_t * 1289 vmem_create(const char *name, vmem_addr_t base, vmem_size_t size, 1290 vmem_size_t quantum, vmem_size_t qcache_max, int flags) 1291 { 1292 1293 vmem_t *vm; 1294 1295 vm = uma_zalloc(vmem_zone, flags & (M_WAITOK|M_NOWAIT)); 1296 if (vm == NULL) 1297 return (NULL); 1298 if (vmem_init(vm, name, base, size, quantum, qcache_max, 1299 flags) == NULL) 1300 return (NULL); 1301 return (vm); 1302 } 1303 1304 void 1305 vmem_destroy(vmem_t *vm) 1306 { 1307 1308 mtx_lock(&vmem_list_lock); 1309 LIST_REMOVE(vm, vm_alllist); 1310 mtx_unlock(&vmem_list_lock); 1311 1312 vmem_destroy1(vm); 1313 } 1314 1315 vmem_size_t 1316 vmem_roundup_size(vmem_t *vm, vmem_size_t size) 1317 { 1318 1319 return (size + vm->vm_quantum_mask) & ~vm->vm_quantum_mask; 1320 } 1321 1322 /* 1323 * vmem_alloc: allocate resource from the arena. 1324 */ 1325 int 1326 vmem_alloc(vmem_t *vm, vmem_size_t size, int flags, vmem_addr_t *addrp) 1327 { 1328 const int strat __unused = flags & VMEM_FITMASK; 1329 qcache_t *qc; 1330 1331 flags &= VMEM_FLAGS; 1332 MPASS(size > 0); 1333 MPASS(strat == M_BESTFIT || strat == M_FIRSTFIT || strat == M_NEXTFIT); 1334 if ((flags & M_NOWAIT) == 0) 1335 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "vmem_alloc"); 1336 1337 if (size <= vm->vm_qcache_max) { 1338 /* 1339 * Resource 0 cannot be cached, so avoid a blocking allocation 1340 * in qc_import() and give the vmem_xalloc() call below a chance 1341 * to return 0. 1342 */ 1343 qc = &vm->vm_qcache[(size - 1) >> vm->vm_quantum_shift]; 1344 *addrp = (vmem_addr_t)uma_zalloc(qc->qc_cache, 1345 (flags & ~M_WAITOK) | M_NOWAIT); 1346 if (__predict_true(*addrp != 0)) 1347 return (0); 1348 } 1349 1350 return (vmem_xalloc(vm, size, 0, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX, 1351 flags, addrp)); 1352 } 1353 1354 int 1355 vmem_xalloc(vmem_t *vm, const vmem_size_t size0, vmem_size_t align, 1356 const vmem_size_t phase, const vmem_size_t nocross, 1357 const vmem_addr_t minaddr, const vmem_addr_t maxaddr, int flags, 1358 vmem_addr_t *addrp) 1359 { 1360 const vmem_size_t size = vmem_roundup_size(vm, size0); 1361 struct vmem_freelist *list; 1362 struct vmem_freelist *first; 1363 struct vmem_freelist *end; 1364 bt_t *bt; 1365 int error; 1366 int strat; 1367 1368 flags &= VMEM_FLAGS; 1369 strat = flags & VMEM_FITMASK; 1370 MPASS(size0 > 0); 1371 MPASS(size > 0); 1372 MPASS(strat == M_BESTFIT || strat == M_FIRSTFIT || strat == M_NEXTFIT); 1373 MPASS((flags & (M_NOWAIT|M_WAITOK)) != (M_NOWAIT|M_WAITOK)); 1374 if ((flags & M_NOWAIT) == 0) 1375 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "vmem_xalloc"); 1376 MPASS((align & vm->vm_quantum_mask) == 0); 1377 MPASS((align & (align - 1)) == 0); 1378 MPASS((phase & vm->vm_quantum_mask) == 0); 1379 MPASS((nocross & vm->vm_quantum_mask) == 0); 1380 MPASS((nocross & (nocross - 1)) == 0); 1381 MPASS((align == 0 && phase == 0) || phase < align); 1382 MPASS(nocross == 0 || nocross >= size); 1383 MPASS(minaddr <= maxaddr); 1384 MPASS(!VMEM_CROSS_P(phase, phase + size - 1, nocross)); 1385 if (strat == M_NEXTFIT) 1386 MPASS(minaddr == VMEM_ADDR_MIN && maxaddr == VMEM_ADDR_MAX); 1387 1388 if (align == 0) 1389 align = vm->vm_quantum_mask + 1; 1390 *addrp = 0; 1391 1392 /* 1393 * Next-fit allocations don't use the freelists. 1394 */ 1395 if (strat == M_NEXTFIT) 1396 return (vmem_xalloc_nextfit(vm, size0, align, phase, nocross, 1397 flags, addrp)); 1398 1399 end = &vm->vm_freelist[VMEM_MAXORDER]; 1400 /* 1401 * choose a free block from which we allocate. 1402 */ 1403 first = bt_freehead_toalloc(vm, size, strat); 1404 VMEM_LOCK(vm); 1405 1406 /* 1407 * Make sure we have enough tags to complete the operation. 1408 */ 1409 error = bt_fill(vm, flags); 1410 if (error != 0) 1411 goto out; 1412 for (;;) { 1413 /* 1414 * Scan freelists looking for a tag that satisfies the 1415 * allocation. If we're doing BESTFIT we may encounter 1416 * sizes below the request. If we're doing FIRSTFIT we 1417 * inspect only the first element from each list. 1418 */ 1419 for (list = first; list < end; list++) { 1420 LIST_FOREACH(bt, list, bt_freelist) { 1421 if (bt->bt_size >= size) { 1422 error = vmem_fit(bt, size, align, phase, 1423 nocross, minaddr, maxaddr, addrp); 1424 if (error == 0) { 1425 vmem_clip(vm, bt, *addrp, size); 1426 goto out; 1427 } 1428 } 1429 /* FIRST skips to the next list. */ 1430 if (strat == M_FIRSTFIT) 1431 break; 1432 } 1433 } 1434 1435 /* 1436 * Retry if the fast algorithm failed. 1437 */ 1438 if (strat == M_FIRSTFIT) { 1439 strat = M_BESTFIT; 1440 first = bt_freehead_toalloc(vm, size, strat); 1441 continue; 1442 } 1443 1444 /* 1445 * Try a few measures to bring additional resources into the 1446 * arena. If all else fails, we will sleep waiting for 1447 * resources to be freed. 1448 */ 1449 if (!vmem_try_fetch(vm, size, align, flags)) { 1450 error = ENOMEM; 1451 break; 1452 } 1453 } 1454 out: 1455 VMEM_UNLOCK(vm); 1456 if (error != 0 && (flags & M_NOWAIT) == 0) 1457 panic("failed to allocate waiting allocation\n"); 1458 1459 return (error); 1460 } 1461 1462 /* 1463 * vmem_free: free the resource to the arena. 1464 */ 1465 void 1466 vmem_free(vmem_t *vm, vmem_addr_t addr, vmem_size_t size) 1467 { 1468 qcache_t *qc; 1469 MPASS(size > 0); 1470 1471 if (size <= vm->vm_qcache_max && 1472 __predict_true(addr >= VMEM_ADDR_QCACHE_MIN)) { 1473 qc = &vm->vm_qcache[(size - 1) >> vm->vm_quantum_shift]; 1474 uma_zfree(qc->qc_cache, (void *)addr); 1475 } else 1476 vmem_xfree(vm, addr, size); 1477 } 1478 1479 void 1480 vmem_xfree(vmem_t *vm, vmem_addr_t addr, vmem_size_t size __unused) 1481 { 1482 bt_t *bt; 1483 bt_t *t; 1484 1485 MPASS(size > 0); 1486 1487 VMEM_LOCK(vm); 1488 bt = bt_lookupbusy(vm, addr); 1489 MPASS(bt != NULL); 1490 MPASS(bt->bt_start == addr); 1491 MPASS(bt->bt_size == vmem_roundup_size(vm, size) || 1492 bt->bt_size - vmem_roundup_size(vm, size) <= vm->vm_quantum_mask); 1493 MPASS(bt->bt_type == BT_TYPE_BUSY); 1494 bt_rembusy(vm, bt); 1495 bt->bt_type = BT_TYPE_FREE; 1496 1497 /* coalesce */ 1498 t = TAILQ_NEXT(bt, bt_seglist); 1499 if (t != NULL && t->bt_type == BT_TYPE_FREE) { 1500 MPASS(BT_END(bt) < t->bt_start); /* YYY */ 1501 bt->bt_size += t->bt_size; 1502 bt_remfree(vm, t); 1503 bt_remseg(vm, t); 1504 } 1505 t = TAILQ_PREV(bt, vmem_seglist, bt_seglist); 1506 if (t != NULL && t->bt_type == BT_TYPE_FREE) { 1507 MPASS(BT_END(t) < bt->bt_start); /* YYY */ 1508 bt->bt_size += t->bt_size; 1509 bt->bt_start = t->bt_start; 1510 bt_remfree(vm, t); 1511 bt_remseg(vm, t); 1512 } 1513 1514 if (!vmem_try_release(vm, bt, false)) { 1515 bt_insfree(vm, bt); 1516 VMEM_CONDVAR_BROADCAST(vm); 1517 bt_freetrim(vm, BT_MAXFREE); 1518 } 1519 } 1520 1521 /* 1522 * vmem_add: 1523 * 1524 */ 1525 int 1526 vmem_add(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, int flags) 1527 { 1528 int error; 1529 1530 flags &= VMEM_FLAGS; 1531 1532 VMEM_LOCK(vm); 1533 error = bt_fill(vm, flags); 1534 if (error == 0) 1535 vmem_add1(vm, addr, size, BT_TYPE_SPAN_STATIC); 1536 VMEM_UNLOCK(vm); 1537 1538 return (error); 1539 } 1540 1541 /* 1542 * vmem_size: information about arenas size 1543 */ 1544 vmem_size_t 1545 vmem_size(vmem_t *vm, int typemask) 1546 { 1547 int i; 1548 1549 switch (typemask) { 1550 case VMEM_ALLOC: 1551 return vm->vm_inuse; 1552 case VMEM_FREE: 1553 return vm->vm_size - vm->vm_inuse; 1554 case VMEM_FREE|VMEM_ALLOC: 1555 return vm->vm_size; 1556 case VMEM_MAXFREE: 1557 VMEM_LOCK(vm); 1558 for (i = VMEM_MAXORDER - 1; i >= 0; i--) { 1559 if (LIST_EMPTY(&vm->vm_freelist[i])) 1560 continue; 1561 VMEM_UNLOCK(vm); 1562 return ((vmem_size_t)ORDER2SIZE(i) << 1563 vm->vm_quantum_shift); 1564 } 1565 VMEM_UNLOCK(vm); 1566 return (0); 1567 default: 1568 panic("vmem_size"); 1569 } 1570 } 1571 1572 /* ---- debug */ 1573 1574 #if defined(DDB) || defined(DIAGNOSTIC) 1575 1576 static void bt_dump(const bt_t *, int (*)(const char *, ...) 1577 __printflike(1, 2)); 1578 1579 static const char * 1580 bt_type_string(int type) 1581 { 1582 1583 switch (type) { 1584 case BT_TYPE_BUSY: 1585 return "busy"; 1586 case BT_TYPE_FREE: 1587 return "free"; 1588 case BT_TYPE_SPAN: 1589 return "span"; 1590 case BT_TYPE_SPAN_STATIC: 1591 return "static span"; 1592 case BT_TYPE_CURSOR: 1593 return "cursor"; 1594 default: 1595 break; 1596 } 1597 return "BOGUS"; 1598 } 1599 1600 static void 1601 bt_dump(const bt_t *bt, int (*pr)(const char *, ...)) 1602 { 1603 1604 (*pr)("\t%p: %jx %jx, %d(%s)\n", 1605 bt, (intmax_t)bt->bt_start, (intmax_t)bt->bt_size, 1606 bt->bt_type, bt_type_string(bt->bt_type)); 1607 } 1608 1609 static void 1610 vmem_dump(const vmem_t *vm , int (*pr)(const char *, ...) __printflike(1, 2)) 1611 { 1612 const bt_t *bt; 1613 int i; 1614 1615 (*pr)("vmem %p '%s'\n", vm, vm->vm_name); 1616 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { 1617 bt_dump(bt, pr); 1618 } 1619 1620 for (i = 0; i < VMEM_MAXORDER; i++) { 1621 const struct vmem_freelist *fl = &vm->vm_freelist[i]; 1622 1623 if (LIST_EMPTY(fl)) { 1624 continue; 1625 } 1626 1627 (*pr)("freelist[%d]\n", i); 1628 LIST_FOREACH(bt, fl, bt_freelist) { 1629 bt_dump(bt, pr); 1630 } 1631 } 1632 } 1633 1634 #endif /* defined(DDB) || defined(DIAGNOSTIC) */ 1635 1636 #if defined(DDB) 1637 #include <ddb/ddb.h> 1638 1639 static bt_t * 1640 vmem_whatis_lookup(vmem_t *vm, vmem_addr_t addr) 1641 { 1642 bt_t *bt; 1643 1644 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { 1645 if (BT_ISSPAN_P(bt)) { 1646 continue; 1647 } 1648 if (bt->bt_start <= addr && addr <= BT_END(bt)) { 1649 return bt; 1650 } 1651 } 1652 1653 return NULL; 1654 } 1655 1656 void 1657 vmem_whatis(vmem_addr_t addr, int (*pr)(const char *, ...)) 1658 { 1659 vmem_t *vm; 1660 1661 LIST_FOREACH(vm, &vmem_list, vm_alllist) { 1662 bt_t *bt; 1663 1664 bt = vmem_whatis_lookup(vm, addr); 1665 if (bt == NULL) { 1666 continue; 1667 } 1668 (*pr)("%p is %p+%zu in VMEM '%s' (%s)\n", 1669 (void *)addr, (void *)bt->bt_start, 1670 (vmem_size_t)(addr - bt->bt_start), vm->vm_name, 1671 (bt->bt_type == BT_TYPE_BUSY) ? "allocated" : "free"); 1672 } 1673 } 1674 1675 void 1676 vmem_printall(const char *modif, int (*pr)(const char *, ...)) 1677 { 1678 const vmem_t *vm; 1679 1680 LIST_FOREACH(vm, &vmem_list, vm_alllist) { 1681 vmem_dump(vm, pr); 1682 } 1683 } 1684 1685 void 1686 vmem_print(vmem_addr_t addr, const char *modif, int (*pr)(const char *, ...)) 1687 { 1688 const vmem_t *vm = (const void *)addr; 1689 1690 vmem_dump(vm, pr); 1691 } 1692 1693 DB_SHOW_COMMAND(vmemdump, vmemdump) 1694 { 1695 1696 if (!have_addr) { 1697 db_printf("usage: show vmemdump <addr>\n"); 1698 return; 1699 } 1700 1701 vmem_dump((const vmem_t *)addr, db_printf); 1702 } 1703 1704 DB_SHOW_ALL_COMMAND(vmemdump, vmemdumpall) 1705 { 1706 const vmem_t *vm; 1707 1708 LIST_FOREACH(vm, &vmem_list, vm_alllist) 1709 vmem_dump(vm, db_printf); 1710 } 1711 1712 DB_SHOW_COMMAND(vmem, vmem_summ) 1713 { 1714 const vmem_t *vm = (const void *)addr; 1715 const bt_t *bt; 1716 size_t ft[VMEM_MAXORDER], ut[VMEM_MAXORDER]; 1717 size_t fs[VMEM_MAXORDER], us[VMEM_MAXORDER]; 1718 int ord; 1719 1720 if (!have_addr) { 1721 db_printf("usage: show vmem <addr>\n"); 1722 return; 1723 } 1724 1725 db_printf("vmem %p '%s'\n", vm, vm->vm_name); 1726 db_printf("\tquantum:\t%zu\n", vm->vm_quantum_mask + 1); 1727 db_printf("\tsize:\t%zu\n", vm->vm_size); 1728 db_printf("\tinuse:\t%zu\n", vm->vm_inuse); 1729 db_printf("\tfree:\t%zu\n", vm->vm_size - vm->vm_inuse); 1730 db_printf("\tbusy tags:\t%d\n", vm->vm_nbusytag); 1731 db_printf("\tfree tags:\t%d\n", vm->vm_nfreetags); 1732 1733 memset(&ft, 0, sizeof(ft)); 1734 memset(&ut, 0, sizeof(ut)); 1735 memset(&fs, 0, sizeof(fs)); 1736 memset(&us, 0, sizeof(us)); 1737 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { 1738 ord = SIZE2ORDER(bt->bt_size >> vm->vm_quantum_shift); 1739 if (bt->bt_type == BT_TYPE_BUSY) { 1740 ut[ord]++; 1741 us[ord] += bt->bt_size; 1742 } else if (bt->bt_type == BT_TYPE_FREE) { 1743 ft[ord]++; 1744 fs[ord] += bt->bt_size; 1745 } 1746 } 1747 db_printf("\t\t\tinuse\tsize\t\tfree\tsize\n"); 1748 for (ord = 0; ord < VMEM_MAXORDER; ord++) { 1749 if (ut[ord] == 0 && ft[ord] == 0) 1750 continue; 1751 db_printf("\t%-15zu %zu\t%-15zu %zu\t%-16zu\n", 1752 ORDER2SIZE(ord) << vm->vm_quantum_shift, 1753 ut[ord], us[ord], ft[ord], fs[ord]); 1754 } 1755 } 1756 1757 DB_SHOW_ALL_COMMAND(vmem, vmem_summall) 1758 { 1759 const vmem_t *vm; 1760 1761 LIST_FOREACH(vm, &vmem_list, vm_alllist) 1762 vmem_summ((db_expr_t)vm, TRUE, count, modif); 1763 } 1764 #endif /* defined(DDB) */ 1765 1766 #define vmem_printf printf 1767 1768 #if defined(DIAGNOSTIC) 1769 1770 static bool 1771 vmem_check_sanity(vmem_t *vm) 1772 { 1773 const bt_t *bt, *bt2; 1774 1775 MPASS(vm != NULL); 1776 1777 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { 1778 if (bt->bt_start > BT_END(bt)) { 1779 printf("corrupted tag\n"); 1780 bt_dump(bt, vmem_printf); 1781 return false; 1782 } 1783 } 1784 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { 1785 if (bt->bt_type == BT_TYPE_CURSOR) { 1786 if (bt->bt_start != 0 || bt->bt_size != 0) { 1787 printf("corrupted cursor\n"); 1788 return false; 1789 } 1790 continue; 1791 } 1792 TAILQ_FOREACH(bt2, &vm->vm_seglist, bt_seglist) { 1793 if (bt == bt2) { 1794 continue; 1795 } 1796 if (bt2->bt_type == BT_TYPE_CURSOR) { 1797 continue; 1798 } 1799 if (BT_ISSPAN_P(bt) != BT_ISSPAN_P(bt2)) { 1800 continue; 1801 } 1802 if (bt->bt_start <= BT_END(bt2) && 1803 bt2->bt_start <= BT_END(bt)) { 1804 printf("overwrapped tags\n"); 1805 bt_dump(bt, vmem_printf); 1806 bt_dump(bt2, vmem_printf); 1807 return false; 1808 } 1809 } 1810 } 1811 1812 return true; 1813 } 1814 1815 static void 1816 vmem_check(vmem_t *vm) 1817 { 1818 1819 if (!vmem_check_sanity(vm)) { 1820 panic("insanity vmem %p", vm); 1821 } 1822 } 1823 1824 #endif /* defined(DIAGNOSTIC) */
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