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