1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c)2006,2007,2008,2009 YAMAMOTO Takashi, 5 * Copyright (c) 2013 EMC Corp. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 /* 31 * From: 32 * $NetBSD: vmem_impl.h,v 1.2 2013/01/29 21:26:24 para Exp $ 33 * $NetBSD: subr_vmem.c,v 1.83 2013/03/06 11:20:10 yamt Exp $ 34 */ 35 36 /* 37 * reference: 38 * - Magazines and Vmem: Extending the Slab Allocator 39 * to Many CPUs and Arbitrary Resources 40 * http://www.usenix.org/event/usenix01/bonwick.html 41 */ 42 43 #include <sys/cdefs.h> 44 __FBSDID("$FreeBSD$"); 45 46 #include "opt_ddb.h" 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/kernel.h> 51 #include <sys/queue.h> 52 #include <sys/callout.h> 53 #include <sys/hash.h> 54 #include <sys/lock.h> 55 #include <sys/malloc.h> 56 #include <sys/mutex.h> 57 #include <sys/smp.h> 58 #include <sys/condvar.h> 59 #include <sys/sysctl.h> 60 #include <sys/taskqueue.h> 61 #include <sys/vmem.h> 62 #include <sys/vmmeter.h> 63 64 #include "opt_vm.h" 65 66 #include <vm/uma.h> 67 #include <vm/vm.h> 68 #include <vm/pmap.h> 69 #include <vm/vm_map.h> 70 #include <vm/vm_object.h> 71 #include <vm/vm_kern.h> 72 #include <vm/vm_extern.h> 73 #include <vm/vm_param.h> 74 #include <vm/vm_page.h> 75 #include <vm/vm_pageout.h> 76 #include <vm/vm_phys.h> 77 #include <vm/vm_pagequeue.h> 78 #include <vm/uma_int.h> 79 80 #define VMEM_OPTORDER 5 81 #define VMEM_OPTVALUE (1 << VMEM_OPTORDER) 82 #define VMEM_MAXORDER \ 83 (VMEM_OPTVALUE - 1 + sizeof(vmem_size_t) * NBBY - VMEM_OPTORDER) 84 85 #define VMEM_HASHSIZE_MIN 16 86 #define VMEM_HASHSIZE_MAX 131072 87 88 #define VMEM_QCACHE_IDX_MAX 16 89 90 #define VMEM_FITMASK (M_BESTFIT | M_FIRSTFIT | M_NEXTFIT) 91 92 #define VMEM_FLAGS (M_NOWAIT | M_WAITOK | M_USE_RESERVE | M_NOVM | \ 93 M_BESTFIT | M_FIRSTFIT | M_NEXTFIT) 94 95 #define BT_FLAGS (M_NOWAIT | M_WAITOK | M_USE_RESERVE | M_NOVM) 96 97 #define QC_NAME_MAX 16 98 99 /* 100 * Data structures private to vmem. 101 */ 102 MALLOC_DEFINE(M_VMEM, "vmem", "vmem internal structures"); 103 104 typedef struct vmem_btag bt_t; 105 106 TAILQ_HEAD(vmem_seglist, vmem_btag); 107 LIST_HEAD(vmem_freelist, vmem_btag); 108 LIST_HEAD(vmem_hashlist, vmem_btag); 109 110 struct qcache { 111 uma_zone_t qc_cache; 112 vmem_t *qc_vmem; 113 vmem_size_t qc_size; 114 char qc_name[QC_NAME_MAX]; 115 }; 116 typedef struct qcache qcache_t; 117 #define QC_POOL_TO_QCACHE(pool) ((qcache_t *)(pool->pr_qcache)) 118 119 #define VMEM_NAME_MAX 16 120 121 /* boundary tag */ 122 struct vmem_btag { 123 TAILQ_ENTRY(vmem_btag) bt_seglist; 124 union { 125 LIST_ENTRY(vmem_btag) u_freelist; /* BT_TYPE_FREE */ 126 LIST_ENTRY(vmem_btag) u_hashlist; /* BT_TYPE_BUSY */ 127 } bt_u; 128 #define bt_hashlist bt_u.u_hashlist 129 #define bt_freelist bt_u.u_freelist 130 vmem_addr_t bt_start; 131 vmem_size_t bt_size; 132 int bt_type; 133 }; 134 135 /* vmem arena */ 136 struct vmem { 137 struct mtx_padalign vm_lock; 138 struct cv vm_cv; 139 char vm_name[VMEM_NAME_MAX+1]; 140 LIST_ENTRY(vmem) vm_alllist; 141 struct vmem_hashlist vm_hash0[VMEM_HASHSIZE_MIN]; 142 struct vmem_freelist vm_freelist[VMEM_MAXORDER]; 143 struct vmem_seglist vm_seglist; 144 struct vmem_hashlist *vm_hashlist; 145 vmem_size_t vm_hashsize; 146 147 /* Constant after init */ 148 vmem_size_t vm_qcache_max; 149 vmem_size_t vm_quantum_mask; 150 vmem_size_t vm_import_quantum; 151 int vm_quantum_shift; 152 153 /* Written on alloc/free */ 154 LIST_HEAD(, vmem_btag) vm_freetags; 155 int vm_nfreetags; 156 int vm_nbusytag; 157 vmem_size_t vm_inuse; 158 vmem_size_t vm_size; 159 vmem_size_t vm_limit; 160 struct vmem_btag vm_cursor; 161 162 /* Used on import. */ 163 vmem_import_t *vm_importfn; 164 vmem_release_t *vm_releasefn; 165 void *vm_arg; 166 167 /* Space exhaustion callback. */ 168 vmem_reclaim_t *vm_reclaimfn; 169 170 /* quantum cache */ 171 qcache_t vm_qcache[VMEM_QCACHE_IDX_MAX]; 172 }; 173 174 #define BT_TYPE_SPAN 1 /* Allocated from importfn */ 175 #define BT_TYPE_SPAN_STATIC 2 /* vmem_add() or create. */ 176 #define BT_TYPE_FREE 3 /* Available space. */ 177 #define BT_TYPE_BUSY 4 /* Used space. */ 178 #define BT_TYPE_CURSOR 5 /* Cursor for nextfit allocations. */ 179 #define BT_ISSPAN_P(bt) ((bt)->bt_type <= BT_TYPE_SPAN_STATIC) 180 181 #define BT_END(bt) ((bt)->bt_start + (bt)->bt_size - 1) 182 183 #if defined(DIAGNOSTIC) 184 static int enable_vmem_check = 1; 185 SYSCTL_INT(_debug, OID_AUTO, vmem_check, CTLFLAG_RWTUN, 186 &enable_vmem_check, 0, "Enable vmem check"); 187 static void vmem_check(vmem_t *); 188 #endif 189 190 static struct callout vmem_periodic_ch; 191 static int vmem_periodic_interval; 192 static struct task vmem_periodic_wk; 193 194 static struct mtx_padalign __exclusive_cache_line vmem_list_lock; 195 static LIST_HEAD(, vmem) vmem_list = LIST_HEAD_INITIALIZER(vmem_list); 196 static uma_zone_t vmem_zone; 197 198 /* ---- misc */ 199 #define VMEM_CONDVAR_INIT(vm, wchan) cv_init(&vm->vm_cv, wchan) 200 #define VMEM_CONDVAR_DESTROY(vm) cv_destroy(&vm->vm_cv) 201 #define VMEM_CONDVAR_WAIT(vm) cv_wait(&vm->vm_cv, &vm->vm_lock) 202 #define VMEM_CONDVAR_BROADCAST(vm) cv_broadcast(&vm->vm_cv) 203 204 #define VMEM_LOCK(vm) mtx_lock(&vm->vm_lock) 205 #define VMEM_TRYLOCK(vm) mtx_trylock(&vm->vm_lock) 206 #define VMEM_UNLOCK(vm) mtx_unlock(&vm->vm_lock) 207 #define VMEM_LOCK_INIT(vm, name) mtx_init(&vm->vm_lock, (name), NULL, MTX_DEF) 208 #define VMEM_LOCK_DESTROY(vm) mtx_destroy(&vm->vm_lock) 209 #define VMEM_ASSERT_LOCKED(vm) mtx_assert(&vm->vm_lock, MA_OWNED); 210 211 #define VMEM_ALIGNUP(addr, align) (-(-(addr) & -(align))) 212 213 #define VMEM_CROSS_P(addr1, addr2, boundary) \ 214 ((((addr1) ^ (addr2)) & -(boundary)) != 0) 215 216 #define ORDER2SIZE(order) ((order) < VMEM_OPTVALUE ? ((order) + 1) : \ 217 (vmem_size_t)1 << ((order) - (VMEM_OPTVALUE - VMEM_OPTORDER - 1))) 218 #define SIZE2ORDER(size) ((size) <= VMEM_OPTVALUE ? ((size) - 1) : \ 219 (flsl(size) + (VMEM_OPTVALUE - VMEM_OPTORDER - 2))) 220 221 /* 222 * Maximum number of boundary tags that may be required to satisfy an 223 * allocation. Two may be required to import. Another two may be 224 * required to clip edges. 225 */ 226 #define BT_MAXALLOC 4 227 228 /* 229 * Max free limits the number of locally cached boundary tags. We 230 * just want to avoid hitting the zone allocator for every call. 231 */ 232 #define BT_MAXFREE (BT_MAXALLOC * 8) 233 234 /* Allocator for boundary tags. */ 235 static uma_zone_t vmem_bt_zone; 236 237 /* boot time arena storage. */ 238 static struct vmem kernel_arena_storage; 239 static struct vmem buffer_arena_storage; 240 static struct vmem transient_arena_storage; 241 /* kernel and kmem arenas are aliased for backwards KPI compat. */ 242 vmem_t *kernel_arena = &kernel_arena_storage; 243 vmem_t *kmem_arena = &kernel_arena_storage; 244 vmem_t *buffer_arena = &buffer_arena_storage; 245 vmem_t *transient_arena = &transient_arena_storage; 246 247 #ifdef DEBUG_MEMGUARD 248 static struct vmem memguard_arena_storage; 249 vmem_t *memguard_arena = &memguard_arena_storage; 250 #endif 251 252 /* 253 * Fill the vmem's boundary tag cache. We guarantee that boundary tag 254 * allocation will not fail once bt_fill() passes. To do so we cache 255 * at least the maximum possible tag allocations in the arena. 256 */ 257 static int 258 bt_fill(vmem_t *vm, int flags) 259 { 260 bt_t *bt; 261 262 VMEM_ASSERT_LOCKED(vm); 263 264 /* 265 * Only allow the kernel arena and arenas derived from kernel arena to 266 * dip into reserve tags. They are where new tags come from. 267 */ 268 flags &= BT_FLAGS; 269 if (vm != kernel_arena && vm->vm_arg != kernel_arena) 270 flags &= ~M_USE_RESERVE; 271 272 /* 273 * Loop until we meet the reserve. To minimize the lock shuffle 274 * and prevent simultaneous fills we first try a NOWAIT regardless 275 * of the caller's flags. Specify M_NOVM so we don't recurse while 276 * holding a vmem lock. 277 */ 278 while (vm->vm_nfreetags < BT_MAXALLOC) { 279 bt = uma_zalloc(vmem_bt_zone, 280 (flags & M_USE_RESERVE) | M_NOWAIT | M_NOVM); 281 if (bt == NULL) { 282 VMEM_UNLOCK(vm); 283 bt = uma_zalloc(vmem_bt_zone, flags); 284 VMEM_LOCK(vm); 285 if (bt == NULL) 286 break; 287 } 288 LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist); 289 vm->vm_nfreetags++; 290 } 291 292 if (vm->vm_nfreetags < BT_MAXALLOC) 293 return ENOMEM; 294 295 return 0; 296 } 297 298 /* 299 * Pop a tag off of the freetag stack. 300 */ 301 static bt_t * 302 bt_alloc(vmem_t *vm) 303 { 304 bt_t *bt; 305 306 VMEM_ASSERT_LOCKED(vm); 307 bt = LIST_FIRST(&vm->vm_freetags); 308 MPASS(bt != NULL); 309 LIST_REMOVE(bt, bt_freelist); 310 vm->vm_nfreetags--; 311 312 return bt; 313 } 314 315 /* 316 * Trim the per-vmem free list. Returns with the lock released to 317 * avoid allocator recursions. 318 */ 319 static void 320 bt_freetrim(vmem_t *vm, int freelimit) 321 { 322 LIST_HEAD(, vmem_btag) freetags; 323 bt_t *bt; 324 325 LIST_INIT(&freetags); 326 VMEM_ASSERT_LOCKED(vm); 327 while (vm->vm_nfreetags > freelimit) { 328 bt = LIST_FIRST(&vm->vm_freetags); 329 LIST_REMOVE(bt, bt_freelist); 330 vm->vm_nfreetags--; 331 LIST_INSERT_HEAD(&freetags, bt, bt_freelist); 332 } 333 VMEM_UNLOCK(vm); 334 while ((bt = LIST_FIRST(&freetags)) != NULL) { 335 LIST_REMOVE(bt, bt_freelist); 336 uma_zfree(vmem_bt_zone, bt); 337 } 338 } 339 340 static inline void 341 bt_free(vmem_t *vm, bt_t *bt) 342 { 343 344 VMEM_ASSERT_LOCKED(vm); 345 MPASS(LIST_FIRST(&vm->vm_freetags) != bt); 346 LIST_INSERT_HEAD(&vm->vm_freetags, bt, bt_freelist); 347 vm->vm_nfreetags++; 348 } 349 350 /* 351 * freelist[0] ... [1, 1] 352 * freelist[1] ... [2, 2] 353 * : 354 * freelist[29] ... [30, 30] 355 * freelist[30] ... [31, 31] 356 * freelist[31] ... [32, 63] 357 * freelist[33] ... [64, 127] 358 * : 359 * freelist[n] ... [(1 << (n - 26)), (1 << (n - 25)) - 1] 360 * : 361 */ 362 363 static struct vmem_freelist * 364 bt_freehead_tofree(vmem_t *vm, vmem_size_t size) 365 { 366 const vmem_size_t qsize = size >> vm->vm_quantum_shift; 367 const int idx = SIZE2ORDER(qsize); 368 369 MPASS(size != 0 && qsize != 0); 370 MPASS((size & vm->vm_quantum_mask) == 0); 371 MPASS(idx >= 0); 372 MPASS(idx < VMEM_MAXORDER); 373 374 return &vm->vm_freelist[idx]; 375 } 376 377 /* 378 * bt_freehead_toalloc: return the freelist for the given size and allocation 379 * strategy. 380 * 381 * For M_FIRSTFIT, return the list in which any blocks are large enough 382 * for the requested size. otherwise, return the list which can have blocks 383 * large enough for the requested size. 384 */ 385 static struct vmem_freelist * 386 bt_freehead_toalloc(vmem_t *vm, vmem_size_t size, int strat) 387 { 388 const vmem_size_t qsize = size >> vm->vm_quantum_shift; 389 int idx = SIZE2ORDER(qsize); 390 391 MPASS(size != 0 && qsize != 0); 392 MPASS((size & vm->vm_quantum_mask) == 0); 393 394 if (strat == M_FIRSTFIT && ORDER2SIZE(idx) != qsize) { 395 idx++; 396 /* check too large request? */ 397 } 398 MPASS(idx >= 0); 399 MPASS(idx < VMEM_MAXORDER); 400 401 return &vm->vm_freelist[idx]; 402 } 403 404 /* ---- boundary tag hash */ 405 406 static struct vmem_hashlist * 407 bt_hashhead(vmem_t *vm, vmem_addr_t addr) 408 { 409 struct vmem_hashlist *list; 410 unsigned int hash; 411 412 hash = hash32_buf(&addr, sizeof(addr), 0); 413 list = &vm->vm_hashlist[hash % vm->vm_hashsize]; 414 415 return list; 416 } 417 418 static bt_t * 419 bt_lookupbusy(vmem_t *vm, vmem_addr_t addr) 420 { 421 struct vmem_hashlist *list; 422 bt_t *bt; 423 424 VMEM_ASSERT_LOCKED(vm); 425 list = bt_hashhead(vm, addr); 426 LIST_FOREACH(bt, list, bt_hashlist) { 427 if (bt->bt_start == addr) { 428 break; 429 } 430 } 431 432 return bt; 433 } 434 435 static void 436 bt_rembusy(vmem_t *vm, bt_t *bt) 437 { 438 439 VMEM_ASSERT_LOCKED(vm); 440 MPASS(vm->vm_nbusytag > 0); 441 vm->vm_inuse -= bt->bt_size; 442 vm->vm_nbusytag--; 443 LIST_REMOVE(bt, bt_hashlist); 444 } 445 446 static void 447 bt_insbusy(vmem_t *vm, bt_t *bt) 448 { 449 struct vmem_hashlist *list; 450 451 VMEM_ASSERT_LOCKED(vm); 452 MPASS(bt->bt_type == BT_TYPE_BUSY); 453 454 list = bt_hashhead(vm, bt->bt_start); 455 LIST_INSERT_HEAD(list, bt, bt_hashlist); 456 vm->vm_nbusytag++; 457 vm->vm_inuse += bt->bt_size; 458 } 459 460 /* ---- boundary tag list */ 461 462 static void 463 bt_remseg(vmem_t *vm, bt_t *bt) 464 { 465 466 MPASS(bt->bt_type != BT_TYPE_CURSOR); 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 * We use VMEM_ADDR_QCACHE_MIN instead of 0: uma_zalloc() returns 0 to indicate 509 * failure, so UMA can't be used to cache a resource with value 0. 510 */ 511 static int 512 qc_import(void *arg, void **store, int cnt, int domain, int flags) 513 { 514 qcache_t *qc; 515 vmem_addr_t addr; 516 int i; 517 518 KASSERT((flags & M_WAITOK) == 0, ("blocking allocation")); 519 520 qc = arg; 521 for (i = 0; i < cnt; i++) { 522 if (vmem_xalloc(qc->qc_vmem, qc->qc_size, 0, 0, 0, 523 VMEM_ADDR_QCACHE_MIN, VMEM_ADDR_MAX, flags, &addr) != 0) 524 break; 525 store[i] = (void *)addr; 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, 0); 565 MPASS(qc->qc_cache); 566 } 567 } 568 569 static void 570 qc_destroy(vmem_t *vm) 571 { 572 int qcache_idx_max; 573 int i; 574 575 qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift; 576 for (i = 0; i < qcache_idx_max; i++) 577 uma_zdestroy(vm->vm_qcache[i].qc_cache); 578 } 579 580 static void 581 qc_drain(vmem_t *vm) 582 { 583 int qcache_idx_max; 584 int i; 585 586 qcache_idx_max = vm->vm_qcache_max >> vm->vm_quantum_shift; 587 for (i = 0; i < qcache_idx_max; i++) 588 uma_zone_reclaim(vm->vm_qcache[i].qc_cache, UMA_RECLAIM_DRAIN); 589 } 590 591 #ifndef UMA_MD_SMALL_ALLOC 592 593 static struct mtx_padalign __exclusive_cache_line vmem_bt_lock; 594 595 /* 596 * vmem_bt_alloc: Allocate a new page of boundary tags. 597 * 598 * On architectures with uma_small_alloc there is no recursion; no address 599 * space need be allocated to allocate boundary tags. For the others, we 600 * must handle recursion. Boundary tags are necessary to allocate new 601 * boundary tags. 602 * 603 * UMA guarantees that enough tags are held in reserve to allocate a new 604 * page of kva. We dip into this reserve by specifying M_USE_RESERVE only 605 * when allocating the page to hold new boundary tags. In this way the 606 * reserve is automatically filled by the allocation that uses the reserve. 607 * 608 * We still have to guarantee that the new tags are allocated atomically since 609 * many threads may try concurrently. The bt_lock provides this guarantee. 610 * We convert WAITOK allocations to NOWAIT and then handle the blocking here 611 * on failure. It's ok to return NULL for a WAITOK allocation as UMA will 612 * loop again after checking to see if we lost the race to allocate. 613 * 614 * There is a small race between vmem_bt_alloc() returning the page and the 615 * zone lock being acquired to add the page to the zone. For WAITOK 616 * allocations we just pause briefly. NOWAIT may experience a transient 617 * failure. To alleviate this we permit a small number of simultaneous 618 * fills to proceed concurrently so NOWAIT is less likely to fail unless 619 * we are really out of KVA. 620 */ 621 static void * 622 vmem_bt_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag, 623 int wait) 624 { 625 vmem_addr_t addr; 626 627 *pflag = UMA_SLAB_KERNEL; 628 629 /* 630 * Single thread boundary tag allocation so that the address space 631 * and memory are added in one atomic operation. 632 */ 633 mtx_lock(&vmem_bt_lock); 634 if (vmem_xalloc(vm_dom[domain].vmd_kernel_arena, bytes, 0, 0, 0, 635 VMEM_ADDR_MIN, VMEM_ADDR_MAX, 636 M_NOWAIT | M_NOVM | M_USE_RESERVE | M_BESTFIT, &addr) == 0) { 637 if (kmem_back_domain(domain, kernel_object, addr, bytes, 638 M_NOWAIT | M_USE_RESERVE) == 0) { 639 mtx_unlock(&vmem_bt_lock); 640 return ((void *)addr); 641 } 642 vmem_xfree(vm_dom[domain].vmd_kernel_arena, addr, bytes); 643 mtx_unlock(&vmem_bt_lock); 644 /* 645 * Out of memory, not address space. This may not even be 646 * possible due to M_USE_RESERVE page allocation. 647 */ 648 if (wait & M_WAITOK) 649 vm_wait_domain(domain); 650 return (NULL); 651 } 652 mtx_unlock(&vmem_bt_lock); 653 /* 654 * We're either out of address space or lost a fill race. 655 */ 656 if (wait & M_WAITOK) 657 pause("btalloc", 1); 658 659 return (NULL); 660 } 661 #endif 662 663 void 664 vmem_startup(void) 665 { 666 667 mtx_init(&vmem_list_lock, "vmem list lock", NULL, MTX_DEF); 668 vmem_zone = uma_zcreate("vmem", 669 sizeof(struct vmem), NULL, NULL, NULL, NULL, 670 UMA_ALIGN_PTR, 0); 671 vmem_bt_zone = uma_zcreate("vmem btag", 672 sizeof(struct vmem_btag), NULL, NULL, NULL, NULL, 673 UMA_ALIGN_PTR, UMA_ZONE_VM); 674 #ifndef UMA_MD_SMALL_ALLOC 675 mtx_init(&vmem_bt_lock, "btag lock", NULL, MTX_DEF); 676 uma_prealloc(vmem_bt_zone, BT_MAXALLOC); 677 /* 678 * Reserve enough tags to allocate new tags. We allow multiple 679 * CPUs to attempt to allocate new tags concurrently to limit 680 * false restarts in UMA. vmem_bt_alloc() allocates from a per-domain 681 * arena, which may involve importing a range from the kernel arena, 682 * so we need to keep at least 2 * BT_MAXALLOC tags reserved. 683 */ 684 uma_zone_reserve(vmem_bt_zone, 2 * BT_MAXALLOC * mp_ncpus); 685 uma_zone_set_allocf(vmem_bt_zone, vmem_bt_alloc); 686 #endif 687 } 688 689 /* ---- rehash */ 690 691 static int 692 vmem_rehash(vmem_t *vm, vmem_size_t newhashsize) 693 { 694 bt_t *bt; 695 int i; 696 struct vmem_hashlist *newhashlist; 697 struct vmem_hashlist *oldhashlist; 698 vmem_size_t oldhashsize; 699 700 MPASS(newhashsize > 0); 701 702 newhashlist = malloc(sizeof(struct vmem_hashlist) * newhashsize, 703 M_VMEM, M_NOWAIT); 704 if (newhashlist == NULL) 705 return ENOMEM; 706 for (i = 0; i < newhashsize; i++) { 707 LIST_INIT(&newhashlist[i]); 708 } 709 710 VMEM_LOCK(vm); 711 oldhashlist = vm->vm_hashlist; 712 oldhashsize = vm->vm_hashsize; 713 vm->vm_hashlist = newhashlist; 714 vm->vm_hashsize = newhashsize; 715 if (oldhashlist == NULL) { 716 VMEM_UNLOCK(vm); 717 return 0; 718 } 719 for (i = 0; i < oldhashsize; i++) { 720 while ((bt = LIST_FIRST(&oldhashlist[i])) != NULL) { 721 bt_rembusy(vm, bt); 722 bt_insbusy(vm, bt); 723 } 724 } 725 VMEM_UNLOCK(vm); 726 727 if (oldhashlist != vm->vm_hash0) { 728 free(oldhashlist, M_VMEM); 729 } 730 731 return 0; 732 } 733 734 static void 735 vmem_periodic_kick(void *dummy) 736 { 737 738 taskqueue_enqueue(taskqueue_thread, &vmem_periodic_wk); 739 } 740 741 static void 742 vmem_periodic(void *unused, int pending) 743 { 744 vmem_t *vm; 745 vmem_size_t desired; 746 vmem_size_t current; 747 748 mtx_lock(&vmem_list_lock); 749 LIST_FOREACH(vm, &vmem_list, vm_alllist) { 750 #ifdef DIAGNOSTIC 751 /* Convenient time to verify vmem state. */ 752 if (enable_vmem_check == 1) { 753 VMEM_LOCK(vm); 754 vmem_check(vm); 755 VMEM_UNLOCK(vm); 756 } 757 #endif 758 desired = 1 << flsl(vm->vm_nbusytag); 759 desired = MIN(MAX(desired, VMEM_HASHSIZE_MIN), 760 VMEM_HASHSIZE_MAX); 761 current = vm->vm_hashsize; 762 763 /* Grow in powers of two. Shrink less aggressively. */ 764 if (desired >= current * 2 || desired * 4 <= current) 765 vmem_rehash(vm, desired); 766 767 /* 768 * Periodically wake up threads waiting for resources, 769 * so they could ask for reclamation again. 770 */ 771 VMEM_CONDVAR_BROADCAST(vm); 772 } 773 mtx_unlock(&vmem_list_lock); 774 775 callout_reset(&vmem_periodic_ch, vmem_periodic_interval, 776 vmem_periodic_kick, NULL); 777 } 778 779 static void 780 vmem_start_callout(void *unused) 781 { 782 783 TASK_INIT(&vmem_periodic_wk, 0, vmem_periodic, NULL); 784 vmem_periodic_interval = hz * 10; 785 callout_init(&vmem_periodic_ch, 1); 786 callout_reset(&vmem_periodic_ch, vmem_periodic_interval, 787 vmem_periodic_kick, NULL); 788 } 789 SYSINIT(vfs, SI_SUB_CONFIGURE, SI_ORDER_ANY, vmem_start_callout, NULL); 790 791 static void 792 vmem_add1(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, int type) 793 { 794 bt_t *btspan; 795 bt_t *btfree; 796 797 MPASS(type == BT_TYPE_SPAN || type == BT_TYPE_SPAN_STATIC); 798 MPASS((size & vm->vm_quantum_mask) == 0); 799 800 btspan = bt_alloc(vm); 801 btspan->bt_type = type; 802 btspan->bt_start = addr; 803 btspan->bt_size = size; 804 bt_insseg_tail(vm, btspan); 805 806 btfree = bt_alloc(vm); 807 btfree->bt_type = BT_TYPE_FREE; 808 btfree->bt_start = addr; 809 btfree->bt_size = size; 810 bt_insseg(vm, btfree, btspan); 811 bt_insfree(vm, btfree); 812 813 vm->vm_size += size; 814 } 815 816 static void 817 vmem_destroy1(vmem_t *vm) 818 { 819 bt_t *bt; 820 821 /* 822 * Drain per-cpu quantum caches. 823 */ 824 qc_destroy(vm); 825 826 /* 827 * The vmem should now only contain empty segments. 828 */ 829 VMEM_LOCK(vm); 830 MPASS(vm->vm_nbusytag == 0); 831 832 TAILQ_REMOVE(&vm->vm_seglist, &vm->vm_cursor, bt_seglist); 833 while ((bt = TAILQ_FIRST(&vm->vm_seglist)) != NULL) 834 bt_remseg(vm, bt); 835 836 if (vm->vm_hashlist != NULL && vm->vm_hashlist != vm->vm_hash0) 837 free(vm->vm_hashlist, M_VMEM); 838 839 bt_freetrim(vm, 0); 840 841 VMEM_CONDVAR_DESTROY(vm); 842 VMEM_LOCK_DESTROY(vm); 843 uma_zfree(vmem_zone, vm); 844 } 845 846 static int 847 vmem_import(vmem_t *vm, vmem_size_t size, vmem_size_t align, int flags) 848 { 849 vmem_addr_t addr; 850 int error; 851 852 if (vm->vm_importfn == NULL) 853 return (EINVAL); 854 855 /* 856 * To make sure we get a span that meets the alignment we double it 857 * and add the size to the tail. This slightly overestimates. 858 */ 859 if (align != vm->vm_quantum_mask + 1) 860 size = (align * 2) + size; 861 size = roundup(size, vm->vm_import_quantum); 862 863 if (vm->vm_limit != 0 && vm->vm_limit < vm->vm_size + size) 864 return (ENOMEM); 865 866 /* 867 * Hide MAXALLOC tags so we're guaranteed to be able to add this 868 * span and the tag we want to allocate from it. 869 */ 870 MPASS(vm->vm_nfreetags >= BT_MAXALLOC); 871 vm->vm_nfreetags -= BT_MAXALLOC; 872 VMEM_UNLOCK(vm); 873 error = (vm->vm_importfn)(vm->vm_arg, size, flags, &addr); 874 VMEM_LOCK(vm); 875 vm->vm_nfreetags += BT_MAXALLOC; 876 if (error) 877 return (ENOMEM); 878 879 vmem_add1(vm, addr, size, BT_TYPE_SPAN); 880 881 return 0; 882 } 883 884 /* 885 * vmem_fit: check if a bt can satisfy the given restrictions. 886 * 887 * it's a caller's responsibility to ensure the region is big enough 888 * before calling us. 889 */ 890 static int 891 vmem_fit(const bt_t *bt, vmem_size_t size, vmem_size_t align, 892 vmem_size_t phase, vmem_size_t nocross, vmem_addr_t minaddr, 893 vmem_addr_t maxaddr, vmem_addr_t *addrp) 894 { 895 vmem_addr_t start; 896 vmem_addr_t end; 897 898 MPASS(size > 0); 899 MPASS(bt->bt_size >= size); /* caller's responsibility */ 900 901 /* 902 * XXX assumption: vmem_addr_t and vmem_size_t are 903 * unsigned integer of the same size. 904 */ 905 906 start = bt->bt_start; 907 if (start < minaddr) { 908 start = minaddr; 909 } 910 end = BT_END(bt); 911 if (end > maxaddr) 912 end = maxaddr; 913 if (start > end) 914 return (ENOMEM); 915 916 start = VMEM_ALIGNUP(start - phase, align) + phase; 917 if (start < bt->bt_start) 918 start += align; 919 if (VMEM_CROSS_P(start, start + size - 1, nocross)) { 920 MPASS(align < nocross); 921 start = VMEM_ALIGNUP(start - phase, nocross) + phase; 922 } 923 if (start <= end && end - start >= size - 1) { 924 MPASS((start & (align - 1)) == phase); 925 MPASS(!VMEM_CROSS_P(start, start + size - 1, nocross)); 926 MPASS(minaddr <= start); 927 MPASS(maxaddr == 0 || start + size - 1 <= maxaddr); 928 MPASS(bt->bt_start <= start); 929 MPASS(BT_END(bt) - start >= size - 1); 930 *addrp = start; 931 932 return (0); 933 } 934 return (ENOMEM); 935 } 936 937 /* 938 * vmem_clip: Trim the boundary tag edges to the requested start and size. 939 */ 940 static void 941 vmem_clip(vmem_t *vm, bt_t *bt, vmem_addr_t start, vmem_size_t size) 942 { 943 bt_t *btnew; 944 bt_t *btprev; 945 946 VMEM_ASSERT_LOCKED(vm); 947 MPASS(bt->bt_type == BT_TYPE_FREE); 948 MPASS(bt->bt_size >= size); 949 bt_remfree(vm, bt); 950 if (bt->bt_start != start) { 951 btprev = bt_alloc(vm); 952 btprev->bt_type = BT_TYPE_FREE; 953 btprev->bt_start = bt->bt_start; 954 btprev->bt_size = start - bt->bt_start; 955 bt->bt_start = start; 956 bt->bt_size -= btprev->bt_size; 957 bt_insfree(vm, btprev); 958 bt_insseg(vm, btprev, 959 TAILQ_PREV(bt, vmem_seglist, bt_seglist)); 960 } 961 MPASS(bt->bt_start == start); 962 if (bt->bt_size != size && bt->bt_size - size > vm->vm_quantum_mask) { 963 /* split */ 964 btnew = bt_alloc(vm); 965 btnew->bt_type = BT_TYPE_BUSY; 966 btnew->bt_start = bt->bt_start; 967 btnew->bt_size = size; 968 bt->bt_start = bt->bt_start + size; 969 bt->bt_size -= size; 970 bt_insfree(vm, bt); 971 bt_insseg(vm, btnew, 972 TAILQ_PREV(bt, vmem_seglist, bt_seglist)); 973 bt_insbusy(vm, btnew); 974 bt = btnew; 975 } else { 976 bt->bt_type = BT_TYPE_BUSY; 977 bt_insbusy(vm, bt); 978 } 979 MPASS(bt->bt_size >= size); 980 } 981 982 static int 983 vmem_try_fetch(vmem_t *vm, const vmem_size_t size, vmem_size_t align, int flags) 984 { 985 vmem_size_t avail; 986 987 VMEM_ASSERT_LOCKED(vm); 988 989 /* 990 * XXX it is possible to fail to meet xalloc constraints with the 991 * imported region. It is up to the user to specify the 992 * import quantum such that it can satisfy any allocation. 993 */ 994 if (vmem_import(vm, size, align, flags) == 0) 995 return (1); 996 997 /* 998 * Try to free some space from the quantum cache or reclaim 999 * functions if available. 1000 */ 1001 if (vm->vm_qcache_max != 0 || vm->vm_reclaimfn != NULL) { 1002 avail = vm->vm_size - vm->vm_inuse; 1003 VMEM_UNLOCK(vm); 1004 if (vm->vm_qcache_max != 0) 1005 qc_drain(vm); 1006 if (vm->vm_reclaimfn != NULL) 1007 vm->vm_reclaimfn(vm, flags); 1008 VMEM_LOCK(vm); 1009 /* If we were successful retry even NOWAIT. */ 1010 if (vm->vm_size - vm->vm_inuse > avail) 1011 return (1); 1012 } 1013 if ((flags & M_NOWAIT) != 0) 1014 return (0); 1015 VMEM_CONDVAR_WAIT(vm); 1016 return (1); 1017 } 1018 1019 static int 1020 vmem_try_release(vmem_t *vm, struct vmem_btag *bt, const bool remfree) 1021 { 1022 struct vmem_btag *prev; 1023 1024 MPASS(bt->bt_type == BT_TYPE_FREE); 1025 1026 if (vm->vm_releasefn == NULL) 1027 return (0); 1028 1029 prev = TAILQ_PREV(bt, vmem_seglist, bt_seglist); 1030 MPASS(prev != NULL); 1031 MPASS(prev->bt_type != BT_TYPE_FREE); 1032 1033 if (prev->bt_type == BT_TYPE_SPAN && prev->bt_size == bt->bt_size) { 1034 vmem_addr_t spanaddr; 1035 vmem_size_t spansize; 1036 1037 MPASS(prev->bt_start == bt->bt_start); 1038 spanaddr = prev->bt_start; 1039 spansize = prev->bt_size; 1040 if (remfree) 1041 bt_remfree(vm, bt); 1042 bt_remseg(vm, bt); 1043 bt_remseg(vm, prev); 1044 vm->vm_size -= spansize; 1045 VMEM_CONDVAR_BROADCAST(vm); 1046 bt_freetrim(vm, BT_MAXFREE); 1047 vm->vm_releasefn(vm->vm_arg, spanaddr, spansize); 1048 return (1); 1049 } 1050 return (0); 1051 } 1052 1053 static int 1054 vmem_xalloc_nextfit(vmem_t *vm, const vmem_size_t size, vmem_size_t align, 1055 const vmem_size_t phase, const vmem_size_t nocross, int flags, 1056 vmem_addr_t *addrp) 1057 { 1058 struct vmem_btag *bt, *cursor, *next, *prev; 1059 int error; 1060 1061 error = ENOMEM; 1062 VMEM_LOCK(vm); 1063 retry: 1064 /* 1065 * Make sure we have enough tags to complete the operation. 1066 */ 1067 if (vm->vm_nfreetags < BT_MAXALLOC && bt_fill(vm, flags) != 0) 1068 goto out; 1069 1070 /* 1071 * Find the next free tag meeting our constraints. If one is found, 1072 * perform the allocation. 1073 */ 1074 for (cursor = &vm->vm_cursor, bt = TAILQ_NEXT(cursor, bt_seglist); 1075 bt != cursor; bt = TAILQ_NEXT(bt, bt_seglist)) { 1076 if (bt == NULL) 1077 bt = TAILQ_FIRST(&vm->vm_seglist); 1078 if (bt->bt_type == BT_TYPE_FREE && bt->bt_size >= size && 1079 (error = vmem_fit(bt, size, align, phase, nocross, 1080 VMEM_ADDR_MIN, VMEM_ADDR_MAX, addrp)) == 0) { 1081 vmem_clip(vm, bt, *addrp, size); 1082 break; 1083 } 1084 } 1085 1086 /* 1087 * Try to coalesce free segments around the cursor. If we succeed, and 1088 * have not yet satisfied the allocation request, try again with the 1089 * newly coalesced segment. 1090 */ 1091 if ((next = TAILQ_NEXT(cursor, bt_seglist)) != NULL && 1092 (prev = TAILQ_PREV(cursor, vmem_seglist, bt_seglist)) != NULL && 1093 next->bt_type == BT_TYPE_FREE && prev->bt_type == BT_TYPE_FREE && 1094 prev->bt_start + prev->bt_size == next->bt_start) { 1095 prev->bt_size += next->bt_size; 1096 bt_remfree(vm, next); 1097 bt_remseg(vm, next); 1098 1099 /* 1100 * The coalesced segment might be able to satisfy our request. 1101 * If not, we might need to release it from the arena. 1102 */ 1103 if (error == ENOMEM && prev->bt_size >= size && 1104 (error = vmem_fit(prev, size, align, phase, nocross, 1105 VMEM_ADDR_MIN, VMEM_ADDR_MAX, addrp)) == 0) { 1106 vmem_clip(vm, prev, *addrp, size); 1107 bt = prev; 1108 } else 1109 (void)vmem_try_release(vm, prev, true); 1110 } 1111 1112 /* 1113 * If the allocation was successful, advance the cursor. 1114 */ 1115 if (error == 0) { 1116 TAILQ_REMOVE(&vm->vm_seglist, cursor, bt_seglist); 1117 for (; bt != NULL && bt->bt_start < *addrp + size; 1118 bt = TAILQ_NEXT(bt, bt_seglist)) 1119 ; 1120 if (bt != NULL) 1121 TAILQ_INSERT_BEFORE(bt, cursor, bt_seglist); 1122 else 1123 TAILQ_INSERT_HEAD(&vm->vm_seglist, cursor, bt_seglist); 1124 } 1125 1126 /* 1127 * Attempt to bring additional resources into the arena. If that fails 1128 * and M_WAITOK is specified, sleep waiting for resources to be freed. 1129 */ 1130 if (error == ENOMEM && vmem_try_fetch(vm, size, align, flags)) 1131 goto retry; 1132 1133 out: 1134 VMEM_UNLOCK(vm); 1135 return (error); 1136 } 1137 1138 /* ---- vmem API */ 1139 1140 void 1141 vmem_set_import(vmem_t *vm, vmem_import_t *importfn, 1142 vmem_release_t *releasefn, void *arg, vmem_size_t import_quantum) 1143 { 1144 1145 VMEM_LOCK(vm); 1146 vm->vm_importfn = importfn; 1147 vm->vm_releasefn = releasefn; 1148 vm->vm_arg = arg; 1149 vm->vm_import_quantum = import_quantum; 1150 VMEM_UNLOCK(vm); 1151 } 1152 1153 void 1154 vmem_set_limit(vmem_t *vm, vmem_size_t limit) 1155 { 1156 1157 VMEM_LOCK(vm); 1158 vm->vm_limit = limit; 1159 VMEM_UNLOCK(vm); 1160 } 1161 1162 void 1163 vmem_set_reclaim(vmem_t *vm, vmem_reclaim_t *reclaimfn) 1164 { 1165 1166 VMEM_LOCK(vm); 1167 vm->vm_reclaimfn = reclaimfn; 1168 VMEM_UNLOCK(vm); 1169 } 1170 1171 /* 1172 * vmem_init: Initializes vmem arena. 1173 */ 1174 vmem_t * 1175 vmem_init(vmem_t *vm, const char *name, vmem_addr_t base, vmem_size_t size, 1176 vmem_size_t quantum, vmem_size_t qcache_max, int flags) 1177 { 1178 int i; 1179 1180 MPASS(quantum > 0); 1181 MPASS((quantum & (quantum - 1)) == 0); 1182 1183 bzero(vm, sizeof(*vm)); 1184 1185 VMEM_CONDVAR_INIT(vm, name); 1186 VMEM_LOCK_INIT(vm, name); 1187 vm->vm_nfreetags = 0; 1188 LIST_INIT(&vm->vm_freetags); 1189 strlcpy(vm->vm_name, name, sizeof(vm->vm_name)); 1190 vm->vm_quantum_mask = quantum - 1; 1191 vm->vm_quantum_shift = flsl(quantum) - 1; 1192 vm->vm_nbusytag = 0; 1193 vm->vm_size = 0; 1194 vm->vm_limit = 0; 1195 vm->vm_inuse = 0; 1196 qc_init(vm, qcache_max); 1197 1198 TAILQ_INIT(&vm->vm_seglist); 1199 vm->vm_cursor.bt_start = vm->vm_cursor.bt_size = 0; 1200 vm->vm_cursor.bt_type = BT_TYPE_CURSOR; 1201 TAILQ_INSERT_TAIL(&vm->vm_seglist, &vm->vm_cursor, bt_seglist); 1202 1203 for (i = 0; i < VMEM_MAXORDER; i++) 1204 LIST_INIT(&vm->vm_freelist[i]); 1205 1206 memset(&vm->vm_hash0, 0, sizeof(vm->vm_hash0)); 1207 vm->vm_hashsize = VMEM_HASHSIZE_MIN; 1208 vm->vm_hashlist = vm->vm_hash0; 1209 1210 if (size != 0) { 1211 if (vmem_add(vm, base, size, flags) != 0) { 1212 vmem_destroy1(vm); 1213 return NULL; 1214 } 1215 } 1216 1217 mtx_lock(&vmem_list_lock); 1218 LIST_INSERT_HEAD(&vmem_list, vm, vm_alllist); 1219 mtx_unlock(&vmem_list_lock); 1220 1221 return vm; 1222 } 1223 1224 /* 1225 * vmem_create: create an arena. 1226 */ 1227 vmem_t * 1228 vmem_create(const char *name, vmem_addr_t base, vmem_size_t size, 1229 vmem_size_t quantum, vmem_size_t qcache_max, int flags) 1230 { 1231 1232 vmem_t *vm; 1233 1234 vm = uma_zalloc(vmem_zone, flags & (M_WAITOK|M_NOWAIT)); 1235 if (vm == NULL) 1236 return (NULL); 1237 if (vmem_init(vm, name, base, size, quantum, qcache_max, 1238 flags) == NULL) 1239 return (NULL); 1240 return (vm); 1241 } 1242 1243 void 1244 vmem_destroy(vmem_t *vm) 1245 { 1246 1247 mtx_lock(&vmem_list_lock); 1248 LIST_REMOVE(vm, vm_alllist); 1249 mtx_unlock(&vmem_list_lock); 1250 1251 vmem_destroy1(vm); 1252 } 1253 1254 vmem_size_t 1255 vmem_roundup_size(vmem_t *vm, vmem_size_t size) 1256 { 1257 1258 return (size + vm->vm_quantum_mask) & ~vm->vm_quantum_mask; 1259 } 1260 1261 /* 1262 * vmem_alloc: allocate resource from the arena. 1263 */ 1264 int 1265 vmem_alloc(vmem_t *vm, vmem_size_t size, int flags, vmem_addr_t *addrp) 1266 { 1267 const int strat __unused = flags & VMEM_FITMASK; 1268 qcache_t *qc; 1269 1270 flags &= VMEM_FLAGS; 1271 MPASS(size > 0); 1272 MPASS(strat == M_BESTFIT || strat == M_FIRSTFIT || strat == M_NEXTFIT); 1273 if ((flags & M_NOWAIT) == 0) 1274 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "vmem_alloc"); 1275 1276 if (size <= vm->vm_qcache_max) { 1277 /* 1278 * Resource 0 cannot be cached, so avoid a blocking allocation 1279 * in qc_import() and give the vmem_xalloc() call below a chance 1280 * to return 0. 1281 */ 1282 qc = &vm->vm_qcache[(size - 1) >> vm->vm_quantum_shift]; 1283 *addrp = (vmem_addr_t)uma_zalloc(qc->qc_cache, 1284 (flags & ~M_WAITOK) | M_NOWAIT); 1285 if (__predict_true(*addrp != 0)) 1286 return (0); 1287 } 1288 1289 return (vmem_xalloc(vm, size, 0, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX, 1290 flags, addrp)); 1291 } 1292 1293 int 1294 vmem_xalloc(vmem_t *vm, const vmem_size_t size0, vmem_size_t align, 1295 const vmem_size_t phase, const vmem_size_t nocross, 1296 const vmem_addr_t minaddr, const vmem_addr_t maxaddr, int flags, 1297 vmem_addr_t *addrp) 1298 { 1299 const vmem_size_t size = vmem_roundup_size(vm, size0); 1300 struct vmem_freelist *list; 1301 struct vmem_freelist *first; 1302 struct vmem_freelist *end; 1303 bt_t *bt; 1304 int error; 1305 int strat; 1306 1307 flags &= VMEM_FLAGS; 1308 strat = flags & VMEM_FITMASK; 1309 MPASS(size0 > 0); 1310 MPASS(size > 0); 1311 MPASS(strat == M_BESTFIT || strat == M_FIRSTFIT || strat == M_NEXTFIT); 1312 MPASS((flags & (M_NOWAIT|M_WAITOK)) != (M_NOWAIT|M_WAITOK)); 1313 if ((flags & M_NOWAIT) == 0) 1314 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "vmem_xalloc"); 1315 MPASS((align & vm->vm_quantum_mask) == 0); 1316 MPASS((align & (align - 1)) == 0); 1317 MPASS((phase & vm->vm_quantum_mask) == 0); 1318 MPASS((nocross & vm->vm_quantum_mask) == 0); 1319 MPASS((nocross & (nocross - 1)) == 0); 1320 MPASS((align == 0 && phase == 0) || phase < align); 1321 MPASS(nocross == 0 || nocross >= size); 1322 MPASS(minaddr <= maxaddr); 1323 MPASS(!VMEM_CROSS_P(phase, phase + size - 1, nocross)); 1324 if (strat == M_NEXTFIT) 1325 MPASS(minaddr == VMEM_ADDR_MIN && maxaddr == VMEM_ADDR_MAX); 1326 1327 if (align == 0) 1328 align = vm->vm_quantum_mask + 1; 1329 *addrp = 0; 1330 1331 /* 1332 * Next-fit allocations don't use the freelists. 1333 */ 1334 if (strat == M_NEXTFIT) 1335 return (vmem_xalloc_nextfit(vm, size0, align, phase, nocross, 1336 flags, addrp)); 1337 1338 end = &vm->vm_freelist[VMEM_MAXORDER]; 1339 /* 1340 * choose a free block from which we allocate. 1341 */ 1342 first = bt_freehead_toalloc(vm, size, strat); 1343 VMEM_LOCK(vm); 1344 for (;;) { 1345 /* 1346 * Make sure we have enough tags to complete the 1347 * operation. 1348 */ 1349 if (vm->vm_nfreetags < BT_MAXALLOC && 1350 bt_fill(vm, flags) != 0) { 1351 error = ENOMEM; 1352 break; 1353 } 1354 1355 /* 1356 * Scan freelists looking for a tag that satisfies the 1357 * allocation. If we're doing BESTFIT we may encounter 1358 * sizes below the request. If we're doing FIRSTFIT we 1359 * inspect only the first element from each list. 1360 */ 1361 for (list = first; list < end; list++) { 1362 LIST_FOREACH(bt, list, bt_freelist) { 1363 if (bt->bt_size >= size) { 1364 error = vmem_fit(bt, size, align, phase, 1365 nocross, minaddr, maxaddr, addrp); 1366 if (error == 0) { 1367 vmem_clip(vm, bt, *addrp, size); 1368 goto out; 1369 } 1370 } 1371 /* FIRST skips to the next list. */ 1372 if (strat == M_FIRSTFIT) 1373 break; 1374 } 1375 } 1376 1377 /* 1378 * Retry if the fast algorithm failed. 1379 */ 1380 if (strat == M_FIRSTFIT) { 1381 strat = M_BESTFIT; 1382 first = bt_freehead_toalloc(vm, size, strat); 1383 continue; 1384 } 1385 1386 /* 1387 * Try a few measures to bring additional resources into the 1388 * arena. If all else fails, we will sleep waiting for 1389 * resources to be freed. 1390 */ 1391 if (!vmem_try_fetch(vm, size, align, flags)) { 1392 error = ENOMEM; 1393 break; 1394 } 1395 } 1396 out: 1397 VMEM_UNLOCK(vm); 1398 if (error != 0 && (flags & M_NOWAIT) == 0) 1399 panic("failed to allocate waiting allocation\n"); 1400 1401 return (error); 1402 } 1403 1404 /* 1405 * vmem_free: free the resource to the arena. 1406 */ 1407 void 1408 vmem_free(vmem_t *vm, vmem_addr_t addr, vmem_size_t size) 1409 { 1410 qcache_t *qc; 1411 MPASS(size > 0); 1412 1413 if (size <= vm->vm_qcache_max && 1414 __predict_true(addr >= VMEM_ADDR_QCACHE_MIN)) { 1415 qc = &vm->vm_qcache[(size - 1) >> vm->vm_quantum_shift]; 1416 uma_zfree(qc->qc_cache, (void *)addr); 1417 } else 1418 vmem_xfree(vm, addr, size); 1419 } 1420 1421 void 1422 vmem_xfree(vmem_t *vm, vmem_addr_t addr, vmem_size_t size) 1423 { 1424 bt_t *bt; 1425 bt_t *t; 1426 1427 MPASS(size > 0); 1428 1429 VMEM_LOCK(vm); 1430 bt = bt_lookupbusy(vm, addr); 1431 MPASS(bt != NULL); 1432 MPASS(bt->bt_start == addr); 1433 MPASS(bt->bt_size == vmem_roundup_size(vm, size) || 1434 bt->bt_size - vmem_roundup_size(vm, size) <= vm->vm_quantum_mask); 1435 MPASS(bt->bt_type == BT_TYPE_BUSY); 1436 bt_rembusy(vm, bt); 1437 bt->bt_type = BT_TYPE_FREE; 1438 1439 /* coalesce */ 1440 t = TAILQ_NEXT(bt, bt_seglist); 1441 if (t != NULL && t->bt_type == BT_TYPE_FREE) { 1442 MPASS(BT_END(bt) < t->bt_start); /* YYY */ 1443 bt->bt_size += t->bt_size; 1444 bt_remfree(vm, t); 1445 bt_remseg(vm, t); 1446 } 1447 t = TAILQ_PREV(bt, vmem_seglist, bt_seglist); 1448 if (t != NULL && t->bt_type == BT_TYPE_FREE) { 1449 MPASS(BT_END(t) < bt->bt_start); /* YYY */ 1450 bt->bt_size += t->bt_size; 1451 bt->bt_start = t->bt_start; 1452 bt_remfree(vm, t); 1453 bt_remseg(vm, t); 1454 } 1455 1456 if (!vmem_try_release(vm, bt, false)) { 1457 bt_insfree(vm, bt); 1458 VMEM_CONDVAR_BROADCAST(vm); 1459 bt_freetrim(vm, BT_MAXFREE); 1460 } 1461 } 1462 1463 /* 1464 * vmem_add: 1465 * 1466 */ 1467 int 1468 vmem_add(vmem_t *vm, vmem_addr_t addr, vmem_size_t size, int flags) 1469 { 1470 int error; 1471 1472 error = 0; 1473 flags &= VMEM_FLAGS; 1474 VMEM_LOCK(vm); 1475 if (vm->vm_nfreetags >= BT_MAXALLOC || bt_fill(vm, flags) == 0) 1476 vmem_add1(vm, addr, size, BT_TYPE_SPAN_STATIC); 1477 else 1478 error = ENOMEM; 1479 VMEM_UNLOCK(vm); 1480 1481 return (error); 1482 } 1483 1484 /* 1485 * vmem_size: information about arenas size 1486 */ 1487 vmem_size_t 1488 vmem_size(vmem_t *vm, int typemask) 1489 { 1490 int i; 1491 1492 switch (typemask) { 1493 case VMEM_ALLOC: 1494 return vm->vm_inuse; 1495 case VMEM_FREE: 1496 return vm->vm_size - vm->vm_inuse; 1497 case VMEM_FREE|VMEM_ALLOC: 1498 return vm->vm_size; 1499 case VMEM_MAXFREE: 1500 VMEM_LOCK(vm); 1501 for (i = VMEM_MAXORDER - 1; i >= 0; i--) { 1502 if (LIST_EMPTY(&vm->vm_freelist[i])) 1503 continue; 1504 VMEM_UNLOCK(vm); 1505 return ((vmem_size_t)ORDER2SIZE(i) << 1506 vm->vm_quantum_shift); 1507 } 1508 VMEM_UNLOCK(vm); 1509 return (0); 1510 default: 1511 panic("vmem_size"); 1512 } 1513 } 1514 1515 /* ---- debug */ 1516 1517 #if defined(DDB) || defined(DIAGNOSTIC) 1518 1519 static void bt_dump(const bt_t *, int (*)(const char *, ...) 1520 __printflike(1, 2)); 1521 1522 static const char * 1523 bt_type_string(int type) 1524 { 1525 1526 switch (type) { 1527 case BT_TYPE_BUSY: 1528 return "busy"; 1529 case BT_TYPE_FREE: 1530 return "free"; 1531 case BT_TYPE_SPAN: 1532 return "span"; 1533 case BT_TYPE_SPAN_STATIC: 1534 return "static span"; 1535 case BT_TYPE_CURSOR: 1536 return "cursor"; 1537 default: 1538 break; 1539 } 1540 return "BOGUS"; 1541 } 1542 1543 static void 1544 bt_dump(const bt_t *bt, int (*pr)(const char *, ...)) 1545 { 1546 1547 (*pr)("\t%p: %jx %jx, %d(%s)\n", 1548 bt, (intmax_t)bt->bt_start, (intmax_t)bt->bt_size, 1549 bt->bt_type, bt_type_string(bt->bt_type)); 1550 } 1551 1552 static void 1553 vmem_dump(const vmem_t *vm , int (*pr)(const char *, ...) __printflike(1, 2)) 1554 { 1555 const bt_t *bt; 1556 int i; 1557 1558 (*pr)("vmem %p '%s'\n", vm, vm->vm_name); 1559 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { 1560 bt_dump(bt, pr); 1561 } 1562 1563 for (i = 0; i < VMEM_MAXORDER; i++) { 1564 const struct vmem_freelist *fl = &vm->vm_freelist[i]; 1565 1566 if (LIST_EMPTY(fl)) { 1567 continue; 1568 } 1569 1570 (*pr)("freelist[%d]\n", i); 1571 LIST_FOREACH(bt, fl, bt_freelist) { 1572 bt_dump(bt, pr); 1573 } 1574 } 1575 } 1576 1577 #endif /* defined(DDB) || defined(DIAGNOSTIC) */ 1578 1579 #if defined(DDB) 1580 #include <ddb/ddb.h> 1581 1582 static bt_t * 1583 vmem_whatis_lookup(vmem_t *vm, vmem_addr_t addr) 1584 { 1585 bt_t *bt; 1586 1587 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { 1588 if (BT_ISSPAN_P(bt)) { 1589 continue; 1590 } 1591 if (bt->bt_start <= addr && addr <= BT_END(bt)) { 1592 return bt; 1593 } 1594 } 1595 1596 return NULL; 1597 } 1598 1599 void 1600 vmem_whatis(vmem_addr_t addr, int (*pr)(const char *, ...)) 1601 { 1602 vmem_t *vm; 1603 1604 LIST_FOREACH(vm, &vmem_list, vm_alllist) { 1605 bt_t *bt; 1606 1607 bt = vmem_whatis_lookup(vm, addr); 1608 if (bt == NULL) { 1609 continue; 1610 } 1611 (*pr)("%p is %p+%zu in VMEM '%s' (%s)\n", 1612 (void *)addr, (void *)bt->bt_start, 1613 (vmem_size_t)(addr - bt->bt_start), vm->vm_name, 1614 (bt->bt_type == BT_TYPE_BUSY) ? "allocated" : "free"); 1615 } 1616 } 1617 1618 void 1619 vmem_printall(const char *modif, int (*pr)(const char *, ...)) 1620 { 1621 const vmem_t *vm; 1622 1623 LIST_FOREACH(vm, &vmem_list, vm_alllist) { 1624 vmem_dump(vm, pr); 1625 } 1626 } 1627 1628 void 1629 vmem_print(vmem_addr_t addr, const char *modif, int (*pr)(const char *, ...)) 1630 { 1631 const vmem_t *vm = (const void *)addr; 1632 1633 vmem_dump(vm, pr); 1634 } 1635 1636 DB_SHOW_COMMAND(vmemdump, vmemdump) 1637 { 1638 1639 if (!have_addr) { 1640 db_printf("usage: show vmemdump <addr>\n"); 1641 return; 1642 } 1643 1644 vmem_dump((const vmem_t *)addr, db_printf); 1645 } 1646 1647 DB_SHOW_ALL_COMMAND(vmemdump, vmemdumpall) 1648 { 1649 const vmem_t *vm; 1650 1651 LIST_FOREACH(vm, &vmem_list, vm_alllist) 1652 vmem_dump(vm, db_printf); 1653 } 1654 1655 DB_SHOW_COMMAND(vmem, vmem_summ) 1656 { 1657 const vmem_t *vm = (const void *)addr; 1658 const bt_t *bt; 1659 size_t ft[VMEM_MAXORDER], ut[VMEM_MAXORDER]; 1660 size_t fs[VMEM_MAXORDER], us[VMEM_MAXORDER]; 1661 int ord; 1662 1663 if (!have_addr) { 1664 db_printf("usage: show vmem <addr>\n"); 1665 return; 1666 } 1667 1668 db_printf("vmem %p '%s'\n", vm, vm->vm_name); 1669 db_printf("\tquantum:\t%zu\n", vm->vm_quantum_mask + 1); 1670 db_printf("\tsize:\t%zu\n", vm->vm_size); 1671 db_printf("\tinuse:\t%zu\n", vm->vm_inuse); 1672 db_printf("\tfree:\t%zu\n", vm->vm_size - vm->vm_inuse); 1673 db_printf("\tbusy tags:\t%d\n", vm->vm_nbusytag); 1674 db_printf("\tfree tags:\t%d\n", vm->vm_nfreetags); 1675 1676 memset(&ft, 0, sizeof(ft)); 1677 memset(&ut, 0, sizeof(ut)); 1678 memset(&fs, 0, sizeof(fs)); 1679 memset(&us, 0, sizeof(us)); 1680 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { 1681 ord = SIZE2ORDER(bt->bt_size >> vm->vm_quantum_shift); 1682 if (bt->bt_type == BT_TYPE_BUSY) { 1683 ut[ord]++; 1684 us[ord] += bt->bt_size; 1685 } else if (bt->bt_type == BT_TYPE_FREE) { 1686 ft[ord]++; 1687 fs[ord] += bt->bt_size; 1688 } 1689 } 1690 db_printf("\t\t\tinuse\tsize\t\tfree\tsize\n"); 1691 for (ord = 0; ord < VMEM_MAXORDER; ord++) { 1692 if (ut[ord] == 0 && ft[ord] == 0) 1693 continue; 1694 db_printf("\t%-15zu %zu\t%-15zu %zu\t%-16zu\n", 1695 ORDER2SIZE(ord) << vm->vm_quantum_shift, 1696 ut[ord], us[ord], ft[ord], fs[ord]); 1697 } 1698 } 1699 1700 DB_SHOW_ALL_COMMAND(vmem, vmem_summall) 1701 { 1702 const vmem_t *vm; 1703 1704 LIST_FOREACH(vm, &vmem_list, vm_alllist) 1705 vmem_summ((db_expr_t)vm, TRUE, count, modif); 1706 } 1707 #endif /* defined(DDB) */ 1708 1709 #define vmem_printf printf 1710 1711 #if defined(DIAGNOSTIC) 1712 1713 static bool 1714 vmem_check_sanity(vmem_t *vm) 1715 { 1716 const bt_t *bt, *bt2; 1717 1718 MPASS(vm != NULL); 1719 1720 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { 1721 if (bt->bt_start > BT_END(bt)) { 1722 printf("corrupted tag\n"); 1723 bt_dump(bt, vmem_printf); 1724 return false; 1725 } 1726 } 1727 TAILQ_FOREACH(bt, &vm->vm_seglist, bt_seglist) { 1728 if (bt->bt_type == BT_TYPE_CURSOR) { 1729 if (bt->bt_start != 0 || bt->bt_size != 0) { 1730 printf("corrupted cursor\n"); 1731 return false; 1732 } 1733 continue; 1734 } 1735 TAILQ_FOREACH(bt2, &vm->vm_seglist, bt_seglist) { 1736 if (bt == bt2) { 1737 continue; 1738 } 1739 if (bt2->bt_type == BT_TYPE_CURSOR) { 1740 continue; 1741 } 1742 if (BT_ISSPAN_P(bt) != BT_ISSPAN_P(bt2)) { 1743 continue; 1744 } 1745 if (bt->bt_start <= BT_END(bt2) && 1746 bt2->bt_start <= BT_END(bt)) { 1747 printf("overwrapped tags\n"); 1748 bt_dump(bt, vmem_printf); 1749 bt_dump(bt2, vmem_printf); 1750 return false; 1751 } 1752 } 1753 } 1754 1755 return true; 1756 } 1757 1758 static void 1759 vmem_check(vmem_t *vm) 1760 { 1761 1762 if (!vmem_check_sanity(vm)) { 1763 panic("insanity vmem %p", vm); 1764 } 1765 } 1766 1767 #endif /* defined(DIAGNOSTIC) */ 1768