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: releng/12.0/sys/kern/subr_vmem.c 338836 2018-09-20 18:29:55Z markj $"); 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 int vmem_startup_count(void); 81 82 #define VMEM_OPTORDER 5 83 #define VMEM_OPTVALUE (1 << VMEM_OPTORDER) 84 #define VMEM_MAXORDER \ 85 (VMEM_OPTVALUE - 1 + sizeof(vmem_size_t) * NBBY - VMEM_OPTORDER) 86 87 #define VMEM_HASHSIZE_MIN 16 88 #define VMEM_HASHSIZE_MAX 131072 89 90 #define VMEM_QCACHE_IDX_MAX 16 91 92 #define VMEM_FITMASK (M_BESTFIT | M_FIRSTFIT) 93 94 #define VMEM_FLAGS \ 95 (M_NOWAIT | M_WAITOK | M_USE_RESERVE | M_NOVM | M_BESTFIT | M_FIRSTFIT) 96 97 #define BT_FLAGS (M_NOWAIT | M_WAITOK | M_USE_RESERVE | M_NOVM) 98 99 #define QC_NAME_MAX 16 100 101 /* 102 * Data structures private to vmem. 103 */ 104 MALLOC_DEFINE(M_VMEM, "vmem", "vmem internal structures"); 105 106 typedef struct vmem_btag bt_t; 107 108 TAILQ_HEAD(vmem_seglist, vmem_btag); 109 LIST_HEAD(vmem_freelist, vmem_btag); 110 LIST_HEAD(vmem_hashlist, vmem_btag); 111 112 struct qcache { 113 uma_zone_t qc_cache; 114 vmem_t *qc_vmem; 115 vmem_size_t qc_size; 116 char qc_name[QC_NAME_MAX]; 117 }; 118 typedef struct qcache qcache_t; 119 #define QC_POOL_TO_QCACHE(pool) ((qcache_t *)(pool->pr_qcache)) 120 121 #define VMEM_NAME_MAX 16 122 123 /* vmem arena */ 124 struct vmem { 125 struct mtx_padalign vm_lock; 126 struct cv vm_cv; 127 char vm_name[VMEM_NAME_MAX+1]; 128 LIST_ENTRY(vmem) vm_alllist; 129 struct vmem_hashlist vm_hash0[VMEM_HASHSIZE_MIN]; 130 struct vmem_freelist vm_freelist[VMEM_MAXORDER]; 131 struct vmem_seglist vm_seglist; 132 struct vmem_hashlist *vm_hashlist; 133 vmem_size_t vm_hashsize; 134 135 /* Constant after init */ 136 vmem_size_t vm_qcache_max; 137 vmem_size_t vm_quantum_mask; 138 vmem_size_t vm_import_quantum; 139 int vm_quantum_shift; 140 141 /* Written on alloc/free */ 142 LIST_HEAD(, vmem_btag) vm_freetags; 143 int vm_nfreetags; 144 int vm_nbusytag; 145 vmem_size_t vm_inuse; 146 vmem_size_t vm_size; 147 vmem_size_t vm_limit; 148 149 /* Used on import. */ 150 vmem_import_t *vm_importfn; 151 vmem_release_t *vm_releasefn; 152 void *vm_arg; 153 154 /* Space exhaustion callback. */ 155 vmem_reclaim_t *vm_reclaimfn; 156 157 /* quantum cache */ 158 qcache_t vm_qcache[VMEM_QCACHE_IDX_MAX]; 159 }; 160 161 /* boundary tag */ 162 struct vmem_btag { 163 TAILQ_ENTRY(vmem_btag) bt_seglist; 164 union { 165 LIST_ENTRY(vmem_btag) u_freelist; /* BT_TYPE_FREE */ 166 LIST_ENTRY(vmem_btag) u_hashlist; /* BT_TYPE_BUSY */ 167 } bt_u; 168 #define bt_hashlist bt_u.u_hashlist 169 #define bt_freelist bt_u.u_freelist 170 vmem_addr_t bt_start; 171 vmem_size_t bt_size; 172 int bt_type; 173 }; 174 175 #define BT_TYPE_SPAN 1 /* Allocated from importfn */ 176 #define BT_TYPE_SPAN_STATIC 2 /* vmem_add() or create. */ 177 #define BT_TYPE_FREE 3 /* Available space. */ 178 #define BT_TYPE_BUSY 4 /* Used space. */ 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) 203 204 205 #define VMEM_LOCK(vm) mtx_lock(&vm->vm_lock) 206 #define VMEM_TRYLOCK(vm) mtx_trylock(&vm->vm_lock) 207 #define VMEM_UNLOCK(vm) mtx_unlock(&vm->vm_lock) 208 #define VMEM_LOCK_INIT(vm, name) mtx_init(&vm->vm_lock, (name), NULL, MTX_DEF) 209 #define VMEM_LOCK_DESTROY(vm) mtx_destroy(&vm->vm_lock) 210 #define VMEM_ASSERT_LOCKED(vm) mtx_assert(&vm->vm_lock, MA_OWNED); 211 212 #define VMEM_ALIGNUP(addr, align) (-(-(addr) & -(align))) 213 214 #define VMEM_CROSS_P(addr1, addr2, boundary) \ 215 ((((addr1) ^ (addr2)) & -(boundary)) != 0) 216 217 #define ORDER2SIZE(order) ((order) < VMEM_OPTVALUE ? ((order) + 1) : \ 218 (vmem_size_t)1 << ((order) - (VMEM_OPTVALUE - VMEM_OPTORDER - 1))) 219 #define SIZE2ORDER(size) ((size) <= VMEM_OPTVALUE ? ((size) - 1) : \ 220 (flsl(size) + (VMEM_OPTVALUE - VMEM_OPTORDER - 2))) 221 222 /* 223 * Maximum number of boundary tags that may be required to satisfy an 224 * allocation. Two may be required to import. Another two may be 225 * required to clip edges. 226 */ 227 #define BT_MAXALLOC 4 228 229 /* 230 * Max free limits the number of locally cached boundary tags. We 231 * just want to avoid hitting the zone allocator for every call. 232 */ 233 #define BT_MAXFREE (BT_MAXALLOC * 8) 234 235 /* Allocator for boundary tags. */ 236 static uma_zone_t vmem_bt_zone; 237 238 /* boot time arena storage. */ 239 static struct vmem kernel_arena_storage; 240 static struct vmem buffer_arena_storage; 241 static struct vmem transient_arena_storage; 242 /* kernel and kmem arenas are aliased for backwards KPI compat. */ 243 vmem_t *kernel_arena = &kernel_arena_storage; 244 vmem_t *kmem_arena = &kernel_arena_storage; 245 vmem_t *buffer_arena = &buffer_arena_storage; 246 vmem_t *transient_arena = &transient_arena_storage; 247 248 #ifdef DEBUG_MEMGUARD 249 static struct vmem memguard_arena_storage; 250 vmem_t *memguard_arena = &memguard_arena_storage; 251 #endif 252 253 /* 254 * Fill the vmem's boundary tag cache. We guarantee that boundary tag 255 * allocation will not fail once bt_fill() passes. To do so we cache 256 * at least the maximum possible tag allocations in the arena. 257 */ 258 static int 259 bt_fill(vmem_t *vm, int flags) 260 { 261 bt_t *bt; 262 263 VMEM_ASSERT_LOCKED(vm); 264 265 /* 266 * Only allow the kernel arena and arenas derived from kernel arena to 267 * dip into reserve tags. They are where new tags come from. 268 */ 269 flags &= BT_FLAGS; 270 if (vm != kernel_arena && vm->vm_arg != kernel_arena) 271 flags &= ~M_USE_RESERVE; 272 273 /* 274 * Loop until we meet the reserve. To minimize the lock shuffle 275 * and prevent simultaneous fills we first try a NOWAIT regardless 276 * of the caller's flags. Specify M_NOVM so we don't recurse while 277 * holding a vmem lock. 278 */ 279 while (vm->vm_nfreetags < BT_MAXALLOC) { 280 bt = uma_zalloc(vmem_bt_zone, 281 (flags & M_USE_RESERVE) | M_NOWAIT | M_NOVM); 282 if (bt == NULL) { 283 VMEM_UNLOCK(vm); 284 bt = uma_zalloc(vmem_bt_zone, flags); 285 VMEM_LOCK(vm); 286 if (bt == NULL && (flags & M_NOWAIT) != 0) 287 break; 288 } 289 LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist); 290 vm->vm_nfreetags++; 291 } 292 293 if (vm->vm_nfreetags < BT_MAXALLOC) 294 return ENOMEM; 295 296 return 0; 297 } 298 299 /* 300 * Pop a tag off of the freetag stack. 301 */ 302 static bt_t * 303 bt_alloc(vmem_t *vm) 304 { 305 bt_t *bt; 306 307 VMEM_ASSERT_LOCKED(vm); 308 bt = LIST_FIRST(&vm->vm_freetags); 309 MPASS(bt != NULL); 310 LIST_REMOVE(bt, bt_freelist); 311 vm->vm_nfreetags--; 312 313 return bt; 314 } 315 316 /* 317 * Trim the per-vmem free list. Returns with the lock released to 318 * avoid allocator recursions. 319 */ 320 static void 321 bt_freetrim(vmem_t *vm, int freelimit) 322 { 323 LIST_HEAD(, vmem_btag) freetags; 324 bt_t *bt; 325 326 LIST_INIT(&freetags); 327 VMEM_ASSERT_LOCKED(vm); 328 while (vm->vm_nfreetags > freelimit) { 329 bt = LIST_FIRST(&vm->vm_freetags); 330 LIST_REMOVE(bt, bt_freelist); 331 vm->vm_nfreetags--; 332 LIST_INSERT_HEAD(&freetags, bt, bt_freelist); 333 } 334 VMEM_UNLOCK(vm); 335 while ((bt = LIST_FIRST(&freetags)) != NULL) { 336 LIST_REMOVE(bt, bt_freelist); 337 uma_zfree(vmem_bt_zone, bt); 338 } 339 } 340 341 static inline void 342 bt_free(vmem_t *vm, bt_t *bt) 343 { 344 345 VMEM_ASSERT_LOCKED(vm); 346 MPASS(LIST_FIRST(&vm->vm_freetags) != bt); 347 LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist); 348 vm->vm_nfreetags++; 349 } 350 351 /* 352 * freelist[0] ... [1, 1] 353 * freelist[1] ... [2, 2] 354 * : 355 * freelist[29] ... [30, 30] 356 * freelist[30] ... [31, 31] 357 * freelist[31] ... [32, 63] 358 * freelist[33] ... [64, 127] 359 * : 360 * freelist[n] ... [(1 << (n - 26)), (1 << (n - 25)) - 1] 361 * : 362 */ 363 364 static struct vmem_freelist * 365 bt_freehead_tofree(vmem_t *vm, vmem_size_t size) 366 { 367 const vmem_size_t qsize = size >> vm->vm_quantum_shift; 368 const int idx = SIZE2ORDER(qsize); 369 370 MPASS(size != 0 && qsize != 0); 371 MPASS((size & vm->vm_quantum_mask) == 0); 372 MPASS(idx >= 0); 373 MPASS(idx < VMEM_MAXORDER); 374 375 return &vm->vm_freelist[idx]; 376 } 377 378 /* 379 * bt_freehead_toalloc: return the freelist for the given size and allocation 380 * strategy. 381 * 382 * For M_FIRSTFIT, return the list in which any blocks are large enough 383 * for the requested size. otherwise, return the list which can have blocks 384 * large enough for the requested size. 385 */ 386 static struct vmem_freelist * 387 bt_freehead_toalloc(vmem_t *vm, vmem_size_t size, int strat) 388 { 389 const vmem_size_t qsize = size >> vm->vm_quantum_shift; 390 int idx = SIZE2ORDER(qsize); 391 392 MPASS(size != 0 && qsize != 0); 393 MPASS((size & vm->vm_quantum_mask) == 0); 394 395 if (strat == M_FIRSTFIT && ORDER2SIZE(idx) != qsize) { 396 idx++; 397 /* check too large request? */ 398 } 399 MPASS(idx >= 0); 400 MPASS(idx < VMEM_MAXORDER); 401 402 return &vm->vm_freelist[idx]; 403 } 404 405 /* ---- boundary tag hash */ 406 407 static struct vmem_hashlist * 408 bt_hashhead(vmem_t *vm, vmem_addr_t addr) 409 { 410 struct vmem_hashlist *list; 411 unsigned int hash; 412 413 hash = hash32_buf(&addr, sizeof(addr), 0); 414 list = &vm->vm_hashlist[hash % vm->vm_hashsize]; 415 416 return list; 417 } 418 419 static bt_t * 420 bt_lookupbusy(vmem_t *vm, vmem_addr_t addr) 421 { 422 struct vmem_hashlist *list; 423 bt_t *bt; 424 425 VMEM_ASSERT_LOCKED(vm); 426 list = bt_hashhead(vm, addr); 427 LIST_FOREACH(bt, list, bt_hashlist) { 428 if (bt->bt_start == addr) { 429 break; 430 } 431 } 432 433 return bt; 434 } 435 436 static void 437 bt_rembusy(vmem_t *vm, bt_t *bt) 438 { 439 440 VMEM_ASSERT_LOCKED(vm); 441 MPASS(vm->vm_nbusytag > 0); 442 vm->vm_inuse -= bt->bt_size; 443 vm->vm_nbusytag--; 444 LIST_REMOVE(bt, bt_hashlist); 445 } 446 447 static void 448 bt_insbusy(vmem_t *vm, bt_t *bt) 449 { 450 struct vmem_hashlist *list; 451 452 VMEM_ASSERT_LOCKED(vm); 453 MPASS(bt->bt_type == BT_TYPE_BUSY); 454 455 list = bt_hashhead(vm, bt->bt_start); 456 LIST_INSERT_HEAD(list, bt, bt_hashlist); 457 vm->vm_nbusytag++; 458 vm->vm_inuse += bt->bt_size; 459 } 460 461 /* ---- boundary tag list */ 462 463 static void 464 bt_remseg(vmem_t *vm, bt_t *bt) 465 { 466 467 TAILQ_REMOVE(&vm->vm_seglist, bt, bt_seglist); 468 bt_free(vm, bt); 469 } 470 471 static void 472 bt_insseg(vmem_t *vm, bt_t *bt, bt_t *prev) 473 { 474 475 TAILQ_INSERT_AFTER(&vm->vm_seglist, prev, bt, bt_seglist); 476 } 477 478 static void 479 bt_insseg_tail(vmem_t *vm, bt_t *bt) 480 { 481 482 TAILQ_INSERT_TAIL(&vm->vm_seglist, bt, bt_seglist); 483 } 484 485 static void 486 bt_remfree(vmem_t *vm, bt_t *bt) 487 { 488 489 MPASS(bt->bt_type == BT_TYPE_FREE); 490 491 LIST_REMOVE(bt, bt_freelist); 492 } 493 494 static void 495 bt_insfree(vmem_t *vm, bt_t *bt) 496 { 497 struct vmem_freelist *list; 498 499 list = bt_freehead_tofree(vm, bt->bt_size); 500 LIST_INSERT_HEAD(list, bt, bt_freelist); 501 } 502 503 /* ---- vmem internal functions */ 504 505 /* 506 * Import from the arena into the quantum cache in UMA. 507 */ 508 static int 509 qc_import(void *arg, void **store, int cnt, int domain, int flags) 510 { 511 qcache_t *qc; 512 vmem_addr_t addr; 513 int i; 514 515 qc = arg; 516 if ((flags & VMEM_FITMASK) == 0) 517 flags |= M_BESTFIT; 518 for (i = 0; i < cnt; i++) { 519 if (vmem_xalloc(qc->qc_vmem, qc->qc_size, 0, 0, 0, 520 VMEM_ADDR_MIN, VMEM_ADDR_MAX, flags, &addr) != 0) 521 break; 522 store[i] = (void *)addr; 523 /* Only guarantee one allocation. */ 524 flags &= ~M_WAITOK; 525 flags |= M_NOWAIT; 526 } 527 return i; 528 } 529 530 /* 531 * Release memory from the UMA cache to the arena. 532 */ 533 static void 534 qc_release(void *arg, void **store, int cnt) 535 { 536 qcache_t *qc; 537 int i; 538 539 qc = arg; 540 for (i = 0; i < cnt; i++) 541 vmem_xfree(qc->qc_vmem, (vmem_addr_t)store[i], qc->qc_size); 542 } 543 544 static void 545 qc_init(vmem_t *vm, vmem_size_t qcache_max) 546 { 547 qcache_t *qc; 548 vmem_size_t size; 549 int qcache_idx_max; 550 int i; 551 552 MPASS((qcache_max & vm->vm_quantum_mask) == 0); 553 qcache_idx_max = MIN(qcache_max >> vm->vm_quantum_shift, 554 VMEM_QCACHE_IDX_MAX); 555 vm->vm_qcache_max = qcache_idx_max << vm->vm_quantum_shift; 556 for (i = 0; i < qcache_idx_max; i++) { 557 qc = &vm->vm_qcache[i]; 558 size = (i + 1) << vm->vm_quantum_shift; 559 snprintf(qc->qc_name, sizeof(qc->qc_name), "%s-%zu", 560 vm->vm_name, size); 561 qc->qc_vmem = vm; 562 qc->qc_size = size; 563 qc->qc_cache = uma_zcache_create(qc->qc_name, size, 564 NULL, NULL, NULL, NULL, qc_import, qc_release, qc, 565 UMA_ZONE_VM); 566 MPASS(qc->qc_cache); 567 } 568 } 569 570 static void 571 qc_destroy(vmem_t *vm) 572 { 573 int qcache_idx_max; 574 int i; 575 576 qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift; 577 for (i = 0; i < qcache_idx_max; i++) 578 uma_zdestroy(vm->vm_qcache[i].qc_cache); 579 } 580 581 static void 582 qc_drain(vmem_t *vm) 583 { 584 int qcache_idx_max; 585 int i; 586 587 qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift; 588 for (i = 0; i < qcache_idx_max; i++) 589 zone_drain(vm->vm_qcache[i].qc_cache); 590 } 591 592 #ifndef UMA_MD_SMALL_ALLOC 593 594 static struct mtx_padalign __exclusive_cache_line vmem_bt_lock; 595 596 /* 597 * vmem_bt_alloc: Allocate a new page of boundary tags. 598 * 599 * On architectures with uma_small_alloc there is no recursion; no address 600 * space need be allocated to allocate boundary tags. For the others, we 601 * must handle recursion. Boundary tags are necessary to allocate new 602 * boundary tags. 603 * 604 * UMA guarantees that enough tags are held in reserve to allocate a new 605 * page of kva. We dip into this reserve by specifying M_USE_RESERVE only 606 * when allocating the page to hold new boundary tags. In this way the 607 * reserve is automatically filled by the allocation that uses the reserve. 608 * 609 * We still have to guarantee that the new tags are allocated atomically since 610 * many threads may try concurrently. The bt_lock provides this guarantee. 611 * We convert WAITOK allocations to NOWAIT and then handle the blocking here 612 * on failure. It's ok to return NULL for a WAITOK allocation as UMA will 613 * loop again after checking to see if we lost the race to allocate. 614 * 615 * There is a small race between vmem_bt_alloc() returning the page and the 616 * zone lock being acquired to add the page to the zone. For WAITOK 617 * allocations we just pause briefly. NOWAIT may experience a transient 618 * failure. To alleviate this we permit a small number of simultaneous 619 * fills to proceed concurrently so NOWAIT is less likely to fail unless 620 * we are really out of KVA. 621 */ 622 static void * 623 vmem_bt_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag, 624 int wait) 625 { 626 vmem_addr_t addr; 627 628 *pflag = UMA_SLAB_KERNEL; 629 630 /* 631 * Single thread boundary tag allocation so that the address space 632 * and memory are added in one atomic operation. 633 */ 634 mtx_lock(&vmem_bt_lock); 635 if (vmem_xalloc(vm_dom[domain].vmd_kernel_arena, bytes, 0, 0, 0, 636 VMEM_ADDR_MIN, VMEM_ADDR_MAX, 637 M_NOWAIT | M_NOVM | M_USE_RESERVE | M_BESTFIT, &addr) == 0) { 638 if (kmem_back_domain(domain, kernel_object, addr, bytes, 639 M_NOWAIT | M_USE_RESERVE) == 0) { 640 mtx_unlock(&vmem_bt_lock); 641 return ((void *)addr); 642 } 643 vmem_xfree(vm_dom[domain].vmd_kernel_arena, addr, bytes); 644 mtx_unlock(&vmem_bt_lock); 645 /* 646 * Out of memory, not address space. This may not even be 647 * possible due to M_USE_RESERVE page allocation. 648 */ 649 if (wait & M_WAITOK) 650 vm_wait_domain(domain); 651 return (NULL); 652 } 653 mtx_unlock(&vmem_bt_lock); 654 /* 655 * We're either out of address space or lost a fill race. 656 */ 657 if (wait & M_WAITOK) 658 pause("btalloc", 1); 659 660 return (NULL); 661 } 662 663 /* 664 * How many pages do we need to startup_alloc. 665 */ 666 int 667 vmem_startup_count(void) 668 { 669 670 return (howmany(BT_MAXALLOC, 671 UMA_SLAB_SPACE / sizeof(struct vmem_btag))); 672 } 673 #endif 674 675 void 676 vmem_startup(void) 677 { 678 679 mtx_init(&vmem_list_lock, "vmem list lock", NULL, MTX_DEF); 680 vmem_zone = uma_zcreate("vmem", 681 sizeof(struct vmem), NULL, NULL, NULL, NULL, 682 UMA_ALIGN_PTR, UMA_ZONE_VM); 683 vmem_bt_zone = uma_zcreate("vmem btag", 684 sizeof(struct vmem_btag), NULL, NULL, NULL, NULL, 685 UMA_ALIGN_PTR, UMA_ZONE_VM | UMA_ZONE_NOFREE); 686 #ifndef UMA_MD_SMALL_ALLOC 687 mtx_init(&vmem_bt_lock, "btag lock", NULL, MTX_DEF); 688 uma_prealloc(vmem_bt_zone, BT_MAXALLOC); 689 /* 690 * Reserve enough tags to allocate new tags. We allow multiple 691 * CPUs to attempt to allocate new tags concurrently to limit 692 * false restarts in UMA. 693 */ 694 uma_zone_reserve(vmem_bt_zone, BT_MAXALLOC * (mp_ncpus + 1) / 2); 695 uma_zone_set_allocf(vmem_bt_zone, vmem_bt_alloc); 696 #endif 697 } 698 699 /* ---- rehash */ 700 701 static int 702 vmem_rehash(vmem_t *vm, vmem_size_t newhashsize) 703 { 704 bt_t *bt; 705 int i; 706 struct vmem_hashlist *newhashlist; 707 struct vmem_hashlist *oldhashlist; 708 vmem_size_t oldhashsize; 709 710 MPASS(newhashsize > 0); 711 712 newhashlist = malloc(sizeof(struct vmem_hashlist) * newhashsize, 713 M_VMEM, M_NOWAIT); 714 if (newhashlist == NULL) 715 return ENOMEM; 716 for (i = 0; i < newhashsize; i++) { 717 LIST_INIT(&newhashlist[i]); 718 } 719 720 VMEM_LOCK(vm); 721 oldhashlist = vm->vm_hashlist; 722 oldhashsize = vm->vm_hashsize; 723 vm->vm_hashlist = newhashlist; 724 vm->vm_hashsize = newhashsize; 725 if (oldhashlist == NULL) { 726 VMEM_UNLOCK(vm); 727 return 0; 728 } 729 for (i = 0; i < oldhashsize; i++) { 730 while ((bt = LIST_FIRST(&oldhashlist[i])) != NULL) { 731 bt_rembusy(vm, bt); 732 bt_insbusy(vm, bt); 733 } 734 } 735 VMEM_UNLOCK(vm); 736 737 if (oldhashlist != vm->vm_hash0) { 738 free(oldhashlist, M_VMEM); 739 } 740 741 return 0; 742 } 743 744 static void 745 vmem_periodic_kick(void *dummy) 746 { 747 748 taskqueue_enqueue(taskqueue_thread, &vmem_periodic_wk); 749 } 750 751 static void 752 vmem_periodic(void *unused, int pending) 753 { 754 vmem_t *vm; 755 vmem_size_t desired; 756 vmem_size_t current; 757 758 mtx_lock(&vmem_list_lock); 759 LIST_FOREACH(vm, &vmem_list, vm_alllist) { 760 #ifdef DIAGNOSTIC 761 /* Convenient time to verify vmem state. */ 762 if (enable_vmem_check == 1) { 763 VMEM_LOCK(vm); 764 vmem_check(vm); 765 VMEM_UNLOCK(vm); 766 } 767 #endif 768 desired = 1 << flsl(vm->vm_nbusytag); 769 desired = MIN(MAX(desired, VMEM_HASHSIZE_MIN), 770 VMEM_HASHSIZE_MAX); 771 current = vm->vm_hashsize; 772 773 /* Grow in powers of two. Shrink less aggressively. */ 774 if (desired >= current * 2 || desired * 4 <= current) 775 vmem_rehash(vm, desired); 776 777 /* 778 * Periodically wake up threads waiting for resources, 779 * so they could ask for reclamation again. 780 */ 781 VMEM_CONDVAR_BROADCAST(vm); 782 } 783 mtx_unlock(&vmem_list_lock); 784 785 callout_reset(&vmem_periodic_ch, vmem_periodic_interval, 786 vmem_periodic_kick, NULL); 787 } 788 789 static void 790 vmem_start_callout(void *unused) 791 { 792 793 TASK_INIT(&vmem_periodic_wk, 0, vmem_periodic, NULL); 794 vmem_periodic_interval = hz * 10; 795 callout_init(&vmem_periodic_ch, 1); 796 callout_reset(&vmem_periodic_ch, vmem_periodic_interval, 797 vmem_periodic_kick, NULL); 798 } 799 SYSINIT(vfs, SI_SUB_CONFIGURE, SI_ORDER_ANY, vmem_start_callout, NULL); 800 801 static void 802 vmem_add1(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, int type) 803 { 804 bt_t *btspan; 805 bt_t *btfree; 806 807 MPASS(type == BT_TYPE_SPAN || type == BT_TYPE_SPAN_STATIC); 808 MPASS((size & vm->vm_quantum_mask) == 0); 809 810 btspan = bt_alloc(vm); 811 btspan->bt_type = type; 812 btspan->bt_start = addr; 813 btspan->bt_size = size; 814 bt_insseg_tail(vm, btspan); 815 816 btfree = bt_alloc(vm); 817 btfree->bt_type = BT_TYPE_FREE; 818 btfree->bt_start = addr; 819 btfree->bt_size = size; 820 bt_insseg(vm, btfree, btspan); 821 bt_insfree(vm, btfree); 822 823 vm->vm_size += size; 824 } 825 826 static void 827 vmem_destroy1(vmem_t *vm) 828 { 829 bt_t *bt; 830 831 /* 832 * Drain per-cpu quantum caches. 833 */ 834 qc_destroy(vm); 835 836 /* 837 * The vmem should now only contain empty segments. 838 */ 839 VMEM_LOCK(vm); 840 MPASS(vm->vm_nbusytag == 0); 841 842 while ((bt = TAILQ_FIRST(&vm->vm_seglist)) != NULL) 843 bt_remseg(vm, bt); 844 845 if (vm->vm_hashlist != NULL && vm->vm_hashlist != vm->vm_hash0) 846 free(vm->vm_hashlist, M_VMEM); 847 848 bt_freetrim(vm, 0); 849 850 VMEM_CONDVAR_DESTROY(vm); 851 VMEM_LOCK_DESTROY(vm); 852 uma_zfree(vmem_zone, vm); 853 } 854 855 static int 856 vmem_import(vmem_t *vm, vmem_size_t size, vmem_size_t align, int flags) 857 { 858 vmem_addr_t addr; 859 int error; 860 861 if (vm->vm_importfn == NULL) 862 return (EINVAL); 863 864 /* 865 * To make sure we get a span that meets the alignment we double it 866 * and add the size to the tail. This slightly overestimates. 867 */ 868 if (align != vm->vm_quantum_mask + 1) 869 size = (align * 2) + size; 870 size = roundup(size, vm->vm_import_quantum); 871 872 if (vm->vm_limit != 0 && vm->vm_limit < vm->vm_size + size) 873 return (ENOMEM); 874 875 /* 876 * Hide MAXALLOC tags so we're guaranteed to be able to add this 877 * span and the tag we want to allocate from it. 878 */ 879 MPASS(vm->vm_nfreetags >= BT_MAXALLOC); 880 vm->vm_nfreetags -= BT_MAXALLOC; 881 VMEM_UNLOCK(vm); 882 error = (vm->vm_importfn)(vm->vm_arg, size, flags, &addr); 883 VMEM_LOCK(vm); 884 vm->vm_nfreetags += BT_MAXALLOC; 885 if (error) 886 return (ENOMEM); 887 888 vmem_add1(vm, addr, size, BT_TYPE_SPAN); 889 890 return 0; 891 } 892 893 /* 894 * vmem_fit: check if a bt can satisfy the given restrictions. 895 * 896 * it's a caller's responsibility to ensure the region is big enough 897 * before calling us. 898 */ 899 static int 900 vmem_fit(const bt_t *bt, vmem_size_t size, vmem_size_t align, 901 vmem_size_t phase, vmem_size_t nocross, vmem_addr_t minaddr, 902 vmem_addr_t maxaddr, vmem_addr_t *addrp) 903 { 904 vmem_addr_t start; 905 vmem_addr_t end; 906 907 MPASS(size > 0); 908 MPASS(bt->bt_size >= size); /* caller's responsibility */ 909 910 /* 911 * XXX assumption: vmem_addr_t and vmem_size_t are 912 * unsigned integer of the same size. 913 */ 914 915 start = bt->bt_start; 916 if (start < minaddr) { 917 start = minaddr; 918 } 919 end = BT_END(bt); 920 if (end > maxaddr) 921 end = maxaddr; 922 if (start > end) 923 return (ENOMEM); 924 925 start = VMEM_ALIGNUP(start - phase, align) + phase; 926 if (start < bt->bt_start) 927 start += align; 928 if (VMEM_CROSS_P(start, start + size - 1, nocross)) { 929 MPASS(align < nocross); 930 start = VMEM_ALIGNUP(start - phase, nocross) + phase; 931 } 932 if (start <= end && end - start >= size - 1) { 933 MPASS((start & (align - 1)) == phase); 934 MPASS(!VMEM_CROSS_P(start, start + size - 1, nocross)); 935 MPASS(minaddr <= start); 936 MPASS(maxaddr == 0 || start + size - 1 <= maxaddr); 937 MPASS(bt->bt_start <= start); 938 MPASS(BT_END(bt) - start >= size - 1); 939 *addrp = start; 940 941 return (0); 942 } 943 return (ENOMEM); 944 } 945 946 /* 947 * vmem_clip: Trim the boundary tag edges to the requested start and size. 948 */ 949 static void 950 vmem_clip(vmem_t *vm, bt_t *bt, vmem_addr_t start, vmem_size_t size) 951 { 952 bt_t *btnew; 953 bt_t *btprev; 954 955 VMEM_ASSERT_LOCKED(vm); 956 MPASS(bt->bt_type == BT_TYPE_FREE); 957 MPASS(bt->bt_size >= size); 958 bt_remfree(vm, bt); 959 if (bt->bt_start != start) { 960 btprev = bt_alloc(vm); 961 btprev->bt_type = BT_TYPE_FREE; 962 btprev->bt_start = bt->bt_start; 963 btprev->bt_size = start - bt->bt_start; 964 bt->bt_start = start; 965 bt->bt_size -= btprev->bt_size; 966 bt_insfree(vm, btprev); 967 bt_insseg(vm, btprev, 968 TAILQ_PREV(bt, vmem_seglist, bt_seglist)); 969 } 970 MPASS(bt->bt_start == start); 971 if (bt->bt_size != size && bt->bt_size - size > vm->vm_quantum_mask) { 972 /* split */ 973 btnew = bt_alloc(vm); 974 btnew->bt_type = BT_TYPE_BUSY; 975 btnew->bt_start = bt->bt_start; 976 btnew->bt_size = size; 977 bt->bt_start = bt->bt_start + size; 978 bt->bt_size -= size; 979 bt_insfree(vm, bt); 980 bt_insseg(vm, btnew, 981 TAILQ_PREV(bt, vmem_seglist, bt_seglist)); 982 bt_insbusy(vm, btnew); 983 bt = btnew; 984 } else { 985 bt->bt_type = BT_TYPE_BUSY; 986 bt_insbusy(vm, bt); 987 } 988 MPASS(bt->bt_size >= size); 989 } 990 991 /* ---- vmem API */ 992 993 void 994 vmem_set_import(vmem_t *vm, vmem_import_t *importfn, 995 vmem_release_t *releasefn, void *arg, vmem_size_t import_quantum) 996 { 997 998 VMEM_LOCK(vm); 999 vm->vm_importfn = importfn; 1000 vm->vm_releasefn = releasefn; 1001 vm->vm_arg = arg; 1002 vm->vm_import_quantum = import_quantum; 1003 VMEM_UNLOCK(vm); 1004 } 1005 1006 void 1007 vmem_set_limit(vmem_t *vm, vmem_size_t limit) 1008 { 1009 1010 VMEM_LOCK(vm); 1011 vm->vm_limit = limit; 1012 VMEM_UNLOCK(vm); 1013 } 1014 1015 void 1016 vmem_set_reclaim(vmem_t *vm, vmem_reclaim_t *reclaimfn) 1017 { 1018 1019 VMEM_LOCK(vm); 1020 vm->vm_reclaimfn = reclaimfn; 1021 VMEM_UNLOCK(vm); 1022 } 1023 1024 /* 1025 * vmem_init: Initializes vmem arena. 1026 */ 1027 vmem_t * 1028 vmem_init(vmem_t *vm, const char *name, vmem_addr_t base, vmem_size_t size, 1029 vmem_size_t quantum, vmem_size_t qcache_max, int flags) 1030 { 1031 int i; 1032 1033 MPASS(quantum > 0); 1034 MPASS((quantum & (quantum - 1)) == 0); 1035 1036 bzero(vm, sizeof(*vm)); 1037 1038 VMEM_CONDVAR_INIT(vm, name); 1039 VMEM_LOCK_INIT(vm, name); 1040 vm->vm_nfreetags = 0; 1041 LIST_INIT(&vm->vm_freetags); 1042 strlcpy(vm->vm_name, name, sizeof(vm->vm_name)); 1043 vm->vm_quantum_mask = quantum - 1; 1044 vm->vm_quantum_shift = flsl(quantum) - 1; 1045 vm->vm_nbusytag = 0; 1046 vm->vm_size = 0; 1047 vm->vm_limit = 0; 1048 vm->vm_inuse = 0; 1049 qc_init(vm, qcache_max); 1050 1051 TAILQ_INIT(&vm->vm_seglist); 1052 for (i = 0; i < VMEM_MAXORDER; i++) { 1053 LIST_INIT(&vm->vm_freelist[i]); 1054 } 1055 memset(&vm->vm_hash0, 0, sizeof(vm->vm_hash0)); 1056 vm->vm_hashsize = VMEM_HASHSIZE_MIN; 1057 vm->vm_hashlist = vm->vm_hash0; 1058 1059 if (size != 0) { 1060 if (vmem_add(vm, base, size, flags) != 0) { 1061 vmem_destroy1(vm); 1062 return NULL; 1063 } 1064 } 1065 1066 mtx_lock(&vmem_list_lock); 1067 LIST_INSERT_HEAD(&vmem_list, vm, vm_alllist); 1068 mtx_unlock(&vmem_list_lock); 1069 1070 return vm; 1071 } 1072 1073 /* 1074 * vmem_create: create an arena. 1075 */ 1076 vmem_t * 1077 vmem_create(const char *name, vmem_addr_t base, vmem_size_t size, 1078 vmem_size_t quantum, vmem_size_t qcache_max, int flags) 1079 { 1080 1081 vmem_t *vm; 1082 1083 vm = uma_zalloc(vmem_zone, flags & (M_WAITOK|M_NOWAIT)); 1084 if (vm == NULL) 1085 return (NULL); 1086 if (vmem_init(vm, name, base, size, quantum, qcache_max, 1087 flags) == NULL) 1088 return (NULL); 1089 return (vm); 1090 } 1091 1092 void 1093 vmem_destroy(vmem_t *vm) 1094 { 1095 1096 mtx_lock(&vmem_list_lock); 1097 LIST_REMOVE(vm, vm_alllist); 1098 mtx_unlock(&vmem_list_lock); 1099 1100 vmem_destroy1(vm); 1101 } 1102 1103 vmem_size_t 1104 vmem_roundup_size(vmem_t *vm, vmem_size_t size) 1105 { 1106 1107 return (size + vm->vm_quantum_mask) & ~vm->vm_quantum_mask; 1108 } 1109 1110 /* 1111 * vmem_alloc: allocate resource from the arena. 1112 */ 1113 int 1114 vmem_alloc(vmem_t *vm, vmem_size_t size, int flags, vmem_addr_t *addrp) 1115 { 1116 const int strat __unused = flags & VMEM_FITMASK; 1117 qcache_t *qc; 1118 1119 flags &= VMEM_FLAGS; 1120 MPASS(size > 0); 1121 MPASS(strat == M_BESTFIT || strat == M_FIRSTFIT); 1122 if ((flags & M_NOWAIT) == 0) 1123 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "vmem_alloc"); 1124 1125 if (size <= vm->vm_qcache_max) { 1126 qc = &vm->vm_qcache[(size - 1) >> vm->vm_quantum_shift]; 1127 *addrp = (vmem_addr_t)uma_zalloc(qc->qc_cache, flags); 1128 if (*addrp == 0) 1129 return (ENOMEM); 1130 return (0); 1131 } 1132 1133 return vmem_xalloc(vm, size, 0, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX, 1134 flags, addrp); 1135 } 1136 1137 int 1138 vmem_xalloc(vmem_t *vm, const vmem_size_t size0, vmem_size_t align, 1139 const vmem_size_t phase, const vmem_size_t nocross, 1140 const vmem_addr_t minaddr, const vmem_addr_t maxaddr, int flags, 1141 vmem_addr_t *addrp) 1142 { 1143 const vmem_size_t size = vmem_roundup_size(vm, size0); 1144 struct vmem_freelist *list; 1145 struct vmem_freelist *first; 1146 struct vmem_freelist *end; 1147 vmem_size_t avail; 1148 bt_t *bt; 1149 int error; 1150 int strat; 1151 1152 flags &= VMEM_FLAGS; 1153 strat = flags & VMEM_FITMASK; 1154 MPASS(size0 > 0); 1155 MPASS(size > 0); 1156 MPASS(strat == M_BESTFIT || strat == M_FIRSTFIT); 1157 MPASS((flags & (M_NOWAIT|M_WAITOK)) != (M_NOWAIT|M_WAITOK)); 1158 if ((flags & M_NOWAIT) == 0) 1159 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "vmem_xalloc"); 1160 MPASS((align & vm->vm_quantum_mask) == 0); 1161 MPASS((align & (align - 1)) == 0); 1162 MPASS((phase & vm->vm_quantum_mask) == 0); 1163 MPASS((nocross & vm->vm_quantum_mask) == 0); 1164 MPASS((nocross & (nocross - 1)) == 0); 1165 MPASS((align == 0 && phase == 0) || phase < align); 1166 MPASS(nocross == 0 || nocross >= size); 1167 MPASS(minaddr <= maxaddr); 1168 MPASS(!VMEM_CROSS_P(phase, phase + size - 1, nocross)); 1169 1170 if (align == 0) 1171 align = vm->vm_quantum_mask + 1; 1172 1173 *addrp = 0; 1174 end = &vm->vm_freelist[VMEM_MAXORDER]; 1175 /* 1176 * choose a free block from which we allocate. 1177 */ 1178 first = bt_freehead_toalloc(vm, size, strat); 1179 VMEM_LOCK(vm); 1180 for (;;) { 1181 /* 1182 * Make sure we have enough tags to complete the 1183 * operation. 1184 */ 1185 if (vm->vm_nfreetags < BT_MAXALLOC && 1186 bt_fill(vm, flags) != 0) { 1187 error = ENOMEM; 1188 break; 1189 } 1190 /* 1191 * Scan freelists looking for a tag that satisfies the 1192 * allocation. If we're doing BESTFIT we may encounter 1193 * sizes below the request. If we're doing FIRSTFIT we 1194 * inspect only the first element from each list. 1195 */ 1196 for (list = first; list < end; list++) { 1197 LIST_FOREACH(bt, list, bt_freelist) { 1198 if (bt->bt_size >= size) { 1199 error = vmem_fit(bt, size, align, phase, 1200 nocross, minaddr, maxaddr, addrp); 1201 if (error == 0) { 1202 vmem_clip(vm, bt, *addrp, size); 1203 goto out; 1204 } 1205 } 1206 /* FIRST skips to the next list. */ 1207 if (strat == M_FIRSTFIT) 1208 break; 1209 } 1210 } 1211 /* 1212 * Retry if the fast algorithm failed. 1213 */ 1214 if (strat == M_FIRSTFIT) { 1215 strat = M_BESTFIT; 1216 first = bt_freehead_toalloc(vm, size, strat); 1217 continue; 1218 } 1219 /* 1220 * XXX it is possible to fail to meet restrictions with the 1221 * imported region. It is up to the user to specify the 1222 * import quantum such that it can satisfy any allocation. 1223 */ 1224 if (vmem_import(vm, size, align, flags) == 0) 1225 continue; 1226 1227 /* 1228 * Try to free some space from the quantum cache or reclaim 1229 * functions if available. 1230 */ 1231 if (vm->vm_qcache_max != 0 || vm->vm_reclaimfn != NULL) { 1232 avail = vm->vm_size - vm->vm_inuse; 1233 VMEM_UNLOCK(vm); 1234 if (vm->vm_qcache_max != 0) 1235 qc_drain(vm); 1236 if (vm->vm_reclaimfn != NULL) 1237 vm->vm_reclaimfn(vm, flags); 1238 VMEM_LOCK(vm); 1239 /* If we were successful retry even NOWAIT. */ 1240 if (vm->vm_size - vm->vm_inuse > avail) 1241 continue; 1242 } 1243 if ((flags & M_NOWAIT) != 0) { 1244 error = ENOMEM; 1245 break; 1246 } 1247 VMEM_CONDVAR_WAIT(vm); 1248 } 1249 out: 1250 VMEM_UNLOCK(vm); 1251 if (error != 0 && (flags & M_NOWAIT) == 0) 1252 panic("failed to allocate waiting allocation\n"); 1253 1254 return (error); 1255 } 1256 1257 /* 1258 * vmem_free: free the resource to the arena. 1259 */ 1260 void 1261 vmem_free(vmem_t *vm, vmem_addr_t addr, vmem_size_t size) 1262 { 1263 qcache_t *qc; 1264 MPASS(size > 0); 1265 1266 if (size <= vm->vm_qcache_max) { 1267 qc = &vm->vm_qcache[(size - 1) >> vm->vm_quantum_shift]; 1268 uma_zfree(qc->qc_cache, (void *)addr); 1269 } else 1270 vmem_xfree(vm, addr, size); 1271 } 1272 1273 void 1274 vmem_xfree(vmem_t *vm, vmem_addr_t addr, vmem_size_t size) 1275 { 1276 bt_t *bt; 1277 bt_t *t; 1278 1279 MPASS(size > 0); 1280 1281 VMEM_LOCK(vm); 1282 bt = bt_lookupbusy(vm, addr); 1283 MPASS(bt != NULL); 1284 MPASS(bt->bt_start == addr); 1285 MPASS(bt->bt_size == vmem_roundup_size(vm, size) || 1286 bt->bt_size - vmem_roundup_size(vm, size) <= vm->vm_quantum_mask); 1287 MPASS(bt->bt_type == BT_TYPE_BUSY); 1288 bt_rembusy(vm, bt); 1289 bt->bt_type = BT_TYPE_FREE; 1290 1291 /* coalesce */ 1292 t = TAILQ_NEXT(bt, bt_seglist); 1293 if (t != NULL && t->bt_type == BT_TYPE_FREE) { 1294 MPASS(BT_END(bt) < t->bt_start); /* YYY */ 1295 bt->bt_size += t->bt_size; 1296 bt_remfree(vm, t); 1297 bt_remseg(vm, t); 1298 } 1299 t = TAILQ_PREV(bt, vmem_seglist, bt_seglist); 1300 if (t != NULL && t->bt_type == BT_TYPE_FREE) { 1301 MPASS(BT_END(t) < bt->bt_start); /* YYY */ 1302 bt->bt_size += t->bt_size; 1303 bt->bt_start = t->bt_start; 1304 bt_remfree(vm, t); 1305 bt_remseg(vm, t); 1306 } 1307 1308 t = TAILQ_PREV(bt, vmem_seglist, bt_seglist); 1309 MPASS(t != NULL); 1310 MPASS(BT_ISSPAN_P(t) || t->bt_type == BT_TYPE_BUSY); 1311 if (vm->vm_releasefn != NULL && t->bt_type == BT_TYPE_SPAN && 1312 t->bt_size == bt->bt_size) { 1313 vmem_addr_t spanaddr; 1314 vmem_size_t spansize; 1315 1316 MPASS(t->bt_start == bt->bt_start); 1317 spanaddr = bt->bt_start; 1318 spansize = bt->bt_size; 1319 bt_remseg(vm, bt); 1320 bt_remseg(vm, t); 1321 vm->vm_size -= spansize; 1322 VMEM_CONDVAR_BROADCAST(vm); 1323 bt_freetrim(vm, BT_MAXFREE); 1324 (*vm->vm_releasefn)(vm->vm_arg, spanaddr, spansize); 1325 } else { 1326 bt_insfree(vm, bt); 1327 VMEM_CONDVAR_BROADCAST(vm); 1328 bt_freetrim(vm, BT_MAXFREE); 1329 } 1330 } 1331 1332 /* 1333 * vmem_add: 1334 * 1335 */ 1336 int 1337 vmem_add(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, int flags) 1338 { 1339 int error; 1340 1341 error = 0; 1342 flags &= VMEM_FLAGS; 1343 VMEM_LOCK(vm); 1344 if (vm->vm_nfreetags >= BT_MAXALLOC || bt_fill(vm, flags) == 0) 1345 vmem_add1(vm, addr, size, BT_TYPE_SPAN_STATIC); 1346 else 1347 error = ENOMEM; 1348 VMEM_UNLOCK(vm); 1349 1350 return (error); 1351 } 1352 1353 /* 1354 * vmem_size: information about arenas size 1355 */ 1356 vmem_size_t 1357 vmem_size(vmem_t *vm, int typemask) 1358 { 1359 int i; 1360 1361 switch (typemask) { 1362 case VMEM_ALLOC: 1363 return vm->vm_inuse; 1364 case VMEM_FREE: 1365 return vm->vm_size - vm->vm_inuse; 1366 case VMEM_FREE|VMEM_ALLOC: 1367 return vm->vm_size; 1368 case VMEM_MAXFREE: 1369 VMEM_LOCK(vm); 1370 for (i = VMEM_MAXORDER - 1; i >= 0; i--) { 1371 if (LIST_EMPTY(&vm->vm_freelist[i])) 1372 continue; 1373 VMEM_UNLOCK(vm); 1374 return ((vmem_size_t)ORDER2SIZE(i) << 1375 vm->vm_quantum_shift); 1376 } 1377 VMEM_UNLOCK(vm); 1378 return (0); 1379 default: 1380 panic("vmem_size"); 1381 } 1382 } 1383 1384 /* ---- debug */ 1385 1386 #if defined(DDB) || defined(DIAGNOSTIC) 1387 1388 static void bt_dump(const bt_t *, int (*)(const char *, ...) 1389 __printflike(1, 2)); 1390 1391 static const char * 1392 bt_type_string(int type) 1393 { 1394 1395 switch (type) { 1396 case BT_TYPE_BUSY: 1397 return "busy"; 1398 case BT_TYPE_FREE: 1399 return "free"; 1400 case BT_TYPE_SPAN: 1401 return "span"; 1402 case BT_TYPE_SPAN_STATIC: 1403 return "static span"; 1404 default: 1405 break; 1406 } 1407 return "BOGUS"; 1408 } 1409 1410 static void 1411 bt_dump(const bt_t *bt, int (*pr)(const char *, ...)) 1412 { 1413 1414 (*pr)("\t%p: %jx %jx, %d(%s)\n", 1415 bt, (intmax_t)bt->bt_start, (intmax_t)bt->bt_size, 1416 bt->bt_type, bt_type_string(bt->bt_type)); 1417 } 1418 1419 static void 1420 vmem_dump(const vmem_t *vm , int (*pr)(const char *, ...) __printflike(1, 2)) 1421 { 1422 const bt_t *bt; 1423 int i; 1424 1425 (*pr)("vmem %p '%s'\n", vm, vm->vm_name); 1426 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { 1427 bt_dump(bt, pr); 1428 } 1429 1430 for (i = 0; i < VMEM_MAXORDER; i++) { 1431 const struct vmem_freelist *fl = &vm->vm_freelist[i]; 1432 1433 if (LIST_EMPTY(fl)) { 1434 continue; 1435 } 1436 1437 (*pr)("freelist[%d]\n", i); 1438 LIST_FOREACH(bt, fl, bt_freelist) { 1439 bt_dump(bt, pr); 1440 } 1441 } 1442 } 1443 1444 #endif /* defined(DDB) || defined(DIAGNOSTIC) */ 1445 1446 #if defined(DDB) 1447 #include <ddb/ddb.h> 1448 1449 static bt_t * 1450 vmem_whatis_lookup(vmem_t *vm, vmem_addr_t addr) 1451 { 1452 bt_t *bt; 1453 1454 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { 1455 if (BT_ISSPAN_P(bt)) { 1456 continue; 1457 } 1458 if (bt->bt_start <= addr && addr <= BT_END(bt)) { 1459 return bt; 1460 } 1461 } 1462 1463 return NULL; 1464 } 1465 1466 void 1467 vmem_whatis(vmem_addr_t addr, int (*pr)(const char *, ...)) 1468 { 1469 vmem_t *vm; 1470 1471 LIST_FOREACH(vm, &vmem_list, vm_alllist) { 1472 bt_t *bt; 1473 1474 bt = vmem_whatis_lookup(vm, addr); 1475 if (bt == NULL) { 1476 continue; 1477 } 1478 (*pr)("%p is %p+%zu in VMEM '%s' (%s)\n", 1479 (void *)addr, (void *)bt->bt_start, 1480 (vmem_size_t)(addr - bt->bt_start), vm->vm_name, 1481 (bt->bt_type == BT_TYPE_BUSY) ? "allocated" : "free"); 1482 } 1483 } 1484 1485 void 1486 vmem_printall(const char *modif, int (*pr)(const char *, ...)) 1487 { 1488 const vmem_t *vm; 1489 1490 LIST_FOREACH(vm, &vmem_list, vm_alllist) { 1491 vmem_dump(vm, pr); 1492 } 1493 } 1494 1495 void 1496 vmem_print(vmem_addr_t addr, const char *modif, int (*pr)(const char *, ...)) 1497 { 1498 const vmem_t *vm = (const void *)addr; 1499 1500 vmem_dump(vm, pr); 1501 } 1502 1503 DB_SHOW_COMMAND(vmemdump, vmemdump) 1504 { 1505 1506 if (!have_addr) { 1507 db_printf("usage: show vmemdump <addr>\n"); 1508 return; 1509 } 1510 1511 vmem_dump((const vmem_t *)addr, db_printf); 1512 } 1513 1514 DB_SHOW_ALL_COMMAND(vmemdump, vmemdumpall) 1515 { 1516 const vmem_t *vm; 1517 1518 LIST_FOREACH(vm, &vmem_list, vm_alllist) 1519 vmem_dump(vm, db_printf); 1520 } 1521 1522 DB_SHOW_COMMAND(vmem, vmem_summ) 1523 { 1524 const vmem_t *vm = (const void *)addr; 1525 const bt_t *bt; 1526 size_t ft[VMEM_MAXORDER], ut[VMEM_MAXORDER]; 1527 size_t fs[VMEM_MAXORDER], us[VMEM_MAXORDER]; 1528 int ord; 1529 1530 if (!have_addr) { 1531 db_printf("usage: show vmem <addr>\n"); 1532 return; 1533 } 1534 1535 db_printf("vmem %p '%s'\n", vm, vm->vm_name); 1536 db_printf("\tquantum:\t%zu\n", vm->vm_quantum_mask + 1); 1537 db_printf("\tsize:\t%zu\n", vm->vm_size); 1538 db_printf("\tinuse:\t%zu\n", vm->vm_inuse); 1539 db_printf("\tfree:\t%zu\n", vm->vm_size - vm->vm_inuse); 1540 db_printf("\tbusy tags:\t%d\n", vm->vm_nbusytag); 1541 db_printf("\tfree tags:\t%d\n", vm->vm_nfreetags); 1542 1543 memset(&ft, 0, sizeof(ft)); 1544 memset(&ut, 0, sizeof(ut)); 1545 memset(&fs, 0, sizeof(fs)); 1546 memset(&us, 0, sizeof(us)); 1547 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { 1548 ord = SIZE2ORDER(bt->bt_size >> vm->vm_quantum_shift); 1549 if (bt->bt_type == BT_TYPE_BUSY) { 1550 ut[ord]++; 1551 us[ord] += bt->bt_size; 1552 } else if (bt->bt_type == BT_TYPE_FREE) { 1553 ft[ord]++; 1554 fs[ord] += bt->bt_size; 1555 } 1556 } 1557 db_printf("\t\t\tinuse\tsize\t\tfree\tsize\n"); 1558 for (ord = 0; ord < VMEM_MAXORDER; ord++) { 1559 if (ut[ord] == 0 && ft[ord] == 0) 1560 continue; 1561 db_printf("\t%-15zu %zu\t%-15zu %zu\t%-16zu\n", 1562 ORDER2SIZE(ord) << vm->vm_quantum_shift, 1563 ut[ord], us[ord], ft[ord], fs[ord]); 1564 } 1565 } 1566 1567 DB_SHOW_ALL_COMMAND(vmem, vmem_summall) 1568 { 1569 const vmem_t *vm; 1570 1571 LIST_FOREACH(vm, &vmem_list, vm_alllist) 1572 vmem_summ((db_expr_t)vm, TRUE, count, modif); 1573 } 1574 #endif /* defined(DDB) */ 1575 1576 #define vmem_printf printf 1577 1578 #if defined(DIAGNOSTIC) 1579 1580 static bool 1581 vmem_check_sanity(vmem_t *vm) 1582 { 1583 const bt_t *bt, *bt2; 1584 1585 MPASS(vm != NULL); 1586 1587 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { 1588 if (bt->bt_start > BT_END(bt)) { 1589 printf("corrupted tag\n"); 1590 bt_dump(bt, vmem_printf); 1591 return false; 1592 } 1593 } 1594 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { 1595 TAILQ_FOREACH(bt2, &vm->vm_seglist, bt_seglist) { 1596 if (bt == bt2) { 1597 continue; 1598 } 1599 if (BT_ISSPAN_P(bt) != BT_ISSPAN_P(bt2)) { 1600 continue; 1601 } 1602 if (bt->bt_start <= BT_END(bt2) && 1603 bt2->bt_start <= BT_END(bt)) { 1604 printf("overwrapped tags\n"); 1605 bt_dump(bt, vmem_printf); 1606 bt_dump(bt2, vmem_printf); 1607 return false; 1608 } 1609 } 1610 } 1611 1612 return true; 1613 } 1614 1615 static void 1616 vmem_check(vmem_t *vm) 1617 { 1618 1619 if (!vmem_check_sanity(vm)) { 1620 panic("insanity vmem %p", vm); 1621 } 1622 } 1623 1624 #endif /* defined(DIAGNOSTIC) */
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