1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2010 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25
26 /*
27 * Copyright (c) 2012, 2015 by Delphix. All rights reserved.
28 * Copyright (c) 2012, Joyent, Inc. All rights reserved.
29 */
30
31 /*
32 * Big Theory Statement for the virtual memory allocator.
33 *
34 * For a more complete description of the main ideas, see:
35 *
36 * Jeff Bonwick and Jonathan Adams,
37 *
38 * Magazines and vmem: Extending the Slab Allocator to Many CPUs and
39 * Arbitrary Resources.
40 *
41 * Proceedings of the 2001 Usenix Conference.
42 * Available as http://www.usenix.org/event/usenix01/bonwick.html
43 *
44 *
45 * 1. General Concepts
46 * -------------------
47 *
48 * 1.1 Overview
49 * ------------
50 * We divide the kernel address space into a number of logically distinct
51 * pieces, or *arenas*: text, data, heap, stack, and so on. Within these
52 * arenas we often subdivide further; for example, we use heap addresses
53 * not only for the kernel heap (kmem_alloc() space), but also for DVMA,
54 * bp_mapin(), /dev/kmem, and even some device mappings like the TOD chip.
55 * The kernel address space, therefore, is most accurately described as
56 * a tree of arenas in which each node of the tree *imports* some subset
57 * of its parent. The virtual memory allocator manages these arenas and
58 * supports their natural hierarchical structure.
59 *
60 * 1.2 Arenas
61 * ----------
62 * An arena is nothing more than a set of integers. These integers most
63 * commonly represent virtual addresses, but in fact they can represent
64 * anything at all. For example, we could use an arena containing the
65 * integers minpid through maxpid to allocate process IDs. vmem_create()
66 * and vmem_destroy() create and destroy vmem arenas. In order to
67 * differentiate between arenas used for adresses and arenas used for
68 * identifiers, the VMC_IDENTIFIER flag is passed to vmem_create(). This
69 * prevents identifier exhaustion from being diagnosed as general memory
70 * failure.
71 *
72 * 1.3 Spans
73 * ---------
74 * We represent the integers in an arena as a collection of *spans*, or
75 * contiguous ranges of integers. For example, the kernel heap consists
76 * of just one span: [kernelheap, ekernelheap). Spans can be added to an
77 * arena in two ways: explicitly, by vmem_add(), or implicitly, by
78 * importing, as described in Section 1.5 below.
79 *
80 * 1.4 Segments
81 * ------------
82 * Spans are subdivided into *segments*, each of which is either allocated
83 * or free. A segment, like a span, is a contiguous range of integers.
84 * Each allocated segment [addr, addr + size) represents exactly one
85 * vmem_alloc(size) that returned addr. Free segments represent the space
86 * between allocated segments. If two free segments are adjacent, we
87 * coalesce them into one larger segment; that is, if segments [a, b) and
88 * [b, c) are both free, we merge them into a single segment [a, c).
89 * The segments within a span are linked together in increasing-address order
90 * so we can easily determine whether coalescing is possible.
91 *
92 * Segments never cross span boundaries. When all segments within
93 * an imported span become free, we return the span to its source.
94 *
95 * 1.5 Imported Memory
96 * -------------------
97 * As mentioned in the overview, some arenas are logical subsets of
98 * other arenas. For example, kmem_va_arena (a virtual address cache
99 * that satisfies most kmem_slab_create() requests) is just a subset
100 * of heap_arena (the kernel heap) that provides caching for the most
101 * common slab sizes. When kmem_va_arena runs out of virtual memory,
102 * it *imports* more from the heap; we say that heap_arena is the
103 * *vmem source* for kmem_va_arena. vmem_create() allows you to
104 * specify any existing vmem arena as the source for your new arena.
105 * Topologically, since every arena is a child of at most one source,
106 * the set of all arenas forms a collection of trees.
107 *
108 * 1.6 Constrained Allocations
109 * ---------------------------
110 * Some vmem clients are quite picky about the kind of address they want.
111 * For example, the DVMA code may need an address that is at a particular
112 * phase with respect to some alignment (to get good cache coloring), or
113 * that lies within certain limits (the addressable range of a device),
114 * or that doesn't cross some boundary (a DMA counter restriction) --
115 * or all of the above. vmem_xalloc() allows the client to specify any
116 * or all of these constraints.
117 *
118 * 1.7 The Vmem Quantum
119 * --------------------
120 * Every arena has a notion of 'quantum', specified at vmem_create() time,
121 * that defines the arena's minimum unit of currency. Most commonly the
122 * quantum is either 1 or PAGESIZE, but any power of 2 is legal.
123 * All vmem allocations are guaranteed to be quantum-aligned.
124 *
125 * 1.8 Quantum Caching
126 * -------------------
127 * A vmem arena may be so hot (frequently used) that the scalability of vmem
128 * allocation is a significant concern. We address this by allowing the most
129 * common allocation sizes to be serviced by the kernel memory allocator,
130 * which provides low-latency per-cpu caching. The qcache_max argument to
131 * vmem_create() specifies the largest allocation size to cache.
132 *
133 * 1.9 Relationship to Kernel Memory Allocator
134 * -------------------------------------------
135 * Every kmem cache has a vmem arena as its slab supplier. The kernel memory
136 * allocator uses vmem_alloc() and vmem_free() to create and destroy slabs.
137 *
138 *
139 * 2. Implementation
140 * -----------------
141 *
142 * 2.1 Segment lists and markers
143 * -----------------------------
144 * The segment structure (vmem_seg_t) contains two doubly-linked lists.
145 *
146 * The arena list (vs_anext/vs_aprev) links all segments in the arena.
147 * In addition to the allocated and free segments, the arena contains
148 * special marker segments at span boundaries. Span markers simplify
149 * coalescing and importing logic by making it easy to tell both when
150 * we're at a span boundary (so we don't coalesce across it), and when
151 * a span is completely free (its neighbors will both be span markers).
152 *
153 * Imported spans will have vs_import set.
154 *
155 * The next-of-kin list (vs_knext/vs_kprev) links segments of the same type:
156 * (1) for allocated segments, vs_knext is the hash chain linkage;
157 * (2) for free segments, vs_knext is the freelist linkage;
158 * (3) for span marker segments, vs_knext is the next span marker.
159 *
160 * 2.2 Allocation hashing
161 * ----------------------
162 * We maintain a hash table of all allocated segments, hashed by address.
163 * This allows vmem_free() to discover the target segment in constant time.
164 * vmem_update() periodically resizes hash tables to keep hash chains short.
165 *
166 * 2.3 Freelist management
167 * -----------------------
168 * We maintain power-of-2 freelists for free segments, i.e. free segments
169 * of size >= 2^n reside in vmp->vm_freelist[n]. To ensure constant-time
170 * allocation, vmem_xalloc() looks not in the first freelist that *might*
171 * satisfy the allocation, but in the first freelist that *definitely*
172 * satisfies the allocation (unless VM_BESTFIT is specified, or all larger
173 * freelists are empty). For example, a 1000-byte allocation will be
174 * satisfied not from the 512..1023-byte freelist, whose members *might*
175 * contains a 1000-byte segment, but from a 1024-byte or larger freelist,
176 * the first member of which will *definitely* satisfy the allocation.
177 * This ensures that vmem_xalloc() works in constant time.
178 *
179 * We maintain a bit map to determine quickly which freelists are non-empty.
180 * vmp->vm_freemap & (1 << n) is non-zero iff vmp->vm_freelist[n] is non-empty.
181 *
182 * The different freelists are linked together into one large freelist,
183 * with the freelist heads serving as markers. Freelist markers simplify
184 * the maintenance of vm_freemap by making it easy to tell when we're taking
185 * the last member of a freelist (both of its neighbors will be markers).
186 *
187 * 2.4 Vmem Locking
188 * ----------------
189 * For simplicity, all arena state is protected by a per-arena lock.
190 * For very hot arenas, use quantum caching for scalability.
191 *
192 * 2.5 Vmem Population
193 * -------------------
194 * Any internal vmem routine that might need to allocate new segment
195 * structures must prepare in advance by calling vmem_populate(), which
196 * will preallocate enough vmem_seg_t's to get is through the entire
197 * operation without dropping the arena lock.
198 *
199 * 2.6 Auditing
200 * ------------
201 * If KMF_AUDIT is set in kmem_flags, we audit vmem allocations as well.
202 * Since virtual addresses cannot be scribbled on, there is no equivalent
203 * in vmem to redzone checking, deadbeef, or other kmem debugging features.
204 * Moreover, we do not audit frees because segment coalescing destroys the
205 * association between an address and its segment structure. Auditing is
206 * thus intended primarily to keep track of who's consuming the arena.
207 * Debugging support could certainly be extended in the future if it proves
208 * necessary, but we do so much live checking via the allocation hash table
209 * that even non-DEBUG systems get quite a bit of sanity checking already.
210 */
211
212 #include <sys/vmem_impl.h>
213 #include <sys/kmem.h>
214 #include <sys/kstat.h>
215 #include <sys/param.h>
216 #include <sys/systm.h>
217 #include <sys/atomic.h>
218 #include <sys/bitmap.h>
219 #include <sys/sysmacros.h>
220 #include <sys/cmn_err.h>
221 #include <sys/debug.h>
222 #include <sys/panic.h>
223
224 #define VMEM_INITIAL 10 /* early vmem arenas */
225 #define VMEM_SEG_INITIAL 200 /* early segments */
226
227 /*
228 * Adding a new span to an arena requires two segment structures: one to
229 * represent the span, and one to represent the free segment it contains.
230 */
231 #define VMEM_SEGS_PER_SPAN_CREATE 2
232
233 /*
234 * Allocating a piece of an existing segment requires 0-2 segment structures
235 * depending on how much of the segment we're allocating.
236 *
237 * To allocate the entire segment, no new segment structures are needed; we
238 * simply move the existing segment structure from the freelist to the
239 * allocation hash table.
240 *
241 * To allocate a piece from the left or right end of the segment, we must
242 * split the segment into two pieces (allocated part and remainder), so we
243 * need one new segment structure to represent the remainder.
244 *
245 * To allocate from the middle of a segment, we need two new segment strucures
246 * to represent the remainders on either side of the allocated part.
247 */
248 #define VMEM_SEGS_PER_EXACT_ALLOC 0
249 #define VMEM_SEGS_PER_LEFT_ALLOC 1
250 #define VMEM_SEGS_PER_RIGHT_ALLOC 1
251 #define VMEM_SEGS_PER_MIDDLE_ALLOC 2
252
253 /*
254 * vmem_populate() preallocates segment structures for vmem to do its work.
255 * It must preallocate enough for the worst case, which is when we must import
256 * a new span and then allocate from the middle of it.
257 */
258 #define VMEM_SEGS_PER_ALLOC_MAX \
259 (VMEM_SEGS_PER_SPAN_CREATE + VMEM_SEGS_PER_MIDDLE_ALLOC)
260
261 /*
262 * The segment structures themselves are allocated from vmem_seg_arena, so
263 * we have a recursion problem when vmem_seg_arena needs to populate itself.
264 * We address this by working out the maximum number of segment structures
265 * this act will require, and multiplying by the maximum number of threads
266 * that we'll allow to do it simultaneously.
267 *
268 * The worst-case segment consumption to populate vmem_seg_arena is as
269 * follows (depicted as a stack trace to indicate why events are occurring):
270 *
271 * (In order to lower the fragmentation in the heap_arena, we specify a
272 * minimum import size for the vmem_metadata_arena which is the same size
273 * as the kmem_va quantum cache allocations. This causes the worst-case
274 * allocation from the vmem_metadata_arena to be 3 segments.)
275 *
276 * vmem_alloc(vmem_seg_arena) -> 2 segs (span create + exact alloc)
277 * segkmem_alloc(vmem_metadata_arena)
278 * vmem_alloc(vmem_metadata_arena) -> 3 segs (span create + left alloc)
279 * vmem_alloc(heap_arena) -> 1 seg (left alloc)
280 * page_create()
281 * hat_memload()
282 * kmem_cache_alloc()
283 * kmem_slab_create()
284 * vmem_alloc(hat_memload_arena) -> 2 segs (span create + exact alloc)
285 * segkmem_alloc(heap_arena)
286 * vmem_alloc(heap_arena) -> 1 seg (left alloc)
287 * page_create()
288 * hat_memload() -> (hat layer won't recurse further)
289 *
290 * The worst-case consumption for each arena is 3 segment structures.
291 * Of course, a 3-seg reserve could easily be blown by multiple threads.
292 * Therefore, we serialize all allocations from vmem_seg_arena (which is OK
293 * because they're rare). We cannot allow a non-blocking allocation to get
294 * tied up behind a blocking allocation, however, so we use separate locks
295 * for VM_SLEEP and VM_NOSLEEP allocations. Similarly, VM_PUSHPAGE allocations
296 * must not block behind ordinary VM_SLEEPs. In addition, if the system is
297 * panicking then we must keep enough resources for panic_thread to do its
298 * work. Thus we have at most four threads trying to allocate from
299 * vmem_seg_arena, and each thread consumes at most three segment structures,
300 * so we must maintain a 12-seg reserve.
301 */
302 #define VMEM_POPULATE_RESERVE 12
303
304 /*
305 * vmem_populate() ensures that each arena has VMEM_MINFREE seg structures
306 * so that it can satisfy the worst-case allocation *and* participate in
307 * worst-case allocation from vmem_seg_arena.
308 */
309 #define VMEM_MINFREE (VMEM_POPULATE_RESERVE + VMEM_SEGS_PER_ALLOC_MAX)
310
311 static vmem_t vmem0[VMEM_INITIAL];
312 static vmem_t *vmem_populator[VMEM_INITIAL];
313 static uint32_t vmem_id;
314 static uint32_t vmem_populators;
315 static vmem_seg_t vmem_seg0[VMEM_SEG_INITIAL];
316 static vmem_seg_t *vmem_segfree;
317 static kmutex_t vmem_list_lock;
318 static kmutex_t vmem_segfree_lock;
319 static kmutex_t vmem_sleep_lock;
320 static kmutex_t vmem_nosleep_lock;
321 static kmutex_t vmem_pushpage_lock;
322 static kmutex_t vmem_panic_lock;
323 static vmem_t *vmem_list;
324 static vmem_t *vmem_metadata_arena;
325 static vmem_t *vmem_seg_arena;
326 static vmem_t *vmem_hash_arena;
327 static vmem_t *vmem_vmem_arena;
328 static long vmem_update_interval = 15; /* vmem_update() every 15 seconds */
329 uint32_t vmem_mtbf; /* mean time between failures [default: off] */
330 size_t vmem_seg_size = sizeof (vmem_seg_t);
331
332 static vmem_kstat_t vmem_kstat_template = {
333 { "mem_inuse", KSTAT_DATA_UINT64 },
334 { "mem_import", KSTAT_DATA_UINT64 },
335 { "mem_total", KSTAT_DATA_UINT64 },
336 { "vmem_source", KSTAT_DATA_UINT32 },
337 { "alloc", KSTAT_DATA_UINT64 },
338 { "free", KSTAT_DATA_UINT64 },
339 { "wait", KSTAT_DATA_UINT64 },
340 { "fail", KSTAT_DATA_UINT64 },
341 { "lookup", KSTAT_DATA_UINT64 },
342 { "search", KSTAT_DATA_UINT64 },
343 { "populate_wait", KSTAT_DATA_UINT64 },
344 { "populate_fail", KSTAT_DATA_UINT64 },
345 { "contains", KSTAT_DATA_UINT64 },
346 { "contains_search", KSTAT_DATA_UINT64 },
347 };
348
349 /*
350 * Insert/delete from arena list (type 'a') or next-of-kin list (type 'k').
351 */
352 #define VMEM_INSERT(vprev, vsp, type) \
353 { \
354 vmem_seg_t *vnext = (vprev)->vs_##type##next; \
355 (vsp)->vs_##type##next = (vnext); \
356 (vsp)->vs_##type##prev = (vprev); \
357 (vprev)->vs_##type##next = (vsp); \
358 (vnext)->vs_##type##prev = (vsp); \
359 }
360
361 #define VMEM_DELETE(vsp, type) \
362 { \
363 vmem_seg_t *vprev = (vsp)->vs_##type##prev; \
364 vmem_seg_t *vnext = (vsp)->vs_##type##next; \
365 (vprev)->vs_##type##next = (vnext); \
366 (vnext)->vs_##type##prev = (vprev); \
367 }
368
369 /*
370 * Get a vmem_seg_t from the global segfree list.
371 */
372 static vmem_seg_t *
373 vmem_getseg_global(void)
374 {
375 vmem_seg_t *vsp;
376
377 mutex_enter(&vmem_segfree_lock);
378 if ((vsp = vmem_segfree) != NULL)
379 vmem_segfree = vsp->vs_knext;
380 mutex_exit(&vmem_segfree_lock);
381
382 return (vsp);
383 }
384
385 /*
386 * Put a vmem_seg_t on the global segfree list.
387 */
388 static void
389 vmem_putseg_global(vmem_seg_t *vsp)
390 {
391 mutex_enter(&vmem_segfree_lock);
392 vsp->vs_knext = vmem_segfree;
393 vmem_segfree = vsp;
394 mutex_exit(&vmem_segfree_lock);
395 }
396
397 /*
398 * Get a vmem_seg_t from vmp's segfree list.
399 */
400 static vmem_seg_t *
401 vmem_getseg(vmem_t *vmp)
402 {
403 vmem_seg_t *vsp;
404
405 ASSERT(vmp->vm_nsegfree > 0);
406
407 vsp = vmp->vm_segfree;
408 vmp->vm_segfree = vsp->vs_knext;
409 vmp->vm_nsegfree--;
410
411 return (vsp);
412 }
413
414 /*
415 * Put a vmem_seg_t on vmp's segfree list.
416 */
417 static void
418 vmem_putseg(vmem_t *vmp, vmem_seg_t *vsp)
419 {
420 vsp->vs_knext = vmp->vm_segfree;
421 vmp->vm_segfree = vsp;
422 vmp->vm_nsegfree++;
423 }
424
425 /*
426 * Add vsp to the appropriate freelist.
427 */
428 static void
429 vmem_freelist_insert(vmem_t *vmp, vmem_seg_t *vsp)
430 {
431 vmem_seg_t *vprev;
432
433 ASSERT(*VMEM_HASH(vmp, vsp->vs_start) != vsp);
434
435 vprev = (vmem_seg_t *)&vmp->vm_freelist[highbit(VS_SIZE(vsp)) - 1];
436 vsp->vs_type = VMEM_FREE;
437 vmp->vm_freemap |= VS_SIZE(vprev);
438 VMEM_INSERT(vprev, vsp, k);
439
440 cv_broadcast(&vmp->vm_cv);
441 }
442
443 /*
444 * Take vsp from the freelist.
445 */
446 static void
447 vmem_freelist_delete(vmem_t *vmp, vmem_seg_t *vsp)
448 {
449 ASSERT(*VMEM_HASH(vmp, vsp->vs_start) != vsp);
450 ASSERT(vsp->vs_type == VMEM_FREE);
451
452 if (vsp->vs_knext->vs_start == 0 && vsp->vs_kprev->vs_start == 0) {
453 /*
454 * The segments on both sides of 'vsp' are freelist heads,
455 * so taking vsp leaves the freelist at vsp->vs_kprev empty.
456 */
457 ASSERT(vmp->vm_freemap & VS_SIZE(vsp->vs_kprev));
458 vmp->vm_freemap ^= VS_SIZE(vsp->vs_kprev);
459 }
460 VMEM_DELETE(vsp, k);
461 }
462
463 /*
464 * Add vsp to the allocated-segment hash table and update kstats.
465 */
466 static void
467 vmem_hash_insert(vmem_t *vmp, vmem_seg_t *vsp)
468 {
469 vmem_seg_t **bucket;
470
471 vsp->vs_type = VMEM_ALLOC;
472 bucket = VMEM_HASH(vmp, vsp->vs_start);
473 vsp->vs_knext = *bucket;
474 *bucket = vsp;
475
476 if (vmem_seg_size == sizeof (vmem_seg_t)) {
477 vsp->vs_depth = (uint8_t)getpcstack(vsp->vs_stack,
478 VMEM_STACK_DEPTH);
479 vsp->vs_thread = curthread;
480 vsp->vs_timestamp = gethrtime();
481 } else {
482 vsp->vs_depth = 0;
483 }
484
485 vmp->vm_kstat.vk_alloc.value.ui64++;
486 vmp->vm_kstat.vk_mem_inuse.value.ui64 += VS_SIZE(vsp);
487 }
488
489 /*
490 * Remove vsp from the allocated-segment hash table and update kstats.
491 */
492 static vmem_seg_t *
493 vmem_hash_delete(vmem_t *vmp, uintptr_t addr, size_t size)
494 {
495 vmem_seg_t *vsp, **prev_vspp;
496
497 prev_vspp = VMEM_HASH(vmp, addr);
498 while ((vsp = *prev_vspp) != NULL) {
499 if (vsp->vs_start == addr) {
500 *prev_vspp = vsp->vs_knext;
501 break;
502 }
503 vmp->vm_kstat.vk_lookup.value.ui64++;
504 prev_vspp = &vsp->vs_knext;
505 }
506
507 if (vsp == NULL)
508 panic("vmem_hash_delete(%p, %lx, %lu): bad free",
509 (void *)vmp, addr, size);
510 if (VS_SIZE(vsp) != size)
511 panic("vmem_hash_delete(%p, %lx, %lu): wrong size (expect %lu)",
512 (void *)vmp, addr, size, VS_SIZE(vsp));
513
514 vmp->vm_kstat.vk_free.value.ui64++;
515 vmp->vm_kstat.vk_mem_inuse.value.ui64 -= size;
516
517 return (vsp);
518 }
519
520 /*
521 * Create a segment spanning the range [start, end) and add it to the arena.
522 */
523 static vmem_seg_t *
524 vmem_seg_create(vmem_t *vmp, vmem_seg_t *vprev, uintptr_t start, uintptr_t end)
525 {
526 vmem_seg_t *newseg = vmem_getseg(vmp);
527
528 newseg->vs_start = start;
529 newseg->vs_end = end;
530 newseg->vs_type = 0;
531 newseg->vs_import = 0;
532
533 VMEM_INSERT(vprev, newseg, a);
534
535 return (newseg);
536 }
537
538 /*
539 * Remove segment vsp from the arena.
540 */
541 static void
542 vmem_seg_destroy(vmem_t *vmp, vmem_seg_t *vsp)
543 {
544 ASSERT(vsp->vs_type != VMEM_ROTOR);
545 VMEM_DELETE(vsp, a);
546
547 vmem_putseg(vmp, vsp);
548 }
549
550 /*
551 * Add the span [vaddr, vaddr + size) to vmp and update kstats.
552 */
553 static vmem_seg_t *
554 vmem_span_create(vmem_t *vmp, void *vaddr, size_t size, uint8_t import)
555 {
556 vmem_seg_t *newseg, *span;
557 uintptr_t start = (uintptr_t)vaddr;
558 uintptr_t end = start + size;
559
560 ASSERT(MUTEX_HELD(&vmp->vm_lock));
561
562 if ((start | end) & (vmp->vm_quantum - 1))
563 panic("vmem_span_create(%p, %p, %lu): misaligned",
564 (void *)vmp, vaddr, size);
565
566 span = vmem_seg_create(vmp, vmp->vm_seg0.vs_aprev, start, end);
567 span->vs_type = VMEM_SPAN;
568 span->vs_import = import;
569 VMEM_INSERT(vmp->vm_seg0.vs_kprev, span, k);
570
571 newseg = vmem_seg_create(vmp, span, start, end);
572 vmem_freelist_insert(vmp, newseg);
573
574 if (import)
575 vmp->vm_kstat.vk_mem_import.value.ui64 += size;
576 vmp->vm_kstat.vk_mem_total.value.ui64 += size;
577
578 return (newseg);
579 }
580
581 /*
582 * Remove span vsp from vmp and update kstats.
583 */
584 static void
585 vmem_span_destroy(vmem_t *vmp, vmem_seg_t *vsp)
586 {
587 vmem_seg_t *span = vsp->vs_aprev;
588 size_t size = VS_SIZE(vsp);
589
590 ASSERT(MUTEX_HELD(&vmp->vm_lock));
591 ASSERT(span->vs_type == VMEM_SPAN);
592
593 if (span->vs_import)
594 vmp->vm_kstat.vk_mem_import.value.ui64 -= size;
595 vmp->vm_kstat.vk_mem_total.value.ui64 -= size;
596
597 VMEM_DELETE(span, k);
598
599 vmem_seg_destroy(vmp, vsp);
600 vmem_seg_destroy(vmp, span);
601 }
602
603 /*
604 * Allocate the subrange [addr, addr + size) from segment vsp.
605 * If there are leftovers on either side, place them on the freelist.
606 * Returns a pointer to the segment representing [addr, addr + size).
607 */
608 static vmem_seg_t *
609 vmem_seg_alloc(vmem_t *vmp, vmem_seg_t *vsp, uintptr_t addr, size_t size)
610 {
611 uintptr_t vs_start = vsp->vs_start;
612 uintptr_t vs_end = vsp->vs_end;
613 size_t vs_size = vs_end - vs_start;
614 size_t realsize = P2ROUNDUP(size, vmp->vm_quantum);
615 uintptr_t addr_end = addr + realsize;
616
617 ASSERT(P2PHASE(vs_start, vmp->vm_quantum) == 0);
618 ASSERT(P2PHASE(addr, vmp->vm_quantum) == 0);
619 ASSERT(vsp->vs_type == VMEM_FREE);
620 ASSERT(addr >= vs_start && addr_end - 1 <= vs_end - 1);
621 ASSERT(addr - 1 <= addr_end - 1);
622
623 /*
624 * If we're allocating from the start of the segment, and the
625 * remainder will be on the same freelist, we can save quite
626 * a bit of work.
627 */
628 if (P2SAMEHIGHBIT(vs_size, vs_size - realsize) && addr == vs_start) {
629 ASSERT(highbit(vs_size) == highbit(vs_size - realsize));
630 vsp->vs_start = addr_end;
631 vsp = vmem_seg_create(vmp, vsp->vs_aprev, addr, addr + size);
632 vmem_hash_insert(vmp, vsp);
633 return (vsp);
634 }
635
636 vmem_freelist_delete(vmp, vsp);
637
638 if (vs_end != addr_end)
639 vmem_freelist_insert(vmp,
640 vmem_seg_create(vmp, vsp, addr_end, vs_end));
641
642 if (vs_start != addr)
643 vmem_freelist_insert(vmp,
644 vmem_seg_create(vmp, vsp->vs_aprev, vs_start, addr));
645
646 vsp->vs_start = addr;
647 vsp->vs_end = addr + size;
648
649 vmem_hash_insert(vmp, vsp);
650 return (vsp);
651 }
652
653 /*
654 * Returns 1 if we are populating, 0 otherwise.
655 * Call it if we want to prevent recursion from HAT.
656 */
657 int
658 vmem_is_populator()
659 {
660 return (mutex_owner(&vmem_sleep_lock) == curthread ||
661 mutex_owner(&vmem_nosleep_lock) == curthread ||
662 mutex_owner(&vmem_pushpage_lock) == curthread ||
663 mutex_owner(&vmem_panic_lock) == curthread);
664 }
665
666 /*
667 * Populate vmp's segfree list with VMEM_MINFREE vmem_seg_t structures.
668 */
669 static int
670 vmem_populate(vmem_t *vmp, int vmflag)
671 {
672 char *p;
673 vmem_seg_t *vsp;
674 ssize_t nseg;
675 size_t size;
676 kmutex_t *lp;
677 int i;
678
679 while (vmp->vm_nsegfree < VMEM_MINFREE &&
680 (vsp = vmem_getseg_global()) != NULL)
681 vmem_putseg(vmp, vsp);
682
683 if (vmp->vm_nsegfree >= VMEM_MINFREE)
684 return (1);
685
686 /*
687 * If we're already populating, tap the reserve.
688 */
689 if (vmem_is_populator()) {
690 ASSERT(vmp->vm_cflags & VMC_POPULATOR);
691 return (1);
692 }
693
694 mutex_exit(&vmp->vm_lock);
695
696 if (panic_thread == curthread)
697 lp = &vmem_panic_lock;
698 else if (vmflag & VM_NOSLEEP)
699 lp = &vmem_nosleep_lock;
700 else if (vmflag & VM_PUSHPAGE)
701 lp = &vmem_pushpage_lock;
702 else
703 lp = &vmem_sleep_lock;
704
705 mutex_enter(lp);
706
707 nseg = VMEM_MINFREE + vmem_populators * VMEM_POPULATE_RESERVE;
708 size = P2ROUNDUP(nseg * vmem_seg_size, vmem_seg_arena->vm_quantum);
709 nseg = size / vmem_seg_size;
710
711 /*
712 * The following vmem_alloc() may need to populate vmem_seg_arena
713 * and all the things it imports from. When doing so, it will tap
714 * each arena's reserve to prevent recursion (see the block comment
715 * above the definition of VMEM_POPULATE_RESERVE).
716 */
717 p = vmem_alloc(vmem_seg_arena, size, vmflag & VM_KMFLAGS);
718 if (p == NULL) {
719 mutex_exit(lp);
720 mutex_enter(&vmp->vm_lock);
721 vmp->vm_kstat.vk_populate_fail.value.ui64++;
722 return (0);
723 }
724
725 /*
726 * Restock the arenas that may have been depleted during population.
727 */
728 for (i = 0; i < vmem_populators; i++) {
729 mutex_enter(&vmem_populator[i]->vm_lock);
730 while (vmem_populator[i]->vm_nsegfree < VMEM_POPULATE_RESERVE)
731 vmem_putseg(vmem_populator[i],
732 (vmem_seg_t *)(p + --nseg * vmem_seg_size));
733 mutex_exit(&vmem_populator[i]->vm_lock);
734 }
735
736 mutex_exit(lp);
737 mutex_enter(&vmp->vm_lock);
738
739 /*
740 * Now take our own segments.
741 */
742 ASSERT(nseg >= VMEM_MINFREE);
743 while (vmp->vm_nsegfree < VMEM_MINFREE)
744 vmem_putseg(vmp, (vmem_seg_t *)(p + --nseg * vmem_seg_size));
745
746 /*
747 * Give the remainder to charity.
748 */
749 while (nseg > 0)
750 vmem_putseg_global((vmem_seg_t *)(p + --nseg * vmem_seg_size));
751
752 return (1);
753 }
754
755 /*
756 * Advance a walker from its previous position to 'afterme'.
757 * Note: may drop and reacquire vmp->vm_lock.
758 */
759 static void
760 vmem_advance(vmem_t *vmp, vmem_seg_t *walker, vmem_seg_t *afterme)
761 {
762 vmem_seg_t *vprev = walker->vs_aprev;
763 vmem_seg_t *vnext = walker->vs_anext;
764 vmem_seg_t *vsp = NULL;
765
766 VMEM_DELETE(walker, a);
767
768 if (afterme != NULL)
769 VMEM_INSERT(afterme, walker, a);
770
771 /*
772 * The walker segment's presence may have prevented its neighbors
773 * from coalescing. If so, coalesce them now.
774 */
775 if (vprev->vs_type == VMEM_FREE) {
776 if (vnext->vs_type == VMEM_FREE) {
777 ASSERT(vprev->vs_end == vnext->vs_start);
778 vmem_freelist_delete(vmp, vnext);
779 vmem_freelist_delete(vmp, vprev);
780 vprev->vs_end = vnext->vs_end;
781 vmem_freelist_insert(vmp, vprev);
782 vmem_seg_destroy(vmp, vnext);
783 }
784 vsp = vprev;
785 } else if (vnext->vs_type == VMEM_FREE) {
786 vsp = vnext;
787 }
788
789 /*
790 * vsp could represent a complete imported span,
791 * in which case we must return it to the source.
792 */
793 if (vsp != NULL && vsp->vs_aprev->vs_import &&
794 vmp->vm_source_free != NULL &&
795 vsp->vs_aprev->vs_type == VMEM_SPAN &&
796 vsp->vs_anext->vs_type == VMEM_SPAN) {
797 void *vaddr = (void *)vsp->vs_start;
798 size_t size = VS_SIZE(vsp);
799 ASSERT(size == VS_SIZE(vsp->vs_aprev));
800 vmem_freelist_delete(vmp, vsp);
801 vmem_span_destroy(vmp, vsp);
802 mutex_exit(&vmp->vm_lock);
803 vmp->vm_source_free(vmp->vm_source, vaddr, size);
804 mutex_enter(&vmp->vm_lock);
805 }
806 }
807
808 /*
809 * VM_NEXTFIT allocations deliberately cycle through all virtual addresses
810 * in an arena, so that we avoid reusing addresses for as long as possible.
811 * This helps to catch used-after-freed bugs. It's also the perfect policy
812 * for allocating things like process IDs, where we want to cycle through
813 * all values in order.
814 */
815 static void *
816 vmem_nextfit_alloc(vmem_t *vmp, size_t size, int vmflag)
817 {
818 vmem_seg_t *vsp, *rotor;
819 uintptr_t addr;
820 size_t realsize = P2ROUNDUP(size, vmp->vm_quantum);
821 size_t vs_size;
822
823 mutex_enter(&vmp->vm_lock);
824
825 if (vmp->vm_nsegfree < VMEM_MINFREE && !vmem_populate(vmp, vmflag)) {
826 mutex_exit(&vmp->vm_lock);
827 return (NULL);
828 }
829
830 /*
831 * The common case is that the segment right after the rotor is free,
832 * and large enough that extracting 'size' bytes won't change which
833 * freelist it's on. In this case we can avoid a *lot* of work.
834 * Instead of the normal vmem_seg_alloc(), we just advance the start
835 * address of the victim segment. Instead of moving the rotor, we
836 * create the new segment structure *behind the rotor*, which has
837 * the same effect. And finally, we know we don't have to coalesce
838 * the rotor's neighbors because the new segment lies between them.
839 */
840 rotor = &vmp->vm_rotor;
841 vsp = rotor->vs_anext;
842 if (vsp->vs_type == VMEM_FREE && (vs_size = VS_SIZE(vsp)) > realsize &&
843 P2SAMEHIGHBIT(vs_size, vs_size - realsize)) {
844 ASSERT(highbit(vs_size) == highbit(vs_size - realsize));
845 addr = vsp->vs_start;
846 vsp->vs_start = addr + realsize;
847 vmem_hash_insert(vmp,
848 vmem_seg_create(vmp, rotor->vs_aprev, addr, addr + size));
849 mutex_exit(&vmp->vm_lock);
850 return ((void *)addr);
851 }
852
853 /*
854 * Starting at the rotor, look for a segment large enough to
855 * satisfy the allocation.
856 */
857 for (;;) {
858 vmp->vm_kstat.vk_search.value.ui64++;
859 if (vsp->vs_type == VMEM_FREE && VS_SIZE(vsp) >= size)
860 break;
861 vsp = vsp->vs_anext;
862 if (vsp == rotor) {
863 /*
864 * We've come full circle. One possibility is that the
865 * there's actually enough space, but the rotor itself
866 * is preventing the allocation from succeeding because
867 * it's sitting between two free segments. Therefore,
868 * we advance the rotor and see if that liberates a
869 * suitable segment.
870 */
871 vmem_advance(vmp, rotor, rotor->vs_anext);
872 vsp = rotor->vs_aprev;
873 if (vsp->vs_type == VMEM_FREE && VS_SIZE(vsp) >= size)
874 break;
875 /*
876 * If there's a lower arena we can import from, or it's
877 * a VM_NOSLEEP allocation, let vmem_xalloc() handle it.
878 * Otherwise, wait until another thread frees something.
879 */
880 if (vmp->vm_source_alloc != NULL ||
881 (vmflag & VM_NOSLEEP)) {
882 mutex_exit(&vmp->vm_lock);
883 return (vmem_xalloc(vmp, size, vmp->vm_quantum,
884 0, 0, NULL, NULL, vmflag & VM_KMFLAGS));
885 }
886 vmp->vm_kstat.vk_wait.value.ui64++;
887 cv_wait(&vmp->vm_cv, &vmp->vm_lock);
888 vsp = rotor->vs_anext;
889 }
890 }
891
892 /*
893 * We found a segment. Extract enough space to satisfy the allocation.
894 */
895 addr = vsp->vs_start;
896 vsp = vmem_seg_alloc(vmp, vsp, addr, size);
897 ASSERT(vsp->vs_type == VMEM_ALLOC &&
898 vsp->vs_start == addr && vsp->vs_end == addr + size);
899
900 /*
901 * Advance the rotor to right after the newly-allocated segment.
902 * That's where the next VM_NEXTFIT allocation will begin searching.
903 */
904 vmem_advance(vmp, rotor, vsp);
905 mutex_exit(&vmp->vm_lock);
906 return ((void *)addr);
907 }
908
909 /*
910 * Checks if vmp is guaranteed to have a size-byte buffer somewhere on its
911 * freelist. If size is not a power-of-2, it can return a false-negative.
912 *
913 * Used to decide if a newly imported span is superfluous after re-acquiring
914 * the arena lock.
915 */
916 static int
917 vmem_canalloc(vmem_t *vmp, size_t size)
918 {
919 int hb;
920 int flist = 0;
921 ASSERT(MUTEX_HELD(&vmp->vm_lock));
922
923 if (ISP2(size))
924 flist = lowbit(P2ALIGN(vmp->vm_freemap, size));
925 else if ((hb = highbit(size)) < VMEM_FREELISTS)
926 flist = lowbit(P2ALIGN(vmp->vm_freemap, 1UL << hb));
927
928 return (flist);
929 }
930
931 /*
932 * Allocate size bytes at offset phase from an align boundary such that the
933 * resulting segment [addr, addr + size) is a subset of [minaddr, maxaddr)
934 * that does not straddle a nocross-aligned boundary.
935 */
936 void *
937 vmem_xalloc(vmem_t *vmp, size_t size, size_t align_arg, size_t phase,
938 size_t nocross, void *minaddr, void *maxaddr, int vmflag)
939 {
940 vmem_seg_t *vsp;
941 vmem_seg_t *vbest = NULL;
942 uintptr_t addr, taddr, start, end;
943 uintptr_t align = (align_arg != 0) ? align_arg : vmp->vm_quantum;
944 void *vaddr, *xvaddr = NULL;
945 size_t xsize;
946 int hb, flist, resv;
947 uint32_t mtbf;
948
949 if ((align | phase | nocross) & (vmp->vm_quantum - 1))
950 panic("vmem_xalloc(%p, %lu, %lu, %lu, %lu, %p, %p, %x): "
951 "parameters not vm_quantum aligned",
952 (void *)vmp, size, align_arg, phase, nocross,
953 minaddr, maxaddr, vmflag);
954
955 if (nocross != 0 &&
956 (align > nocross || P2ROUNDUP(phase + size, align) > nocross))
957 panic("vmem_xalloc(%p, %lu, %lu, %lu, %lu, %p, %p, %x): "
958 "overconstrained allocation",
959 (void *)vmp, size, align_arg, phase, nocross,
960 minaddr, maxaddr, vmflag);
961
962 if (phase >= align || !ISP2(align) || !ISP2(nocross))
963 panic("vmem_xalloc(%p, %lu, %lu, %lu, %lu, %p, %p, %x): "
964 "parameters inconsistent or invalid",
965 (void *)vmp, size, align_arg, phase, nocross,
966 minaddr, maxaddr, vmflag);
967
968 if ((mtbf = vmem_mtbf | vmp->vm_mtbf) != 0 && gethrtime() % mtbf == 0 &&
969 (vmflag & (VM_NOSLEEP | VM_PANIC)) == VM_NOSLEEP)
970 return (NULL);
971
972 mutex_enter(&vmp->vm_lock);
973 for (;;) {
974 if (vmp->vm_nsegfree < VMEM_MINFREE &&
975 !vmem_populate(vmp, vmflag))
976 break;
977 do_alloc:
978 /*
979 * highbit() returns the highest bit + 1, which is exactly
980 * what we want: we want to search the first freelist whose
981 * members are *definitely* large enough to satisfy our
982 * allocation. However, there are certain cases in which we
983 * want to look at the next-smallest freelist (which *might*
984 * be able to satisfy the allocation):
985 *
986 * (1) The size is exactly a power of 2, in which case
987 * the smaller freelist is always big enough;
988 *
989 * (2) All other freelists are empty;
990 *
991 * (3) We're in the highest possible freelist, which is
992 * always empty (e.g. the 4GB freelist on 32-bit systems);
993 *
994 * (4) We're doing a best-fit or first-fit allocation.
995 */
996 if (ISP2(size)) {
997 flist = lowbit(P2ALIGN(vmp->vm_freemap, size));
998 } else {
999 hb = highbit(size);
1000 if ((vmp->vm_freemap >> hb) == 0 ||
1001 hb == VMEM_FREELISTS ||
1002 (vmflag & (VM_BESTFIT | VM_FIRSTFIT)))
1003 hb--;
1004 flist = lowbit(P2ALIGN(vmp->vm_freemap, 1UL << hb));
1005 }
1006
1007 for (vbest = NULL, vsp = (flist == 0) ? NULL :
1008 vmp->vm_freelist[flist - 1].vs_knext;
1009 vsp != NULL; vsp = vsp->vs_knext) {
1010 vmp->vm_kstat.vk_search.value.ui64++;
1011 if (vsp->vs_start == 0) {
1012 /*
1013 * We're moving up to a larger freelist,
1014 * so if we've already found a candidate,
1015 * the fit can't possibly get any better.
1016 */
1017 if (vbest != NULL)
1018 break;
1019 /*
1020 * Find the next non-empty freelist.
1021 */
1022 flist = lowbit(P2ALIGN(vmp->vm_freemap,
1023 VS_SIZE(vsp)));
1024 if (flist-- == 0)
1025 break;
1026 vsp = (vmem_seg_t *)&vmp->vm_freelist[flist];
1027 ASSERT(vsp->vs_knext->vs_type == VMEM_FREE);
1028 continue;
1029 }
1030 if (vsp->vs_end - 1 < (uintptr_t)minaddr)
1031 continue;
1032 if (vsp->vs_start > (uintptr_t)maxaddr - 1)
1033 continue;
1034 start = MAX(vsp->vs_start, (uintptr_t)minaddr);
1035 end = MIN(vsp->vs_end - 1, (uintptr_t)maxaddr - 1) + 1;
1036 taddr = P2PHASEUP(start, align, phase);
1037 if (P2BOUNDARY(taddr, size, nocross))
1038 taddr +=
1039 P2ROUNDUP(P2NPHASE(taddr, nocross), align);
1040 if ((taddr - start) + size > end - start ||
1041 (vbest != NULL && VS_SIZE(vsp) >= VS_SIZE(vbest)))
1042 continue;
1043 vbest = vsp;
1044 addr = taddr;
1045 if (!(vmflag & VM_BESTFIT) || VS_SIZE(vbest) == size)
1046 break;
1047 }
1048 if (vbest != NULL)
1049 break;
1050 ASSERT(xvaddr == NULL);
1051 if (size == 0)
1052 panic("vmem_xalloc(): size == 0");
1053 if (vmp->vm_source_alloc != NULL && nocross == 0 &&
1054 minaddr == NULL && maxaddr == NULL) {
1055 size_t aneeded, asize;
1056 size_t aquantum = MAX(vmp->vm_quantum,
1057 vmp->vm_source->vm_quantum);
1058 size_t aphase = phase;
1059 if ((align > aquantum) &&
1060 !(vmp->vm_cflags & VMC_XALIGN)) {
1061 aphase = (P2PHASE(phase, aquantum) != 0) ?
1062 align - vmp->vm_quantum : align - aquantum;
1063 ASSERT(aphase >= phase);
1064 }
1065 aneeded = MAX(size + aphase, vmp->vm_min_import);
1066 asize = P2ROUNDUP(aneeded, aquantum);
1067
1068 if (asize < size) {
1069 /*
1070 * The rounding induced overflow; return NULL
1071 * if we are permitted to fail the allocation
1072 * (and explicitly panic if we aren't).
1073 */
1074 if ((vmflag & VM_NOSLEEP) &&
1075 !(vmflag & VM_PANIC)) {
1076 mutex_exit(&vmp->vm_lock);
1077 return (NULL);
1078 }
1079
1080 panic("vmem_xalloc(): size overflow");
1081 }
1082
1083 /*
1084 * Determine how many segment structures we'll consume.
1085 * The calculation must be precise because if we're
1086 * here on behalf of vmem_populate(), we are taking
1087 * segments from a very limited reserve.
1088 */
1089 if (size == asize && !(vmp->vm_cflags & VMC_XALLOC))
1090 resv = VMEM_SEGS_PER_SPAN_CREATE +
1091 VMEM_SEGS_PER_EXACT_ALLOC;
1092 else if (phase == 0 &&
1093 align <= vmp->vm_source->vm_quantum)
1094 resv = VMEM_SEGS_PER_SPAN_CREATE +
1095 VMEM_SEGS_PER_LEFT_ALLOC;
1096 else
1097 resv = VMEM_SEGS_PER_ALLOC_MAX;
1098
1099 ASSERT(vmp->vm_nsegfree >= resv);
1100 vmp->vm_nsegfree -= resv; /* reserve our segs */
1101 mutex_exit(&vmp->vm_lock);
1102 if (vmp->vm_cflags & VMC_XALLOC) {
1103 size_t oasize = asize;
1104 vaddr = ((vmem_ximport_t *)
1105 vmp->vm_source_alloc)(vmp->vm_source,
1106 &asize, align, vmflag & VM_KMFLAGS);
1107 ASSERT(asize >= oasize);
1108 ASSERT(P2PHASE(asize,
1109 vmp->vm_source->vm_quantum) == 0);
1110 ASSERT(!(vmp->vm_cflags & VMC_XALIGN) ||
1111 IS_P2ALIGNED(vaddr, align));
1112 } else {
1113 vaddr = vmp->vm_source_alloc(vmp->vm_source,
1114 asize, vmflag & VM_KMFLAGS);
1115 }
1116 mutex_enter(&vmp->vm_lock);
1117 vmp->vm_nsegfree += resv; /* claim reservation */
1118 aneeded = size + align - vmp->vm_quantum;
1119 aneeded = P2ROUNDUP(aneeded, vmp->vm_quantum);
1120 if (vaddr != NULL) {
1121 /*
1122 * Since we dropped the vmem lock while
1123 * calling the import function, other
1124 * threads could have imported space
1125 * and made our import unnecessary. In
1126 * order to save space, we return
1127 * excess imports immediately.
1128 */
1129 if (asize > aneeded &&
1130 vmp->vm_source_free != NULL &&
1131 vmem_canalloc(vmp, aneeded)) {
1132 ASSERT(resv >=
1133 VMEM_SEGS_PER_MIDDLE_ALLOC);
1134 xvaddr = vaddr;
1135 xsize = asize;
1136 goto do_alloc;
1137 }
1138 vbest = vmem_span_create(vmp, vaddr, asize, 1);
1139 addr = P2PHASEUP(vbest->vs_start, align, phase);
1140 break;
1141 } else if (vmem_canalloc(vmp, aneeded)) {
1142 /*
1143 * Our import failed, but another thread
1144 * added sufficient free memory to the arena
1145 * to satisfy our request. Go back and
1146 * grab it.
1147 */
1148 ASSERT(resv >= VMEM_SEGS_PER_MIDDLE_ALLOC);
1149 goto do_alloc;
1150 }
1151 }
1152
1153 /*
1154 * If the requestor chooses to fail the allocation attempt
1155 * rather than reap wait and retry - get out of the loop.
1156 */
1157 if (vmflag & VM_ABORT)
1158 break;
1159 mutex_exit(&vmp->vm_lock);
1160 if (vmp->vm_cflags & VMC_IDENTIFIER)
1161 kmem_reap_idspace();
1162 else
1163 kmem_reap();
1164 mutex_enter(&vmp->vm_lock);
1165 if (vmflag & VM_NOSLEEP)
1166 break;
1167 vmp->vm_kstat.vk_wait.value.ui64++;
1168 cv_wait(&vmp->vm_cv, &vmp->vm_lock);
1169 }
1170 if (vbest != NULL) {
1171 ASSERT(vbest->vs_type == VMEM_FREE);
1172 ASSERT(vbest->vs_knext != vbest);
1173 /* re-position to end of buffer */
1174 if (vmflag & VM_ENDALLOC) {
1175 addr += ((vbest->vs_end - (addr + size)) / align) *
1176 align;
1177 }
1178 (void) vmem_seg_alloc(vmp, vbest, addr, size);
1179 mutex_exit(&vmp->vm_lock);
1180 if (xvaddr)
1181 vmp->vm_source_free(vmp->vm_source, xvaddr, xsize);
1182 ASSERT(P2PHASE(addr, align) == phase);
1183 ASSERT(!P2BOUNDARY(addr, size, nocross));
1184 ASSERT(addr >= (uintptr_t)minaddr);
1185 ASSERT(addr + size - 1 <= (uintptr_t)maxaddr - 1);
1186 return ((void *)addr);
1187 }
1188 vmp->vm_kstat.vk_fail.value.ui64++;
1189 mutex_exit(&vmp->vm_lock);
1190 if (vmflag & VM_PANIC)
1191 panic("vmem_xalloc(%p, %lu, %lu, %lu, %lu, %p, %p, %x): "
1192 "cannot satisfy mandatory allocation",
1193 (void *)vmp, size, align_arg, phase, nocross,
1194 minaddr, maxaddr, vmflag);
1195 ASSERT(xvaddr == NULL);
1196 return (NULL);
1197 }
1198
1199 /*
1200 * Free the segment [vaddr, vaddr + size), where vaddr was a constrained
1201 * allocation. vmem_xalloc() and vmem_xfree() must always be paired because
1202 * both routines bypass the quantum caches.
1203 */
1204 void
1205 vmem_xfree(vmem_t *vmp, void *vaddr, size_t size)
1206 {
1207 vmem_seg_t *vsp, *vnext, *vprev;
1208
1209 mutex_enter(&vmp->vm_lock);
1210
1211 vsp = vmem_hash_delete(vmp, (uintptr_t)vaddr, size);
1212 vsp->vs_end = P2ROUNDUP(vsp->vs_end, vmp->vm_quantum);
1213
1214 /*
1215 * Attempt to coalesce with the next segment.
1216 */
1217 vnext = vsp->vs_anext;
1218 if (vnext->vs_type == VMEM_FREE) {
1219 ASSERT(vsp->vs_end == vnext->vs_start);
1220 vmem_freelist_delete(vmp, vnext);
1221 vsp->vs_end = vnext->vs_end;
1222 vmem_seg_destroy(vmp, vnext);
1223 }
1224
1225 /*
1226 * Attempt to coalesce with the previous segment.
1227 */
1228 vprev = vsp->vs_aprev;
1229 if (vprev->vs_type == VMEM_FREE) {
1230 ASSERT(vprev->vs_end == vsp->vs_start);
1231 vmem_freelist_delete(vmp, vprev);
1232 vprev->vs_end = vsp->vs_end;
1233 vmem_seg_destroy(vmp, vsp);
1234 vsp = vprev;
1235 }
1236
1237 /*
1238 * If the entire span is free, return it to the source.
1239 */
1240 if (vsp->vs_aprev->vs_import && vmp->vm_source_free != NULL &&
1241 vsp->vs_aprev->vs_type == VMEM_SPAN &&
1242 vsp->vs_anext->vs_type == VMEM_SPAN) {
1243 vaddr = (void *)vsp->vs_start;
1244 size = VS_SIZE(vsp);
1245 ASSERT(size == VS_SIZE(vsp->vs_aprev));
1246 vmem_span_destroy(vmp, vsp);
1247 mutex_exit(&vmp->vm_lock);
1248 vmp->vm_source_free(vmp->vm_source, vaddr, size);
1249 } else {
1250 vmem_freelist_insert(vmp, vsp);
1251 mutex_exit(&vmp->vm_lock);
1252 }
1253 }
1254
1255 /*
1256 * Allocate size bytes from arena vmp. Returns the allocated address
1257 * on success, NULL on failure. vmflag specifies VM_SLEEP or VM_NOSLEEP,
1258 * and may also specify best-fit, first-fit, or next-fit allocation policy
1259 * instead of the default instant-fit policy. VM_SLEEP allocations are
1260 * guaranteed to succeed.
1261 */
1262 void *
1263 vmem_alloc(vmem_t *vmp, size_t size, int vmflag)
1264 {
1265 vmem_seg_t *vsp;
1266 uintptr_t addr;
1267 int hb;
1268 int flist = 0;
1269 uint32_t mtbf;
1270
1271 if (size - 1 < vmp->vm_qcache_max)
1272 return (kmem_cache_alloc(vmp->vm_qcache[(size - 1) >>
1273 vmp->vm_qshift], vmflag & VM_KMFLAGS));
1274
1275 if ((mtbf = vmem_mtbf | vmp->vm_mtbf) != 0 && gethrtime() % mtbf == 0 &&
1276 (vmflag & (VM_NOSLEEP | VM_PANIC)) == VM_NOSLEEP)
1277 return (NULL);
1278
1279 if (vmflag & VM_NEXTFIT)
1280 return (vmem_nextfit_alloc(vmp, size, vmflag));
1281
1282 if (vmflag & (VM_BESTFIT | VM_FIRSTFIT))
1283 return (vmem_xalloc(vmp, size, vmp->vm_quantum, 0, 0,
1284 NULL, NULL, vmflag));
1285
1286 /*
1287 * Unconstrained instant-fit allocation from the segment list.
1288 */
1289 mutex_enter(&vmp->vm_lock);
1290
1291 if (vmp->vm_nsegfree >= VMEM_MINFREE || vmem_populate(vmp, vmflag)) {
1292 if (ISP2(size))
1293 flist = lowbit(P2ALIGN(vmp->vm_freemap, size));
1294 else if ((hb = highbit(size)) < VMEM_FREELISTS)
1295 flist = lowbit(P2ALIGN(vmp->vm_freemap, 1UL << hb));
1296 }
1297
1298 if (flist-- == 0) {
1299 mutex_exit(&vmp->vm_lock);
1300 return (vmem_xalloc(vmp, size, vmp->vm_quantum,
1301 0, 0, NULL, NULL, vmflag));
1302 }
1303
1304 ASSERT(size <= (1UL << flist));
1305 vsp = vmp->vm_freelist[flist].vs_knext;
1306 addr = vsp->vs_start;
1307 if (vmflag & VM_ENDALLOC) {
1308 addr += vsp->vs_end - (addr + size);
1309 }
1310 (void) vmem_seg_alloc(vmp, vsp, addr, size);
1311 mutex_exit(&vmp->vm_lock);
1312 return ((void *)addr);
1313 }
1314
1315 /*
1316 * Free the segment [vaddr, vaddr + size).
1317 */
1318 void
1319 vmem_free(vmem_t *vmp, void *vaddr, size_t size)
1320 {
1321 if (size - 1 < vmp->vm_qcache_max)
1322 kmem_cache_free(vmp->vm_qcache[(size - 1) >> vmp->vm_qshift],
1323 vaddr);
1324 else
1325 vmem_xfree(vmp, vaddr, size);
1326 }
1327
1328 /*
1329 * Determine whether arena vmp contains the segment [vaddr, vaddr + size).
1330 */
1331 int
1332 vmem_contains(vmem_t *vmp, void *vaddr, size_t size)
1333 {
1334 uintptr_t start = (uintptr_t)vaddr;
1335 uintptr_t end = start + size;
1336 vmem_seg_t *vsp;
1337 vmem_seg_t *seg0 = &vmp->vm_seg0;
1338
1339 mutex_enter(&vmp->vm_lock);
1340 vmp->vm_kstat.vk_contains.value.ui64++;
1341 for (vsp = seg0->vs_knext; vsp != seg0; vsp = vsp->vs_knext) {
1342 vmp->vm_kstat.vk_contains_search.value.ui64++;
1343 ASSERT(vsp->vs_type == VMEM_SPAN);
1344 if (start >= vsp->vs_start && end - 1 <= vsp->vs_end - 1)
1345 break;
1346 }
1347 mutex_exit(&vmp->vm_lock);
1348 return (vsp != seg0);
1349 }
1350
1351 /*
1352 * Add the span [vaddr, vaddr + size) to arena vmp.
1353 */
1354 void *
1355 vmem_add(vmem_t *vmp, void *vaddr, size_t size, int vmflag)
1356 {
1357 if (vaddr == NULL || size == 0)
1358 panic("vmem_add(%p, %p, %lu): bad arguments",
1359 (void *)vmp, vaddr, size);
1360
1361 ASSERT(!vmem_contains(vmp, vaddr, size));
1362
1363 mutex_enter(&vmp->vm_lock);
1364 if (vmem_populate(vmp, vmflag))
1365 (void) vmem_span_create(vmp, vaddr, size, 0);
1366 else
1367 vaddr = NULL;
1368 mutex_exit(&vmp->vm_lock);
1369 return (vaddr);
1370 }
1371
1372 /*
1373 * Walk the vmp arena, applying func to each segment matching typemask.
1374 * If VMEM_REENTRANT is specified, the arena lock is dropped across each
1375 * call to func(); otherwise, it is held for the duration of vmem_walk()
1376 * to ensure a consistent snapshot. Note that VMEM_REENTRANT callbacks
1377 * are *not* necessarily consistent, so they may only be used when a hint
1378 * is adequate.
1379 */
1380 void
1381 vmem_walk(vmem_t *vmp, int typemask,
1382 void (*func)(void *, void *, size_t), void *arg)
1383 {
1384 vmem_seg_t *vsp;
1385 vmem_seg_t *seg0 = &vmp->vm_seg0;
1386 vmem_seg_t walker;
1387
1388 if (typemask & VMEM_WALKER)
1389 return;
1390
1391 bzero(&walker, sizeof (walker));
1392 walker.vs_type = VMEM_WALKER;
1393
1394 mutex_enter(&vmp->vm_lock);
1395 VMEM_INSERT(seg0, &walker, a);
1396 for (vsp = seg0->vs_anext; vsp != seg0; vsp = vsp->vs_anext) {
1397 if (vsp->vs_type & typemask) {
1398 void *start = (void *)vsp->vs_start;
1399 size_t size = VS_SIZE(vsp);
1400 if (typemask & VMEM_REENTRANT) {
1401 vmem_advance(vmp, &walker, vsp);
1402 mutex_exit(&vmp->vm_lock);
1403 func(arg, start, size);
1404 mutex_enter(&vmp->vm_lock);
1405 vsp = &walker;
1406 } else {
1407 func(arg, start, size);
1408 }
1409 }
1410 }
1411 vmem_advance(vmp, &walker, NULL);
1412 mutex_exit(&vmp->vm_lock);
1413 }
1414
1415 /*
1416 * Return the total amount of memory whose type matches typemask. Thus:
1417 *
1418 * typemask VMEM_ALLOC yields total memory allocated (in use).
1419 * typemask VMEM_FREE yields total memory free (available).
1420 * typemask (VMEM_ALLOC | VMEM_FREE) yields total arena size.
1421 */
1422 size_t
1423 vmem_size(vmem_t *vmp, int typemask)
1424 {
1425 uint64_t size = 0;
1426
1427 if (typemask & VMEM_ALLOC)
1428 size += vmp->vm_kstat.vk_mem_inuse.value.ui64;
1429 if (typemask & VMEM_FREE)
1430 size += vmp->vm_kstat.vk_mem_total.value.ui64 -
1431 vmp->vm_kstat.vk_mem_inuse.value.ui64;
1432 return ((size_t)size);
1433 }
1434
1435 /*
1436 * Create an arena called name whose initial span is [base, base + size).
1437 * The arena's natural unit of currency is quantum, so vmem_alloc()
1438 * guarantees quantum-aligned results. The arena may import new spans
1439 * by invoking afunc() on source, and may return those spans by invoking
1440 * ffunc() on source. To make small allocations fast and scalable,
1441 * the arena offers high-performance caching for each integer multiple
1442 * of quantum up to qcache_max.
1443 */
1444 static vmem_t *
1445 vmem_create_common(const char *name, void *base, size_t size, size_t quantum,
1446 void *(*afunc)(vmem_t *, size_t, int),
1447 void (*ffunc)(vmem_t *, void *, size_t),
1448 vmem_t *source, size_t qcache_max, int vmflag)
1449 {
1450 int i;
1451 size_t nqcache;
1452 vmem_t *vmp, *cur, **vmpp;
1453 vmem_seg_t *vsp;
1454 vmem_freelist_t *vfp;
1455 uint32_t id = atomic_inc_32_nv(&vmem_id);
1456
1457 if (vmem_vmem_arena != NULL) {
1458 vmp = vmem_alloc(vmem_vmem_arena, sizeof (vmem_t),
1459 vmflag & VM_KMFLAGS);
1460 } else {
1461 ASSERT(id <= VMEM_INITIAL);
1462 vmp = &vmem0[id - 1];
1463 }
1464
1465 /* An identifier arena must inherit from another identifier arena */
1466 ASSERT(source == NULL || ((source->vm_cflags & VMC_IDENTIFIER) ==
1467 (vmflag & VMC_IDENTIFIER)));
1468
1469 if (vmp == NULL)
1470 return (NULL);
1471 bzero(vmp, sizeof (vmem_t));
1472
1473 (void) snprintf(vmp->vm_name, VMEM_NAMELEN, "%s", name);
1474 mutex_init(&vmp->vm_lock, NULL, MUTEX_DEFAULT, NULL);
1475 cv_init(&vmp->vm_cv, NULL, CV_DEFAULT, NULL);
1476 vmp->vm_cflags = vmflag;
1477 vmflag &= VM_KMFLAGS;
1478
1479 vmp->vm_quantum = quantum;
1480 vmp->vm_qshift = highbit(quantum) - 1;
1481 nqcache = MIN(qcache_max >> vmp->vm_qshift, VMEM_NQCACHE_MAX);
1482
1483 for (i = 0; i <= VMEM_FREELISTS; i++) {
1484 vfp = &vmp->vm_freelist[i];
1485 vfp->vs_end = 1UL << i;
1486 vfp->vs_knext = (vmem_seg_t *)(vfp + 1);
1487 vfp->vs_kprev = (vmem_seg_t *)(vfp - 1);
1488 }
1489
1490 vmp->vm_freelist[0].vs_kprev = NULL;
1491 vmp->vm_freelist[VMEM_FREELISTS].vs_knext = NULL;
1492 vmp->vm_freelist[VMEM_FREELISTS].vs_end = 0;
1493 vmp->vm_hash_table = vmp->vm_hash0;
1494 vmp->vm_hash_mask = VMEM_HASH_INITIAL - 1;
1495 vmp->vm_hash_shift = highbit(vmp->vm_hash_mask);
1496
1497 vsp = &vmp->vm_seg0;
1498 vsp->vs_anext = vsp;
1499 vsp->vs_aprev = vsp;
1500 vsp->vs_knext = vsp;
1501 vsp->vs_kprev = vsp;
1502 vsp->vs_type = VMEM_SPAN;
1503
1504 vsp = &vmp->vm_rotor;
1505 vsp->vs_type = VMEM_ROTOR;
1506 VMEM_INSERT(&vmp->vm_seg0, vsp, a);
1507
1508 bcopy(&vmem_kstat_template, &vmp->vm_kstat, sizeof (vmem_kstat_t));
1509
1510 vmp->vm_id = id;
1511 if (source != NULL)
1512 vmp->vm_kstat.vk_source_id.value.ui32 = source->vm_id;
1513 vmp->vm_source = source;
1514 vmp->vm_source_alloc = afunc;
1515 vmp->vm_source_free = ffunc;
1516
1517 /*
1518 * Some arenas (like vmem_metadata and kmem_metadata) cannot
1519 * use quantum caching to lower fragmentation. Instead, we
1520 * increase their imports, giving a similar effect.
1521 */
1522 if (vmp->vm_cflags & VMC_NO_QCACHE) {
1523 vmp->vm_min_import =
1524 VMEM_QCACHE_SLABSIZE(nqcache << vmp->vm_qshift);
1525 nqcache = 0;
1526 }
1527
1528 if (nqcache != 0) {
1529 ASSERT(!(vmflag & VM_NOSLEEP));
1530 vmp->vm_qcache_max = nqcache << vmp->vm_qshift;
1531 for (i = 0; i < nqcache; i++) {
1532 char buf[VMEM_NAMELEN + 21];
1533 (void) sprintf(buf, "%s_%lu", vmp->vm_name,
1534 (i + 1) * quantum);
1535 vmp->vm_qcache[i] = kmem_cache_create(buf,
1536 (i + 1) * quantum, quantum, NULL, NULL, NULL,
1537 NULL, vmp, KMC_QCACHE | KMC_NOTOUCH);
1538 }
1539 }
1540
1541 if ((vmp->vm_ksp = kstat_create("vmem", vmp->vm_id, vmp->vm_name,
1542 "vmem", KSTAT_TYPE_NAMED, sizeof (vmem_kstat_t) /
1543 sizeof (kstat_named_t), KSTAT_FLAG_VIRTUAL)) != NULL) {
1544 vmp->vm_ksp->ks_data = &vmp->vm_kstat;
1545 kstat_install(vmp->vm_ksp);
1546 }
1547
1548 mutex_enter(&vmem_list_lock);
1549 vmpp = &vmem_list;
1550 while ((cur = *vmpp) != NULL)
1551 vmpp = &cur->vm_next;
1552 *vmpp = vmp;
1553 mutex_exit(&vmem_list_lock);
1554
1555 if (vmp->vm_cflags & VMC_POPULATOR) {
1556 ASSERT(vmem_populators < VMEM_INITIAL);
1557 vmem_populator[atomic_inc_32_nv(&vmem_populators) - 1] = vmp;
1558 mutex_enter(&vmp->vm_lock);
1559 (void) vmem_populate(vmp, vmflag | VM_PANIC);
1560 mutex_exit(&vmp->vm_lock);
1561 }
1562
1563 if ((base || size) && vmem_add(vmp, base, size, vmflag) == NULL) {
1564 vmem_destroy(vmp);
1565 return (NULL);
1566 }
1567
1568 return (vmp);
1569 }
1570
1571 vmem_t *
1572 vmem_xcreate(const char *name, void *base, size_t size, size_t quantum,
1573 vmem_ximport_t *afunc, vmem_free_t *ffunc, vmem_t *source,
1574 size_t qcache_max, int vmflag)
1575 {
1576 ASSERT(!(vmflag & (VMC_POPULATOR | VMC_XALLOC)));
1577 vmflag &= ~(VMC_POPULATOR | VMC_XALLOC);
1578
1579 return (vmem_create_common(name, base, size, quantum,
1580 (vmem_alloc_t *)afunc, ffunc, source, qcache_max,
1581 vmflag | VMC_XALLOC));
1582 }
1583
1584 vmem_t *
1585 vmem_create(const char *name, void *base, size_t size, size_t quantum,
1586 vmem_alloc_t *afunc, vmem_free_t *ffunc, vmem_t *source,
1587 size_t qcache_max, int vmflag)
1588 {
1589 ASSERT(!(vmflag & (VMC_XALLOC | VMC_XALIGN)));
1590 vmflag &= ~(VMC_XALLOC | VMC_XALIGN);
1591
1592 return (vmem_create_common(name, base, size, quantum,
1593 afunc, ffunc, source, qcache_max, vmflag));
1594 }
1595
1596 /*
1597 * Destroy arena vmp.
1598 */
1599 void
1600 vmem_destroy(vmem_t *vmp)
1601 {
1602 vmem_t *cur, **vmpp;
1603 vmem_seg_t *seg0 = &vmp->vm_seg0;
1604 vmem_seg_t *vsp, *anext;
1605 size_t leaked;
1606 int i;
1607
1608 mutex_enter(&vmem_list_lock);
1609 vmpp = &vmem_list;
1610 while ((cur = *vmpp) != vmp)
1611 vmpp = &cur->vm_next;
1612 *vmpp = vmp->vm_next;
1613 mutex_exit(&vmem_list_lock);
1614
1615 for (i = 0; i < VMEM_NQCACHE_MAX; i++)
1616 if (vmp->vm_qcache[i])
1617 kmem_cache_destroy(vmp->vm_qcache[i]);
1618
1619 leaked = vmem_size(vmp, VMEM_ALLOC);
1620 if (leaked != 0)
1621 cmn_err(CE_WARN, "vmem_destroy('%s'): leaked %lu %s",
1622 vmp->vm_name, leaked, (vmp->vm_cflags & VMC_IDENTIFIER) ?
1623 "identifiers" : "bytes");
1624
1625 if (vmp->vm_hash_table != vmp->vm_hash0)
1626 vmem_free(vmem_hash_arena, vmp->vm_hash_table,
1627 (vmp->vm_hash_mask + 1) * sizeof (void *));
1628
1629 /*
1630 * Give back the segment structures for anything that's left in the
1631 * arena, e.g. the primary spans and their free segments.
1632 */
1633 VMEM_DELETE(&vmp->vm_rotor, a);
1634 for (vsp = seg0->vs_anext; vsp != seg0; vsp = anext) {
1635 anext = vsp->vs_anext;
1636 vmem_putseg_global(vsp);
1637 }
1638
1639 while (vmp->vm_nsegfree > 0)
1640 vmem_putseg_global(vmem_getseg(vmp));
1641
1642 kstat_delete(vmp->vm_ksp);
1643
1644 mutex_destroy(&vmp->vm_lock);
1645 cv_destroy(&vmp->vm_cv);
1646 vmem_free(vmem_vmem_arena, vmp, sizeof (vmem_t));
1647 }
1648
1649 /*
1650 * Only shrink vmem hashtable if it is 1<<vmem_rescale_minshift times (8x)
1651 * larger than necessary.
1652 */
1653 int vmem_rescale_minshift = 3;
1654
1655 /*
1656 * Resize vmp's hash table to keep the average lookup depth near 1.0.
1657 */
1658 static void
1659 vmem_hash_rescale(vmem_t *vmp)
1660 {
1661 vmem_seg_t **old_table, **new_table, *vsp;
1662 size_t old_size, new_size, h, nseg;
1663
1664 nseg = (size_t)(vmp->vm_kstat.vk_alloc.value.ui64 -
1665 vmp->vm_kstat.vk_free.value.ui64);
1666
1667 new_size = MAX(VMEM_HASH_INITIAL, 1 << (highbit(3 * nseg + 4) - 2));
1668 old_size = vmp->vm_hash_mask + 1;
1669
1670 if ((old_size >> vmem_rescale_minshift) <= new_size &&
1671 new_size <= (old_size << 1))
1672 return;
1673
1674 new_table = vmem_alloc(vmem_hash_arena, new_size * sizeof (void *),
1675 VM_NOSLEEP);
1676 if (new_table == NULL)
1677 return;
1678 bzero(new_table, new_size * sizeof (void *));
1679
1680 mutex_enter(&vmp->vm_lock);
1681
1682 old_size = vmp->vm_hash_mask + 1;
1683 old_table = vmp->vm_hash_table;
1684
1685 vmp->vm_hash_mask = new_size - 1;
1686 vmp->vm_hash_table = new_table;
1687 vmp->vm_hash_shift = highbit(vmp->vm_hash_mask);
1688
1689 for (h = 0; h < old_size; h++) {
1690 vsp = old_table[h];
1691 while (vsp != NULL) {
1692 uintptr_t addr = vsp->vs_start;
1693 vmem_seg_t *next_vsp = vsp->vs_knext;
1694 vmem_seg_t **hash_bucket = VMEM_HASH(vmp, addr);
1695 vsp->vs_knext = *hash_bucket;
1696 *hash_bucket = vsp;
1697 vsp = next_vsp;
1698 }
1699 }
1700
1701 mutex_exit(&vmp->vm_lock);
1702
1703 if (old_table != vmp->vm_hash0)
1704 vmem_free(vmem_hash_arena, old_table,
1705 old_size * sizeof (void *));
1706 }
1707
1708 /*
1709 * Perform periodic maintenance on all vmem arenas.
1710 */
1711 void
1712 vmem_update(void *dummy)
1713 {
1714 vmem_t *vmp;
1715
1716 mutex_enter(&vmem_list_lock);
1717 for (vmp = vmem_list; vmp != NULL; vmp = vmp->vm_next) {
1718 /*
1719 * If threads are waiting for resources, wake them up
1720 * periodically so they can issue another kmem_reap()
1721 * to reclaim resources cached by the slab allocator.
1722 */
1723 cv_broadcast(&vmp->vm_cv);
1724
1725 /*
1726 * Rescale the hash table to keep the hash chains short.
1727 */
1728 vmem_hash_rescale(vmp);
1729 }
1730 mutex_exit(&vmem_list_lock);
1731
1732 (void) timeout(vmem_update, dummy, vmem_update_interval * hz);
1733 }
1734
1735 void
1736 vmem_qcache_reap(vmem_t *vmp)
1737 {
1738 int i;
1739
1740 /*
1741 * Reap any quantum caches that may be part of this vmem.
1742 */
1743 for (i = 0; i < VMEM_NQCACHE_MAX; i++)
1744 if (vmp->vm_qcache[i])
1745 kmem_cache_reap_now(vmp->vm_qcache[i]);
1746 }
1747
1748 /*
1749 * Prepare vmem for use.
1750 */
1751 vmem_t *
1752 vmem_init(const char *heap_name,
1753 void *heap_start, size_t heap_size, size_t heap_quantum,
1754 void *(*heap_alloc)(vmem_t *, size_t, int),
1755 void (*heap_free)(vmem_t *, void *, size_t))
1756 {
1757 uint32_t id;
1758 int nseg = VMEM_SEG_INITIAL;
1759 vmem_t *heap;
1760
1761 while (--nseg >= 0)
1762 vmem_putseg_global(&vmem_seg0[nseg]);
1763
1764 heap = vmem_create(heap_name,
1765 heap_start, heap_size, heap_quantum,
1766 NULL, NULL, NULL, 0,
1767 VM_SLEEP | VMC_POPULATOR);
1768
1769 vmem_metadata_arena = vmem_create("vmem_metadata",
1770 NULL, 0, heap_quantum,
1771 vmem_alloc, vmem_free, heap, 8 * heap_quantum,
1772 VM_SLEEP | VMC_POPULATOR | VMC_NO_QCACHE);
1773
1774 vmem_seg_arena = vmem_create("vmem_seg",
1775 NULL, 0, heap_quantum,
1776 heap_alloc, heap_free, vmem_metadata_arena, 0,
1777 VM_SLEEP | VMC_POPULATOR);
1778
1779 vmem_hash_arena = vmem_create("vmem_hash",
1780 NULL, 0, 8,
1781 heap_alloc, heap_free, vmem_metadata_arena, 0,
1782 VM_SLEEP);
1783
1784 vmem_vmem_arena = vmem_create("vmem_vmem",
1785 vmem0, sizeof (vmem0), 1,
1786 heap_alloc, heap_free, vmem_metadata_arena, 0,
1787 VM_SLEEP);
1788
1789 for (id = 0; id < vmem_id; id++)
1790 (void) vmem_xalloc(vmem_vmem_arena, sizeof (vmem_t),
1791 1, 0, 0, &vmem0[id], &vmem0[id + 1],
1792 VM_NOSLEEP | VM_BESTFIT | VM_PANIC);
1793
1794 return (heap);
1795 }