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