xref: /titanic_51/usr/src/uts/common/os/kmem.c (revision 6528affb110ab8cf8b4464874b4a07f3f937475d)
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 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 /*
29  * Kernel memory allocator, as described in the following two papers:
30  *
31  * Jeff Bonwick,
32  * The Slab Allocator: An Object-Caching Kernel Memory Allocator.
33  * Proceedings of the Summer 1994 Usenix Conference.
34  * Available as /shared/sac/PSARC/1994/028/materials/kmem.pdf.
35  *
36  * Jeff Bonwick and Jonathan Adams,
37  * Magazines and vmem: Extending the Slab Allocator to Many CPUs and
38  * Arbitrary Resources.
39  * Proceedings of the 2001 Usenix Conference.
40  * Available as /shared/sac/PSARC/2000/550/materials/vmem.pdf.
41  */
42 
43 #include <sys/kmem_impl.h>
44 #include <sys/vmem_impl.h>
45 #include <sys/param.h>
46 #include <sys/sysmacros.h>
47 #include <sys/vm.h>
48 #include <sys/proc.h>
49 #include <sys/tuneable.h>
50 #include <sys/systm.h>
51 #include <sys/cmn_err.h>
52 #include <sys/debug.h>
53 #include <sys/mutex.h>
54 #include <sys/bitmap.h>
55 #include <sys/atomic.h>
56 #include <sys/kobj.h>
57 #include <sys/disp.h>
58 #include <vm/seg_kmem.h>
59 #include <sys/log.h>
60 #include <sys/callb.h>
61 #include <sys/taskq.h>
62 #include <sys/modctl.h>
63 #include <sys/reboot.h>
64 #include <sys/id32.h>
65 #include <sys/zone.h>
66 #include <sys/netstack.h>
67 
68 extern void streams_msg_init(void);
69 extern int segkp_fromheap;
70 extern void segkp_cache_free(void);
71 
72 struct kmem_cache_kstat {
73 	kstat_named_t	kmc_buf_size;
74 	kstat_named_t	kmc_align;
75 	kstat_named_t	kmc_chunk_size;
76 	kstat_named_t	kmc_slab_size;
77 	kstat_named_t	kmc_alloc;
78 	kstat_named_t	kmc_alloc_fail;
79 	kstat_named_t	kmc_free;
80 	kstat_named_t	kmc_depot_alloc;
81 	kstat_named_t	kmc_depot_free;
82 	kstat_named_t	kmc_depot_contention;
83 	kstat_named_t	kmc_slab_alloc;
84 	kstat_named_t	kmc_slab_free;
85 	kstat_named_t	kmc_buf_constructed;
86 	kstat_named_t	kmc_buf_avail;
87 	kstat_named_t	kmc_buf_inuse;
88 	kstat_named_t	kmc_buf_total;
89 	kstat_named_t	kmc_buf_max;
90 	kstat_named_t	kmc_slab_create;
91 	kstat_named_t	kmc_slab_destroy;
92 	kstat_named_t	kmc_vmem_source;
93 	kstat_named_t	kmc_hash_size;
94 	kstat_named_t	kmc_hash_lookup_depth;
95 	kstat_named_t	kmc_hash_rescale;
96 	kstat_named_t	kmc_full_magazines;
97 	kstat_named_t	kmc_empty_magazines;
98 	kstat_named_t	kmc_magazine_size;
99 } kmem_cache_kstat = {
100 	{ "buf_size",		KSTAT_DATA_UINT64 },
101 	{ "align",		KSTAT_DATA_UINT64 },
102 	{ "chunk_size",		KSTAT_DATA_UINT64 },
103 	{ "slab_size",		KSTAT_DATA_UINT64 },
104 	{ "alloc",		KSTAT_DATA_UINT64 },
105 	{ "alloc_fail",		KSTAT_DATA_UINT64 },
106 	{ "free",		KSTAT_DATA_UINT64 },
107 	{ "depot_alloc",	KSTAT_DATA_UINT64 },
108 	{ "depot_free",		KSTAT_DATA_UINT64 },
109 	{ "depot_contention",	KSTAT_DATA_UINT64 },
110 	{ "slab_alloc",		KSTAT_DATA_UINT64 },
111 	{ "slab_free",		KSTAT_DATA_UINT64 },
112 	{ "buf_constructed",	KSTAT_DATA_UINT64 },
113 	{ "buf_avail",		KSTAT_DATA_UINT64 },
114 	{ "buf_inuse",		KSTAT_DATA_UINT64 },
115 	{ "buf_total",		KSTAT_DATA_UINT64 },
116 	{ "buf_max",		KSTAT_DATA_UINT64 },
117 	{ "slab_create",	KSTAT_DATA_UINT64 },
118 	{ "slab_destroy",	KSTAT_DATA_UINT64 },
119 	{ "vmem_source",	KSTAT_DATA_UINT64 },
120 	{ "hash_size",		KSTAT_DATA_UINT64 },
121 	{ "hash_lookup_depth",	KSTAT_DATA_UINT64 },
122 	{ "hash_rescale",	KSTAT_DATA_UINT64 },
123 	{ "full_magazines",	KSTAT_DATA_UINT64 },
124 	{ "empty_magazines",	KSTAT_DATA_UINT64 },
125 	{ "magazine_size",	KSTAT_DATA_UINT64 },
126 };
127 
128 static kmutex_t kmem_cache_kstat_lock;
129 
130 /*
131  * The default set of caches to back kmem_alloc().
132  * These sizes should be reevaluated periodically.
133  *
134  * We want allocations that are multiples of the coherency granularity
135  * (64 bytes) to be satisfied from a cache which is a multiple of 64
136  * bytes, so that it will be 64-byte aligned.  For all multiples of 64,
137  * the next kmem_cache_size greater than or equal to it must be a
138  * multiple of 64.
139  */
140 static const int kmem_alloc_sizes[] = {
141 	1 * 8,
142 	2 * 8,
143 	3 * 8,
144 	4 * 8,		5 * 8,		6 * 8,		7 * 8,
145 	4 * 16,		5 * 16,		6 * 16,		7 * 16,
146 	4 * 32,		5 * 32,		6 * 32,		7 * 32,
147 	4 * 64,		5 * 64,		6 * 64,		7 * 64,
148 	4 * 128,	5 * 128,	6 * 128,	7 * 128,
149 	P2ALIGN(8192 / 7, 64),
150 	P2ALIGN(8192 / 6, 64),
151 	P2ALIGN(8192 / 5, 64),
152 	P2ALIGN(8192 / 4, 64),
153 	P2ALIGN(8192 / 3, 64),
154 	P2ALIGN(8192 / 2, 64),
155 	P2ALIGN(8192 / 1, 64),
156 	4096 * 3,
157 	8192 * 2,
158 	8192 * 3,
159 	8192 * 4,
160 };
161 
162 #define	KMEM_MAXBUF	32768
163 
164 static kmem_cache_t *kmem_alloc_table[KMEM_MAXBUF >> KMEM_ALIGN_SHIFT];
165 
166 static kmem_magtype_t kmem_magtype[] = {
167 	{ 1,	8,	3200,	65536	},
168 	{ 3,	16,	256,	32768	},
169 	{ 7,	32,	64,	16384	},
170 	{ 15,	64,	0,	8192	},
171 	{ 31,	64,	0,	4096	},
172 	{ 47,	64,	0,	2048	},
173 	{ 63,	64,	0,	1024	},
174 	{ 95,	64,	0,	512	},
175 	{ 143,	64,	0,	0	},
176 };
177 
178 static uint32_t kmem_reaping;
179 static uint32_t kmem_reaping_idspace;
180 
181 /*
182  * kmem tunables
183  */
184 clock_t kmem_reap_interval;	/* cache reaping rate [15 * HZ ticks] */
185 int kmem_depot_contention = 3;	/* max failed tryenters per real interval */
186 pgcnt_t kmem_reapahead = 0;	/* start reaping N pages before pageout */
187 int kmem_panic = 1;		/* whether to panic on error */
188 int kmem_logging = 1;		/* kmem_log_enter() override */
189 uint32_t kmem_mtbf = 0;		/* mean time between failures [default: off] */
190 size_t kmem_transaction_log_size; /* transaction log size [2% of memory] */
191 size_t kmem_content_log_size;	/* content log size [2% of memory] */
192 size_t kmem_failure_log_size;	/* failure log [4 pages per CPU] */
193 size_t kmem_slab_log_size;	/* slab create log [4 pages per CPU] */
194 size_t kmem_content_maxsave = 256; /* KMF_CONTENTS max bytes to log */
195 size_t kmem_lite_minsize = 0;	/* minimum buffer size for KMF_LITE */
196 size_t kmem_lite_maxalign = 1024; /* maximum buffer alignment for KMF_LITE */
197 int kmem_lite_pcs = 4;		/* number of PCs to store in KMF_LITE mode */
198 size_t kmem_maxverify;		/* maximum bytes to inspect in debug routines */
199 size_t kmem_minfirewall;	/* hardware-enforced redzone threshold */
200 
201 #ifdef DEBUG
202 int kmem_flags = KMF_AUDIT | KMF_DEADBEEF | KMF_REDZONE | KMF_CONTENTS;
203 #else
204 int kmem_flags = 0;
205 #endif
206 int kmem_ready;
207 
208 static kmem_cache_t	*kmem_slab_cache;
209 static kmem_cache_t	*kmem_bufctl_cache;
210 static kmem_cache_t	*kmem_bufctl_audit_cache;
211 
212 static kmutex_t		kmem_cache_lock;	/* inter-cache linkage only */
213 kmem_cache_t		kmem_null_cache;
214 
215 static taskq_t		*kmem_taskq;
216 static kmutex_t		kmem_flags_lock;
217 static vmem_t		*kmem_metadata_arena;
218 static vmem_t		*kmem_msb_arena;	/* arena for metadata caches */
219 static vmem_t		*kmem_cache_arena;
220 static vmem_t		*kmem_hash_arena;
221 static vmem_t		*kmem_log_arena;
222 static vmem_t		*kmem_oversize_arena;
223 static vmem_t		*kmem_va_arena;
224 static vmem_t		*kmem_default_arena;
225 static vmem_t		*kmem_firewall_va_arena;
226 static vmem_t		*kmem_firewall_arena;
227 
228 kmem_log_header_t	*kmem_transaction_log;
229 kmem_log_header_t	*kmem_content_log;
230 kmem_log_header_t	*kmem_failure_log;
231 kmem_log_header_t	*kmem_slab_log;
232 
233 static int		kmem_lite_count; /* # of PCs in kmem_buftag_lite_t */
234 
235 #define	KMEM_BUFTAG_LITE_ENTER(bt, count, caller)			\
236 	if ((count) > 0) {						\
237 		pc_t *_s = ((kmem_buftag_lite_t *)(bt))->bt_history;	\
238 		pc_t *_e;						\
239 		/* memmove() the old entries down one notch */		\
240 		for (_e = &_s[(count) - 1]; _e > _s; _e--)		\
241 			*_e = *(_e - 1);				\
242 		*_s = (uintptr_t)(caller);				\
243 	}
244 
245 #define	KMERR_MODIFIED	0	/* buffer modified while on freelist */
246 #define	KMERR_REDZONE	1	/* redzone violation (write past end of buf) */
247 #define	KMERR_DUPFREE	2	/* freed a buffer twice */
248 #define	KMERR_BADADDR	3	/* freed a bad (unallocated) address */
249 #define	KMERR_BADBUFTAG	4	/* buftag corrupted */
250 #define	KMERR_BADBUFCTL	5	/* bufctl corrupted */
251 #define	KMERR_BADCACHE	6	/* freed a buffer to the wrong cache */
252 #define	KMERR_BADSIZE	7	/* alloc size != free size */
253 #define	KMERR_BADBASE	8	/* buffer base address wrong */
254 
255 struct {
256 	hrtime_t	kmp_timestamp;	/* timestamp of panic */
257 	int		kmp_error;	/* type of kmem error */
258 	void		*kmp_buffer;	/* buffer that induced panic */
259 	void		*kmp_realbuf;	/* real start address for buffer */
260 	kmem_cache_t	*kmp_cache;	/* buffer's cache according to client */
261 	kmem_cache_t	*kmp_realcache;	/* actual cache containing buffer */
262 	kmem_slab_t	*kmp_slab;	/* slab accoring to kmem_findslab() */
263 	kmem_bufctl_t	*kmp_bufctl;	/* bufctl */
264 } kmem_panic_info;
265 
266 
267 static void
268 copy_pattern(uint64_t pattern, void *buf_arg, size_t size)
269 {
270 	uint64_t *bufend = (uint64_t *)((char *)buf_arg + size);
271 	uint64_t *buf = buf_arg;
272 
273 	while (buf < bufend)
274 		*buf++ = pattern;
275 }
276 
277 static void *
278 verify_pattern(uint64_t pattern, void *buf_arg, size_t size)
279 {
280 	uint64_t *bufend = (uint64_t *)((char *)buf_arg + size);
281 	uint64_t *buf;
282 
283 	for (buf = buf_arg; buf < bufend; buf++)
284 		if (*buf != pattern)
285 			return (buf);
286 	return (NULL);
287 }
288 
289 static void *
290 verify_and_copy_pattern(uint64_t old, uint64_t new, void *buf_arg, size_t size)
291 {
292 	uint64_t *bufend = (uint64_t *)((char *)buf_arg + size);
293 	uint64_t *buf;
294 
295 	for (buf = buf_arg; buf < bufend; buf++) {
296 		if (*buf != old) {
297 			copy_pattern(old, buf_arg,
298 				(char *)buf - (char *)buf_arg);
299 			return (buf);
300 		}
301 		*buf = new;
302 	}
303 
304 	return (NULL);
305 }
306 
307 static void
308 kmem_cache_applyall(void (*func)(kmem_cache_t *), taskq_t *tq, int tqflag)
309 {
310 	kmem_cache_t *cp;
311 
312 	mutex_enter(&kmem_cache_lock);
313 	for (cp = kmem_null_cache.cache_next; cp != &kmem_null_cache;
314 	    cp = cp->cache_next)
315 		if (tq != NULL)
316 			(void) taskq_dispatch(tq, (task_func_t *)func, cp,
317 			    tqflag);
318 		else
319 			func(cp);
320 	mutex_exit(&kmem_cache_lock);
321 }
322 
323 static void
324 kmem_cache_applyall_id(void (*func)(kmem_cache_t *), taskq_t *tq, int tqflag)
325 {
326 	kmem_cache_t *cp;
327 
328 	mutex_enter(&kmem_cache_lock);
329 	for (cp = kmem_null_cache.cache_next; cp != &kmem_null_cache;
330 	    cp = cp->cache_next) {
331 		if (!(cp->cache_cflags & KMC_IDENTIFIER))
332 			continue;
333 		if (tq != NULL)
334 			(void) taskq_dispatch(tq, (task_func_t *)func, cp,
335 			    tqflag);
336 		else
337 			func(cp);
338 	}
339 	mutex_exit(&kmem_cache_lock);
340 }
341 
342 /*
343  * Debugging support.  Given a buffer address, find its slab.
344  */
345 static kmem_slab_t *
346 kmem_findslab(kmem_cache_t *cp, void *buf)
347 {
348 	kmem_slab_t *sp;
349 
350 	mutex_enter(&cp->cache_lock);
351 	for (sp = cp->cache_nullslab.slab_next;
352 	    sp != &cp->cache_nullslab; sp = sp->slab_next) {
353 		if (KMEM_SLAB_MEMBER(sp, buf)) {
354 			mutex_exit(&cp->cache_lock);
355 			return (sp);
356 		}
357 	}
358 	mutex_exit(&cp->cache_lock);
359 
360 	return (NULL);
361 }
362 
363 static void
364 kmem_error(int error, kmem_cache_t *cparg, void *bufarg)
365 {
366 	kmem_buftag_t *btp = NULL;
367 	kmem_bufctl_t *bcp = NULL;
368 	kmem_cache_t *cp = cparg;
369 	kmem_slab_t *sp;
370 	uint64_t *off;
371 	void *buf = bufarg;
372 
373 	kmem_logging = 0;	/* stop logging when a bad thing happens */
374 
375 	kmem_panic_info.kmp_timestamp = gethrtime();
376 
377 	sp = kmem_findslab(cp, buf);
378 	if (sp == NULL) {
379 		for (cp = kmem_null_cache.cache_prev; cp != &kmem_null_cache;
380 		    cp = cp->cache_prev) {
381 			if ((sp = kmem_findslab(cp, buf)) != NULL)
382 				break;
383 		}
384 	}
385 
386 	if (sp == NULL) {
387 		cp = NULL;
388 		error = KMERR_BADADDR;
389 	} else {
390 		if (cp != cparg)
391 			error = KMERR_BADCACHE;
392 		else
393 			buf = (char *)bufarg - ((uintptr_t)bufarg -
394 			    (uintptr_t)sp->slab_base) % cp->cache_chunksize;
395 		if (buf != bufarg)
396 			error = KMERR_BADBASE;
397 		if (cp->cache_flags & KMF_BUFTAG)
398 			btp = KMEM_BUFTAG(cp, buf);
399 		if (cp->cache_flags & KMF_HASH) {
400 			mutex_enter(&cp->cache_lock);
401 			for (bcp = *KMEM_HASH(cp, buf); bcp; bcp = bcp->bc_next)
402 				if (bcp->bc_addr == buf)
403 					break;
404 			mutex_exit(&cp->cache_lock);
405 			if (bcp == NULL && btp != NULL)
406 				bcp = btp->bt_bufctl;
407 			if (kmem_findslab(cp->cache_bufctl_cache, bcp) ==
408 			    NULL || P2PHASE((uintptr_t)bcp, KMEM_ALIGN) ||
409 			    bcp->bc_addr != buf) {
410 				error = KMERR_BADBUFCTL;
411 				bcp = NULL;
412 			}
413 		}
414 	}
415 
416 	kmem_panic_info.kmp_error = error;
417 	kmem_panic_info.kmp_buffer = bufarg;
418 	kmem_panic_info.kmp_realbuf = buf;
419 	kmem_panic_info.kmp_cache = cparg;
420 	kmem_panic_info.kmp_realcache = cp;
421 	kmem_panic_info.kmp_slab = sp;
422 	kmem_panic_info.kmp_bufctl = bcp;
423 
424 	printf("kernel memory allocator: ");
425 
426 	switch (error) {
427 
428 	case KMERR_MODIFIED:
429 		printf("buffer modified after being freed\n");
430 		off = verify_pattern(KMEM_FREE_PATTERN, buf, cp->cache_verify);
431 		if (off == NULL)	/* shouldn't happen */
432 			off = buf;
433 		printf("modification occurred at offset 0x%lx "
434 		    "(0x%llx replaced by 0x%llx)\n",
435 		    (uintptr_t)off - (uintptr_t)buf,
436 		    (longlong_t)KMEM_FREE_PATTERN, (longlong_t)*off);
437 		break;
438 
439 	case KMERR_REDZONE:
440 		printf("redzone violation: write past end of buffer\n");
441 		break;
442 
443 	case KMERR_BADADDR:
444 		printf("invalid free: buffer not in cache\n");
445 		break;
446 
447 	case KMERR_DUPFREE:
448 		printf("duplicate free: buffer freed twice\n");
449 		break;
450 
451 	case KMERR_BADBUFTAG:
452 		printf("boundary tag corrupted\n");
453 		printf("bcp ^ bxstat = %lx, should be %lx\n",
454 		    (intptr_t)btp->bt_bufctl ^ btp->bt_bxstat,
455 		    KMEM_BUFTAG_FREE);
456 		break;
457 
458 	case KMERR_BADBUFCTL:
459 		printf("bufctl corrupted\n");
460 		break;
461 
462 	case KMERR_BADCACHE:
463 		printf("buffer freed to wrong cache\n");
464 		printf("buffer was allocated from %s,\n", cp->cache_name);
465 		printf("caller attempting free to %s.\n", cparg->cache_name);
466 		break;
467 
468 	case KMERR_BADSIZE:
469 		printf("bad free: free size (%u) != alloc size (%u)\n",
470 		    KMEM_SIZE_DECODE(((uint32_t *)btp)[0]),
471 		    KMEM_SIZE_DECODE(((uint32_t *)btp)[1]));
472 		break;
473 
474 	case KMERR_BADBASE:
475 		printf("bad free: free address (%p) != alloc address (%p)\n",
476 		    bufarg, buf);
477 		break;
478 	}
479 
480 	printf("buffer=%p  bufctl=%p  cache: %s\n",
481 	    bufarg, (void *)bcp, cparg->cache_name);
482 
483 	if (bcp != NULL && (cp->cache_flags & KMF_AUDIT) &&
484 	    error != KMERR_BADBUFCTL) {
485 		int d;
486 		timestruc_t ts;
487 		kmem_bufctl_audit_t *bcap = (kmem_bufctl_audit_t *)bcp;
488 
489 		hrt2ts(kmem_panic_info.kmp_timestamp - bcap->bc_timestamp, &ts);
490 		printf("previous transaction on buffer %p:\n", buf);
491 		printf("thread=%p  time=T-%ld.%09ld  slab=%p  cache: %s\n",
492 		    (void *)bcap->bc_thread, ts.tv_sec, ts.tv_nsec,
493 		    (void *)sp, cp->cache_name);
494 		for (d = 0; d < MIN(bcap->bc_depth, KMEM_STACK_DEPTH); d++) {
495 			ulong_t off;
496 			char *sym = kobj_getsymname(bcap->bc_stack[d], &off);
497 			printf("%s+%lx\n", sym ? sym : "?", off);
498 		}
499 	}
500 	if (kmem_panic > 0)
501 		panic("kernel heap corruption detected");
502 	if (kmem_panic == 0)
503 		debug_enter(NULL);
504 	kmem_logging = 1;	/* resume logging */
505 }
506 
507 static kmem_log_header_t *
508 kmem_log_init(size_t logsize)
509 {
510 	kmem_log_header_t *lhp;
511 	int nchunks = 4 * max_ncpus;
512 	size_t lhsize = (size_t)&((kmem_log_header_t *)0)->lh_cpu[max_ncpus];
513 	int i;
514 
515 	/*
516 	 * Make sure that lhp->lh_cpu[] is nicely aligned
517 	 * to prevent false sharing of cache lines.
518 	 */
519 	lhsize = P2ROUNDUP(lhsize, KMEM_ALIGN);
520 	lhp = vmem_xalloc(kmem_log_arena, lhsize, 64, P2NPHASE(lhsize, 64), 0,
521 	    NULL, NULL, VM_SLEEP);
522 	bzero(lhp, lhsize);
523 
524 	mutex_init(&lhp->lh_lock, NULL, MUTEX_DEFAULT, NULL);
525 	lhp->lh_nchunks = nchunks;
526 	lhp->lh_chunksize = P2ROUNDUP(logsize / nchunks + 1, PAGESIZE);
527 	lhp->lh_base = vmem_alloc(kmem_log_arena,
528 	    lhp->lh_chunksize * nchunks, VM_SLEEP);
529 	lhp->lh_free = vmem_alloc(kmem_log_arena,
530 	    nchunks * sizeof (int), VM_SLEEP);
531 	bzero(lhp->lh_base, lhp->lh_chunksize * nchunks);
532 
533 	for (i = 0; i < max_ncpus; i++) {
534 		kmem_cpu_log_header_t *clhp = &lhp->lh_cpu[i];
535 		mutex_init(&clhp->clh_lock, NULL, MUTEX_DEFAULT, NULL);
536 		clhp->clh_chunk = i;
537 	}
538 
539 	for (i = max_ncpus; i < nchunks; i++)
540 		lhp->lh_free[i] = i;
541 
542 	lhp->lh_head = max_ncpus;
543 	lhp->lh_tail = 0;
544 
545 	return (lhp);
546 }
547 
548 static void *
549 kmem_log_enter(kmem_log_header_t *lhp, void *data, size_t size)
550 {
551 	void *logspace;
552 	kmem_cpu_log_header_t *clhp = &lhp->lh_cpu[CPU->cpu_seqid];
553 
554 	if (lhp == NULL || kmem_logging == 0 || panicstr)
555 		return (NULL);
556 
557 	mutex_enter(&clhp->clh_lock);
558 	clhp->clh_hits++;
559 	if (size > clhp->clh_avail) {
560 		mutex_enter(&lhp->lh_lock);
561 		lhp->lh_hits++;
562 		lhp->lh_free[lhp->lh_tail] = clhp->clh_chunk;
563 		lhp->lh_tail = (lhp->lh_tail + 1) % lhp->lh_nchunks;
564 		clhp->clh_chunk = lhp->lh_free[lhp->lh_head];
565 		lhp->lh_head = (lhp->lh_head + 1) % lhp->lh_nchunks;
566 		clhp->clh_current = lhp->lh_base +
567 			clhp->clh_chunk * lhp->lh_chunksize;
568 		clhp->clh_avail = lhp->lh_chunksize;
569 		if (size > lhp->lh_chunksize)
570 			size = lhp->lh_chunksize;
571 		mutex_exit(&lhp->lh_lock);
572 	}
573 	logspace = clhp->clh_current;
574 	clhp->clh_current += size;
575 	clhp->clh_avail -= size;
576 	bcopy(data, logspace, size);
577 	mutex_exit(&clhp->clh_lock);
578 	return (logspace);
579 }
580 
581 #define	KMEM_AUDIT(lp, cp, bcp)						\
582 {									\
583 	kmem_bufctl_audit_t *_bcp = (kmem_bufctl_audit_t *)(bcp);	\
584 	_bcp->bc_timestamp = gethrtime();				\
585 	_bcp->bc_thread = curthread;					\
586 	_bcp->bc_depth = getpcstack(_bcp->bc_stack, KMEM_STACK_DEPTH);	\
587 	_bcp->bc_lastlog = kmem_log_enter((lp), _bcp, sizeof (*_bcp));	\
588 }
589 
590 static void
591 kmem_log_event(kmem_log_header_t *lp, kmem_cache_t *cp,
592 	kmem_slab_t *sp, void *addr)
593 {
594 	kmem_bufctl_audit_t bca;
595 
596 	bzero(&bca, sizeof (kmem_bufctl_audit_t));
597 	bca.bc_addr = addr;
598 	bca.bc_slab = sp;
599 	bca.bc_cache = cp;
600 	KMEM_AUDIT(lp, cp, &bca);
601 }
602 
603 /*
604  * Create a new slab for cache cp.
605  */
606 static kmem_slab_t *
607 kmem_slab_create(kmem_cache_t *cp, int kmflag)
608 {
609 	size_t slabsize = cp->cache_slabsize;
610 	size_t chunksize = cp->cache_chunksize;
611 	int cache_flags = cp->cache_flags;
612 	size_t color, chunks;
613 	char *buf, *slab;
614 	kmem_slab_t *sp;
615 	kmem_bufctl_t *bcp;
616 	vmem_t *vmp = cp->cache_arena;
617 
618 	color = cp->cache_color + cp->cache_align;
619 	if (color > cp->cache_maxcolor)
620 		color = cp->cache_mincolor;
621 	cp->cache_color = color;
622 
623 	slab = vmem_alloc(vmp, slabsize, kmflag & KM_VMFLAGS);
624 
625 	if (slab == NULL)
626 		goto vmem_alloc_failure;
627 
628 	ASSERT(P2PHASE((uintptr_t)slab, vmp->vm_quantum) == 0);
629 
630 	if (!(cp->cache_cflags & KMC_NOTOUCH))
631 		copy_pattern(KMEM_UNINITIALIZED_PATTERN, slab, slabsize);
632 
633 	if (cache_flags & KMF_HASH) {
634 		if ((sp = kmem_cache_alloc(kmem_slab_cache, kmflag)) == NULL)
635 			goto slab_alloc_failure;
636 		chunks = (slabsize - color) / chunksize;
637 	} else {
638 		sp = KMEM_SLAB(cp, slab);
639 		chunks = (slabsize - sizeof (kmem_slab_t) - color) / chunksize;
640 	}
641 
642 	sp->slab_cache	= cp;
643 	sp->slab_head	= NULL;
644 	sp->slab_refcnt	= 0;
645 	sp->slab_base	= buf = slab + color;
646 	sp->slab_chunks	= chunks;
647 
648 	ASSERT(chunks > 0);
649 	while (chunks-- != 0) {
650 		if (cache_flags & KMF_HASH) {
651 			bcp = kmem_cache_alloc(cp->cache_bufctl_cache, kmflag);
652 			if (bcp == NULL)
653 				goto bufctl_alloc_failure;
654 			if (cache_flags & KMF_AUDIT) {
655 				kmem_bufctl_audit_t *bcap =
656 				    (kmem_bufctl_audit_t *)bcp;
657 				bzero(bcap, sizeof (kmem_bufctl_audit_t));
658 				bcap->bc_cache = cp;
659 			}
660 			bcp->bc_addr = buf;
661 			bcp->bc_slab = sp;
662 		} else {
663 			bcp = KMEM_BUFCTL(cp, buf);
664 		}
665 		if (cache_flags & KMF_BUFTAG) {
666 			kmem_buftag_t *btp = KMEM_BUFTAG(cp, buf);
667 			btp->bt_redzone = KMEM_REDZONE_PATTERN;
668 			btp->bt_bufctl = bcp;
669 			btp->bt_bxstat = (intptr_t)bcp ^ KMEM_BUFTAG_FREE;
670 			if (cache_flags & KMF_DEADBEEF) {
671 				copy_pattern(KMEM_FREE_PATTERN, buf,
672 				    cp->cache_verify);
673 			}
674 		}
675 		bcp->bc_next = sp->slab_head;
676 		sp->slab_head = bcp;
677 		buf += chunksize;
678 	}
679 
680 	kmem_log_event(kmem_slab_log, cp, sp, slab);
681 
682 	return (sp);
683 
684 bufctl_alloc_failure:
685 
686 	while ((bcp = sp->slab_head) != NULL) {
687 		sp->slab_head = bcp->bc_next;
688 		kmem_cache_free(cp->cache_bufctl_cache, bcp);
689 	}
690 	kmem_cache_free(kmem_slab_cache, sp);
691 
692 slab_alloc_failure:
693 
694 	vmem_free(vmp, slab, slabsize);
695 
696 vmem_alloc_failure:
697 
698 	kmem_log_event(kmem_failure_log, cp, NULL, NULL);
699 	atomic_add_64(&cp->cache_alloc_fail, 1);
700 
701 	return (NULL);
702 }
703 
704 /*
705  * Destroy a slab.
706  */
707 static void
708 kmem_slab_destroy(kmem_cache_t *cp, kmem_slab_t *sp)
709 {
710 	vmem_t *vmp = cp->cache_arena;
711 	void *slab = (void *)P2ALIGN((uintptr_t)sp->slab_base, vmp->vm_quantum);
712 
713 	if (cp->cache_flags & KMF_HASH) {
714 		kmem_bufctl_t *bcp;
715 		while ((bcp = sp->slab_head) != NULL) {
716 			sp->slab_head = bcp->bc_next;
717 			kmem_cache_free(cp->cache_bufctl_cache, bcp);
718 		}
719 		kmem_cache_free(kmem_slab_cache, sp);
720 	}
721 	vmem_free(vmp, slab, cp->cache_slabsize);
722 }
723 
724 /*
725  * Allocate a raw (unconstructed) buffer from cp's slab layer.
726  */
727 static void *
728 kmem_slab_alloc(kmem_cache_t *cp, int kmflag)
729 {
730 	kmem_bufctl_t *bcp, **hash_bucket;
731 	kmem_slab_t *sp;
732 	void *buf;
733 
734 	mutex_enter(&cp->cache_lock);
735 	cp->cache_slab_alloc++;
736 	sp = cp->cache_freelist;
737 	ASSERT(sp->slab_cache == cp);
738 	if (sp->slab_head == NULL) {
739 		/*
740 		 * The freelist is empty.  Create a new slab.
741 		 */
742 		mutex_exit(&cp->cache_lock);
743 		if ((sp = kmem_slab_create(cp, kmflag)) == NULL)
744 			return (NULL);
745 		mutex_enter(&cp->cache_lock);
746 		cp->cache_slab_create++;
747 		if ((cp->cache_buftotal += sp->slab_chunks) > cp->cache_bufmax)
748 			cp->cache_bufmax = cp->cache_buftotal;
749 		sp->slab_next = cp->cache_freelist;
750 		sp->slab_prev = cp->cache_freelist->slab_prev;
751 		sp->slab_next->slab_prev = sp;
752 		sp->slab_prev->slab_next = sp;
753 		cp->cache_freelist = sp;
754 	}
755 
756 	sp->slab_refcnt++;
757 	ASSERT(sp->slab_refcnt <= sp->slab_chunks);
758 
759 	/*
760 	 * If we're taking the last buffer in the slab,
761 	 * remove the slab from the cache's freelist.
762 	 */
763 	bcp = sp->slab_head;
764 	if ((sp->slab_head = bcp->bc_next) == NULL) {
765 		cp->cache_freelist = sp->slab_next;
766 		ASSERT(sp->slab_refcnt == sp->slab_chunks);
767 	}
768 
769 	if (cp->cache_flags & KMF_HASH) {
770 		/*
771 		 * Add buffer to allocated-address hash table.
772 		 */
773 		buf = bcp->bc_addr;
774 		hash_bucket = KMEM_HASH(cp, buf);
775 		bcp->bc_next = *hash_bucket;
776 		*hash_bucket = bcp;
777 		if ((cp->cache_flags & (KMF_AUDIT | KMF_BUFTAG)) == KMF_AUDIT) {
778 			KMEM_AUDIT(kmem_transaction_log, cp, bcp);
779 		}
780 	} else {
781 		buf = KMEM_BUF(cp, bcp);
782 	}
783 
784 	ASSERT(KMEM_SLAB_MEMBER(sp, buf));
785 
786 	mutex_exit(&cp->cache_lock);
787 
788 	return (buf);
789 }
790 
791 /*
792  * Free a raw (unconstructed) buffer to cp's slab layer.
793  */
794 static void
795 kmem_slab_free(kmem_cache_t *cp, void *buf)
796 {
797 	kmem_slab_t *sp;
798 	kmem_bufctl_t *bcp, **prev_bcpp;
799 
800 	ASSERT(buf != NULL);
801 
802 	mutex_enter(&cp->cache_lock);
803 	cp->cache_slab_free++;
804 
805 	if (cp->cache_flags & KMF_HASH) {
806 		/*
807 		 * Look up buffer in allocated-address hash table.
808 		 */
809 		prev_bcpp = KMEM_HASH(cp, buf);
810 		while ((bcp = *prev_bcpp) != NULL) {
811 			if (bcp->bc_addr == buf) {
812 				*prev_bcpp = bcp->bc_next;
813 				sp = bcp->bc_slab;
814 				break;
815 			}
816 			cp->cache_lookup_depth++;
817 			prev_bcpp = &bcp->bc_next;
818 		}
819 	} else {
820 		bcp = KMEM_BUFCTL(cp, buf);
821 		sp = KMEM_SLAB(cp, buf);
822 	}
823 
824 	if (bcp == NULL || sp->slab_cache != cp || !KMEM_SLAB_MEMBER(sp, buf)) {
825 		mutex_exit(&cp->cache_lock);
826 		kmem_error(KMERR_BADADDR, cp, buf);
827 		return;
828 	}
829 
830 	if ((cp->cache_flags & (KMF_AUDIT | KMF_BUFTAG)) == KMF_AUDIT) {
831 		if (cp->cache_flags & KMF_CONTENTS)
832 			((kmem_bufctl_audit_t *)bcp)->bc_contents =
833 			    kmem_log_enter(kmem_content_log, buf,
834 				cp->cache_contents);
835 		KMEM_AUDIT(kmem_transaction_log, cp, bcp);
836 	}
837 
838 	/*
839 	 * If this slab isn't currently on the freelist, put it there.
840 	 */
841 	if (sp->slab_head == NULL) {
842 		ASSERT(sp->slab_refcnt == sp->slab_chunks);
843 		ASSERT(cp->cache_freelist != sp);
844 		sp->slab_next->slab_prev = sp->slab_prev;
845 		sp->slab_prev->slab_next = sp->slab_next;
846 		sp->slab_next = cp->cache_freelist;
847 		sp->slab_prev = cp->cache_freelist->slab_prev;
848 		sp->slab_next->slab_prev = sp;
849 		sp->slab_prev->slab_next = sp;
850 		cp->cache_freelist = sp;
851 	}
852 
853 	bcp->bc_next = sp->slab_head;
854 	sp->slab_head = bcp;
855 
856 	ASSERT(sp->slab_refcnt >= 1);
857 	if (--sp->slab_refcnt == 0) {
858 		/*
859 		 * There are no outstanding allocations from this slab,
860 		 * so we can reclaim the memory.
861 		 */
862 		sp->slab_next->slab_prev = sp->slab_prev;
863 		sp->slab_prev->slab_next = sp->slab_next;
864 		if (sp == cp->cache_freelist)
865 			cp->cache_freelist = sp->slab_next;
866 		cp->cache_slab_destroy++;
867 		cp->cache_buftotal -= sp->slab_chunks;
868 		mutex_exit(&cp->cache_lock);
869 		kmem_slab_destroy(cp, sp);
870 		return;
871 	}
872 	mutex_exit(&cp->cache_lock);
873 }
874 
875 static int
876 kmem_cache_alloc_debug(kmem_cache_t *cp, void *buf, int kmflag, int construct,
877     caddr_t caller)
878 {
879 	kmem_buftag_t *btp = KMEM_BUFTAG(cp, buf);
880 	kmem_bufctl_audit_t *bcp = (kmem_bufctl_audit_t *)btp->bt_bufctl;
881 	uint32_t mtbf;
882 
883 	if (btp->bt_bxstat != ((intptr_t)bcp ^ KMEM_BUFTAG_FREE)) {
884 		kmem_error(KMERR_BADBUFTAG, cp, buf);
885 		return (-1);
886 	}
887 
888 	btp->bt_bxstat = (intptr_t)bcp ^ KMEM_BUFTAG_ALLOC;
889 
890 	if ((cp->cache_flags & KMF_HASH) && bcp->bc_addr != buf) {
891 		kmem_error(KMERR_BADBUFCTL, cp, buf);
892 		return (-1);
893 	}
894 
895 	if (cp->cache_flags & KMF_DEADBEEF) {
896 		if (!construct && (cp->cache_flags & KMF_LITE)) {
897 			if (*(uint64_t *)buf != KMEM_FREE_PATTERN) {
898 				kmem_error(KMERR_MODIFIED, cp, buf);
899 				return (-1);
900 			}
901 			if (cp->cache_constructor != NULL)
902 				*(uint64_t *)buf = btp->bt_redzone;
903 			else
904 				*(uint64_t *)buf = KMEM_UNINITIALIZED_PATTERN;
905 		} else {
906 			construct = 1;
907 			if (verify_and_copy_pattern(KMEM_FREE_PATTERN,
908 			    KMEM_UNINITIALIZED_PATTERN, buf,
909 			    cp->cache_verify)) {
910 				kmem_error(KMERR_MODIFIED, cp, buf);
911 				return (-1);
912 			}
913 		}
914 	}
915 	btp->bt_redzone = KMEM_REDZONE_PATTERN;
916 
917 	if ((mtbf = kmem_mtbf | cp->cache_mtbf) != 0 &&
918 	    gethrtime() % mtbf == 0 &&
919 	    (kmflag & (KM_NOSLEEP | KM_PANIC)) == KM_NOSLEEP) {
920 		kmem_log_event(kmem_failure_log, cp, NULL, NULL);
921 		if (!construct && cp->cache_destructor != NULL)
922 			cp->cache_destructor(buf, cp->cache_private);
923 	} else {
924 		mtbf = 0;
925 	}
926 
927 	if (mtbf || (construct && cp->cache_constructor != NULL &&
928 	    cp->cache_constructor(buf, cp->cache_private, kmflag) != 0)) {
929 		atomic_add_64(&cp->cache_alloc_fail, 1);
930 		btp->bt_bxstat = (intptr_t)bcp ^ KMEM_BUFTAG_FREE;
931 		if (cp->cache_flags & KMF_DEADBEEF)
932 			copy_pattern(KMEM_FREE_PATTERN, buf, cp->cache_verify);
933 		kmem_slab_free(cp, buf);
934 		return (-1);
935 	}
936 
937 	if (cp->cache_flags & KMF_AUDIT) {
938 		KMEM_AUDIT(kmem_transaction_log, cp, bcp);
939 	}
940 
941 	if ((cp->cache_flags & KMF_LITE) &&
942 	    !(cp->cache_cflags & KMC_KMEM_ALLOC)) {
943 		KMEM_BUFTAG_LITE_ENTER(btp, kmem_lite_count, caller);
944 	}
945 
946 	return (0);
947 }
948 
949 static int
950 kmem_cache_free_debug(kmem_cache_t *cp, void *buf, caddr_t caller)
951 {
952 	kmem_buftag_t *btp = KMEM_BUFTAG(cp, buf);
953 	kmem_bufctl_audit_t *bcp = (kmem_bufctl_audit_t *)btp->bt_bufctl;
954 	kmem_slab_t *sp;
955 
956 	if (btp->bt_bxstat != ((intptr_t)bcp ^ KMEM_BUFTAG_ALLOC)) {
957 		if (btp->bt_bxstat == ((intptr_t)bcp ^ KMEM_BUFTAG_FREE)) {
958 			kmem_error(KMERR_DUPFREE, cp, buf);
959 			return (-1);
960 		}
961 		sp = kmem_findslab(cp, buf);
962 		if (sp == NULL || sp->slab_cache != cp)
963 			kmem_error(KMERR_BADADDR, cp, buf);
964 		else
965 			kmem_error(KMERR_REDZONE, cp, buf);
966 		return (-1);
967 	}
968 
969 	btp->bt_bxstat = (intptr_t)bcp ^ KMEM_BUFTAG_FREE;
970 
971 	if ((cp->cache_flags & KMF_HASH) && bcp->bc_addr != buf) {
972 		kmem_error(KMERR_BADBUFCTL, cp, buf);
973 		return (-1);
974 	}
975 
976 	if (btp->bt_redzone != KMEM_REDZONE_PATTERN) {
977 		kmem_error(KMERR_REDZONE, cp, buf);
978 		return (-1);
979 	}
980 
981 	if (cp->cache_flags & KMF_AUDIT) {
982 		if (cp->cache_flags & KMF_CONTENTS)
983 			bcp->bc_contents = kmem_log_enter(kmem_content_log,
984 			    buf, cp->cache_contents);
985 		KMEM_AUDIT(kmem_transaction_log, cp, bcp);
986 	}
987 
988 	if ((cp->cache_flags & KMF_LITE) &&
989 	    !(cp->cache_cflags & KMC_KMEM_ALLOC)) {
990 		KMEM_BUFTAG_LITE_ENTER(btp, kmem_lite_count, caller);
991 	}
992 
993 	if (cp->cache_flags & KMF_DEADBEEF) {
994 		if (cp->cache_flags & KMF_LITE)
995 			btp->bt_redzone = *(uint64_t *)buf;
996 		else if (cp->cache_destructor != NULL)
997 			cp->cache_destructor(buf, cp->cache_private);
998 
999 		copy_pattern(KMEM_FREE_PATTERN, buf, cp->cache_verify);
1000 	}
1001 
1002 	return (0);
1003 }
1004 
1005 /*
1006  * Free each object in magazine mp to cp's slab layer, and free mp itself.
1007  */
1008 static void
1009 kmem_magazine_destroy(kmem_cache_t *cp, kmem_magazine_t *mp, int nrounds)
1010 {
1011 	int round;
1012 
1013 	ASSERT(cp->cache_next == NULL || taskq_member(kmem_taskq, curthread));
1014 
1015 	for (round = 0; round < nrounds; round++) {
1016 		void *buf = mp->mag_round[round];
1017 
1018 		if (cp->cache_flags & KMF_DEADBEEF) {
1019 			if (verify_pattern(KMEM_FREE_PATTERN, buf,
1020 			    cp->cache_verify) != NULL) {
1021 				kmem_error(KMERR_MODIFIED, cp, buf);
1022 				continue;
1023 			}
1024 			if ((cp->cache_flags & KMF_LITE) &&
1025 			    cp->cache_destructor != NULL) {
1026 				kmem_buftag_t *btp = KMEM_BUFTAG(cp, buf);
1027 				*(uint64_t *)buf = btp->bt_redzone;
1028 				cp->cache_destructor(buf, cp->cache_private);
1029 				*(uint64_t *)buf = KMEM_FREE_PATTERN;
1030 			}
1031 		} else if (cp->cache_destructor != NULL) {
1032 			cp->cache_destructor(buf, cp->cache_private);
1033 		}
1034 
1035 		kmem_slab_free(cp, buf);
1036 	}
1037 	ASSERT(KMEM_MAGAZINE_VALID(cp, mp));
1038 	kmem_cache_free(cp->cache_magtype->mt_cache, mp);
1039 }
1040 
1041 /*
1042  * Allocate a magazine from the depot.
1043  */
1044 static kmem_magazine_t *
1045 kmem_depot_alloc(kmem_cache_t *cp, kmem_maglist_t *mlp)
1046 {
1047 	kmem_magazine_t *mp;
1048 
1049 	/*
1050 	 * If we can't get the depot lock without contention,
1051 	 * update our contention count.  We use the depot
1052 	 * contention rate to determine whether we need to
1053 	 * increase the magazine size for better scalability.
1054 	 */
1055 	if (!mutex_tryenter(&cp->cache_depot_lock)) {
1056 		mutex_enter(&cp->cache_depot_lock);
1057 		cp->cache_depot_contention++;
1058 	}
1059 
1060 	if ((mp = mlp->ml_list) != NULL) {
1061 		ASSERT(KMEM_MAGAZINE_VALID(cp, mp));
1062 		mlp->ml_list = mp->mag_next;
1063 		if (--mlp->ml_total < mlp->ml_min)
1064 			mlp->ml_min = mlp->ml_total;
1065 		mlp->ml_alloc++;
1066 	}
1067 
1068 	mutex_exit(&cp->cache_depot_lock);
1069 
1070 	return (mp);
1071 }
1072 
1073 /*
1074  * Free a magazine to the depot.
1075  */
1076 static void
1077 kmem_depot_free(kmem_cache_t *cp, kmem_maglist_t *mlp, kmem_magazine_t *mp)
1078 {
1079 	mutex_enter(&cp->cache_depot_lock);
1080 	ASSERT(KMEM_MAGAZINE_VALID(cp, mp));
1081 	mp->mag_next = mlp->ml_list;
1082 	mlp->ml_list = mp;
1083 	mlp->ml_total++;
1084 	mutex_exit(&cp->cache_depot_lock);
1085 }
1086 
1087 /*
1088  * Update the working set statistics for cp's depot.
1089  */
1090 static void
1091 kmem_depot_ws_update(kmem_cache_t *cp)
1092 {
1093 	mutex_enter(&cp->cache_depot_lock);
1094 	cp->cache_full.ml_reaplimit = cp->cache_full.ml_min;
1095 	cp->cache_full.ml_min = cp->cache_full.ml_total;
1096 	cp->cache_empty.ml_reaplimit = cp->cache_empty.ml_min;
1097 	cp->cache_empty.ml_min = cp->cache_empty.ml_total;
1098 	mutex_exit(&cp->cache_depot_lock);
1099 }
1100 
1101 /*
1102  * Reap all magazines that have fallen out of the depot's working set.
1103  */
1104 static void
1105 kmem_depot_ws_reap(kmem_cache_t *cp)
1106 {
1107 	long reap;
1108 	kmem_magazine_t *mp;
1109 
1110 	ASSERT(cp->cache_next == NULL || taskq_member(kmem_taskq, curthread));
1111 
1112 	reap = MIN(cp->cache_full.ml_reaplimit, cp->cache_full.ml_min);
1113 	while (reap-- && (mp = kmem_depot_alloc(cp, &cp->cache_full)) != NULL)
1114 		kmem_magazine_destroy(cp, mp, cp->cache_magtype->mt_magsize);
1115 
1116 	reap = MIN(cp->cache_empty.ml_reaplimit, cp->cache_empty.ml_min);
1117 	while (reap-- && (mp = kmem_depot_alloc(cp, &cp->cache_empty)) != NULL)
1118 		kmem_magazine_destroy(cp, mp, 0);
1119 }
1120 
1121 static void
1122 kmem_cpu_reload(kmem_cpu_cache_t *ccp, kmem_magazine_t *mp, int rounds)
1123 {
1124 	ASSERT((ccp->cc_loaded == NULL && ccp->cc_rounds == -1) ||
1125 	    (ccp->cc_loaded && ccp->cc_rounds + rounds == ccp->cc_magsize));
1126 	ASSERT(ccp->cc_magsize > 0);
1127 
1128 	ccp->cc_ploaded = ccp->cc_loaded;
1129 	ccp->cc_prounds = ccp->cc_rounds;
1130 	ccp->cc_loaded = mp;
1131 	ccp->cc_rounds = rounds;
1132 }
1133 
1134 /*
1135  * Allocate a constructed object from cache cp.
1136  */
1137 void *
1138 kmem_cache_alloc(kmem_cache_t *cp, int kmflag)
1139 {
1140 	kmem_cpu_cache_t *ccp = KMEM_CPU_CACHE(cp);
1141 	kmem_magazine_t *fmp;
1142 	void *buf;
1143 
1144 	mutex_enter(&ccp->cc_lock);
1145 	for (;;) {
1146 		/*
1147 		 * If there's an object available in the current CPU's
1148 		 * loaded magazine, just take it and return.
1149 		 */
1150 		if (ccp->cc_rounds > 0) {
1151 			buf = ccp->cc_loaded->mag_round[--ccp->cc_rounds];
1152 			ccp->cc_alloc++;
1153 			mutex_exit(&ccp->cc_lock);
1154 			if ((ccp->cc_flags & KMF_BUFTAG) &&
1155 			    kmem_cache_alloc_debug(cp, buf, kmflag, 0,
1156 			    caller()) == -1) {
1157 				if (kmflag & KM_NOSLEEP)
1158 					return (NULL);
1159 				mutex_enter(&ccp->cc_lock);
1160 				continue;
1161 			}
1162 			return (buf);
1163 		}
1164 
1165 		/*
1166 		 * The loaded magazine is empty.  If the previously loaded
1167 		 * magazine was full, exchange them and try again.
1168 		 */
1169 		if (ccp->cc_prounds > 0) {
1170 			kmem_cpu_reload(ccp, ccp->cc_ploaded, ccp->cc_prounds);
1171 			continue;
1172 		}
1173 
1174 		/*
1175 		 * If the magazine layer is disabled, break out now.
1176 		 */
1177 		if (ccp->cc_magsize == 0)
1178 			break;
1179 
1180 		/*
1181 		 * Try to get a full magazine from the depot.
1182 		 */
1183 		fmp = kmem_depot_alloc(cp, &cp->cache_full);
1184 		if (fmp != NULL) {
1185 			if (ccp->cc_ploaded != NULL)
1186 				kmem_depot_free(cp, &cp->cache_empty,
1187 				    ccp->cc_ploaded);
1188 			kmem_cpu_reload(ccp, fmp, ccp->cc_magsize);
1189 			continue;
1190 		}
1191 
1192 		/*
1193 		 * There are no full magazines in the depot,
1194 		 * so fall through to the slab layer.
1195 		 */
1196 		break;
1197 	}
1198 	mutex_exit(&ccp->cc_lock);
1199 
1200 	/*
1201 	 * We couldn't allocate a constructed object from the magazine layer,
1202 	 * so get a raw buffer from the slab layer and apply its constructor.
1203 	 */
1204 	buf = kmem_slab_alloc(cp, kmflag);
1205 
1206 	if (buf == NULL)
1207 		return (NULL);
1208 
1209 	if (cp->cache_flags & KMF_BUFTAG) {
1210 		/*
1211 		 * Make kmem_cache_alloc_debug() apply the constructor for us.
1212 		 */
1213 		if (kmem_cache_alloc_debug(cp, buf, kmflag, 1,
1214 		    caller()) == -1) {
1215 			if (kmflag & KM_NOSLEEP)
1216 				return (NULL);
1217 			/*
1218 			 * kmem_cache_alloc_debug() detected corruption
1219 			 * but didn't panic (kmem_panic <= 0).  Try again.
1220 			 */
1221 			return (kmem_cache_alloc(cp, kmflag));
1222 		}
1223 		return (buf);
1224 	}
1225 
1226 	if (cp->cache_constructor != NULL &&
1227 	    cp->cache_constructor(buf, cp->cache_private, kmflag) != 0) {
1228 		atomic_add_64(&cp->cache_alloc_fail, 1);
1229 		kmem_slab_free(cp, buf);
1230 		return (NULL);
1231 	}
1232 
1233 	return (buf);
1234 }
1235 
1236 /*
1237  * Free a constructed object to cache cp.
1238  */
1239 void
1240 kmem_cache_free(kmem_cache_t *cp, void *buf)
1241 {
1242 	kmem_cpu_cache_t *ccp = KMEM_CPU_CACHE(cp);
1243 	kmem_magazine_t *emp;
1244 	kmem_magtype_t *mtp;
1245 
1246 	if (ccp->cc_flags & KMF_BUFTAG)
1247 		if (kmem_cache_free_debug(cp, buf, caller()) == -1)
1248 			return;
1249 
1250 	mutex_enter(&ccp->cc_lock);
1251 	for (;;) {
1252 		/*
1253 		 * If there's a slot available in the current CPU's
1254 		 * loaded magazine, just put the object there and return.
1255 		 */
1256 		if ((uint_t)ccp->cc_rounds < ccp->cc_magsize) {
1257 			ccp->cc_loaded->mag_round[ccp->cc_rounds++] = buf;
1258 			ccp->cc_free++;
1259 			mutex_exit(&ccp->cc_lock);
1260 			return;
1261 		}
1262 
1263 		/*
1264 		 * The loaded magazine is full.  If the previously loaded
1265 		 * magazine was empty, exchange them and try again.
1266 		 */
1267 		if (ccp->cc_prounds == 0) {
1268 			kmem_cpu_reload(ccp, ccp->cc_ploaded, ccp->cc_prounds);
1269 			continue;
1270 		}
1271 
1272 		/*
1273 		 * If the magazine layer is disabled, break out now.
1274 		 */
1275 		if (ccp->cc_magsize == 0)
1276 			break;
1277 
1278 		/*
1279 		 * Try to get an empty magazine from the depot.
1280 		 */
1281 		emp = kmem_depot_alloc(cp, &cp->cache_empty);
1282 		if (emp != NULL) {
1283 			if (ccp->cc_ploaded != NULL)
1284 				kmem_depot_free(cp, &cp->cache_full,
1285 				    ccp->cc_ploaded);
1286 			kmem_cpu_reload(ccp, emp, 0);
1287 			continue;
1288 		}
1289 
1290 		/*
1291 		 * There are no empty magazines in the depot,
1292 		 * so try to allocate a new one.  We must drop all locks
1293 		 * across kmem_cache_alloc() because lower layers may
1294 		 * attempt to allocate from this cache.
1295 		 */
1296 		mtp = cp->cache_magtype;
1297 		mutex_exit(&ccp->cc_lock);
1298 		emp = kmem_cache_alloc(mtp->mt_cache, KM_NOSLEEP);
1299 		mutex_enter(&ccp->cc_lock);
1300 
1301 		if (emp != NULL) {
1302 			/*
1303 			 * We successfully allocated an empty magazine.
1304 			 * However, we had to drop ccp->cc_lock to do it,
1305 			 * so the cache's magazine size may have changed.
1306 			 * If so, free the magazine and try again.
1307 			 */
1308 			if (ccp->cc_magsize != mtp->mt_magsize) {
1309 				mutex_exit(&ccp->cc_lock);
1310 				kmem_cache_free(mtp->mt_cache, emp);
1311 				mutex_enter(&ccp->cc_lock);
1312 				continue;
1313 			}
1314 
1315 			/*
1316 			 * We got a magazine of the right size.  Add it to
1317 			 * the depot and try the whole dance again.
1318 			 */
1319 			kmem_depot_free(cp, &cp->cache_empty, emp);
1320 			continue;
1321 		}
1322 
1323 		/*
1324 		 * We couldn't allocate an empty magazine,
1325 		 * so fall through to the slab layer.
1326 		 */
1327 		break;
1328 	}
1329 	mutex_exit(&ccp->cc_lock);
1330 
1331 	/*
1332 	 * We couldn't free our constructed object to the magazine layer,
1333 	 * so apply its destructor and free it to the slab layer.
1334 	 * Note that if KMF_DEADBEEF is in effect and KMF_LITE is not,
1335 	 * kmem_cache_free_debug() will have already applied the destructor.
1336 	 */
1337 	if ((cp->cache_flags & (KMF_DEADBEEF | KMF_LITE)) != KMF_DEADBEEF &&
1338 	    cp->cache_destructor != NULL) {
1339 		if (cp->cache_flags & KMF_DEADBEEF) {	/* KMF_LITE implied */
1340 			kmem_buftag_t *btp = KMEM_BUFTAG(cp, buf);
1341 			*(uint64_t *)buf = btp->bt_redzone;
1342 			cp->cache_destructor(buf, cp->cache_private);
1343 			*(uint64_t *)buf = KMEM_FREE_PATTERN;
1344 		} else {
1345 			cp->cache_destructor(buf, cp->cache_private);
1346 		}
1347 	}
1348 
1349 	kmem_slab_free(cp, buf);
1350 }
1351 
1352 void *
1353 kmem_zalloc(size_t size, int kmflag)
1354 {
1355 	size_t index = (size - 1) >> KMEM_ALIGN_SHIFT;
1356 	void *buf;
1357 
1358 	if (index < KMEM_MAXBUF >> KMEM_ALIGN_SHIFT) {
1359 		kmem_cache_t *cp = kmem_alloc_table[index];
1360 		buf = kmem_cache_alloc(cp, kmflag);
1361 		if (buf != NULL) {
1362 			if (cp->cache_flags & KMF_BUFTAG) {
1363 				kmem_buftag_t *btp = KMEM_BUFTAG(cp, buf);
1364 				((uint8_t *)buf)[size] = KMEM_REDZONE_BYTE;
1365 				((uint32_t *)btp)[1] = KMEM_SIZE_ENCODE(size);
1366 
1367 				if (cp->cache_flags & KMF_LITE) {
1368 					KMEM_BUFTAG_LITE_ENTER(btp,
1369 					    kmem_lite_count, caller());
1370 				}
1371 			}
1372 			bzero(buf, size);
1373 		}
1374 	} else {
1375 		buf = kmem_alloc(size, kmflag);
1376 		if (buf != NULL)
1377 			bzero(buf, size);
1378 	}
1379 	return (buf);
1380 }
1381 
1382 void *
1383 kmem_alloc(size_t size, int kmflag)
1384 {
1385 	size_t index = (size - 1) >> KMEM_ALIGN_SHIFT;
1386 	void *buf;
1387 
1388 	if (index < KMEM_MAXBUF >> KMEM_ALIGN_SHIFT) {
1389 		kmem_cache_t *cp = kmem_alloc_table[index];
1390 		buf = kmem_cache_alloc(cp, kmflag);
1391 		if ((cp->cache_flags & KMF_BUFTAG) && buf != NULL) {
1392 			kmem_buftag_t *btp = KMEM_BUFTAG(cp, buf);
1393 			((uint8_t *)buf)[size] = KMEM_REDZONE_BYTE;
1394 			((uint32_t *)btp)[1] = KMEM_SIZE_ENCODE(size);
1395 
1396 			if (cp->cache_flags & KMF_LITE) {
1397 				KMEM_BUFTAG_LITE_ENTER(btp, kmem_lite_count,
1398 				    caller());
1399 			}
1400 		}
1401 		return (buf);
1402 	}
1403 	if (size == 0)
1404 		return (NULL);
1405 	buf = vmem_alloc(kmem_oversize_arena, size, kmflag & KM_VMFLAGS);
1406 	if (buf == NULL)
1407 		kmem_log_event(kmem_failure_log, NULL, NULL, (void *)size);
1408 	return (buf);
1409 }
1410 
1411 void
1412 kmem_free(void *buf, size_t size)
1413 {
1414 	size_t index = (size - 1) >> KMEM_ALIGN_SHIFT;
1415 
1416 	if (index < KMEM_MAXBUF >> KMEM_ALIGN_SHIFT) {
1417 		kmem_cache_t *cp = kmem_alloc_table[index];
1418 		if (cp->cache_flags & KMF_BUFTAG) {
1419 			kmem_buftag_t *btp = KMEM_BUFTAG(cp, buf);
1420 			uint32_t *ip = (uint32_t *)btp;
1421 			if (ip[1] != KMEM_SIZE_ENCODE(size)) {
1422 				if (*(uint64_t *)buf == KMEM_FREE_PATTERN) {
1423 					kmem_error(KMERR_DUPFREE, cp, buf);
1424 					return;
1425 				}
1426 				if (KMEM_SIZE_VALID(ip[1])) {
1427 					ip[0] = KMEM_SIZE_ENCODE(size);
1428 					kmem_error(KMERR_BADSIZE, cp, buf);
1429 				} else {
1430 					kmem_error(KMERR_REDZONE, cp, buf);
1431 				}
1432 				return;
1433 			}
1434 			if (((uint8_t *)buf)[size] != KMEM_REDZONE_BYTE) {
1435 				kmem_error(KMERR_REDZONE, cp, buf);
1436 				return;
1437 			}
1438 			btp->bt_redzone = KMEM_REDZONE_PATTERN;
1439 			if (cp->cache_flags & KMF_LITE) {
1440 				KMEM_BUFTAG_LITE_ENTER(btp, kmem_lite_count,
1441 				    caller());
1442 			}
1443 		}
1444 		kmem_cache_free(cp, buf);
1445 	} else {
1446 		if (buf == NULL && size == 0)
1447 			return;
1448 		vmem_free(kmem_oversize_arena, buf, size);
1449 	}
1450 }
1451 
1452 void *
1453 kmem_firewall_va_alloc(vmem_t *vmp, size_t size, int vmflag)
1454 {
1455 	size_t realsize = size + vmp->vm_quantum;
1456 	void *addr;
1457 
1458 	/*
1459 	 * Annoying edge case: if 'size' is just shy of ULONG_MAX, adding
1460 	 * vm_quantum will cause integer wraparound.  Check for this, and
1461 	 * blow off the firewall page in this case.  Note that such a
1462 	 * giant allocation (the entire kernel address space) can never
1463 	 * be satisfied, so it will either fail immediately (VM_NOSLEEP)
1464 	 * or sleep forever (VM_SLEEP).  Thus, there is no need for a
1465 	 * corresponding check in kmem_firewall_va_free().
1466 	 */
1467 	if (realsize < size)
1468 		realsize = size;
1469 
1470 	/*
1471 	 * While boot still owns resource management, make sure that this
1472 	 * redzone virtual address allocation is properly accounted for in
1473 	 * OBPs "virtual-memory" "available" lists because we're
1474 	 * effectively claiming them for a red zone.  If we don't do this,
1475 	 * the available lists become too fragmented and too large for the
1476 	 * current boot/kernel memory list interface.
1477 	 */
1478 	addr = vmem_alloc(vmp, realsize, vmflag | VM_NEXTFIT);
1479 
1480 	if (addr != NULL && kvseg.s_base == NULL && realsize != size)
1481 		(void) boot_virt_alloc((char *)addr + size, vmp->vm_quantum);
1482 
1483 	return (addr);
1484 }
1485 
1486 void
1487 kmem_firewall_va_free(vmem_t *vmp, void *addr, size_t size)
1488 {
1489 	ASSERT((kvseg.s_base == NULL ?
1490 	    va_to_pfn((char *)addr + size) :
1491 	    hat_getpfnum(kas.a_hat, (caddr_t)addr + size)) == PFN_INVALID);
1492 
1493 	vmem_free(vmp, addr, size + vmp->vm_quantum);
1494 }
1495 
1496 /*
1497  * Try to allocate at least `size' bytes of memory without sleeping or
1498  * panicking. Return actual allocated size in `asize'. If allocation failed,
1499  * try final allocation with sleep or panic allowed.
1500  */
1501 void *
1502 kmem_alloc_tryhard(size_t size, size_t *asize, int kmflag)
1503 {
1504 	void *p;
1505 
1506 	*asize = P2ROUNDUP(size, KMEM_ALIGN);
1507 	do {
1508 		p = kmem_alloc(*asize, (kmflag | KM_NOSLEEP) & ~KM_PANIC);
1509 		if (p != NULL)
1510 			return (p);
1511 		*asize += KMEM_ALIGN;
1512 	} while (*asize <= PAGESIZE);
1513 
1514 	*asize = P2ROUNDUP(size, KMEM_ALIGN);
1515 	return (kmem_alloc(*asize, kmflag));
1516 }
1517 
1518 /*
1519  * Reclaim all unused memory from a cache.
1520  */
1521 static void
1522 kmem_cache_reap(kmem_cache_t *cp)
1523 {
1524 	/*
1525 	 * Ask the cache's owner to free some memory if possible.
1526 	 * The idea is to handle things like the inode cache, which
1527 	 * typically sits on a bunch of memory that it doesn't truly
1528 	 * *need*.  Reclaim policy is entirely up to the owner; this
1529 	 * callback is just an advisory plea for help.
1530 	 */
1531 	if (cp->cache_reclaim != NULL)
1532 		cp->cache_reclaim(cp->cache_private);
1533 
1534 	kmem_depot_ws_reap(cp);
1535 }
1536 
1537 static void
1538 kmem_reap_timeout(void *flag_arg)
1539 {
1540 	uint32_t *flag = (uint32_t *)flag_arg;
1541 
1542 	ASSERT(flag == &kmem_reaping || flag == &kmem_reaping_idspace);
1543 	*flag = 0;
1544 }
1545 
1546 static void
1547 kmem_reap_done(void *flag)
1548 {
1549 	(void) timeout(kmem_reap_timeout, flag, kmem_reap_interval);
1550 }
1551 
1552 static void
1553 kmem_reap_start(void *flag)
1554 {
1555 	ASSERT(flag == &kmem_reaping || flag == &kmem_reaping_idspace);
1556 
1557 	if (flag == &kmem_reaping) {
1558 		kmem_cache_applyall(kmem_cache_reap, kmem_taskq, TQ_NOSLEEP);
1559 		/*
1560 		 * if we have segkp under heap, reap segkp cache.
1561 		 */
1562 		if (segkp_fromheap)
1563 			segkp_cache_free();
1564 	}
1565 	else
1566 		kmem_cache_applyall_id(kmem_cache_reap, kmem_taskq, TQ_NOSLEEP);
1567 
1568 	/*
1569 	 * We use taskq_dispatch() to schedule a timeout to clear
1570 	 * the flag so that kmem_reap() becomes self-throttling:
1571 	 * we won't reap again until the current reap completes *and*
1572 	 * at least kmem_reap_interval ticks have elapsed.
1573 	 */
1574 	if (!taskq_dispatch(kmem_taskq, kmem_reap_done, flag, TQ_NOSLEEP))
1575 		kmem_reap_done(flag);
1576 }
1577 
1578 static void
1579 kmem_reap_common(void *flag_arg)
1580 {
1581 	uint32_t *flag = (uint32_t *)flag_arg;
1582 
1583 	if (MUTEX_HELD(&kmem_cache_lock) || kmem_taskq == NULL ||
1584 	    cas32(flag, 0, 1) != 0)
1585 		return;
1586 
1587 	/*
1588 	 * It may not be kosher to do memory allocation when a reap is called
1589 	 * is called (for example, if vmem_populate() is in the call chain).
1590 	 * So we start the reap going with a TQ_NOALLOC dispatch.  If the
1591 	 * dispatch fails, we reset the flag, and the next reap will try again.
1592 	 */
1593 	if (!taskq_dispatch(kmem_taskq, kmem_reap_start, flag, TQ_NOALLOC))
1594 		*flag = 0;
1595 }
1596 
1597 /*
1598  * Reclaim all unused memory from all caches.  Called from the VM system
1599  * when memory gets tight.
1600  */
1601 void
1602 kmem_reap(void)
1603 {
1604 	kmem_reap_common(&kmem_reaping);
1605 }
1606 
1607 /*
1608  * Reclaim all unused memory from identifier arenas, called when a vmem
1609  * arena not back by memory is exhausted.  Since reaping memory-backed caches
1610  * cannot help with identifier exhaustion, we avoid both a large amount of
1611  * work and unwanted side-effects from reclaim callbacks.
1612  */
1613 void
1614 kmem_reap_idspace(void)
1615 {
1616 	kmem_reap_common(&kmem_reaping_idspace);
1617 }
1618 
1619 /*
1620  * Purge all magazines from a cache and set its magazine limit to zero.
1621  * All calls are serialized by the kmem_taskq lock, except for the final
1622  * call from kmem_cache_destroy().
1623  */
1624 static void
1625 kmem_cache_magazine_purge(kmem_cache_t *cp)
1626 {
1627 	kmem_cpu_cache_t *ccp;
1628 	kmem_magazine_t *mp, *pmp;
1629 	int rounds, prounds, cpu_seqid;
1630 
1631 	ASSERT(cp->cache_next == NULL || taskq_member(kmem_taskq, curthread));
1632 	ASSERT(MUTEX_NOT_HELD(&cp->cache_lock));
1633 
1634 	for (cpu_seqid = 0; cpu_seqid < max_ncpus; cpu_seqid++) {
1635 		ccp = &cp->cache_cpu[cpu_seqid];
1636 
1637 		mutex_enter(&ccp->cc_lock);
1638 		mp = ccp->cc_loaded;
1639 		pmp = ccp->cc_ploaded;
1640 		rounds = ccp->cc_rounds;
1641 		prounds = ccp->cc_prounds;
1642 		ccp->cc_loaded = NULL;
1643 		ccp->cc_ploaded = NULL;
1644 		ccp->cc_rounds = -1;
1645 		ccp->cc_prounds = -1;
1646 		ccp->cc_magsize = 0;
1647 		mutex_exit(&ccp->cc_lock);
1648 
1649 		if (mp)
1650 			kmem_magazine_destroy(cp, mp, rounds);
1651 		if (pmp)
1652 			kmem_magazine_destroy(cp, pmp, prounds);
1653 	}
1654 
1655 	/*
1656 	 * Updating the working set statistics twice in a row has the
1657 	 * effect of setting the working set size to zero, so everything
1658 	 * is eligible for reaping.
1659 	 */
1660 	kmem_depot_ws_update(cp);
1661 	kmem_depot_ws_update(cp);
1662 
1663 	kmem_depot_ws_reap(cp);
1664 }
1665 
1666 /*
1667  * Enable per-cpu magazines on a cache.
1668  */
1669 static void
1670 kmem_cache_magazine_enable(kmem_cache_t *cp)
1671 {
1672 	int cpu_seqid;
1673 
1674 	if (cp->cache_flags & KMF_NOMAGAZINE)
1675 		return;
1676 
1677 	for (cpu_seqid = 0; cpu_seqid < max_ncpus; cpu_seqid++) {
1678 		kmem_cpu_cache_t *ccp = &cp->cache_cpu[cpu_seqid];
1679 		mutex_enter(&ccp->cc_lock);
1680 		ccp->cc_magsize = cp->cache_magtype->mt_magsize;
1681 		mutex_exit(&ccp->cc_lock);
1682 	}
1683 
1684 }
1685 
1686 /*
1687  * Reap (almost) everything right now.  See kmem_cache_magazine_purge()
1688  * for explanation of the back-to-back kmem_depot_ws_update() calls.
1689  */
1690 void
1691 kmem_cache_reap_now(kmem_cache_t *cp)
1692 {
1693 	kmem_depot_ws_update(cp);
1694 	kmem_depot_ws_update(cp);
1695 
1696 	(void) taskq_dispatch(kmem_taskq,
1697 	    (task_func_t *)kmem_depot_ws_reap, cp, TQ_SLEEP);
1698 	taskq_wait(kmem_taskq);
1699 }
1700 
1701 /*
1702  * Recompute a cache's magazine size.  The trade-off is that larger magazines
1703  * provide a higher transfer rate with the depot, while smaller magazines
1704  * reduce memory consumption.  Magazine resizing is an expensive operation;
1705  * it should not be done frequently.
1706  *
1707  * Changes to the magazine size are serialized by the kmem_taskq lock.
1708  *
1709  * Note: at present this only grows the magazine size.  It might be useful
1710  * to allow shrinkage too.
1711  */
1712 static void
1713 kmem_cache_magazine_resize(kmem_cache_t *cp)
1714 {
1715 	kmem_magtype_t *mtp = cp->cache_magtype;
1716 
1717 	ASSERT(taskq_member(kmem_taskq, curthread));
1718 
1719 	if (cp->cache_chunksize < mtp->mt_maxbuf) {
1720 		kmem_cache_magazine_purge(cp);
1721 		mutex_enter(&cp->cache_depot_lock);
1722 		cp->cache_magtype = ++mtp;
1723 		cp->cache_depot_contention_prev =
1724 		    cp->cache_depot_contention + INT_MAX;
1725 		mutex_exit(&cp->cache_depot_lock);
1726 		kmem_cache_magazine_enable(cp);
1727 	}
1728 }
1729 
1730 /*
1731  * Rescale a cache's hash table, so that the table size is roughly the
1732  * cache size.  We want the average lookup time to be extremely small.
1733  */
1734 static void
1735 kmem_hash_rescale(kmem_cache_t *cp)
1736 {
1737 	kmem_bufctl_t **old_table, **new_table, *bcp;
1738 	size_t old_size, new_size, h;
1739 
1740 	ASSERT(taskq_member(kmem_taskq, curthread));
1741 
1742 	new_size = MAX(KMEM_HASH_INITIAL,
1743 	    1 << (highbit(3 * cp->cache_buftotal + 4) - 2));
1744 	old_size = cp->cache_hash_mask + 1;
1745 
1746 	if ((old_size >> 1) <= new_size && new_size <= (old_size << 1))
1747 		return;
1748 
1749 	new_table = vmem_alloc(kmem_hash_arena, new_size * sizeof (void *),
1750 	    VM_NOSLEEP);
1751 	if (new_table == NULL)
1752 		return;
1753 	bzero(new_table, new_size * sizeof (void *));
1754 
1755 	mutex_enter(&cp->cache_lock);
1756 
1757 	old_size = cp->cache_hash_mask + 1;
1758 	old_table = cp->cache_hash_table;
1759 
1760 	cp->cache_hash_mask = new_size - 1;
1761 	cp->cache_hash_table = new_table;
1762 	cp->cache_rescale++;
1763 
1764 	for (h = 0; h < old_size; h++) {
1765 		bcp = old_table[h];
1766 		while (bcp != NULL) {
1767 			void *addr = bcp->bc_addr;
1768 			kmem_bufctl_t *next_bcp = bcp->bc_next;
1769 			kmem_bufctl_t **hash_bucket = KMEM_HASH(cp, addr);
1770 			bcp->bc_next = *hash_bucket;
1771 			*hash_bucket = bcp;
1772 			bcp = next_bcp;
1773 		}
1774 	}
1775 
1776 	mutex_exit(&cp->cache_lock);
1777 
1778 	vmem_free(kmem_hash_arena, old_table, old_size * sizeof (void *));
1779 }
1780 
1781 /*
1782  * Perform periodic maintenance on a cache: hash rescaling,
1783  * depot working-set update, and magazine resizing.
1784  */
1785 static void
1786 kmem_cache_update(kmem_cache_t *cp)
1787 {
1788 	int need_hash_rescale = 0;
1789 	int need_magazine_resize = 0;
1790 
1791 	ASSERT(MUTEX_HELD(&kmem_cache_lock));
1792 
1793 	/*
1794 	 * If the cache has become much larger or smaller than its hash table,
1795 	 * fire off a request to rescale the hash table.
1796 	 */
1797 	mutex_enter(&cp->cache_lock);
1798 
1799 	if ((cp->cache_flags & KMF_HASH) &&
1800 	    (cp->cache_buftotal > (cp->cache_hash_mask << 1) ||
1801 	    (cp->cache_buftotal < (cp->cache_hash_mask >> 1) &&
1802 	    cp->cache_hash_mask > KMEM_HASH_INITIAL)))
1803 		need_hash_rescale = 1;
1804 
1805 	mutex_exit(&cp->cache_lock);
1806 
1807 	/*
1808 	 * Update the depot working set statistics.
1809 	 */
1810 	kmem_depot_ws_update(cp);
1811 
1812 	/*
1813 	 * If there's a lot of contention in the depot,
1814 	 * increase the magazine size.
1815 	 */
1816 	mutex_enter(&cp->cache_depot_lock);
1817 
1818 	if (cp->cache_chunksize < cp->cache_magtype->mt_maxbuf &&
1819 	    (int)(cp->cache_depot_contention -
1820 	    cp->cache_depot_contention_prev) > kmem_depot_contention)
1821 		need_magazine_resize = 1;
1822 
1823 	cp->cache_depot_contention_prev = cp->cache_depot_contention;
1824 
1825 	mutex_exit(&cp->cache_depot_lock);
1826 
1827 	if (need_hash_rescale)
1828 		(void) taskq_dispatch(kmem_taskq,
1829 		    (task_func_t *)kmem_hash_rescale, cp, TQ_NOSLEEP);
1830 
1831 	if (need_magazine_resize)
1832 		(void) taskq_dispatch(kmem_taskq,
1833 		    (task_func_t *)kmem_cache_magazine_resize, cp, TQ_NOSLEEP);
1834 }
1835 
1836 static void
1837 kmem_update_timeout(void *dummy)
1838 {
1839 	static void kmem_update(void *);
1840 
1841 	(void) timeout(kmem_update, dummy, kmem_reap_interval);
1842 }
1843 
1844 static void
1845 kmem_update(void *dummy)
1846 {
1847 	kmem_cache_applyall(kmem_cache_update, NULL, TQ_NOSLEEP);
1848 
1849 	/*
1850 	 * We use taskq_dispatch() to reschedule the timeout so that
1851 	 * kmem_update() becomes self-throttling: it won't schedule
1852 	 * new tasks until all previous tasks have completed.
1853 	 */
1854 	if (!taskq_dispatch(kmem_taskq, kmem_update_timeout, dummy, TQ_NOSLEEP))
1855 		kmem_update_timeout(NULL);
1856 }
1857 
1858 static int
1859 kmem_cache_kstat_update(kstat_t *ksp, int rw)
1860 {
1861 	struct kmem_cache_kstat *kmcp = &kmem_cache_kstat;
1862 	kmem_cache_t *cp = ksp->ks_private;
1863 	kmem_slab_t *sp;
1864 	uint64_t cpu_buf_avail;
1865 	uint64_t buf_avail = 0;
1866 	int cpu_seqid;
1867 
1868 	ASSERT(MUTEX_HELD(&kmem_cache_kstat_lock));
1869 
1870 	if (rw == KSTAT_WRITE)
1871 		return (EACCES);
1872 
1873 	mutex_enter(&cp->cache_lock);
1874 
1875 	kmcp->kmc_alloc_fail.value.ui64		= cp->cache_alloc_fail;
1876 	kmcp->kmc_alloc.value.ui64		= cp->cache_slab_alloc;
1877 	kmcp->kmc_free.value.ui64		= cp->cache_slab_free;
1878 	kmcp->kmc_slab_alloc.value.ui64		= cp->cache_slab_alloc;
1879 	kmcp->kmc_slab_free.value.ui64		= cp->cache_slab_free;
1880 
1881 	for (cpu_seqid = 0; cpu_seqid < max_ncpus; cpu_seqid++) {
1882 		kmem_cpu_cache_t *ccp = &cp->cache_cpu[cpu_seqid];
1883 
1884 		mutex_enter(&ccp->cc_lock);
1885 
1886 		cpu_buf_avail = 0;
1887 		if (ccp->cc_rounds > 0)
1888 			cpu_buf_avail += ccp->cc_rounds;
1889 		if (ccp->cc_prounds > 0)
1890 			cpu_buf_avail += ccp->cc_prounds;
1891 
1892 		kmcp->kmc_alloc.value.ui64	+= ccp->cc_alloc;
1893 		kmcp->kmc_free.value.ui64	+= ccp->cc_free;
1894 		buf_avail			+= cpu_buf_avail;
1895 
1896 		mutex_exit(&ccp->cc_lock);
1897 	}
1898 
1899 	mutex_enter(&cp->cache_depot_lock);
1900 
1901 	kmcp->kmc_depot_alloc.value.ui64	= cp->cache_full.ml_alloc;
1902 	kmcp->kmc_depot_free.value.ui64		= cp->cache_empty.ml_alloc;
1903 	kmcp->kmc_depot_contention.value.ui64	= cp->cache_depot_contention;
1904 	kmcp->kmc_full_magazines.value.ui64	= cp->cache_full.ml_total;
1905 	kmcp->kmc_empty_magazines.value.ui64	= cp->cache_empty.ml_total;
1906 	kmcp->kmc_magazine_size.value.ui64	=
1907 	    (cp->cache_flags & KMF_NOMAGAZINE) ?
1908 	    0 : cp->cache_magtype->mt_magsize;
1909 
1910 	kmcp->kmc_alloc.value.ui64		+= cp->cache_full.ml_alloc;
1911 	kmcp->kmc_free.value.ui64		+= cp->cache_empty.ml_alloc;
1912 	buf_avail += cp->cache_full.ml_total * cp->cache_magtype->mt_magsize;
1913 
1914 	mutex_exit(&cp->cache_depot_lock);
1915 
1916 	kmcp->kmc_buf_size.value.ui64	= cp->cache_bufsize;
1917 	kmcp->kmc_align.value.ui64	= cp->cache_align;
1918 	kmcp->kmc_chunk_size.value.ui64	= cp->cache_chunksize;
1919 	kmcp->kmc_slab_size.value.ui64	= cp->cache_slabsize;
1920 	kmcp->kmc_buf_constructed.value.ui64 = buf_avail;
1921 	for (sp = cp->cache_freelist; sp != &cp->cache_nullslab;
1922 	    sp = sp->slab_next)
1923 		buf_avail += sp->slab_chunks - sp->slab_refcnt;
1924 	kmcp->kmc_buf_avail.value.ui64	= buf_avail;
1925 	kmcp->kmc_buf_inuse.value.ui64	= cp->cache_buftotal - buf_avail;
1926 	kmcp->kmc_buf_total.value.ui64	= cp->cache_buftotal;
1927 	kmcp->kmc_buf_max.value.ui64	= cp->cache_bufmax;
1928 	kmcp->kmc_slab_create.value.ui64	= cp->cache_slab_create;
1929 	kmcp->kmc_slab_destroy.value.ui64	= cp->cache_slab_destroy;
1930 	kmcp->kmc_hash_size.value.ui64	= (cp->cache_flags & KMF_HASH) ?
1931 	    cp->cache_hash_mask + 1 : 0;
1932 	kmcp->kmc_hash_lookup_depth.value.ui64	= cp->cache_lookup_depth;
1933 	kmcp->kmc_hash_rescale.value.ui64	= cp->cache_rescale;
1934 	kmcp->kmc_vmem_source.value.ui64	= cp->cache_arena->vm_id;
1935 
1936 	mutex_exit(&cp->cache_lock);
1937 	return (0);
1938 }
1939 
1940 /*
1941  * Return a named statistic about a particular cache.
1942  * This shouldn't be called very often, so it's currently designed for
1943  * simplicity (leverages existing kstat support) rather than efficiency.
1944  */
1945 uint64_t
1946 kmem_cache_stat(kmem_cache_t *cp, char *name)
1947 {
1948 	int i;
1949 	kstat_t *ksp = cp->cache_kstat;
1950 	kstat_named_t *knp = (kstat_named_t *)&kmem_cache_kstat;
1951 	uint64_t value = 0;
1952 
1953 	if (ksp != NULL) {
1954 		mutex_enter(&kmem_cache_kstat_lock);
1955 		(void) kmem_cache_kstat_update(ksp, KSTAT_READ);
1956 		for (i = 0; i < ksp->ks_ndata; i++) {
1957 			if (strcmp(knp[i].name, name) == 0) {
1958 				value = knp[i].value.ui64;
1959 				break;
1960 			}
1961 		}
1962 		mutex_exit(&kmem_cache_kstat_lock);
1963 	}
1964 	return (value);
1965 }
1966 
1967 /*
1968  * Return an estimate of currently available kernel heap memory.
1969  * On 32-bit systems, physical memory may exceed virtual memory,
1970  * we just truncate the result at 1GB.
1971  */
1972 size_t
1973 kmem_avail(void)
1974 {
1975 	spgcnt_t rmem = availrmem - tune.t_minarmem;
1976 	spgcnt_t fmem = freemem - minfree;
1977 
1978 	return ((size_t)ptob(MIN(MAX(MIN(rmem, fmem), 0),
1979 	    1 << (30 - PAGESHIFT))));
1980 }
1981 
1982 /*
1983  * Return the maximum amount of memory that is (in theory) allocatable
1984  * from the heap. This may be used as an estimate only since there
1985  * is no guarentee this space will still be available when an allocation
1986  * request is made, nor that the space may be allocated in one big request
1987  * due to kernel heap fragmentation.
1988  */
1989 size_t
1990 kmem_maxavail(void)
1991 {
1992 	spgcnt_t pmem = availrmem - tune.t_minarmem;
1993 	spgcnt_t vmem = btop(vmem_size(heap_arena, VMEM_FREE));
1994 
1995 	return ((size_t)ptob(MAX(MIN(pmem, vmem), 0)));
1996 }
1997 
1998 /*
1999  * Indicate whether memory-intensive kmem debugging is enabled.
2000  */
2001 int
2002 kmem_debugging(void)
2003 {
2004 	return (kmem_flags & (KMF_AUDIT | KMF_REDZONE));
2005 }
2006 
2007 kmem_cache_t *
2008 kmem_cache_create(
2009 	char *name,		/* descriptive name for this cache */
2010 	size_t bufsize,		/* size of the objects it manages */
2011 	size_t align,		/* required object alignment */
2012 	int (*constructor)(void *, void *, int), /* object constructor */
2013 	void (*destructor)(void *, void *),	/* object destructor */
2014 	void (*reclaim)(void *), /* memory reclaim callback */
2015 	void *private,		/* pass-thru arg for constr/destr/reclaim */
2016 	vmem_t *vmp,		/* vmem source for slab allocation */
2017 	int cflags)		/* cache creation flags */
2018 {
2019 	int cpu_seqid;
2020 	size_t chunksize;
2021 	kmem_cache_t *cp, *cnext, *cprev;
2022 	kmem_magtype_t *mtp;
2023 	size_t csize = KMEM_CACHE_SIZE(max_ncpus);
2024 
2025 #ifdef	DEBUG
2026 	/*
2027 	 * Cache names should conform to the rules for valid C identifiers
2028 	 */
2029 	if (!strident_valid(name)) {
2030 		cmn_err(CE_CONT,
2031 		    "kmem_cache_create: '%s' is an invalid cache name\n"
2032 		    "cache names must conform to the rules for "
2033 		    "C identifiers\n", name);
2034 	}
2035 #endif	/* DEBUG */
2036 
2037 	if (vmp == NULL)
2038 		vmp = kmem_default_arena;
2039 
2040 	/*
2041 	 * If this kmem cache has an identifier vmem arena as its source, mark
2042 	 * it such to allow kmem_reap_idspace().
2043 	 */
2044 	ASSERT(!(cflags & KMC_IDENTIFIER));   /* consumer should not set this */
2045 	if (vmp->vm_cflags & VMC_IDENTIFIER)
2046 		cflags |= KMC_IDENTIFIER;
2047 
2048 	/*
2049 	 * Get a kmem_cache structure.  We arrange that cp->cache_cpu[]
2050 	 * is aligned on a KMEM_CPU_CACHE_SIZE boundary to prevent
2051 	 * false sharing of per-CPU data.
2052 	 */
2053 	cp = vmem_xalloc(kmem_cache_arena, csize, KMEM_CPU_CACHE_SIZE,
2054 	    P2NPHASE(csize, KMEM_CPU_CACHE_SIZE), 0, NULL, NULL, VM_SLEEP);
2055 	bzero(cp, csize);
2056 
2057 	if (align == 0)
2058 		align = KMEM_ALIGN;
2059 
2060 	/*
2061 	 * If we're not at least KMEM_ALIGN aligned, we can't use free
2062 	 * memory to hold bufctl information (because we can't safely
2063 	 * perform word loads and stores on it).
2064 	 */
2065 	if (align < KMEM_ALIGN)
2066 		cflags |= KMC_NOTOUCH;
2067 
2068 	if ((align & (align - 1)) != 0 || align > vmp->vm_quantum)
2069 		panic("kmem_cache_create: bad alignment %lu", align);
2070 
2071 	mutex_enter(&kmem_flags_lock);
2072 	if (kmem_flags & KMF_RANDOMIZE)
2073 		kmem_flags = (((kmem_flags | ~KMF_RANDOM) + 1) & KMF_RANDOM) |
2074 		    KMF_RANDOMIZE;
2075 	cp->cache_flags = (kmem_flags | cflags) & KMF_DEBUG;
2076 	mutex_exit(&kmem_flags_lock);
2077 
2078 	/*
2079 	 * Make sure all the various flags are reasonable.
2080 	 */
2081 	ASSERT(!(cflags & KMC_NOHASH) || !(cflags & KMC_NOTOUCH));
2082 
2083 	if (cp->cache_flags & KMF_LITE) {
2084 		if (bufsize >= kmem_lite_minsize &&
2085 		    align <= kmem_lite_maxalign &&
2086 		    P2PHASE(bufsize, kmem_lite_maxalign) != 0) {
2087 			cp->cache_flags |= KMF_BUFTAG;
2088 			cp->cache_flags &= ~(KMF_AUDIT | KMF_FIREWALL);
2089 		} else {
2090 			cp->cache_flags &= ~KMF_DEBUG;
2091 		}
2092 	}
2093 
2094 	if (cp->cache_flags & KMF_DEADBEEF)
2095 		cp->cache_flags |= KMF_REDZONE;
2096 
2097 	if ((cflags & KMC_QCACHE) && (cp->cache_flags & KMF_AUDIT))
2098 		cp->cache_flags |= KMF_NOMAGAZINE;
2099 
2100 	if (cflags & KMC_NODEBUG)
2101 		cp->cache_flags &= ~KMF_DEBUG;
2102 
2103 	if (cflags & KMC_NOTOUCH)
2104 		cp->cache_flags &= ~KMF_TOUCH;
2105 
2106 	if (cflags & KMC_NOHASH)
2107 		cp->cache_flags &= ~(KMF_AUDIT | KMF_FIREWALL);
2108 
2109 	if (cflags & KMC_NOMAGAZINE)
2110 		cp->cache_flags |= KMF_NOMAGAZINE;
2111 
2112 	if ((cp->cache_flags & KMF_AUDIT) && !(cflags & KMC_NOTOUCH))
2113 		cp->cache_flags |= KMF_REDZONE;
2114 
2115 	if (!(cp->cache_flags & KMF_AUDIT))
2116 		cp->cache_flags &= ~KMF_CONTENTS;
2117 
2118 	if ((cp->cache_flags & KMF_BUFTAG) && bufsize >= kmem_minfirewall &&
2119 	    !(cp->cache_flags & KMF_LITE) && !(cflags & KMC_NOHASH))
2120 		cp->cache_flags |= KMF_FIREWALL;
2121 
2122 	if (vmp != kmem_default_arena || kmem_firewall_arena == NULL)
2123 		cp->cache_flags &= ~KMF_FIREWALL;
2124 
2125 	if (cp->cache_flags & KMF_FIREWALL) {
2126 		cp->cache_flags &= ~KMF_BUFTAG;
2127 		cp->cache_flags |= KMF_NOMAGAZINE;
2128 		ASSERT(vmp == kmem_default_arena);
2129 		vmp = kmem_firewall_arena;
2130 	}
2131 
2132 	/*
2133 	 * Set cache properties.
2134 	 */
2135 	(void) strncpy(cp->cache_name, name, KMEM_CACHE_NAMELEN);
2136 	strident_canon(cp->cache_name, KMEM_CACHE_NAMELEN);
2137 	cp->cache_bufsize = bufsize;
2138 	cp->cache_align = align;
2139 	cp->cache_constructor = constructor;
2140 	cp->cache_destructor = destructor;
2141 	cp->cache_reclaim = reclaim;
2142 	cp->cache_private = private;
2143 	cp->cache_arena = vmp;
2144 	cp->cache_cflags = cflags;
2145 
2146 	/*
2147 	 * Determine the chunk size.
2148 	 */
2149 	chunksize = bufsize;
2150 
2151 	if (align >= KMEM_ALIGN) {
2152 		chunksize = P2ROUNDUP(chunksize, KMEM_ALIGN);
2153 		cp->cache_bufctl = chunksize - KMEM_ALIGN;
2154 	}
2155 
2156 	if (cp->cache_flags & KMF_BUFTAG) {
2157 		cp->cache_bufctl = chunksize;
2158 		cp->cache_buftag = chunksize;
2159 		if (cp->cache_flags & KMF_LITE)
2160 			chunksize += KMEM_BUFTAG_LITE_SIZE(kmem_lite_count);
2161 		else
2162 			chunksize += sizeof (kmem_buftag_t);
2163 	}
2164 
2165 	if (cp->cache_flags & KMF_DEADBEEF) {
2166 		cp->cache_verify = MIN(cp->cache_buftag, kmem_maxverify);
2167 		if (cp->cache_flags & KMF_LITE)
2168 			cp->cache_verify = sizeof (uint64_t);
2169 	}
2170 
2171 	cp->cache_contents = MIN(cp->cache_bufctl, kmem_content_maxsave);
2172 
2173 	cp->cache_chunksize = chunksize = P2ROUNDUP(chunksize, align);
2174 
2175 	/*
2176 	 * Now that we know the chunk size, determine the optimal slab size.
2177 	 */
2178 	if (vmp == kmem_firewall_arena) {
2179 		cp->cache_slabsize = P2ROUNDUP(chunksize, vmp->vm_quantum);
2180 		cp->cache_mincolor = cp->cache_slabsize - chunksize;
2181 		cp->cache_maxcolor = cp->cache_mincolor;
2182 		cp->cache_flags |= KMF_HASH;
2183 		ASSERT(!(cp->cache_flags & KMF_BUFTAG));
2184 	} else if ((cflags & KMC_NOHASH) || (!(cflags & KMC_NOTOUCH) &&
2185 	    !(cp->cache_flags & KMF_AUDIT) &&
2186 	    chunksize < vmp->vm_quantum / KMEM_VOID_FRACTION)) {
2187 		cp->cache_slabsize = vmp->vm_quantum;
2188 		cp->cache_mincolor = 0;
2189 		cp->cache_maxcolor =
2190 		    (cp->cache_slabsize - sizeof (kmem_slab_t)) % chunksize;
2191 		ASSERT(chunksize + sizeof (kmem_slab_t) <= cp->cache_slabsize);
2192 		ASSERT(!(cp->cache_flags & KMF_AUDIT));
2193 	} else {
2194 		size_t chunks, bestfit, waste, slabsize;
2195 		size_t minwaste = LONG_MAX;
2196 
2197 		for (chunks = 1; chunks <= KMEM_VOID_FRACTION; chunks++) {
2198 			slabsize = P2ROUNDUP(chunksize * chunks,
2199 			    vmp->vm_quantum);
2200 			chunks = slabsize / chunksize;
2201 			waste = (slabsize % chunksize) / chunks;
2202 			if (waste < minwaste) {
2203 				minwaste = waste;
2204 				bestfit = slabsize;
2205 			}
2206 		}
2207 		if (cflags & KMC_QCACHE)
2208 			bestfit = VMEM_QCACHE_SLABSIZE(vmp->vm_qcache_max);
2209 		cp->cache_slabsize = bestfit;
2210 		cp->cache_mincolor = 0;
2211 		cp->cache_maxcolor = bestfit % chunksize;
2212 		cp->cache_flags |= KMF_HASH;
2213 	}
2214 
2215 	if (cp->cache_flags & KMF_HASH) {
2216 		ASSERT(!(cflags & KMC_NOHASH));
2217 		cp->cache_bufctl_cache = (cp->cache_flags & KMF_AUDIT) ?
2218 		    kmem_bufctl_audit_cache : kmem_bufctl_cache;
2219 	}
2220 
2221 	if (cp->cache_maxcolor >= vmp->vm_quantum)
2222 		cp->cache_maxcolor = vmp->vm_quantum - 1;
2223 
2224 	cp->cache_color = cp->cache_mincolor;
2225 
2226 	/*
2227 	 * Initialize the rest of the slab layer.
2228 	 */
2229 	mutex_init(&cp->cache_lock, NULL, MUTEX_DEFAULT, NULL);
2230 
2231 	cp->cache_freelist = &cp->cache_nullslab;
2232 	cp->cache_nullslab.slab_cache = cp;
2233 	cp->cache_nullslab.slab_refcnt = -1;
2234 	cp->cache_nullslab.slab_next = &cp->cache_nullslab;
2235 	cp->cache_nullslab.slab_prev = &cp->cache_nullslab;
2236 
2237 	if (cp->cache_flags & KMF_HASH) {
2238 		cp->cache_hash_table = vmem_alloc(kmem_hash_arena,
2239 		    KMEM_HASH_INITIAL * sizeof (void *), VM_SLEEP);
2240 		bzero(cp->cache_hash_table,
2241 		    KMEM_HASH_INITIAL * sizeof (void *));
2242 		cp->cache_hash_mask = KMEM_HASH_INITIAL - 1;
2243 		cp->cache_hash_shift = highbit((ulong_t)chunksize) - 1;
2244 	}
2245 
2246 	/*
2247 	 * Initialize the depot.
2248 	 */
2249 	mutex_init(&cp->cache_depot_lock, NULL, MUTEX_DEFAULT, NULL);
2250 
2251 	for (mtp = kmem_magtype; chunksize <= mtp->mt_minbuf; mtp++)
2252 		continue;
2253 
2254 	cp->cache_magtype = mtp;
2255 
2256 	/*
2257 	 * Initialize the CPU layer.
2258 	 */
2259 	for (cpu_seqid = 0; cpu_seqid < max_ncpus; cpu_seqid++) {
2260 		kmem_cpu_cache_t *ccp = &cp->cache_cpu[cpu_seqid];
2261 		mutex_init(&ccp->cc_lock, NULL, MUTEX_DEFAULT, NULL);
2262 		ccp->cc_flags = cp->cache_flags;
2263 		ccp->cc_rounds = -1;
2264 		ccp->cc_prounds = -1;
2265 	}
2266 
2267 	/*
2268 	 * Create the cache's kstats.
2269 	 */
2270 	if ((cp->cache_kstat = kstat_create("unix", 0, cp->cache_name,
2271 	    "kmem_cache", KSTAT_TYPE_NAMED,
2272 	    sizeof (kmem_cache_kstat) / sizeof (kstat_named_t),
2273 	    KSTAT_FLAG_VIRTUAL)) != NULL) {
2274 		cp->cache_kstat->ks_data = &kmem_cache_kstat;
2275 		cp->cache_kstat->ks_update = kmem_cache_kstat_update;
2276 		cp->cache_kstat->ks_private = cp;
2277 		cp->cache_kstat->ks_lock = &kmem_cache_kstat_lock;
2278 		kstat_install(cp->cache_kstat);
2279 	}
2280 
2281 	/*
2282 	 * Add the cache to the global list.  This makes it visible
2283 	 * to kmem_update(), so the cache must be ready for business.
2284 	 */
2285 	mutex_enter(&kmem_cache_lock);
2286 	cp->cache_next = cnext = &kmem_null_cache;
2287 	cp->cache_prev = cprev = kmem_null_cache.cache_prev;
2288 	cnext->cache_prev = cp;
2289 	cprev->cache_next = cp;
2290 	mutex_exit(&kmem_cache_lock);
2291 
2292 	if (kmem_ready)
2293 		kmem_cache_magazine_enable(cp);
2294 
2295 	return (cp);
2296 }
2297 
2298 void
2299 kmem_cache_destroy(kmem_cache_t *cp)
2300 {
2301 	int cpu_seqid;
2302 
2303 	/*
2304 	 * Remove the cache from the global cache list so that no one else
2305 	 * can schedule tasks on its behalf, wait for any pending tasks to
2306 	 * complete, purge the cache, and then destroy it.
2307 	 */
2308 	mutex_enter(&kmem_cache_lock);
2309 	cp->cache_prev->cache_next = cp->cache_next;
2310 	cp->cache_next->cache_prev = cp->cache_prev;
2311 	cp->cache_prev = cp->cache_next = NULL;
2312 	mutex_exit(&kmem_cache_lock);
2313 
2314 	if (kmem_taskq != NULL)
2315 		taskq_wait(kmem_taskq);
2316 
2317 	kmem_cache_magazine_purge(cp);
2318 
2319 	mutex_enter(&cp->cache_lock);
2320 	if (cp->cache_buftotal != 0)
2321 		cmn_err(CE_WARN, "kmem_cache_destroy: '%s' (%p) not empty",
2322 		    cp->cache_name, (void *)cp);
2323 	cp->cache_reclaim = NULL;
2324 	/*
2325 	 * The cache is now dead.  There should be no further activity.
2326 	 * We enforce this by setting land mines in the constructor and
2327 	 * destructor routines that induce a kernel text fault if invoked.
2328 	 */
2329 	cp->cache_constructor = (int (*)(void *, void *, int))1;
2330 	cp->cache_destructor = (void (*)(void *, void *))2;
2331 	mutex_exit(&cp->cache_lock);
2332 
2333 	kstat_delete(cp->cache_kstat);
2334 
2335 	if (cp->cache_hash_table != NULL)
2336 		vmem_free(kmem_hash_arena, cp->cache_hash_table,
2337 		    (cp->cache_hash_mask + 1) * sizeof (void *));
2338 
2339 	for (cpu_seqid = 0; cpu_seqid < max_ncpus; cpu_seqid++)
2340 		mutex_destroy(&cp->cache_cpu[cpu_seqid].cc_lock);
2341 
2342 	mutex_destroy(&cp->cache_depot_lock);
2343 	mutex_destroy(&cp->cache_lock);
2344 
2345 	vmem_free(kmem_cache_arena, cp, KMEM_CACHE_SIZE(max_ncpus));
2346 }
2347 
2348 /*ARGSUSED*/
2349 static int
2350 kmem_cpu_setup(cpu_setup_t what, int id, void *arg)
2351 {
2352 	ASSERT(MUTEX_HELD(&cpu_lock));
2353 	if (what == CPU_UNCONFIG) {
2354 		kmem_cache_applyall(kmem_cache_magazine_purge,
2355 		    kmem_taskq, TQ_SLEEP);
2356 		kmem_cache_applyall(kmem_cache_magazine_enable,
2357 		    kmem_taskq, TQ_SLEEP);
2358 	}
2359 	return (0);
2360 }
2361 
2362 static void
2363 kmem_cache_init(int pass, int use_large_pages)
2364 {
2365 	int i;
2366 	size_t size;
2367 	kmem_cache_t *cp;
2368 	kmem_magtype_t *mtp;
2369 	char name[KMEM_CACHE_NAMELEN + 1];
2370 
2371 	for (i = 0; i < sizeof (kmem_magtype) / sizeof (*mtp); i++) {
2372 		mtp = &kmem_magtype[i];
2373 		(void) sprintf(name, "kmem_magazine_%d", mtp->mt_magsize);
2374 		mtp->mt_cache = kmem_cache_create(name,
2375 		    (mtp->mt_magsize + 1) * sizeof (void *),
2376 		    mtp->mt_align, NULL, NULL, NULL, NULL,
2377 		    kmem_msb_arena, KMC_NOHASH);
2378 	}
2379 
2380 	kmem_slab_cache = kmem_cache_create("kmem_slab_cache",
2381 	    sizeof (kmem_slab_t), 0, NULL, NULL, NULL, NULL,
2382 	    kmem_msb_arena, KMC_NOHASH);
2383 
2384 	kmem_bufctl_cache = kmem_cache_create("kmem_bufctl_cache",
2385 	    sizeof (kmem_bufctl_t), 0, NULL, NULL, NULL, NULL,
2386 	    kmem_msb_arena, KMC_NOHASH);
2387 
2388 	kmem_bufctl_audit_cache = kmem_cache_create("kmem_bufctl_audit_cache",
2389 	    sizeof (kmem_bufctl_audit_t), 0, NULL, NULL, NULL, NULL,
2390 	    kmem_msb_arena, KMC_NOHASH);
2391 
2392 	if (pass == 2) {
2393 		kmem_va_arena = vmem_create("kmem_va",
2394 		    NULL, 0, PAGESIZE,
2395 		    vmem_alloc, vmem_free, heap_arena,
2396 		    8 * PAGESIZE, VM_SLEEP);
2397 
2398 		if (use_large_pages) {
2399 			kmem_default_arena = vmem_xcreate("kmem_default",
2400 			    NULL, 0, PAGESIZE,
2401 			    segkmem_alloc_lp, segkmem_free_lp, kmem_va_arena,
2402 			    0, VM_SLEEP);
2403 		} else {
2404 			kmem_default_arena = vmem_create("kmem_default",
2405 			    NULL, 0, PAGESIZE,
2406 			    segkmem_alloc, segkmem_free, kmem_va_arena,
2407 			    0, VM_SLEEP);
2408 		}
2409 	} else {
2410 		/*
2411 		 * During the first pass, the kmem_alloc_* caches
2412 		 * are treated as metadata.
2413 		 */
2414 		kmem_default_arena = kmem_msb_arena;
2415 	}
2416 
2417 	/*
2418 	 * Set up the default caches to back kmem_alloc()
2419 	 */
2420 	size = KMEM_ALIGN;
2421 	for (i = 0; i < sizeof (kmem_alloc_sizes) / sizeof (int); i++) {
2422 		size_t align = KMEM_ALIGN;
2423 		size_t cache_size = kmem_alloc_sizes[i];
2424 		/*
2425 		 * If they allocate a multiple of the coherency granularity,
2426 		 * they get a coherency-granularity-aligned address.
2427 		 */
2428 		if (IS_P2ALIGNED(cache_size, 64))
2429 			align = 64;
2430 		if (IS_P2ALIGNED(cache_size, PAGESIZE))
2431 			align = PAGESIZE;
2432 		(void) sprintf(name, "kmem_alloc_%lu", cache_size);
2433 		cp = kmem_cache_create(name, cache_size, align,
2434 		    NULL, NULL, NULL, NULL, NULL, KMC_KMEM_ALLOC);
2435 		while (size <= cache_size) {
2436 			kmem_alloc_table[(size - 1) >> KMEM_ALIGN_SHIFT] = cp;
2437 			size += KMEM_ALIGN;
2438 		}
2439 	}
2440 }
2441 
2442 void
2443 kmem_init(void)
2444 {
2445 	kmem_cache_t *cp;
2446 	int old_kmem_flags = kmem_flags;
2447 	int use_large_pages = 0;
2448 	size_t maxverify, minfirewall;
2449 
2450 	kstat_init();
2451 
2452 	/*
2453 	 * Small-memory systems (< 24 MB) can't handle kmem_flags overhead.
2454 	 */
2455 	if (physmem < btop(24 << 20) && !(old_kmem_flags & KMF_STICKY))
2456 		kmem_flags = 0;
2457 
2458 	/*
2459 	 * Don't do firewalled allocations if the heap is less than 1TB
2460 	 * (i.e. on a 32-bit kernel)
2461 	 * The resulting VM_NEXTFIT allocations would create too much
2462 	 * fragmentation in a small heap.
2463 	 */
2464 #if defined(_LP64)
2465 	maxverify = minfirewall = PAGESIZE / 2;
2466 #else
2467 	maxverify = minfirewall = ULONG_MAX;
2468 #endif
2469 
2470 	/* LINTED */
2471 	ASSERT(sizeof (kmem_cpu_cache_t) == KMEM_CPU_CACHE_SIZE);
2472 
2473 	kmem_null_cache.cache_next = &kmem_null_cache;
2474 	kmem_null_cache.cache_prev = &kmem_null_cache;
2475 
2476 	kmem_metadata_arena = vmem_create("kmem_metadata", NULL, 0, PAGESIZE,
2477 	    vmem_alloc, vmem_free, heap_arena, 8 * PAGESIZE,
2478 	    VM_SLEEP | VMC_NO_QCACHE);
2479 
2480 	kmem_msb_arena = vmem_create("kmem_msb", NULL, 0,
2481 	    PAGESIZE, segkmem_alloc, segkmem_free, kmem_metadata_arena, 0,
2482 	    VM_SLEEP);
2483 
2484 	kmem_cache_arena = vmem_create("kmem_cache", NULL, 0, KMEM_ALIGN,
2485 	    segkmem_alloc, segkmem_free, kmem_metadata_arena, 0, VM_SLEEP);
2486 
2487 	kmem_hash_arena = vmem_create("kmem_hash", NULL, 0, KMEM_ALIGN,
2488 	    segkmem_alloc, segkmem_free, kmem_metadata_arena, 0, VM_SLEEP);
2489 
2490 	kmem_log_arena = vmem_create("kmem_log", NULL, 0, KMEM_ALIGN,
2491 	    segkmem_alloc, segkmem_free, heap_arena, 0, VM_SLEEP);
2492 
2493 	kmem_firewall_va_arena = vmem_create("kmem_firewall_va",
2494 	    NULL, 0, PAGESIZE,
2495 	    kmem_firewall_va_alloc, kmem_firewall_va_free, heap_arena,
2496 	    0, VM_SLEEP);
2497 
2498 	kmem_firewall_arena = vmem_create("kmem_firewall", NULL, 0, PAGESIZE,
2499 	    segkmem_alloc, segkmem_free, kmem_firewall_va_arena, 0, VM_SLEEP);
2500 
2501 	/* temporary oversize arena for mod_read_system_file */
2502 	kmem_oversize_arena = vmem_create("kmem_oversize", NULL, 0, PAGESIZE,
2503 	    segkmem_alloc, segkmem_free, heap_arena, 0, VM_SLEEP);
2504 
2505 	kmem_null_cache.cache_next = &kmem_null_cache;
2506 	kmem_null_cache.cache_prev = &kmem_null_cache;
2507 
2508 	kmem_reap_interval = 15 * hz;
2509 
2510 	/*
2511 	 * Read /etc/system.  This is a chicken-and-egg problem because
2512 	 * kmem_flags may be set in /etc/system, but mod_read_system_file()
2513 	 * needs to use the allocator.  The simplest solution is to create
2514 	 * all the standard kmem caches, read /etc/system, destroy all the
2515 	 * caches we just created, and then create them all again in light
2516 	 * of the (possibly) new kmem_flags and other kmem tunables.
2517 	 */
2518 	kmem_cache_init(1, 0);
2519 
2520 	mod_read_system_file(boothowto & RB_ASKNAME);
2521 
2522 	while ((cp = kmem_null_cache.cache_prev) != &kmem_null_cache)
2523 		kmem_cache_destroy(cp);
2524 
2525 	vmem_destroy(kmem_oversize_arena);
2526 
2527 	if (old_kmem_flags & KMF_STICKY)
2528 		kmem_flags = old_kmem_flags;
2529 
2530 	if (!(kmem_flags & KMF_AUDIT))
2531 		vmem_seg_size = offsetof(vmem_seg_t, vs_thread);
2532 
2533 	if (kmem_maxverify == 0)
2534 		kmem_maxverify = maxverify;
2535 
2536 	if (kmem_minfirewall == 0)
2537 		kmem_minfirewall = minfirewall;
2538 
2539 	/*
2540 	 * give segkmem a chance to figure out if we are using large pages
2541 	 * for the kernel heap
2542 	 */
2543 	use_large_pages = segkmem_lpsetup();
2544 
2545 	/*
2546 	 * To protect against corruption, we keep the actual number of callers
2547 	 * KMF_LITE records seperate from the tunable.  We arbitrarily clamp
2548 	 * to 16, since the overhead for small buffers quickly gets out of
2549 	 * hand.
2550 	 *
2551 	 * The real limit would depend on the needs of the largest KMC_NOHASH
2552 	 * cache.
2553 	 */
2554 	kmem_lite_count = MIN(MAX(0, kmem_lite_pcs), 16);
2555 	kmem_lite_pcs = kmem_lite_count;
2556 
2557 	/*
2558 	 * Normally, we firewall oversized allocations when possible, but
2559 	 * if we are using large pages for kernel memory, and we don't have
2560 	 * any non-LITE debugging flags set, we want to allocate oversized
2561 	 * buffers from large pages, and so skip the firewalling.
2562 	 */
2563 	if (use_large_pages &&
2564 	    ((kmem_flags & KMF_LITE) || !(kmem_flags & KMF_DEBUG))) {
2565 		kmem_oversize_arena = vmem_xcreate("kmem_oversize", NULL, 0,
2566 		    PAGESIZE, segkmem_alloc_lp, segkmem_free_lp, heap_arena,
2567 		    0, VM_SLEEP);
2568 	} else {
2569 		kmem_oversize_arena = vmem_create("kmem_oversize",
2570 		    NULL, 0, PAGESIZE,
2571 		    segkmem_alloc, segkmem_free, kmem_minfirewall < ULONG_MAX?
2572 		    kmem_firewall_va_arena : heap_arena, 0, VM_SLEEP);
2573 	}
2574 
2575 	kmem_cache_init(2, use_large_pages);
2576 
2577 	if (kmem_flags & (KMF_AUDIT | KMF_RANDOMIZE)) {
2578 		if (kmem_transaction_log_size == 0)
2579 			kmem_transaction_log_size = kmem_maxavail() / 50;
2580 		kmem_transaction_log = kmem_log_init(kmem_transaction_log_size);
2581 	}
2582 
2583 	if (kmem_flags & (KMF_CONTENTS | KMF_RANDOMIZE)) {
2584 		if (kmem_content_log_size == 0)
2585 			kmem_content_log_size = kmem_maxavail() / 50;
2586 		kmem_content_log = kmem_log_init(kmem_content_log_size);
2587 	}
2588 
2589 	kmem_failure_log = kmem_log_init(kmem_failure_log_size);
2590 
2591 	kmem_slab_log = kmem_log_init(kmem_slab_log_size);
2592 
2593 	/*
2594 	 * Initialize STREAMS message caches so allocb() is available.
2595 	 * This allows us to initialize the logging framework (cmn_err(9F),
2596 	 * strlog(9F), etc) so we can start recording messages.
2597 	 */
2598 	streams_msg_init();
2599 
2600 	/*
2601 	 * Initialize the ZSD framework in Zones so modules loaded henceforth
2602 	 * can register their callbacks.
2603 	 */
2604 	zone_zsd_init();
2605 
2606 	log_init();
2607 	taskq_init();
2608 
2609 	/*
2610 	 * Warn about invalid or dangerous values of kmem_flags.
2611 	 * Always warn about unsupported values.
2612 	 */
2613 	if (((kmem_flags & ~(KMF_AUDIT | KMF_DEADBEEF | KMF_REDZONE |
2614 	    KMF_CONTENTS | KMF_LITE)) != 0) ||
2615 	    ((kmem_flags & KMF_LITE) && kmem_flags != KMF_LITE))
2616 		cmn_err(CE_WARN, "kmem_flags set to unsupported value 0x%x. "
2617 		    "See the Solaris Tunable Parameters Reference Manual.",
2618 		    kmem_flags);
2619 
2620 #ifdef DEBUG
2621 	if ((kmem_flags & KMF_DEBUG) == 0)
2622 		cmn_err(CE_NOTE, "kmem debugging disabled.");
2623 #else
2624 	/*
2625 	 * For non-debug kernels, the only "normal" flags are 0, KMF_LITE,
2626 	 * KMF_REDZONE, and KMF_CONTENTS (the last because it is only enabled
2627 	 * if KMF_AUDIT is set). We should warn the user about the performance
2628 	 * penalty of KMF_AUDIT or KMF_DEADBEEF if they are set and KMF_LITE
2629 	 * isn't set (since that disables AUDIT).
2630 	 */
2631 	if (!(kmem_flags & KMF_LITE) &&
2632 	    (kmem_flags & (KMF_AUDIT | KMF_DEADBEEF)) != 0)
2633 		cmn_err(CE_WARN, "High-overhead kmem debugging features "
2634 		    "enabled (kmem_flags = 0x%x).  Performance degradation "
2635 		    "and large memory overhead possible. See the Solaris "
2636 		    "Tunable Parameters Reference Manual.", kmem_flags);
2637 #endif /* not DEBUG */
2638 
2639 	kmem_cache_applyall(kmem_cache_magazine_enable, NULL, TQ_SLEEP);
2640 
2641 	kmem_ready = 1;
2642 
2643 	/*
2644 	 * Initialize the platform-specific aligned/DMA memory allocator.
2645 	 */
2646 	ka_init();
2647 
2648 	/*
2649 	 * Initialize 32-bit ID cache.
2650 	 */
2651 	id32_init();
2652 
2653 	/*
2654 	 * Initialize the networking stack so modules loaded can
2655 	 * register their callbacks.
2656 	 */
2657 	netstack_init();
2658 }
2659 
2660 void
2661 kmem_thread_init(void)
2662 {
2663 	kmem_taskq = taskq_create_instance("kmem_taskq", 0, 1, minclsyspri,
2664 	    300, INT_MAX, TASKQ_PREPOPULATE);
2665 }
2666 
2667 void
2668 kmem_mp_init(void)
2669 {
2670 	mutex_enter(&cpu_lock);
2671 	register_cpu_setup_func(kmem_cpu_setup, NULL);
2672 	mutex_exit(&cpu_lock);
2673 
2674 	kmem_update_timeout(NULL);
2675 }
2676