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9018 Replace kmem_cache_reap_now() with kmem_cache_reap_soon()
Reviewed by: Bryan Cantrill <bryan@joyent.com>
Reviewed by: Dan McDonald <danmcd@joyent.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Yuri Pankov <yuripv@yuripv.net>
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--- old/usr/src/uts/common/os/vmem.c
+++ new/usr/src/uts/common/os/vmem.c
1 1 /*
2 2 * CDDL HEADER START
3 3 *
4 4 * The contents of this file are subject to the terms of the
5 5 * Common Development and Distribution License (the "License").
6 6 * You may not use this file except in compliance with the License.
7 7 *
8 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 9 * or http://www.opensolaris.org/os/licensing.
10 10 * See the License for the specific language governing permissions
11 11 * and limitations under the License.
12 12 *
13 13 * When distributing Covered Code, include this CDDL HEADER in each
14 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 15 * If applicable, add the following below this CDDL HEADER, with the
16 16 * fields enclosed by brackets "[]" replaced with your own identifying
17 17 * information: Portions Copyright [yyyy] [name of copyright owner]
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18 18 *
19 19 * CDDL HEADER END
20 20 */
21 21 /*
22 22 * Copyright 2010 Sun Microsystems, Inc. All rights reserved.
23 23 * Use is subject to license terms.
24 24 */
25 25
26 26 /*
27 27 * Copyright (c) 2012, 2015 by Delphix. All rights reserved.
28 - * Copyright (c) 2012, Joyent, Inc. All rights reserved.
28 + * Copyright (c) 2018, Joyent, Inc.
29 29 */
30 30
31 31 /*
32 32 * Big Theory Statement for the virtual memory allocator.
33 33 *
34 34 * For a more complete description of the main ideas, see:
35 35 *
36 36 * Jeff Bonwick and Jonathan Adams,
37 37 *
38 38 * Magazines and vmem: Extending the Slab Allocator to Many CPUs and
39 39 * Arbitrary Resources.
40 40 *
41 41 * Proceedings of the 2001 Usenix Conference.
42 42 * Available as http://www.usenix.org/event/usenix01/bonwick.html
43 43 *
44 44 * Section 1, below, is also the primary contents of vmem(9). If for some
45 45 * reason you are updating this comment, you will also wish to update the
46 46 * manual.
47 47 *
48 48 * 1. General Concepts
49 49 * -------------------
50 50 *
51 51 * 1.1 Overview
52 52 * ------------
53 53 * We divide the kernel address space into a number of logically distinct
54 54 * pieces, or *arenas*: text, data, heap, stack, and so on. Within these
55 55 * arenas we often subdivide further; for example, we use heap addresses
56 56 * not only for the kernel heap (kmem_alloc() space), but also for DVMA,
57 57 * bp_mapin(), /dev/kmem, and even some device mappings like the TOD chip.
58 58 * The kernel address space, therefore, is most accurately described as
59 59 * a tree of arenas in which each node of the tree *imports* some subset
60 60 * of its parent. The virtual memory allocator manages these arenas and
61 61 * supports their natural hierarchical structure.
62 62 *
63 63 * 1.2 Arenas
64 64 * ----------
65 65 * An arena is nothing more than a set of integers. These integers most
66 66 * commonly represent virtual addresses, but in fact they can represent
67 67 * anything at all. For example, we could use an arena containing the
68 68 * integers minpid through maxpid to allocate process IDs. vmem_create()
69 69 * and vmem_destroy() create and destroy vmem arenas. In order to
70 70 * differentiate between arenas used for adresses and arenas used for
71 71 * identifiers, the VMC_IDENTIFIER flag is passed to vmem_create(). This
72 72 * prevents identifier exhaustion from being diagnosed as general memory
73 73 * failure.
74 74 *
75 75 * 1.3 Spans
76 76 * ---------
77 77 * We represent the integers in an arena as a collection of *spans*, or
78 78 * contiguous ranges of integers. For example, the kernel heap consists
79 79 * of just one span: [kernelheap, ekernelheap). Spans can be added to an
80 80 * arena in two ways: explicitly, by vmem_add(), or implicitly, by
81 81 * importing, as described in Section 1.5 below.
82 82 *
83 83 * 1.4 Segments
84 84 * ------------
85 85 * Spans are subdivided into *segments*, each of which is either allocated
86 86 * or free. A segment, like a span, is a contiguous range of integers.
87 87 * Each allocated segment [addr, addr + size) represents exactly one
88 88 * vmem_alloc(size) that returned addr. Free segments represent the space
89 89 * between allocated segments. If two free segments are adjacent, we
90 90 * coalesce them into one larger segment; that is, if segments [a, b) and
91 91 * [b, c) are both free, we merge them into a single segment [a, c).
92 92 * The segments within a span are linked together in increasing-address order
93 93 * so we can easily determine whether coalescing is possible.
94 94 *
95 95 * Segments never cross span boundaries. When all segments within
96 96 * an imported span become free, we return the span to its source.
97 97 *
98 98 * 1.5 Imported Memory
99 99 * -------------------
100 100 * As mentioned in the overview, some arenas are logical subsets of
101 101 * other arenas. For example, kmem_va_arena (a virtual address cache
102 102 * that satisfies most kmem_slab_create() requests) is just a subset
103 103 * of heap_arena (the kernel heap) that provides caching for the most
104 104 * common slab sizes. When kmem_va_arena runs out of virtual memory,
105 105 * it *imports* more from the heap; we say that heap_arena is the
106 106 * *vmem source* for kmem_va_arena. vmem_create() allows you to
107 107 * specify any existing vmem arena as the source for your new arena.
108 108 * Topologically, since every arena is a child of at most one source,
109 109 * the set of all arenas forms a collection of trees.
110 110 *
111 111 * 1.6 Constrained Allocations
112 112 * ---------------------------
113 113 * Some vmem clients are quite picky about the kind of address they want.
114 114 * For example, the DVMA code may need an address that is at a particular
115 115 * phase with respect to some alignment (to get good cache coloring), or
116 116 * that lies within certain limits (the addressable range of a device),
117 117 * or that doesn't cross some boundary (a DMA counter restriction) --
118 118 * or all of the above. vmem_xalloc() allows the client to specify any
119 119 * or all of these constraints.
120 120 *
121 121 * 1.7 The Vmem Quantum
122 122 * --------------------
123 123 * Every arena has a notion of 'quantum', specified at vmem_create() time,
124 124 * that defines the arena's minimum unit of currency. Most commonly the
125 125 * quantum is either 1 or PAGESIZE, but any power of 2 is legal.
126 126 * All vmem allocations are guaranteed to be quantum-aligned.
127 127 *
128 128 * 1.8 Quantum Caching
129 129 * -------------------
130 130 * A vmem arena may be so hot (frequently used) that the scalability of vmem
131 131 * allocation is a significant concern. We address this by allowing the most
132 132 * common allocation sizes to be serviced by the kernel memory allocator,
133 133 * which provides low-latency per-cpu caching. The qcache_max argument to
134 134 * vmem_create() specifies the largest allocation size to cache.
135 135 *
136 136 * 1.9 Relationship to Kernel Memory Allocator
137 137 * -------------------------------------------
138 138 * Every kmem cache has a vmem arena as its slab supplier. The kernel memory
139 139 * allocator uses vmem_alloc() and vmem_free() to create and destroy slabs.
140 140 *
141 141 *
142 142 * 2. Implementation
143 143 * -----------------
144 144 *
145 145 * 2.1 Segment lists and markers
146 146 * -----------------------------
147 147 * The segment structure (vmem_seg_t) contains two doubly-linked lists.
148 148 *
149 149 * The arena list (vs_anext/vs_aprev) links all segments in the arena.
150 150 * In addition to the allocated and free segments, the arena contains
151 151 * special marker segments at span boundaries. Span markers simplify
152 152 * coalescing and importing logic by making it easy to tell both when
153 153 * we're at a span boundary (so we don't coalesce across it), and when
154 154 * a span is completely free (its neighbors will both be span markers).
155 155 *
156 156 * Imported spans will have vs_import set.
157 157 *
158 158 * The next-of-kin list (vs_knext/vs_kprev) links segments of the same type:
159 159 * (1) for allocated segments, vs_knext is the hash chain linkage;
160 160 * (2) for free segments, vs_knext is the freelist linkage;
161 161 * (3) for span marker segments, vs_knext is the next span marker.
162 162 *
163 163 * 2.2 Allocation hashing
164 164 * ----------------------
165 165 * We maintain a hash table of all allocated segments, hashed by address.
166 166 * This allows vmem_free() to discover the target segment in constant time.
167 167 * vmem_update() periodically resizes hash tables to keep hash chains short.
168 168 *
169 169 * 2.3 Freelist management
170 170 * -----------------------
171 171 * We maintain power-of-2 freelists for free segments, i.e. free segments
172 172 * of size >= 2^n reside in vmp->vm_freelist[n]. To ensure constant-time
173 173 * allocation, vmem_xalloc() looks not in the first freelist that *might*
174 174 * satisfy the allocation, but in the first freelist that *definitely*
175 175 * satisfies the allocation (unless VM_BESTFIT is specified, or all larger
176 176 * freelists are empty). For example, a 1000-byte allocation will be
177 177 * satisfied not from the 512..1023-byte freelist, whose members *might*
178 178 * contains a 1000-byte segment, but from a 1024-byte or larger freelist,
179 179 * the first member of which will *definitely* satisfy the allocation.
180 180 * This ensures that vmem_xalloc() works in constant time.
181 181 *
182 182 * We maintain a bit map to determine quickly which freelists are non-empty.
183 183 * vmp->vm_freemap & (1 << n) is non-zero iff vmp->vm_freelist[n] is non-empty.
184 184 *
185 185 * The different freelists are linked together into one large freelist,
186 186 * with the freelist heads serving as markers. Freelist markers simplify
187 187 * the maintenance of vm_freemap by making it easy to tell when we're taking
188 188 * the last member of a freelist (both of its neighbors will be markers).
189 189 *
190 190 * 2.4 Vmem Locking
191 191 * ----------------
192 192 * For simplicity, all arena state is protected by a per-arena lock.
193 193 * For very hot arenas, use quantum caching for scalability.
194 194 *
195 195 * 2.5 Vmem Population
196 196 * -------------------
197 197 * Any internal vmem routine that might need to allocate new segment
198 198 * structures must prepare in advance by calling vmem_populate(), which
199 199 * will preallocate enough vmem_seg_t's to get is through the entire
200 200 * operation without dropping the arena lock.
201 201 *
202 202 * 2.6 Auditing
203 203 * ------------
204 204 * If KMF_AUDIT is set in kmem_flags, we audit vmem allocations as well.
205 205 * Since virtual addresses cannot be scribbled on, there is no equivalent
206 206 * in vmem to redzone checking, deadbeef, or other kmem debugging features.
207 207 * Moreover, we do not audit frees because segment coalescing destroys the
208 208 * association between an address and its segment structure. Auditing is
209 209 * thus intended primarily to keep track of who's consuming the arena.
210 210 * Debugging support could certainly be extended in the future if it proves
211 211 * necessary, but we do so much live checking via the allocation hash table
212 212 * that even non-DEBUG systems get quite a bit of sanity checking already.
213 213 */
214 214
215 215 #include <sys/vmem_impl.h>
216 216 #include <sys/kmem.h>
217 217 #include <sys/kstat.h>
218 218 #include <sys/param.h>
219 219 #include <sys/systm.h>
220 220 #include <sys/atomic.h>
221 221 #include <sys/bitmap.h>
222 222 #include <sys/sysmacros.h>
223 223 #include <sys/cmn_err.h>
224 224 #include <sys/debug.h>
225 225 #include <sys/panic.h>
226 226
227 227 #define VMEM_INITIAL 10 /* early vmem arenas */
228 228 #define VMEM_SEG_INITIAL 200 /* early segments */
229 229
230 230 /*
231 231 * Adding a new span to an arena requires two segment structures: one to
232 232 * represent the span, and one to represent the free segment it contains.
233 233 */
234 234 #define VMEM_SEGS_PER_SPAN_CREATE 2
235 235
236 236 /*
237 237 * Allocating a piece of an existing segment requires 0-2 segment structures
238 238 * depending on how much of the segment we're allocating.
239 239 *
240 240 * To allocate the entire segment, no new segment structures are needed; we
241 241 * simply move the existing segment structure from the freelist to the
242 242 * allocation hash table.
243 243 *
244 244 * To allocate a piece from the left or right end of the segment, we must
245 245 * split the segment into two pieces (allocated part and remainder), so we
246 246 * need one new segment structure to represent the remainder.
247 247 *
248 248 * To allocate from the middle of a segment, we need two new segment strucures
249 249 * to represent the remainders on either side of the allocated part.
250 250 */
251 251 #define VMEM_SEGS_PER_EXACT_ALLOC 0
252 252 #define VMEM_SEGS_PER_LEFT_ALLOC 1
253 253 #define VMEM_SEGS_PER_RIGHT_ALLOC 1
254 254 #define VMEM_SEGS_PER_MIDDLE_ALLOC 2
255 255
256 256 /*
257 257 * vmem_populate() preallocates segment structures for vmem to do its work.
258 258 * It must preallocate enough for the worst case, which is when we must import
259 259 * a new span and then allocate from the middle of it.
260 260 */
261 261 #define VMEM_SEGS_PER_ALLOC_MAX \
262 262 (VMEM_SEGS_PER_SPAN_CREATE + VMEM_SEGS_PER_MIDDLE_ALLOC)
263 263
264 264 /*
265 265 * The segment structures themselves are allocated from vmem_seg_arena, so
266 266 * we have a recursion problem when vmem_seg_arena needs to populate itself.
267 267 * We address this by working out the maximum number of segment structures
268 268 * this act will require, and multiplying by the maximum number of threads
269 269 * that we'll allow to do it simultaneously.
270 270 *
271 271 * The worst-case segment consumption to populate vmem_seg_arena is as
272 272 * follows (depicted as a stack trace to indicate why events are occurring):
273 273 *
274 274 * (In order to lower the fragmentation in the heap_arena, we specify a
275 275 * minimum import size for the vmem_metadata_arena which is the same size
276 276 * as the kmem_va quantum cache allocations. This causes the worst-case
277 277 * allocation from the vmem_metadata_arena to be 3 segments.)
278 278 *
279 279 * vmem_alloc(vmem_seg_arena) -> 2 segs (span create + exact alloc)
280 280 * segkmem_alloc(vmem_metadata_arena)
281 281 * vmem_alloc(vmem_metadata_arena) -> 3 segs (span create + left alloc)
282 282 * vmem_alloc(heap_arena) -> 1 seg (left alloc)
283 283 * page_create()
284 284 * hat_memload()
285 285 * kmem_cache_alloc()
286 286 * kmem_slab_create()
287 287 * vmem_alloc(hat_memload_arena) -> 2 segs (span create + exact alloc)
288 288 * segkmem_alloc(heap_arena)
289 289 * vmem_alloc(heap_arena) -> 1 seg (left alloc)
290 290 * page_create()
291 291 * hat_memload() -> (hat layer won't recurse further)
292 292 *
293 293 * The worst-case consumption for each arena is 3 segment structures.
294 294 * Of course, a 3-seg reserve could easily be blown by multiple threads.
295 295 * Therefore, we serialize all allocations from vmem_seg_arena (which is OK
296 296 * because they're rare). We cannot allow a non-blocking allocation to get
297 297 * tied up behind a blocking allocation, however, so we use separate locks
298 298 * for VM_SLEEP and VM_NOSLEEP allocations. Similarly, VM_PUSHPAGE allocations
299 299 * must not block behind ordinary VM_SLEEPs. In addition, if the system is
300 300 * panicking then we must keep enough resources for panic_thread to do its
301 301 * work. Thus we have at most four threads trying to allocate from
302 302 * vmem_seg_arena, and each thread consumes at most three segment structures,
303 303 * so we must maintain a 12-seg reserve.
304 304 */
305 305 #define VMEM_POPULATE_RESERVE 12
306 306
307 307 /*
308 308 * vmem_populate() ensures that each arena has VMEM_MINFREE seg structures
309 309 * so that it can satisfy the worst-case allocation *and* participate in
310 310 * worst-case allocation from vmem_seg_arena.
311 311 */
312 312 #define VMEM_MINFREE (VMEM_POPULATE_RESERVE + VMEM_SEGS_PER_ALLOC_MAX)
313 313
314 314 static vmem_t vmem0[VMEM_INITIAL];
315 315 static vmem_t *vmem_populator[VMEM_INITIAL];
316 316 static uint32_t vmem_id;
317 317 static uint32_t vmem_populators;
318 318 static vmem_seg_t vmem_seg0[VMEM_SEG_INITIAL];
319 319 static vmem_seg_t *vmem_segfree;
320 320 static kmutex_t vmem_list_lock;
321 321 static kmutex_t vmem_segfree_lock;
322 322 static kmutex_t vmem_sleep_lock;
323 323 static kmutex_t vmem_nosleep_lock;
324 324 static kmutex_t vmem_pushpage_lock;
325 325 static kmutex_t vmem_panic_lock;
326 326 static vmem_t *vmem_list;
327 327 static vmem_t *vmem_metadata_arena;
328 328 static vmem_t *vmem_seg_arena;
329 329 static vmem_t *vmem_hash_arena;
330 330 static vmem_t *vmem_vmem_arena;
331 331 static long vmem_update_interval = 15; /* vmem_update() every 15 seconds */
332 332 uint32_t vmem_mtbf; /* mean time between failures [default: off] */
333 333 size_t vmem_seg_size = sizeof (vmem_seg_t);
334 334
335 335 static vmem_kstat_t vmem_kstat_template = {
336 336 { "mem_inuse", KSTAT_DATA_UINT64 },
337 337 { "mem_import", KSTAT_DATA_UINT64 },
338 338 { "mem_total", KSTAT_DATA_UINT64 },
339 339 { "vmem_source", KSTAT_DATA_UINT32 },
340 340 { "alloc", KSTAT_DATA_UINT64 },
341 341 { "free", KSTAT_DATA_UINT64 },
342 342 { "wait", KSTAT_DATA_UINT64 },
343 343 { "fail", KSTAT_DATA_UINT64 },
344 344 { "lookup", KSTAT_DATA_UINT64 },
345 345 { "search", KSTAT_DATA_UINT64 },
346 346 { "populate_wait", KSTAT_DATA_UINT64 },
347 347 { "populate_fail", KSTAT_DATA_UINT64 },
348 348 { "contains", KSTAT_DATA_UINT64 },
349 349 { "contains_search", KSTAT_DATA_UINT64 },
350 350 };
351 351
352 352 /*
353 353 * Insert/delete from arena list (type 'a') or next-of-kin list (type 'k').
354 354 */
355 355 #define VMEM_INSERT(vprev, vsp, type) \
356 356 { \
357 357 vmem_seg_t *vnext = (vprev)->vs_##type##next; \
358 358 (vsp)->vs_##type##next = (vnext); \
359 359 (vsp)->vs_##type##prev = (vprev); \
360 360 (vprev)->vs_##type##next = (vsp); \
361 361 (vnext)->vs_##type##prev = (vsp); \
362 362 }
363 363
364 364 #define VMEM_DELETE(vsp, type) \
365 365 { \
366 366 vmem_seg_t *vprev = (vsp)->vs_##type##prev; \
367 367 vmem_seg_t *vnext = (vsp)->vs_##type##next; \
368 368 (vprev)->vs_##type##next = (vnext); \
369 369 (vnext)->vs_##type##prev = (vprev); \
370 370 }
371 371
372 372 /*
373 373 * Get a vmem_seg_t from the global segfree list.
374 374 */
375 375 static vmem_seg_t *
376 376 vmem_getseg_global(void)
377 377 {
378 378 vmem_seg_t *vsp;
379 379
380 380 mutex_enter(&vmem_segfree_lock);
381 381 if ((vsp = vmem_segfree) != NULL)
382 382 vmem_segfree = vsp->vs_knext;
383 383 mutex_exit(&vmem_segfree_lock);
384 384
385 385 return (vsp);
386 386 }
387 387
388 388 /*
389 389 * Put a vmem_seg_t on the global segfree list.
390 390 */
391 391 static void
392 392 vmem_putseg_global(vmem_seg_t *vsp)
393 393 {
394 394 mutex_enter(&vmem_segfree_lock);
395 395 vsp->vs_knext = vmem_segfree;
396 396 vmem_segfree = vsp;
397 397 mutex_exit(&vmem_segfree_lock);
398 398 }
399 399
400 400 /*
401 401 * Get a vmem_seg_t from vmp's segfree list.
402 402 */
403 403 static vmem_seg_t *
404 404 vmem_getseg(vmem_t *vmp)
405 405 {
406 406 vmem_seg_t *vsp;
407 407
408 408 ASSERT(vmp->vm_nsegfree > 0);
409 409
410 410 vsp = vmp->vm_segfree;
411 411 vmp->vm_segfree = vsp->vs_knext;
412 412 vmp->vm_nsegfree--;
413 413
414 414 return (vsp);
415 415 }
416 416
417 417 /*
418 418 * Put a vmem_seg_t on vmp's segfree list.
419 419 */
420 420 static void
421 421 vmem_putseg(vmem_t *vmp, vmem_seg_t *vsp)
422 422 {
423 423 vsp->vs_knext = vmp->vm_segfree;
424 424 vmp->vm_segfree = vsp;
425 425 vmp->vm_nsegfree++;
426 426 }
427 427
428 428 /*
429 429 * Add vsp to the appropriate freelist.
430 430 */
431 431 static void
432 432 vmem_freelist_insert(vmem_t *vmp, vmem_seg_t *vsp)
433 433 {
434 434 vmem_seg_t *vprev;
435 435
436 436 ASSERT(*VMEM_HASH(vmp, vsp->vs_start) != vsp);
437 437
438 438 vprev = (vmem_seg_t *)&vmp->vm_freelist[highbit(VS_SIZE(vsp)) - 1];
439 439 vsp->vs_type = VMEM_FREE;
440 440 vmp->vm_freemap |= VS_SIZE(vprev);
441 441 VMEM_INSERT(vprev, vsp, k);
442 442
443 443 cv_broadcast(&vmp->vm_cv);
444 444 }
445 445
446 446 /*
447 447 * Take vsp from the freelist.
448 448 */
449 449 static void
450 450 vmem_freelist_delete(vmem_t *vmp, vmem_seg_t *vsp)
451 451 {
452 452 ASSERT(*VMEM_HASH(vmp, vsp->vs_start) != vsp);
453 453 ASSERT(vsp->vs_type == VMEM_FREE);
454 454
455 455 if (vsp->vs_knext->vs_start == 0 && vsp->vs_kprev->vs_start == 0) {
456 456 /*
457 457 * The segments on both sides of 'vsp' are freelist heads,
458 458 * so taking vsp leaves the freelist at vsp->vs_kprev empty.
459 459 */
460 460 ASSERT(vmp->vm_freemap & VS_SIZE(vsp->vs_kprev));
461 461 vmp->vm_freemap ^= VS_SIZE(vsp->vs_kprev);
462 462 }
463 463 VMEM_DELETE(vsp, k);
464 464 }
465 465
466 466 /*
467 467 * Add vsp to the allocated-segment hash table and update kstats.
468 468 */
469 469 static void
470 470 vmem_hash_insert(vmem_t *vmp, vmem_seg_t *vsp)
471 471 {
472 472 vmem_seg_t **bucket;
473 473
474 474 vsp->vs_type = VMEM_ALLOC;
475 475 bucket = VMEM_HASH(vmp, vsp->vs_start);
476 476 vsp->vs_knext = *bucket;
477 477 *bucket = vsp;
478 478
479 479 if (vmem_seg_size == sizeof (vmem_seg_t)) {
480 480 vsp->vs_depth = (uint8_t)getpcstack(vsp->vs_stack,
481 481 VMEM_STACK_DEPTH);
482 482 vsp->vs_thread = curthread;
483 483 vsp->vs_timestamp = gethrtime();
484 484 } else {
485 485 vsp->vs_depth = 0;
486 486 }
487 487
488 488 vmp->vm_kstat.vk_alloc.value.ui64++;
489 489 vmp->vm_kstat.vk_mem_inuse.value.ui64 += VS_SIZE(vsp);
490 490 }
491 491
492 492 /*
493 493 * Remove vsp from the allocated-segment hash table and update kstats.
494 494 */
495 495 static vmem_seg_t *
496 496 vmem_hash_delete(vmem_t *vmp, uintptr_t addr, size_t size)
497 497 {
498 498 vmem_seg_t *vsp, **prev_vspp;
499 499
500 500 prev_vspp = VMEM_HASH(vmp, addr);
501 501 while ((vsp = *prev_vspp) != NULL) {
502 502 if (vsp->vs_start == addr) {
503 503 *prev_vspp = vsp->vs_knext;
504 504 break;
505 505 }
506 506 vmp->vm_kstat.vk_lookup.value.ui64++;
507 507 prev_vspp = &vsp->vs_knext;
508 508 }
509 509
510 510 if (vsp == NULL)
511 511 panic("vmem_hash_delete(%p, %lx, %lu): bad free",
512 512 (void *)vmp, addr, size);
513 513 if (VS_SIZE(vsp) != size)
514 514 panic("vmem_hash_delete(%p, %lx, %lu): wrong size (expect %lu)",
515 515 (void *)vmp, addr, size, VS_SIZE(vsp));
516 516
517 517 vmp->vm_kstat.vk_free.value.ui64++;
518 518 vmp->vm_kstat.vk_mem_inuse.value.ui64 -= size;
519 519
520 520 return (vsp);
521 521 }
522 522
523 523 /*
524 524 * Create a segment spanning the range [start, end) and add it to the arena.
525 525 */
526 526 static vmem_seg_t *
527 527 vmem_seg_create(vmem_t *vmp, vmem_seg_t *vprev, uintptr_t start, uintptr_t end)
528 528 {
529 529 vmem_seg_t *newseg = vmem_getseg(vmp);
530 530
531 531 newseg->vs_start = start;
532 532 newseg->vs_end = end;
533 533 newseg->vs_type = 0;
534 534 newseg->vs_import = 0;
535 535
536 536 VMEM_INSERT(vprev, newseg, a);
537 537
538 538 return (newseg);
539 539 }
540 540
541 541 /*
542 542 * Remove segment vsp from the arena.
543 543 */
544 544 static void
545 545 vmem_seg_destroy(vmem_t *vmp, vmem_seg_t *vsp)
546 546 {
547 547 ASSERT(vsp->vs_type != VMEM_ROTOR);
548 548 VMEM_DELETE(vsp, a);
549 549
550 550 vmem_putseg(vmp, vsp);
551 551 }
552 552
553 553 /*
554 554 * Add the span [vaddr, vaddr + size) to vmp and update kstats.
555 555 */
556 556 static vmem_seg_t *
557 557 vmem_span_create(vmem_t *vmp, void *vaddr, size_t size, uint8_t import)
558 558 {
559 559 vmem_seg_t *newseg, *span;
560 560 uintptr_t start = (uintptr_t)vaddr;
561 561 uintptr_t end = start + size;
562 562
563 563 ASSERT(MUTEX_HELD(&vmp->vm_lock));
564 564
565 565 if ((start | end) & (vmp->vm_quantum - 1))
566 566 panic("vmem_span_create(%p, %p, %lu): misaligned",
567 567 (void *)vmp, vaddr, size);
568 568
569 569 span = vmem_seg_create(vmp, vmp->vm_seg0.vs_aprev, start, end);
570 570 span->vs_type = VMEM_SPAN;
571 571 span->vs_import = import;
572 572 VMEM_INSERT(vmp->vm_seg0.vs_kprev, span, k);
573 573
574 574 newseg = vmem_seg_create(vmp, span, start, end);
575 575 vmem_freelist_insert(vmp, newseg);
576 576
577 577 if (import)
578 578 vmp->vm_kstat.vk_mem_import.value.ui64 += size;
579 579 vmp->vm_kstat.vk_mem_total.value.ui64 += size;
580 580
581 581 return (newseg);
582 582 }
583 583
584 584 /*
585 585 * Remove span vsp from vmp and update kstats.
586 586 */
587 587 static void
588 588 vmem_span_destroy(vmem_t *vmp, vmem_seg_t *vsp)
589 589 {
590 590 vmem_seg_t *span = vsp->vs_aprev;
591 591 size_t size = VS_SIZE(vsp);
592 592
593 593 ASSERT(MUTEX_HELD(&vmp->vm_lock));
594 594 ASSERT(span->vs_type == VMEM_SPAN);
595 595
596 596 if (span->vs_import)
597 597 vmp->vm_kstat.vk_mem_import.value.ui64 -= size;
598 598 vmp->vm_kstat.vk_mem_total.value.ui64 -= size;
599 599
600 600 VMEM_DELETE(span, k);
601 601
602 602 vmem_seg_destroy(vmp, vsp);
603 603 vmem_seg_destroy(vmp, span);
604 604 }
605 605
606 606 /*
607 607 * Allocate the subrange [addr, addr + size) from segment vsp.
608 608 * If there are leftovers on either side, place them on the freelist.
609 609 * Returns a pointer to the segment representing [addr, addr + size).
610 610 */
611 611 static vmem_seg_t *
612 612 vmem_seg_alloc(vmem_t *vmp, vmem_seg_t *vsp, uintptr_t addr, size_t size)
613 613 {
614 614 uintptr_t vs_start = vsp->vs_start;
615 615 uintptr_t vs_end = vsp->vs_end;
616 616 size_t vs_size = vs_end - vs_start;
617 617 size_t realsize = P2ROUNDUP(size, vmp->vm_quantum);
618 618 uintptr_t addr_end = addr + realsize;
619 619
620 620 ASSERT(P2PHASE(vs_start, vmp->vm_quantum) == 0);
621 621 ASSERT(P2PHASE(addr, vmp->vm_quantum) == 0);
622 622 ASSERT(vsp->vs_type == VMEM_FREE);
623 623 ASSERT(addr >= vs_start && addr_end - 1 <= vs_end - 1);
624 624 ASSERT(addr - 1 <= addr_end - 1);
625 625
626 626 /*
627 627 * If we're allocating from the start of the segment, and the
628 628 * remainder will be on the same freelist, we can save quite
629 629 * a bit of work.
630 630 */
631 631 if (P2SAMEHIGHBIT(vs_size, vs_size - realsize) && addr == vs_start) {
632 632 ASSERT(highbit(vs_size) == highbit(vs_size - realsize));
633 633 vsp->vs_start = addr_end;
634 634 vsp = vmem_seg_create(vmp, vsp->vs_aprev, addr, addr + size);
635 635 vmem_hash_insert(vmp, vsp);
636 636 return (vsp);
637 637 }
638 638
639 639 vmem_freelist_delete(vmp, vsp);
640 640
641 641 if (vs_end != addr_end)
642 642 vmem_freelist_insert(vmp,
643 643 vmem_seg_create(vmp, vsp, addr_end, vs_end));
644 644
645 645 if (vs_start != addr)
646 646 vmem_freelist_insert(vmp,
647 647 vmem_seg_create(vmp, vsp->vs_aprev, vs_start, addr));
648 648
649 649 vsp->vs_start = addr;
650 650 vsp->vs_end = addr + size;
651 651
652 652 vmem_hash_insert(vmp, vsp);
653 653 return (vsp);
654 654 }
655 655
656 656 /*
657 657 * Returns 1 if we are populating, 0 otherwise.
658 658 * Call it if we want to prevent recursion from HAT.
659 659 */
660 660 int
661 661 vmem_is_populator()
662 662 {
663 663 return (mutex_owner(&vmem_sleep_lock) == curthread ||
664 664 mutex_owner(&vmem_nosleep_lock) == curthread ||
665 665 mutex_owner(&vmem_pushpage_lock) == curthread ||
666 666 mutex_owner(&vmem_panic_lock) == curthread);
667 667 }
668 668
669 669 /*
670 670 * Populate vmp's segfree list with VMEM_MINFREE vmem_seg_t structures.
671 671 */
672 672 static int
673 673 vmem_populate(vmem_t *vmp, int vmflag)
674 674 {
675 675 char *p;
676 676 vmem_seg_t *vsp;
677 677 ssize_t nseg;
678 678 size_t size;
679 679 kmutex_t *lp;
680 680 int i;
681 681
682 682 while (vmp->vm_nsegfree < VMEM_MINFREE &&
683 683 (vsp = vmem_getseg_global()) != NULL)
684 684 vmem_putseg(vmp, vsp);
685 685
686 686 if (vmp->vm_nsegfree >= VMEM_MINFREE)
687 687 return (1);
688 688
689 689 /*
690 690 * If we're already populating, tap the reserve.
691 691 */
692 692 if (vmem_is_populator()) {
693 693 ASSERT(vmp->vm_cflags & VMC_POPULATOR);
694 694 return (1);
695 695 }
696 696
697 697 mutex_exit(&vmp->vm_lock);
698 698
699 699 if (panic_thread == curthread)
700 700 lp = &vmem_panic_lock;
701 701 else if (vmflag & VM_NOSLEEP)
702 702 lp = &vmem_nosleep_lock;
703 703 else if (vmflag & VM_PUSHPAGE)
704 704 lp = &vmem_pushpage_lock;
705 705 else
706 706 lp = &vmem_sleep_lock;
707 707
708 708 mutex_enter(lp);
709 709
710 710 nseg = VMEM_MINFREE + vmem_populators * VMEM_POPULATE_RESERVE;
711 711 size = P2ROUNDUP(nseg * vmem_seg_size, vmem_seg_arena->vm_quantum);
712 712 nseg = size / vmem_seg_size;
713 713
714 714 /*
715 715 * The following vmem_alloc() may need to populate vmem_seg_arena
716 716 * and all the things it imports from. When doing so, it will tap
717 717 * each arena's reserve to prevent recursion (see the block comment
718 718 * above the definition of VMEM_POPULATE_RESERVE).
719 719 */
720 720 p = vmem_alloc(vmem_seg_arena, size, vmflag & VM_KMFLAGS);
721 721 if (p == NULL) {
722 722 mutex_exit(lp);
723 723 mutex_enter(&vmp->vm_lock);
724 724 vmp->vm_kstat.vk_populate_fail.value.ui64++;
725 725 return (0);
726 726 }
727 727
728 728 /*
729 729 * Restock the arenas that may have been depleted during population.
730 730 */
731 731 for (i = 0; i < vmem_populators; i++) {
732 732 mutex_enter(&vmem_populator[i]->vm_lock);
733 733 while (vmem_populator[i]->vm_nsegfree < VMEM_POPULATE_RESERVE)
734 734 vmem_putseg(vmem_populator[i],
735 735 (vmem_seg_t *)(p + --nseg * vmem_seg_size));
736 736 mutex_exit(&vmem_populator[i]->vm_lock);
737 737 }
738 738
739 739 mutex_exit(lp);
740 740 mutex_enter(&vmp->vm_lock);
741 741
742 742 /*
743 743 * Now take our own segments.
744 744 */
745 745 ASSERT(nseg >= VMEM_MINFREE);
746 746 while (vmp->vm_nsegfree < VMEM_MINFREE)
747 747 vmem_putseg(vmp, (vmem_seg_t *)(p + --nseg * vmem_seg_size));
748 748
749 749 /*
750 750 * Give the remainder to charity.
751 751 */
752 752 while (nseg > 0)
753 753 vmem_putseg_global((vmem_seg_t *)(p + --nseg * vmem_seg_size));
754 754
755 755 return (1);
756 756 }
757 757
758 758 /*
759 759 * Advance a walker from its previous position to 'afterme'.
760 760 * Note: may drop and reacquire vmp->vm_lock.
761 761 */
762 762 static void
763 763 vmem_advance(vmem_t *vmp, vmem_seg_t *walker, vmem_seg_t *afterme)
764 764 {
765 765 vmem_seg_t *vprev = walker->vs_aprev;
766 766 vmem_seg_t *vnext = walker->vs_anext;
767 767 vmem_seg_t *vsp = NULL;
768 768
769 769 VMEM_DELETE(walker, a);
770 770
771 771 if (afterme != NULL)
772 772 VMEM_INSERT(afterme, walker, a);
773 773
774 774 /*
775 775 * The walker segment's presence may have prevented its neighbors
776 776 * from coalescing. If so, coalesce them now.
777 777 */
778 778 if (vprev->vs_type == VMEM_FREE) {
779 779 if (vnext->vs_type == VMEM_FREE) {
780 780 ASSERT(vprev->vs_end == vnext->vs_start);
781 781 vmem_freelist_delete(vmp, vnext);
782 782 vmem_freelist_delete(vmp, vprev);
783 783 vprev->vs_end = vnext->vs_end;
784 784 vmem_freelist_insert(vmp, vprev);
785 785 vmem_seg_destroy(vmp, vnext);
786 786 }
787 787 vsp = vprev;
788 788 } else if (vnext->vs_type == VMEM_FREE) {
789 789 vsp = vnext;
790 790 }
791 791
792 792 /*
793 793 * vsp could represent a complete imported span,
794 794 * in which case we must return it to the source.
795 795 */
796 796 if (vsp != NULL && vsp->vs_aprev->vs_import &&
797 797 vmp->vm_source_free != NULL &&
798 798 vsp->vs_aprev->vs_type == VMEM_SPAN &&
799 799 vsp->vs_anext->vs_type == VMEM_SPAN) {
800 800 void *vaddr = (void *)vsp->vs_start;
801 801 size_t size = VS_SIZE(vsp);
802 802 ASSERT(size == VS_SIZE(vsp->vs_aprev));
803 803 vmem_freelist_delete(vmp, vsp);
804 804 vmem_span_destroy(vmp, vsp);
805 805 mutex_exit(&vmp->vm_lock);
806 806 vmp->vm_source_free(vmp->vm_source, vaddr, size);
807 807 mutex_enter(&vmp->vm_lock);
808 808 }
809 809 }
810 810
811 811 /*
812 812 * VM_NEXTFIT allocations deliberately cycle through all virtual addresses
813 813 * in an arena, so that we avoid reusing addresses for as long as possible.
814 814 * This helps to catch used-after-freed bugs. It's also the perfect policy
815 815 * for allocating things like process IDs, where we want to cycle through
816 816 * all values in order.
817 817 */
818 818 static void *
819 819 vmem_nextfit_alloc(vmem_t *vmp, size_t size, int vmflag)
820 820 {
821 821 vmem_seg_t *vsp, *rotor;
822 822 uintptr_t addr;
823 823 size_t realsize = P2ROUNDUP(size, vmp->vm_quantum);
824 824 size_t vs_size;
825 825
826 826 mutex_enter(&vmp->vm_lock);
827 827
828 828 if (vmp->vm_nsegfree < VMEM_MINFREE && !vmem_populate(vmp, vmflag)) {
829 829 mutex_exit(&vmp->vm_lock);
830 830 return (NULL);
831 831 }
832 832
833 833 /*
834 834 * The common case is that the segment right after the rotor is free,
835 835 * and large enough that extracting 'size' bytes won't change which
836 836 * freelist it's on. In this case we can avoid a *lot* of work.
837 837 * Instead of the normal vmem_seg_alloc(), we just advance the start
838 838 * address of the victim segment. Instead of moving the rotor, we
839 839 * create the new segment structure *behind the rotor*, which has
840 840 * the same effect. And finally, we know we don't have to coalesce
841 841 * the rotor's neighbors because the new segment lies between them.
842 842 */
843 843 rotor = &vmp->vm_rotor;
844 844 vsp = rotor->vs_anext;
845 845 if (vsp->vs_type == VMEM_FREE && (vs_size = VS_SIZE(vsp)) > realsize &&
846 846 P2SAMEHIGHBIT(vs_size, vs_size - realsize)) {
847 847 ASSERT(highbit(vs_size) == highbit(vs_size - realsize));
848 848 addr = vsp->vs_start;
849 849 vsp->vs_start = addr + realsize;
850 850 vmem_hash_insert(vmp,
851 851 vmem_seg_create(vmp, rotor->vs_aprev, addr, addr + size));
852 852 mutex_exit(&vmp->vm_lock);
853 853 return ((void *)addr);
854 854 }
855 855
856 856 /*
857 857 * Starting at the rotor, look for a segment large enough to
858 858 * satisfy the allocation.
859 859 */
860 860 for (;;) {
861 861 vmp->vm_kstat.vk_search.value.ui64++;
862 862 if (vsp->vs_type == VMEM_FREE && VS_SIZE(vsp) >= size)
863 863 break;
864 864 vsp = vsp->vs_anext;
865 865 if (vsp == rotor) {
866 866 /*
867 867 * We've come full circle. One possibility is that the
868 868 * there's actually enough space, but the rotor itself
869 869 * is preventing the allocation from succeeding because
870 870 * it's sitting between two free segments. Therefore,
871 871 * we advance the rotor and see if that liberates a
872 872 * suitable segment.
873 873 */
874 874 vmem_advance(vmp, rotor, rotor->vs_anext);
875 875 vsp = rotor->vs_aprev;
876 876 if (vsp->vs_type == VMEM_FREE && VS_SIZE(vsp) >= size)
877 877 break;
878 878 /*
879 879 * If there's a lower arena we can import from, or it's
880 880 * a VM_NOSLEEP allocation, let vmem_xalloc() handle it.
881 881 * Otherwise, wait until another thread frees something.
882 882 */
883 883 if (vmp->vm_source_alloc != NULL ||
884 884 (vmflag & VM_NOSLEEP)) {
885 885 mutex_exit(&vmp->vm_lock);
886 886 return (vmem_xalloc(vmp, size, vmp->vm_quantum,
887 887 0, 0, NULL, NULL, vmflag & VM_KMFLAGS));
888 888 }
889 889 vmp->vm_kstat.vk_wait.value.ui64++;
890 890 cv_wait(&vmp->vm_cv, &vmp->vm_lock);
891 891 vsp = rotor->vs_anext;
892 892 }
893 893 }
894 894
895 895 /*
896 896 * We found a segment. Extract enough space to satisfy the allocation.
897 897 */
898 898 addr = vsp->vs_start;
899 899 vsp = vmem_seg_alloc(vmp, vsp, addr, size);
900 900 ASSERT(vsp->vs_type == VMEM_ALLOC &&
901 901 vsp->vs_start == addr && vsp->vs_end == addr + size);
902 902
903 903 /*
904 904 * Advance the rotor to right after the newly-allocated segment.
905 905 * That's where the next VM_NEXTFIT allocation will begin searching.
906 906 */
907 907 vmem_advance(vmp, rotor, vsp);
908 908 mutex_exit(&vmp->vm_lock);
909 909 return ((void *)addr);
910 910 }
911 911
912 912 /*
913 913 * Checks if vmp is guaranteed to have a size-byte buffer somewhere on its
914 914 * freelist. If size is not a power-of-2, it can return a false-negative.
915 915 *
916 916 * Used to decide if a newly imported span is superfluous after re-acquiring
917 917 * the arena lock.
918 918 */
919 919 static int
920 920 vmem_canalloc(vmem_t *vmp, size_t size)
921 921 {
922 922 int hb;
923 923 int flist = 0;
924 924 ASSERT(MUTEX_HELD(&vmp->vm_lock));
925 925
926 926 if (ISP2(size))
927 927 flist = lowbit(P2ALIGN(vmp->vm_freemap, size));
928 928 else if ((hb = highbit(size)) < VMEM_FREELISTS)
929 929 flist = lowbit(P2ALIGN(vmp->vm_freemap, 1UL << hb));
930 930
931 931 return (flist);
932 932 }
933 933
934 934 /*
935 935 * Allocate size bytes at offset phase from an align boundary such that the
936 936 * resulting segment [addr, addr + size) is a subset of [minaddr, maxaddr)
937 937 * that does not straddle a nocross-aligned boundary.
938 938 */
939 939 void *
940 940 vmem_xalloc(vmem_t *vmp, size_t size, size_t align_arg, size_t phase,
941 941 size_t nocross, void *minaddr, void *maxaddr, int vmflag)
942 942 {
943 943 vmem_seg_t *vsp;
944 944 vmem_seg_t *vbest = NULL;
945 945 uintptr_t addr, taddr, start, end;
946 946 uintptr_t align = (align_arg != 0) ? align_arg : vmp->vm_quantum;
947 947 void *vaddr, *xvaddr = NULL;
948 948 size_t xsize;
949 949 int hb, flist, resv;
950 950 uint32_t mtbf;
951 951
952 952 if ((align | phase | nocross) & (vmp->vm_quantum - 1))
953 953 panic("vmem_xalloc(%p, %lu, %lu, %lu, %lu, %p, %p, %x): "
954 954 "parameters not vm_quantum aligned",
955 955 (void *)vmp, size, align_arg, phase, nocross,
956 956 minaddr, maxaddr, vmflag);
957 957
958 958 if (nocross != 0 &&
959 959 (align > nocross || P2ROUNDUP(phase + size, align) > nocross))
960 960 panic("vmem_xalloc(%p, %lu, %lu, %lu, %lu, %p, %p, %x): "
961 961 "overconstrained allocation",
962 962 (void *)vmp, size, align_arg, phase, nocross,
963 963 minaddr, maxaddr, vmflag);
964 964
965 965 if (phase >= align || !ISP2(align) || !ISP2(nocross))
966 966 panic("vmem_xalloc(%p, %lu, %lu, %lu, %lu, %p, %p, %x): "
967 967 "parameters inconsistent or invalid",
968 968 (void *)vmp, size, align_arg, phase, nocross,
969 969 minaddr, maxaddr, vmflag);
970 970
971 971 if ((mtbf = vmem_mtbf | vmp->vm_mtbf) != 0 && gethrtime() % mtbf == 0 &&
972 972 (vmflag & (VM_NOSLEEP | VM_PANIC)) == VM_NOSLEEP)
973 973 return (NULL);
974 974
975 975 mutex_enter(&vmp->vm_lock);
976 976 for (;;) {
977 977 if (vmp->vm_nsegfree < VMEM_MINFREE &&
978 978 !vmem_populate(vmp, vmflag))
979 979 break;
980 980 do_alloc:
981 981 /*
982 982 * highbit() returns the highest bit + 1, which is exactly
983 983 * what we want: we want to search the first freelist whose
984 984 * members are *definitely* large enough to satisfy our
985 985 * allocation. However, there are certain cases in which we
986 986 * want to look at the next-smallest freelist (which *might*
987 987 * be able to satisfy the allocation):
988 988 *
989 989 * (1) The size is exactly a power of 2, in which case
990 990 * the smaller freelist is always big enough;
991 991 *
992 992 * (2) All other freelists are empty;
993 993 *
994 994 * (3) We're in the highest possible freelist, which is
995 995 * always empty (e.g. the 4GB freelist on 32-bit systems);
996 996 *
997 997 * (4) We're doing a best-fit or first-fit allocation.
998 998 */
999 999 if (ISP2(size)) {
1000 1000 flist = lowbit(P2ALIGN(vmp->vm_freemap, size));
1001 1001 } else {
1002 1002 hb = highbit(size);
1003 1003 if ((vmp->vm_freemap >> hb) == 0 ||
1004 1004 hb == VMEM_FREELISTS ||
1005 1005 (vmflag & (VM_BESTFIT | VM_FIRSTFIT)))
1006 1006 hb--;
1007 1007 flist = lowbit(P2ALIGN(vmp->vm_freemap, 1UL << hb));
1008 1008 }
1009 1009
1010 1010 for (vbest = NULL, vsp = (flist == 0) ? NULL :
1011 1011 vmp->vm_freelist[flist - 1].vs_knext;
1012 1012 vsp != NULL; vsp = vsp->vs_knext) {
1013 1013 vmp->vm_kstat.vk_search.value.ui64++;
1014 1014 if (vsp->vs_start == 0) {
1015 1015 /*
1016 1016 * We're moving up to a larger freelist,
1017 1017 * so if we've already found a candidate,
1018 1018 * the fit can't possibly get any better.
1019 1019 */
1020 1020 if (vbest != NULL)
1021 1021 break;
1022 1022 /*
1023 1023 * Find the next non-empty freelist.
1024 1024 */
1025 1025 flist = lowbit(P2ALIGN(vmp->vm_freemap,
1026 1026 VS_SIZE(vsp)));
1027 1027 if (flist-- == 0)
1028 1028 break;
1029 1029 vsp = (vmem_seg_t *)&vmp->vm_freelist[flist];
1030 1030 ASSERT(vsp->vs_knext->vs_type == VMEM_FREE);
1031 1031 continue;
1032 1032 }
1033 1033 if (vsp->vs_end - 1 < (uintptr_t)minaddr)
1034 1034 continue;
1035 1035 if (vsp->vs_start > (uintptr_t)maxaddr - 1)
1036 1036 continue;
1037 1037 start = MAX(vsp->vs_start, (uintptr_t)minaddr);
1038 1038 end = MIN(vsp->vs_end - 1, (uintptr_t)maxaddr - 1) + 1;
1039 1039 taddr = P2PHASEUP(start, align, phase);
1040 1040 if (P2BOUNDARY(taddr, size, nocross))
1041 1041 taddr +=
1042 1042 P2ROUNDUP(P2NPHASE(taddr, nocross), align);
1043 1043 if ((taddr - start) + size > end - start ||
1044 1044 (vbest != NULL && VS_SIZE(vsp) >= VS_SIZE(vbest)))
1045 1045 continue;
1046 1046 vbest = vsp;
1047 1047 addr = taddr;
1048 1048 if (!(vmflag & VM_BESTFIT) || VS_SIZE(vbest) == size)
1049 1049 break;
1050 1050 }
1051 1051 if (vbest != NULL)
1052 1052 break;
1053 1053 ASSERT(xvaddr == NULL);
1054 1054 if (size == 0)
1055 1055 panic("vmem_xalloc(): size == 0");
1056 1056 if (vmp->vm_source_alloc != NULL && nocross == 0 &&
1057 1057 minaddr == NULL && maxaddr == NULL) {
1058 1058 size_t aneeded, asize;
1059 1059 size_t aquantum = MAX(vmp->vm_quantum,
1060 1060 vmp->vm_source->vm_quantum);
1061 1061 size_t aphase = phase;
1062 1062 if ((align > aquantum) &&
1063 1063 !(vmp->vm_cflags & VMC_XALIGN)) {
1064 1064 aphase = (P2PHASE(phase, aquantum) != 0) ?
1065 1065 align - vmp->vm_quantum : align - aquantum;
1066 1066 ASSERT(aphase >= phase);
1067 1067 }
1068 1068 aneeded = MAX(size + aphase, vmp->vm_min_import);
1069 1069 asize = P2ROUNDUP(aneeded, aquantum);
1070 1070
1071 1071 if (asize < size) {
1072 1072 /*
1073 1073 * The rounding induced overflow; return NULL
1074 1074 * if we are permitted to fail the allocation
1075 1075 * (and explicitly panic if we aren't).
1076 1076 */
1077 1077 if ((vmflag & VM_NOSLEEP) &&
1078 1078 !(vmflag & VM_PANIC)) {
1079 1079 mutex_exit(&vmp->vm_lock);
1080 1080 return (NULL);
1081 1081 }
1082 1082
1083 1083 panic("vmem_xalloc(): size overflow");
1084 1084 }
1085 1085
1086 1086 /*
1087 1087 * Determine how many segment structures we'll consume.
1088 1088 * The calculation must be precise because if we're
1089 1089 * here on behalf of vmem_populate(), we are taking
1090 1090 * segments from a very limited reserve.
1091 1091 */
1092 1092 if (size == asize && !(vmp->vm_cflags & VMC_XALLOC))
1093 1093 resv = VMEM_SEGS_PER_SPAN_CREATE +
1094 1094 VMEM_SEGS_PER_EXACT_ALLOC;
1095 1095 else if (phase == 0 &&
1096 1096 align <= vmp->vm_source->vm_quantum)
1097 1097 resv = VMEM_SEGS_PER_SPAN_CREATE +
1098 1098 VMEM_SEGS_PER_LEFT_ALLOC;
1099 1099 else
1100 1100 resv = VMEM_SEGS_PER_ALLOC_MAX;
1101 1101
1102 1102 ASSERT(vmp->vm_nsegfree >= resv);
1103 1103 vmp->vm_nsegfree -= resv; /* reserve our segs */
1104 1104 mutex_exit(&vmp->vm_lock);
1105 1105 if (vmp->vm_cflags & VMC_XALLOC) {
1106 1106 size_t oasize = asize;
1107 1107 vaddr = ((vmem_ximport_t *)
1108 1108 vmp->vm_source_alloc)(vmp->vm_source,
1109 1109 &asize, align, vmflag & VM_KMFLAGS);
1110 1110 ASSERT(asize >= oasize);
1111 1111 ASSERT(P2PHASE(asize,
1112 1112 vmp->vm_source->vm_quantum) == 0);
1113 1113 ASSERT(!(vmp->vm_cflags & VMC_XALIGN) ||
1114 1114 IS_P2ALIGNED(vaddr, align));
1115 1115 } else {
1116 1116 vaddr = vmp->vm_source_alloc(vmp->vm_source,
1117 1117 asize, vmflag & VM_KMFLAGS);
1118 1118 }
1119 1119 mutex_enter(&vmp->vm_lock);
1120 1120 vmp->vm_nsegfree += resv; /* claim reservation */
1121 1121 aneeded = size + align - vmp->vm_quantum;
1122 1122 aneeded = P2ROUNDUP(aneeded, vmp->vm_quantum);
1123 1123 if (vaddr != NULL) {
1124 1124 /*
1125 1125 * Since we dropped the vmem lock while
1126 1126 * calling the import function, other
1127 1127 * threads could have imported space
1128 1128 * and made our import unnecessary. In
1129 1129 * order to save space, we return
1130 1130 * excess imports immediately.
1131 1131 */
1132 1132 if (asize > aneeded &&
1133 1133 vmp->vm_source_free != NULL &&
1134 1134 vmem_canalloc(vmp, aneeded)) {
1135 1135 ASSERT(resv >=
1136 1136 VMEM_SEGS_PER_MIDDLE_ALLOC);
1137 1137 xvaddr = vaddr;
1138 1138 xsize = asize;
1139 1139 goto do_alloc;
1140 1140 }
1141 1141 vbest = vmem_span_create(vmp, vaddr, asize, 1);
1142 1142 addr = P2PHASEUP(vbest->vs_start, align, phase);
1143 1143 break;
1144 1144 } else if (vmem_canalloc(vmp, aneeded)) {
1145 1145 /*
1146 1146 * Our import failed, but another thread
1147 1147 * added sufficient free memory to the arena
1148 1148 * to satisfy our request. Go back and
1149 1149 * grab it.
1150 1150 */
1151 1151 ASSERT(resv >= VMEM_SEGS_PER_MIDDLE_ALLOC);
1152 1152 goto do_alloc;
1153 1153 }
1154 1154 }
1155 1155
1156 1156 /*
1157 1157 * If the requestor chooses to fail the allocation attempt
1158 1158 * rather than reap wait and retry - get out of the loop.
1159 1159 */
1160 1160 if (vmflag & VM_ABORT)
1161 1161 break;
1162 1162 mutex_exit(&vmp->vm_lock);
1163 1163 if (vmp->vm_cflags & VMC_IDENTIFIER)
1164 1164 kmem_reap_idspace();
1165 1165 else
1166 1166 kmem_reap();
1167 1167 mutex_enter(&vmp->vm_lock);
1168 1168 if (vmflag & VM_NOSLEEP)
1169 1169 break;
1170 1170 vmp->vm_kstat.vk_wait.value.ui64++;
1171 1171 cv_wait(&vmp->vm_cv, &vmp->vm_lock);
1172 1172 }
1173 1173 if (vbest != NULL) {
1174 1174 ASSERT(vbest->vs_type == VMEM_FREE);
1175 1175 ASSERT(vbest->vs_knext != vbest);
1176 1176 /* re-position to end of buffer */
1177 1177 if (vmflag & VM_ENDALLOC) {
1178 1178 addr += ((vbest->vs_end - (addr + size)) / align) *
1179 1179 align;
1180 1180 }
1181 1181 (void) vmem_seg_alloc(vmp, vbest, addr, size);
1182 1182 mutex_exit(&vmp->vm_lock);
1183 1183 if (xvaddr)
1184 1184 vmp->vm_source_free(vmp->vm_source, xvaddr, xsize);
1185 1185 ASSERT(P2PHASE(addr, align) == phase);
1186 1186 ASSERT(!P2BOUNDARY(addr, size, nocross));
1187 1187 ASSERT(addr >= (uintptr_t)minaddr);
1188 1188 ASSERT(addr + size - 1 <= (uintptr_t)maxaddr - 1);
1189 1189 return ((void *)addr);
1190 1190 }
1191 1191 vmp->vm_kstat.vk_fail.value.ui64++;
1192 1192 mutex_exit(&vmp->vm_lock);
1193 1193 if (vmflag & VM_PANIC)
1194 1194 panic("vmem_xalloc(%p, %lu, %lu, %lu, %lu, %p, %p, %x): "
1195 1195 "cannot satisfy mandatory allocation",
1196 1196 (void *)vmp, size, align_arg, phase, nocross,
1197 1197 minaddr, maxaddr, vmflag);
1198 1198 ASSERT(xvaddr == NULL);
1199 1199 return (NULL);
1200 1200 }
1201 1201
1202 1202 /*
1203 1203 * Free the segment [vaddr, vaddr + size), where vaddr was a constrained
1204 1204 * allocation. vmem_xalloc() and vmem_xfree() must always be paired because
1205 1205 * both routines bypass the quantum caches.
1206 1206 */
1207 1207 void
1208 1208 vmem_xfree(vmem_t *vmp, void *vaddr, size_t size)
1209 1209 {
1210 1210 vmem_seg_t *vsp, *vnext, *vprev;
1211 1211
1212 1212 mutex_enter(&vmp->vm_lock);
1213 1213
1214 1214 vsp = vmem_hash_delete(vmp, (uintptr_t)vaddr, size);
1215 1215 vsp->vs_end = P2ROUNDUP(vsp->vs_end, vmp->vm_quantum);
1216 1216
1217 1217 /*
1218 1218 * Attempt to coalesce with the next segment.
1219 1219 */
1220 1220 vnext = vsp->vs_anext;
1221 1221 if (vnext->vs_type == VMEM_FREE) {
1222 1222 ASSERT(vsp->vs_end == vnext->vs_start);
1223 1223 vmem_freelist_delete(vmp, vnext);
1224 1224 vsp->vs_end = vnext->vs_end;
1225 1225 vmem_seg_destroy(vmp, vnext);
1226 1226 }
1227 1227
1228 1228 /*
1229 1229 * Attempt to coalesce with the previous segment.
1230 1230 */
1231 1231 vprev = vsp->vs_aprev;
1232 1232 if (vprev->vs_type == VMEM_FREE) {
1233 1233 ASSERT(vprev->vs_end == vsp->vs_start);
1234 1234 vmem_freelist_delete(vmp, vprev);
1235 1235 vprev->vs_end = vsp->vs_end;
1236 1236 vmem_seg_destroy(vmp, vsp);
1237 1237 vsp = vprev;
1238 1238 }
1239 1239
1240 1240 /*
1241 1241 * If the entire span is free, return it to the source.
1242 1242 */
1243 1243 if (vsp->vs_aprev->vs_import && vmp->vm_source_free != NULL &&
1244 1244 vsp->vs_aprev->vs_type == VMEM_SPAN &&
1245 1245 vsp->vs_anext->vs_type == VMEM_SPAN) {
1246 1246 vaddr = (void *)vsp->vs_start;
1247 1247 size = VS_SIZE(vsp);
1248 1248 ASSERT(size == VS_SIZE(vsp->vs_aprev));
1249 1249 vmem_span_destroy(vmp, vsp);
1250 1250 mutex_exit(&vmp->vm_lock);
1251 1251 vmp->vm_source_free(vmp->vm_source, vaddr, size);
1252 1252 } else {
1253 1253 vmem_freelist_insert(vmp, vsp);
1254 1254 mutex_exit(&vmp->vm_lock);
1255 1255 }
1256 1256 }
1257 1257
1258 1258 /*
1259 1259 * Allocate size bytes from arena vmp. Returns the allocated address
1260 1260 * on success, NULL on failure. vmflag specifies VM_SLEEP or VM_NOSLEEP,
1261 1261 * and may also specify best-fit, first-fit, or next-fit allocation policy
1262 1262 * instead of the default instant-fit policy. VM_SLEEP allocations are
1263 1263 * guaranteed to succeed.
1264 1264 */
1265 1265 void *
1266 1266 vmem_alloc(vmem_t *vmp, size_t size, int vmflag)
1267 1267 {
1268 1268 vmem_seg_t *vsp;
1269 1269 uintptr_t addr;
1270 1270 int hb;
1271 1271 int flist = 0;
1272 1272 uint32_t mtbf;
1273 1273
1274 1274 if (size - 1 < vmp->vm_qcache_max)
1275 1275 return (kmem_cache_alloc(vmp->vm_qcache[(size - 1) >>
1276 1276 vmp->vm_qshift], vmflag & VM_KMFLAGS));
1277 1277
1278 1278 if ((mtbf = vmem_mtbf | vmp->vm_mtbf) != 0 && gethrtime() % mtbf == 0 &&
1279 1279 (vmflag & (VM_NOSLEEP | VM_PANIC)) == VM_NOSLEEP)
1280 1280 return (NULL);
1281 1281
1282 1282 if (vmflag & VM_NEXTFIT)
1283 1283 return (vmem_nextfit_alloc(vmp, size, vmflag));
1284 1284
1285 1285 if (vmflag & (VM_BESTFIT | VM_FIRSTFIT))
1286 1286 return (vmem_xalloc(vmp, size, vmp->vm_quantum, 0, 0,
1287 1287 NULL, NULL, vmflag));
1288 1288
1289 1289 /*
1290 1290 * Unconstrained instant-fit allocation from the segment list.
1291 1291 */
1292 1292 mutex_enter(&vmp->vm_lock);
1293 1293
1294 1294 if (vmp->vm_nsegfree >= VMEM_MINFREE || vmem_populate(vmp, vmflag)) {
1295 1295 if (ISP2(size))
1296 1296 flist = lowbit(P2ALIGN(vmp->vm_freemap, size));
1297 1297 else if ((hb = highbit(size)) < VMEM_FREELISTS)
1298 1298 flist = lowbit(P2ALIGN(vmp->vm_freemap, 1UL << hb));
1299 1299 }
1300 1300
1301 1301 if (flist-- == 0) {
1302 1302 mutex_exit(&vmp->vm_lock);
1303 1303 return (vmem_xalloc(vmp, size, vmp->vm_quantum,
1304 1304 0, 0, NULL, NULL, vmflag));
1305 1305 }
1306 1306
1307 1307 ASSERT(size <= (1UL << flist));
1308 1308 vsp = vmp->vm_freelist[flist].vs_knext;
1309 1309 addr = vsp->vs_start;
1310 1310 if (vmflag & VM_ENDALLOC) {
1311 1311 addr += vsp->vs_end - (addr + size);
1312 1312 }
1313 1313 (void) vmem_seg_alloc(vmp, vsp, addr, size);
1314 1314 mutex_exit(&vmp->vm_lock);
1315 1315 return ((void *)addr);
1316 1316 }
1317 1317
1318 1318 /*
1319 1319 * Free the segment [vaddr, vaddr + size).
1320 1320 */
1321 1321 void
1322 1322 vmem_free(vmem_t *vmp, void *vaddr, size_t size)
1323 1323 {
1324 1324 if (size - 1 < vmp->vm_qcache_max)
1325 1325 kmem_cache_free(vmp->vm_qcache[(size - 1) >> vmp->vm_qshift],
1326 1326 vaddr);
1327 1327 else
1328 1328 vmem_xfree(vmp, vaddr, size);
1329 1329 }
1330 1330
1331 1331 /*
1332 1332 * Determine whether arena vmp contains the segment [vaddr, vaddr + size).
1333 1333 */
1334 1334 int
1335 1335 vmem_contains(vmem_t *vmp, void *vaddr, size_t size)
1336 1336 {
1337 1337 uintptr_t start = (uintptr_t)vaddr;
1338 1338 uintptr_t end = start + size;
1339 1339 vmem_seg_t *vsp;
1340 1340 vmem_seg_t *seg0 = &vmp->vm_seg0;
1341 1341
1342 1342 mutex_enter(&vmp->vm_lock);
1343 1343 vmp->vm_kstat.vk_contains.value.ui64++;
1344 1344 for (vsp = seg0->vs_knext; vsp != seg0; vsp = vsp->vs_knext) {
1345 1345 vmp->vm_kstat.vk_contains_search.value.ui64++;
1346 1346 ASSERT(vsp->vs_type == VMEM_SPAN);
1347 1347 if (start >= vsp->vs_start && end - 1 <= vsp->vs_end - 1)
1348 1348 break;
1349 1349 }
1350 1350 mutex_exit(&vmp->vm_lock);
1351 1351 return (vsp != seg0);
1352 1352 }
1353 1353
1354 1354 /*
1355 1355 * Add the span [vaddr, vaddr + size) to arena vmp.
1356 1356 */
1357 1357 void *
1358 1358 vmem_add(vmem_t *vmp, void *vaddr, size_t size, int vmflag)
1359 1359 {
1360 1360 if (vaddr == NULL || size == 0)
1361 1361 panic("vmem_add(%p, %p, %lu): bad arguments",
1362 1362 (void *)vmp, vaddr, size);
1363 1363
1364 1364 ASSERT(!vmem_contains(vmp, vaddr, size));
1365 1365
1366 1366 mutex_enter(&vmp->vm_lock);
1367 1367 if (vmem_populate(vmp, vmflag))
1368 1368 (void) vmem_span_create(vmp, vaddr, size, 0);
1369 1369 else
1370 1370 vaddr = NULL;
1371 1371 mutex_exit(&vmp->vm_lock);
1372 1372 return (vaddr);
1373 1373 }
1374 1374
1375 1375 /*
1376 1376 * Walk the vmp arena, applying func to each segment matching typemask.
1377 1377 * If VMEM_REENTRANT is specified, the arena lock is dropped across each
1378 1378 * call to func(); otherwise, it is held for the duration of vmem_walk()
1379 1379 * to ensure a consistent snapshot. Note that VMEM_REENTRANT callbacks
1380 1380 * are *not* necessarily consistent, so they may only be used when a hint
1381 1381 * is adequate.
1382 1382 */
1383 1383 void
1384 1384 vmem_walk(vmem_t *vmp, int typemask,
1385 1385 void (*func)(void *, void *, size_t), void *arg)
1386 1386 {
1387 1387 vmem_seg_t *vsp;
1388 1388 vmem_seg_t *seg0 = &vmp->vm_seg0;
1389 1389 vmem_seg_t walker;
1390 1390
1391 1391 if (typemask & VMEM_WALKER)
1392 1392 return;
1393 1393
1394 1394 bzero(&walker, sizeof (walker));
1395 1395 walker.vs_type = VMEM_WALKER;
1396 1396
1397 1397 mutex_enter(&vmp->vm_lock);
1398 1398 VMEM_INSERT(seg0, &walker, a);
1399 1399 for (vsp = seg0->vs_anext; vsp != seg0; vsp = vsp->vs_anext) {
1400 1400 if (vsp->vs_type & typemask) {
1401 1401 void *start = (void *)vsp->vs_start;
1402 1402 size_t size = VS_SIZE(vsp);
1403 1403 if (typemask & VMEM_REENTRANT) {
1404 1404 vmem_advance(vmp, &walker, vsp);
1405 1405 mutex_exit(&vmp->vm_lock);
1406 1406 func(arg, start, size);
1407 1407 mutex_enter(&vmp->vm_lock);
1408 1408 vsp = &walker;
1409 1409 } else {
1410 1410 func(arg, start, size);
1411 1411 }
1412 1412 }
1413 1413 }
1414 1414 vmem_advance(vmp, &walker, NULL);
1415 1415 mutex_exit(&vmp->vm_lock);
1416 1416 }
1417 1417
1418 1418 /*
1419 1419 * Return the total amount of memory whose type matches typemask. Thus:
1420 1420 *
1421 1421 * typemask VMEM_ALLOC yields total memory allocated (in use).
1422 1422 * typemask VMEM_FREE yields total memory free (available).
1423 1423 * typemask (VMEM_ALLOC | VMEM_FREE) yields total arena size.
1424 1424 */
1425 1425 size_t
1426 1426 vmem_size(vmem_t *vmp, int typemask)
1427 1427 {
1428 1428 uint64_t size = 0;
1429 1429
1430 1430 if (typemask & VMEM_ALLOC)
1431 1431 size += vmp->vm_kstat.vk_mem_inuse.value.ui64;
1432 1432 if (typemask & VMEM_FREE)
1433 1433 size += vmp->vm_kstat.vk_mem_total.value.ui64 -
1434 1434 vmp->vm_kstat.vk_mem_inuse.value.ui64;
1435 1435 return ((size_t)size);
1436 1436 }
1437 1437
1438 1438 /*
1439 1439 * Create an arena called name whose initial span is [base, base + size).
1440 1440 * The arena's natural unit of currency is quantum, so vmem_alloc()
1441 1441 * guarantees quantum-aligned results. The arena may import new spans
1442 1442 * by invoking afunc() on source, and may return those spans by invoking
1443 1443 * ffunc() on source. To make small allocations fast and scalable,
1444 1444 * the arena offers high-performance caching for each integer multiple
1445 1445 * of quantum up to qcache_max.
1446 1446 */
1447 1447 static vmem_t *
1448 1448 vmem_create_common(const char *name, void *base, size_t size, size_t quantum,
1449 1449 void *(*afunc)(vmem_t *, size_t, int),
1450 1450 void (*ffunc)(vmem_t *, void *, size_t),
1451 1451 vmem_t *source, size_t qcache_max, int vmflag)
1452 1452 {
1453 1453 int i;
1454 1454 size_t nqcache;
1455 1455 vmem_t *vmp, *cur, **vmpp;
1456 1456 vmem_seg_t *vsp;
1457 1457 vmem_freelist_t *vfp;
1458 1458 uint32_t id = atomic_inc_32_nv(&vmem_id);
1459 1459
1460 1460 if (vmem_vmem_arena != NULL) {
1461 1461 vmp = vmem_alloc(vmem_vmem_arena, sizeof (vmem_t),
1462 1462 vmflag & VM_KMFLAGS);
1463 1463 } else {
1464 1464 ASSERT(id <= VMEM_INITIAL);
1465 1465 vmp = &vmem0[id - 1];
1466 1466 }
1467 1467
1468 1468 /* An identifier arena must inherit from another identifier arena */
1469 1469 ASSERT(source == NULL || ((source->vm_cflags & VMC_IDENTIFIER) ==
1470 1470 (vmflag & VMC_IDENTIFIER)));
1471 1471
1472 1472 if (vmp == NULL)
1473 1473 return (NULL);
1474 1474 bzero(vmp, sizeof (vmem_t));
1475 1475
1476 1476 (void) snprintf(vmp->vm_name, VMEM_NAMELEN, "%s", name);
1477 1477 mutex_init(&vmp->vm_lock, NULL, MUTEX_DEFAULT, NULL);
1478 1478 cv_init(&vmp->vm_cv, NULL, CV_DEFAULT, NULL);
1479 1479 vmp->vm_cflags = vmflag;
1480 1480 vmflag &= VM_KMFLAGS;
1481 1481
1482 1482 vmp->vm_quantum = quantum;
1483 1483 vmp->vm_qshift = highbit(quantum) - 1;
1484 1484 nqcache = MIN(qcache_max >> vmp->vm_qshift, VMEM_NQCACHE_MAX);
1485 1485
1486 1486 for (i = 0; i <= VMEM_FREELISTS; i++) {
1487 1487 vfp = &vmp->vm_freelist[i];
1488 1488 vfp->vs_end = 1UL << i;
1489 1489 vfp->vs_knext = (vmem_seg_t *)(vfp + 1);
1490 1490 vfp->vs_kprev = (vmem_seg_t *)(vfp - 1);
1491 1491 }
1492 1492
1493 1493 vmp->vm_freelist[0].vs_kprev = NULL;
1494 1494 vmp->vm_freelist[VMEM_FREELISTS].vs_knext = NULL;
1495 1495 vmp->vm_freelist[VMEM_FREELISTS].vs_end = 0;
1496 1496 vmp->vm_hash_table = vmp->vm_hash0;
1497 1497 vmp->vm_hash_mask = VMEM_HASH_INITIAL - 1;
1498 1498 vmp->vm_hash_shift = highbit(vmp->vm_hash_mask);
1499 1499
1500 1500 vsp = &vmp->vm_seg0;
1501 1501 vsp->vs_anext = vsp;
1502 1502 vsp->vs_aprev = vsp;
1503 1503 vsp->vs_knext = vsp;
1504 1504 vsp->vs_kprev = vsp;
1505 1505 vsp->vs_type = VMEM_SPAN;
1506 1506
1507 1507 vsp = &vmp->vm_rotor;
1508 1508 vsp->vs_type = VMEM_ROTOR;
1509 1509 VMEM_INSERT(&vmp->vm_seg0, vsp, a);
1510 1510
1511 1511 bcopy(&vmem_kstat_template, &vmp->vm_kstat, sizeof (vmem_kstat_t));
1512 1512
1513 1513 vmp->vm_id = id;
1514 1514 if (source != NULL)
1515 1515 vmp->vm_kstat.vk_source_id.value.ui32 = source->vm_id;
1516 1516 vmp->vm_source = source;
1517 1517 vmp->vm_source_alloc = afunc;
1518 1518 vmp->vm_source_free = ffunc;
1519 1519
1520 1520 /*
1521 1521 * Some arenas (like vmem_metadata and kmem_metadata) cannot
1522 1522 * use quantum caching to lower fragmentation. Instead, we
1523 1523 * increase their imports, giving a similar effect.
1524 1524 */
1525 1525 if (vmp->vm_cflags & VMC_NO_QCACHE) {
1526 1526 vmp->vm_min_import =
1527 1527 VMEM_QCACHE_SLABSIZE(nqcache << vmp->vm_qshift);
1528 1528 nqcache = 0;
1529 1529 }
1530 1530
1531 1531 if (nqcache != 0) {
1532 1532 ASSERT(!(vmflag & VM_NOSLEEP));
1533 1533 vmp->vm_qcache_max = nqcache << vmp->vm_qshift;
1534 1534 for (i = 0; i < nqcache; i++) {
1535 1535 char buf[VMEM_NAMELEN + 21];
1536 1536 (void) sprintf(buf, "%s_%lu", vmp->vm_name,
1537 1537 (i + 1) * quantum);
1538 1538 vmp->vm_qcache[i] = kmem_cache_create(buf,
1539 1539 (i + 1) * quantum, quantum, NULL, NULL, NULL,
1540 1540 NULL, vmp, KMC_QCACHE | KMC_NOTOUCH);
1541 1541 }
1542 1542 }
1543 1543
1544 1544 if ((vmp->vm_ksp = kstat_create("vmem", vmp->vm_id, vmp->vm_name,
1545 1545 "vmem", KSTAT_TYPE_NAMED, sizeof (vmem_kstat_t) /
1546 1546 sizeof (kstat_named_t), KSTAT_FLAG_VIRTUAL)) != NULL) {
1547 1547 vmp->vm_ksp->ks_data = &vmp->vm_kstat;
1548 1548 kstat_install(vmp->vm_ksp);
1549 1549 }
1550 1550
1551 1551 mutex_enter(&vmem_list_lock);
1552 1552 vmpp = &vmem_list;
1553 1553 while ((cur = *vmpp) != NULL)
1554 1554 vmpp = &cur->vm_next;
1555 1555 *vmpp = vmp;
1556 1556 mutex_exit(&vmem_list_lock);
1557 1557
1558 1558 if (vmp->vm_cflags & VMC_POPULATOR) {
1559 1559 ASSERT(vmem_populators < VMEM_INITIAL);
1560 1560 vmem_populator[atomic_inc_32_nv(&vmem_populators) - 1] = vmp;
1561 1561 mutex_enter(&vmp->vm_lock);
1562 1562 (void) vmem_populate(vmp, vmflag | VM_PANIC);
1563 1563 mutex_exit(&vmp->vm_lock);
1564 1564 }
1565 1565
1566 1566 if ((base || size) && vmem_add(vmp, base, size, vmflag) == NULL) {
1567 1567 vmem_destroy(vmp);
1568 1568 return (NULL);
1569 1569 }
1570 1570
1571 1571 return (vmp);
1572 1572 }
1573 1573
1574 1574 vmem_t *
1575 1575 vmem_xcreate(const char *name, void *base, size_t size, size_t quantum,
1576 1576 vmem_ximport_t *afunc, vmem_free_t *ffunc, vmem_t *source,
1577 1577 size_t qcache_max, int vmflag)
1578 1578 {
1579 1579 ASSERT(!(vmflag & (VMC_POPULATOR | VMC_XALLOC)));
1580 1580 vmflag &= ~(VMC_POPULATOR | VMC_XALLOC);
1581 1581
1582 1582 return (vmem_create_common(name, base, size, quantum,
1583 1583 (vmem_alloc_t *)afunc, ffunc, source, qcache_max,
1584 1584 vmflag | VMC_XALLOC));
1585 1585 }
1586 1586
1587 1587 vmem_t *
1588 1588 vmem_create(const char *name, void *base, size_t size, size_t quantum,
1589 1589 vmem_alloc_t *afunc, vmem_free_t *ffunc, vmem_t *source,
1590 1590 size_t qcache_max, int vmflag)
1591 1591 {
1592 1592 ASSERT(!(vmflag & (VMC_XALLOC | VMC_XALIGN)));
1593 1593 vmflag &= ~(VMC_XALLOC | VMC_XALIGN);
1594 1594
1595 1595 return (vmem_create_common(name, base, size, quantum,
1596 1596 afunc, ffunc, source, qcache_max, vmflag));
1597 1597 }
1598 1598
1599 1599 /*
1600 1600 * Destroy arena vmp.
1601 1601 */
1602 1602 void
1603 1603 vmem_destroy(vmem_t *vmp)
1604 1604 {
1605 1605 vmem_t *cur, **vmpp;
1606 1606 vmem_seg_t *seg0 = &vmp->vm_seg0;
1607 1607 vmem_seg_t *vsp, *anext;
1608 1608 size_t leaked;
1609 1609 int i;
1610 1610
1611 1611 mutex_enter(&vmem_list_lock);
1612 1612 vmpp = &vmem_list;
1613 1613 while ((cur = *vmpp) != vmp)
1614 1614 vmpp = &cur->vm_next;
1615 1615 *vmpp = vmp->vm_next;
1616 1616 mutex_exit(&vmem_list_lock);
1617 1617
1618 1618 for (i = 0; i < VMEM_NQCACHE_MAX; i++)
1619 1619 if (vmp->vm_qcache[i])
1620 1620 kmem_cache_destroy(vmp->vm_qcache[i]);
1621 1621
1622 1622 leaked = vmem_size(vmp, VMEM_ALLOC);
1623 1623 if (leaked != 0)
1624 1624 cmn_err(CE_WARN, "vmem_destroy('%s'): leaked %lu %s",
1625 1625 vmp->vm_name, leaked, (vmp->vm_cflags & VMC_IDENTIFIER) ?
1626 1626 "identifiers" : "bytes");
1627 1627
1628 1628 if (vmp->vm_hash_table != vmp->vm_hash0)
1629 1629 vmem_free(vmem_hash_arena, vmp->vm_hash_table,
1630 1630 (vmp->vm_hash_mask + 1) * sizeof (void *));
1631 1631
1632 1632 /*
1633 1633 * Give back the segment structures for anything that's left in the
1634 1634 * arena, e.g. the primary spans and their free segments.
1635 1635 */
1636 1636 VMEM_DELETE(&vmp->vm_rotor, a);
1637 1637 for (vsp = seg0->vs_anext; vsp != seg0; vsp = anext) {
1638 1638 anext = vsp->vs_anext;
1639 1639 vmem_putseg_global(vsp);
1640 1640 }
1641 1641
1642 1642 while (vmp->vm_nsegfree > 0)
1643 1643 vmem_putseg_global(vmem_getseg(vmp));
1644 1644
1645 1645 kstat_delete(vmp->vm_ksp);
1646 1646
1647 1647 mutex_destroy(&vmp->vm_lock);
1648 1648 cv_destroy(&vmp->vm_cv);
1649 1649 vmem_free(vmem_vmem_arena, vmp, sizeof (vmem_t));
1650 1650 }
1651 1651
1652 1652 /*
1653 1653 * Only shrink vmem hashtable if it is 1<<vmem_rescale_minshift times (8x)
1654 1654 * larger than necessary.
1655 1655 */
1656 1656 int vmem_rescale_minshift = 3;
1657 1657
1658 1658 /*
1659 1659 * Resize vmp's hash table to keep the average lookup depth near 1.0.
1660 1660 */
1661 1661 static void
1662 1662 vmem_hash_rescale(vmem_t *vmp)
1663 1663 {
1664 1664 vmem_seg_t **old_table, **new_table, *vsp;
1665 1665 size_t old_size, new_size, h, nseg;
1666 1666
1667 1667 nseg = (size_t)(vmp->vm_kstat.vk_alloc.value.ui64 -
1668 1668 vmp->vm_kstat.vk_free.value.ui64);
1669 1669
1670 1670 new_size = MAX(VMEM_HASH_INITIAL, 1 << (highbit(3 * nseg + 4) - 2));
1671 1671 old_size = vmp->vm_hash_mask + 1;
1672 1672
1673 1673 if ((old_size >> vmem_rescale_minshift) <= new_size &&
1674 1674 new_size <= (old_size << 1))
1675 1675 return;
1676 1676
1677 1677 new_table = vmem_alloc(vmem_hash_arena, new_size * sizeof (void *),
1678 1678 VM_NOSLEEP);
1679 1679 if (new_table == NULL)
1680 1680 return;
1681 1681 bzero(new_table, new_size * sizeof (void *));
1682 1682
1683 1683 mutex_enter(&vmp->vm_lock);
1684 1684
1685 1685 old_size = vmp->vm_hash_mask + 1;
1686 1686 old_table = vmp->vm_hash_table;
1687 1687
1688 1688 vmp->vm_hash_mask = new_size - 1;
1689 1689 vmp->vm_hash_table = new_table;
1690 1690 vmp->vm_hash_shift = highbit(vmp->vm_hash_mask);
1691 1691
1692 1692 for (h = 0; h < old_size; h++) {
1693 1693 vsp = old_table[h];
1694 1694 while (vsp != NULL) {
1695 1695 uintptr_t addr = vsp->vs_start;
1696 1696 vmem_seg_t *next_vsp = vsp->vs_knext;
1697 1697 vmem_seg_t **hash_bucket = VMEM_HASH(vmp, addr);
1698 1698 vsp->vs_knext = *hash_bucket;
1699 1699 *hash_bucket = vsp;
1700 1700 vsp = next_vsp;
1701 1701 }
1702 1702 }
1703 1703
1704 1704 mutex_exit(&vmp->vm_lock);
1705 1705
1706 1706 if (old_table != vmp->vm_hash0)
1707 1707 vmem_free(vmem_hash_arena, old_table,
1708 1708 old_size * sizeof (void *));
1709 1709 }
1710 1710
1711 1711 /*
1712 1712 * Perform periodic maintenance on all vmem arenas.
1713 1713 */
1714 1714 void
1715 1715 vmem_update(void *dummy)
1716 1716 {
1717 1717 vmem_t *vmp;
1718 1718
1719 1719 mutex_enter(&vmem_list_lock);
1720 1720 for (vmp = vmem_list; vmp != NULL; vmp = vmp->vm_next) {
1721 1721 /*
1722 1722 * If threads are waiting for resources, wake them up
1723 1723 * periodically so they can issue another kmem_reap()
1724 1724 * to reclaim resources cached by the slab allocator.
1725 1725 */
1726 1726 cv_broadcast(&vmp->vm_cv);
1727 1727
1728 1728 /*
1729 1729 * Rescale the hash table to keep the hash chains short.
1730 1730 */
1731 1731 vmem_hash_rescale(vmp);
1732 1732 }
1733 1733 mutex_exit(&vmem_list_lock);
1734 1734
1735 1735 (void) timeout(vmem_update, dummy, vmem_update_interval * hz);
1736 1736 }
1737 1737
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1738 1738 void
1739 1739 vmem_qcache_reap(vmem_t *vmp)
1740 1740 {
1741 1741 int i;
1742 1742
1743 1743 /*
1744 1744 * Reap any quantum caches that may be part of this vmem.
1745 1745 */
1746 1746 for (i = 0; i < VMEM_NQCACHE_MAX; i++)
1747 1747 if (vmp->vm_qcache[i])
1748 - kmem_cache_reap_now(vmp->vm_qcache[i]);
1748 + kmem_cache_reap_soon(vmp->vm_qcache[i]);
1749 1749 }
1750 1750
1751 1751 /*
1752 1752 * Prepare vmem for use.
1753 1753 */
1754 1754 vmem_t *
1755 1755 vmem_init(const char *heap_name,
1756 1756 void *heap_start, size_t heap_size, size_t heap_quantum,
1757 1757 void *(*heap_alloc)(vmem_t *, size_t, int),
1758 1758 void (*heap_free)(vmem_t *, void *, size_t))
1759 1759 {
1760 1760 uint32_t id;
1761 1761 int nseg = VMEM_SEG_INITIAL;
1762 1762 vmem_t *heap;
1763 1763
1764 1764 while (--nseg >= 0)
1765 1765 vmem_putseg_global(&vmem_seg0[nseg]);
1766 1766
1767 1767 heap = vmem_create(heap_name,
1768 1768 heap_start, heap_size, heap_quantum,
1769 1769 NULL, NULL, NULL, 0,
1770 1770 VM_SLEEP | VMC_POPULATOR);
1771 1771
1772 1772 vmem_metadata_arena = vmem_create("vmem_metadata",
1773 1773 NULL, 0, heap_quantum,
1774 1774 vmem_alloc, vmem_free, heap, 8 * heap_quantum,
1775 1775 VM_SLEEP | VMC_POPULATOR | VMC_NO_QCACHE);
1776 1776
1777 1777 vmem_seg_arena = vmem_create("vmem_seg",
1778 1778 NULL, 0, heap_quantum,
1779 1779 heap_alloc, heap_free, vmem_metadata_arena, 0,
1780 1780 VM_SLEEP | VMC_POPULATOR);
1781 1781
1782 1782 vmem_hash_arena = vmem_create("vmem_hash",
1783 1783 NULL, 0, 8,
1784 1784 heap_alloc, heap_free, vmem_metadata_arena, 0,
1785 1785 VM_SLEEP);
1786 1786
1787 1787 vmem_vmem_arena = vmem_create("vmem_vmem",
1788 1788 vmem0, sizeof (vmem0), 1,
1789 1789 heap_alloc, heap_free, vmem_metadata_arena, 0,
1790 1790 VM_SLEEP);
1791 1791
1792 1792 for (id = 0; id < vmem_id; id++)
1793 1793 (void) vmem_xalloc(vmem_vmem_arena, sizeof (vmem_t),
1794 1794 1, 0, 0, &vmem0[id], &vmem0[id + 1],
1795 1795 VM_NOSLEEP | VM_BESTFIT | VM_PANIC);
1796 1796
1797 1797 return (heap);
1798 1798 }
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