xref: /freebsd/sys/kern/kern_malloc.c (revision 830940567b49bb0c08dfaed40418999e76616909)
1 /*-
2  * Copyright (c) 1987, 1991, 1993
3  *	The Regents of the University of California.
4  * Copyright (c) 2005-2009 Robert N. M. Watson
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 4. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)kern_malloc.c	8.3 (Berkeley) 1/4/94
32  */
33 
34 /*
35  * Kernel malloc(9) implementation -- general purpose kernel memory allocator
36  * based on memory types.  Back end is implemented using the UMA(9) zone
37  * allocator.  A set of fixed-size buckets are used for smaller allocations,
38  * and a special UMA allocation interface is used for larger allocations.
39  * Callers declare memory types, and statistics are maintained independently
40  * for each memory type.  Statistics are maintained per-CPU for performance
41  * reasons.  See malloc(9) and comments in malloc.h for a detailed
42  * description.
43  */
44 
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
47 
48 #include "opt_ddb.h"
49 #include "opt_kdtrace.h"
50 #include "opt_vm.h"
51 
52 #include <sys/param.h>
53 #include <sys/systm.h>
54 #include <sys/kdb.h>
55 #include <sys/kernel.h>
56 #include <sys/lock.h>
57 #include <sys/malloc.h>
58 #include <sys/mbuf.h>
59 #include <sys/mutex.h>
60 #include <sys/vmmeter.h>
61 #include <sys/proc.h>
62 #include <sys/sbuf.h>
63 #include <sys/sysctl.h>
64 #include <sys/time.h>
65 
66 #include <vm/vm.h>
67 #include <vm/pmap.h>
68 #include <vm/vm_param.h>
69 #include <vm/vm_kern.h>
70 #include <vm/vm_extern.h>
71 #include <vm/vm_map.h>
72 #include <vm/vm_page.h>
73 #include <vm/uma.h>
74 #include <vm/uma_int.h>
75 #include <vm/uma_dbg.h>
76 
77 #ifdef DEBUG_MEMGUARD
78 #include <vm/memguard.h>
79 #endif
80 #ifdef DEBUG_REDZONE
81 #include <vm/redzone.h>
82 #endif
83 
84 #if defined(INVARIANTS) && defined(__i386__)
85 #include <machine/cpu.h>
86 #endif
87 
88 #include <ddb/ddb.h>
89 
90 #ifdef KDTRACE_HOOKS
91 #include <sys/dtrace_bsd.h>
92 
93 dtrace_malloc_probe_func_t	dtrace_malloc_probe;
94 #endif
95 
96 /*
97  * When realloc() is called, if the new size is sufficiently smaller than
98  * the old size, realloc() will allocate a new, smaller block to avoid
99  * wasting memory. 'Sufficiently smaller' is defined as: newsize <=
100  * oldsize / 2^n, where REALLOC_FRACTION defines the value of 'n'.
101  */
102 #ifndef REALLOC_FRACTION
103 #define	REALLOC_FRACTION	1	/* new block if <= half the size */
104 #endif
105 
106 /*
107  * Centrally define some common malloc types.
108  */
109 MALLOC_DEFINE(M_CACHE, "cache", "Various Dynamically allocated caches");
110 MALLOC_DEFINE(M_DEVBUF, "devbuf", "device driver memory");
111 MALLOC_DEFINE(M_TEMP, "temp", "misc temporary data buffers");
112 
113 MALLOC_DEFINE(M_IP6OPT, "ip6opt", "IPv6 options");
114 MALLOC_DEFINE(M_IP6NDP, "ip6ndp", "IPv6 Neighbor Discovery");
115 
116 static void kmeminit(void *);
117 SYSINIT(kmem, SI_SUB_KMEM, SI_ORDER_FIRST, kmeminit, NULL);
118 
119 static MALLOC_DEFINE(M_FREE, "free", "should be on free list");
120 
121 static struct malloc_type *kmemstatistics;
122 static vm_offset_t kmembase;
123 static vm_offset_t kmemlimit;
124 static int kmemcount;
125 
126 #define KMEM_ZSHIFT	4
127 #define KMEM_ZBASE	16
128 #define KMEM_ZMASK	(KMEM_ZBASE - 1)
129 
130 #define KMEM_ZMAX	PAGE_SIZE
131 #define KMEM_ZSIZE	(KMEM_ZMAX >> KMEM_ZSHIFT)
132 static u_int8_t kmemsize[KMEM_ZSIZE + 1];
133 
134 /*
135  * Small malloc(9) memory allocations are allocated from a set of UMA buckets
136  * of various sizes.
137  *
138  * XXX: The comment here used to read "These won't be powers of two for
139  * long."  It's possible that a significant amount of wasted memory could be
140  * recovered by tuning the sizes of these buckets.
141  */
142 struct {
143 	int kz_size;
144 	char *kz_name;
145 	uma_zone_t kz_zone;
146 } kmemzones[] = {
147 	{16, "16", NULL},
148 	{32, "32", NULL},
149 	{64, "64", NULL},
150 	{128, "128", NULL},
151 	{256, "256", NULL},
152 	{512, "512", NULL},
153 	{1024, "1024", NULL},
154 	{2048, "2048", NULL},
155 	{4096, "4096", NULL},
156 #if PAGE_SIZE > 4096
157 	{8192, "8192", NULL},
158 #if PAGE_SIZE > 8192
159 	{16384, "16384", NULL},
160 #if PAGE_SIZE > 16384
161 	{32768, "32768", NULL},
162 #if PAGE_SIZE > 32768
163 	{65536, "65536", NULL},
164 #if PAGE_SIZE > 65536
165 #error	"Unsupported PAGE_SIZE"
166 #endif	/* 65536 */
167 #endif	/* 32768 */
168 #endif	/* 16384 */
169 #endif	/* 8192 */
170 #endif	/* 4096 */
171 	{0, NULL},
172 };
173 
174 /*
175  * Zone to allocate malloc type descriptions from.  For ABI reasons, memory
176  * types are described by a data structure passed by the declaring code, but
177  * the malloc(9) implementation has its own data structure describing the
178  * type and statistics.  This permits the malloc(9)-internal data structures
179  * to be modified without breaking binary-compiled kernel modules that
180  * declare malloc types.
181  */
182 static uma_zone_t mt_zone;
183 
184 u_long vm_kmem_size;
185 SYSCTL_ULONG(_vm, OID_AUTO, kmem_size, CTLFLAG_RD, &vm_kmem_size, 0,
186     "Size of kernel memory");
187 
188 static u_long vm_kmem_size_min;
189 SYSCTL_ULONG(_vm, OID_AUTO, kmem_size_min, CTLFLAG_RD, &vm_kmem_size_min, 0,
190     "Minimum size of kernel memory");
191 
192 static u_long vm_kmem_size_max;
193 SYSCTL_ULONG(_vm, OID_AUTO, kmem_size_max, CTLFLAG_RD, &vm_kmem_size_max, 0,
194     "Maximum size of kernel memory");
195 
196 static u_int vm_kmem_size_scale;
197 SYSCTL_UINT(_vm, OID_AUTO, kmem_size_scale, CTLFLAG_RD, &vm_kmem_size_scale, 0,
198     "Scale factor for kernel memory size");
199 
200 /*
201  * The malloc_mtx protects the kmemstatistics linked list.
202  */
203 struct mtx malloc_mtx;
204 
205 #ifdef MALLOC_PROFILE
206 uint64_t krequests[KMEM_ZSIZE + 1];
207 
208 static int sysctl_kern_mprof(SYSCTL_HANDLER_ARGS);
209 #endif
210 
211 static int sysctl_kern_malloc_stats(SYSCTL_HANDLER_ARGS);
212 
213 /*
214  * time_uptime of the last malloc(9) failure (induced or real).
215  */
216 static time_t t_malloc_fail;
217 
218 /*
219  * malloc(9) fault injection -- cause malloc failures every (n) mallocs when
220  * the caller specifies M_NOWAIT.  If set to 0, no failures are caused.
221  */
222 #ifdef MALLOC_MAKE_FAILURES
223 SYSCTL_NODE(_debug, OID_AUTO, malloc, CTLFLAG_RD, 0,
224     "Kernel malloc debugging options");
225 
226 static int malloc_failure_rate;
227 static int malloc_nowait_count;
228 static int malloc_failure_count;
229 SYSCTL_INT(_debug_malloc, OID_AUTO, failure_rate, CTLFLAG_RW,
230     &malloc_failure_rate, 0, "Every (n) mallocs with M_NOWAIT will fail");
231 TUNABLE_INT("debug.malloc.failure_rate", &malloc_failure_rate);
232 SYSCTL_INT(_debug_malloc, OID_AUTO, failure_count, CTLFLAG_RD,
233     &malloc_failure_count, 0, "Number of imposed M_NOWAIT malloc failures");
234 #endif
235 
236 int
237 malloc_last_fail(void)
238 {
239 
240 	return (time_uptime - t_malloc_fail);
241 }
242 
243 /*
244  * An allocation has succeeded -- update malloc type statistics for the
245  * amount of bucket size.  Occurs within a critical section so that the
246  * thread isn't preempted and doesn't migrate while updating per-PCU
247  * statistics.
248  */
249 static void
250 malloc_type_zone_allocated(struct malloc_type *mtp, unsigned long size,
251     int zindx)
252 {
253 	struct malloc_type_internal *mtip;
254 	struct malloc_type_stats *mtsp;
255 
256 	critical_enter();
257 	mtip = mtp->ks_handle;
258 	mtsp = &mtip->mti_stats[curcpu];
259 	if (size > 0) {
260 		mtsp->mts_memalloced += size;
261 		mtsp->mts_numallocs++;
262 	}
263 	if (zindx != -1)
264 		mtsp->mts_size |= 1 << zindx;
265 
266 #ifdef KDTRACE_HOOKS
267 	if (dtrace_malloc_probe != NULL) {
268 		uint32_t probe_id = mtip->mti_probes[DTMALLOC_PROBE_MALLOC];
269 		if (probe_id != 0)
270 			(dtrace_malloc_probe)(probe_id,
271 			    (uintptr_t) mtp, (uintptr_t) mtip,
272 			    (uintptr_t) mtsp, size, zindx);
273 	}
274 #endif
275 
276 	critical_exit();
277 }
278 
279 void
280 malloc_type_allocated(struct malloc_type *mtp, unsigned long size)
281 {
282 
283 	if (size > 0)
284 		malloc_type_zone_allocated(mtp, size, -1);
285 }
286 
287 /*
288  * A free operation has occurred -- update malloc type statistics for the
289  * amount of the bucket size.  Occurs within a critical section so that the
290  * thread isn't preempted and doesn't migrate while updating per-CPU
291  * statistics.
292  */
293 void
294 malloc_type_freed(struct malloc_type *mtp, unsigned long size)
295 {
296 	struct malloc_type_internal *mtip;
297 	struct malloc_type_stats *mtsp;
298 
299 	critical_enter();
300 	mtip = mtp->ks_handle;
301 	mtsp = &mtip->mti_stats[curcpu];
302 	mtsp->mts_memfreed += size;
303 	mtsp->mts_numfrees++;
304 
305 #ifdef KDTRACE_HOOKS
306 	if (dtrace_malloc_probe != NULL) {
307 		uint32_t probe_id = mtip->mti_probes[DTMALLOC_PROBE_FREE];
308 		if (probe_id != 0)
309 			(dtrace_malloc_probe)(probe_id,
310 			    (uintptr_t) mtp, (uintptr_t) mtip,
311 			    (uintptr_t) mtsp, size, 0);
312 	}
313 #endif
314 
315 	critical_exit();
316 }
317 
318 /*
319  *	malloc:
320  *
321  *	Allocate a block of memory.
322  *
323  *	If M_NOWAIT is set, this routine will not block and return NULL if
324  *	the allocation fails.
325  */
326 void *
327 malloc(unsigned long size, struct malloc_type *mtp, int flags)
328 {
329 	int indx;
330 	caddr_t va;
331 	uma_zone_t zone;
332 #if defined(DIAGNOSTIC) || defined(DEBUG_REDZONE)
333 	unsigned long osize = size;
334 #endif
335 
336 #ifdef INVARIANTS
337 	KASSERT(mtp->ks_magic == M_MAGIC, ("malloc: bad malloc type magic"));
338 	/*
339 	 * Check that exactly one of M_WAITOK or M_NOWAIT is specified.
340 	 */
341 	indx = flags & (M_WAITOK | M_NOWAIT);
342 	if (indx != M_NOWAIT && indx != M_WAITOK) {
343 		static	struct timeval lasterr;
344 		static	int curerr, once;
345 		if (once == 0 && ppsratecheck(&lasterr, &curerr, 1)) {
346 			printf("Bad malloc flags: %x\n", indx);
347 			kdb_backtrace();
348 			flags |= M_WAITOK;
349 			once++;
350 		}
351 	}
352 #endif
353 #ifdef MALLOC_MAKE_FAILURES
354 	if ((flags & M_NOWAIT) && (malloc_failure_rate != 0)) {
355 		atomic_add_int(&malloc_nowait_count, 1);
356 		if ((malloc_nowait_count % malloc_failure_rate) == 0) {
357 			atomic_add_int(&malloc_failure_count, 1);
358 			t_malloc_fail = time_uptime;
359 			return (NULL);
360 		}
361 	}
362 #endif
363 	if (flags & M_WAITOK)
364 		KASSERT(curthread->td_intr_nesting_level == 0,
365 		   ("malloc(M_WAITOK) in interrupt context"));
366 
367 #ifdef DEBUG_MEMGUARD
368 	if (memguard_cmp(mtp))
369 		return memguard_alloc(size, flags);
370 #endif
371 
372 #ifdef DEBUG_REDZONE
373 	size = redzone_size_ntor(size);
374 #endif
375 
376 	if (size <= KMEM_ZMAX) {
377 		if (size & KMEM_ZMASK)
378 			size = (size & ~KMEM_ZMASK) + KMEM_ZBASE;
379 		indx = kmemsize[size >> KMEM_ZSHIFT];
380 		zone = kmemzones[indx].kz_zone;
381 #ifdef MALLOC_PROFILE
382 		krequests[size >> KMEM_ZSHIFT]++;
383 #endif
384 		va = uma_zalloc(zone, flags);
385 		if (va != NULL)
386 			size = zone->uz_size;
387 		malloc_type_zone_allocated(mtp, va == NULL ? 0 : size, indx);
388 	} else {
389 		size = roundup(size, PAGE_SIZE);
390 		zone = NULL;
391 		va = uma_large_malloc(size, flags);
392 		malloc_type_allocated(mtp, va == NULL ? 0 : size);
393 	}
394 	if (flags & M_WAITOK)
395 		KASSERT(va != NULL, ("malloc(M_WAITOK) returned NULL"));
396 	else if (va == NULL)
397 		t_malloc_fail = time_uptime;
398 #ifdef DIAGNOSTIC
399 	if (va != NULL && !(flags & M_ZERO)) {
400 		memset(va, 0x70, osize);
401 	}
402 #endif
403 #ifdef DEBUG_REDZONE
404 	if (va != NULL)
405 		va = redzone_setup(va, osize);
406 #endif
407 	return ((void *) va);
408 }
409 
410 /*
411  *	free:
412  *
413  *	Free a block of memory allocated by malloc.
414  *
415  *	This routine may not block.
416  */
417 void
418 free(void *addr, struct malloc_type *mtp)
419 {
420 	uma_slab_t slab;
421 	u_long size;
422 
423 	KASSERT(mtp->ks_magic == M_MAGIC, ("free: bad malloc type magic"));
424 
425 	/* free(NULL, ...) does nothing */
426 	if (addr == NULL)
427 		return;
428 
429 #ifdef DEBUG_MEMGUARD
430 	if (memguard_cmp(mtp)) {
431 		memguard_free(addr);
432 		return;
433 	}
434 #endif
435 
436 #ifdef DEBUG_REDZONE
437 	redzone_check(addr);
438 	addr = redzone_addr_ntor(addr);
439 #endif
440 
441 	slab = vtoslab((vm_offset_t)addr & (~UMA_SLAB_MASK));
442 
443 	if (slab == NULL)
444 		panic("free: address %p(%p) has not been allocated.\n",
445 		    addr, (void *)((u_long)addr & (~UMA_SLAB_MASK)));
446 
447 
448 	if (!(slab->us_flags & UMA_SLAB_MALLOC)) {
449 #ifdef INVARIANTS
450 		struct malloc_type **mtpp = addr;
451 #endif
452 		size = slab->us_keg->uk_size;
453 #ifdef INVARIANTS
454 		/*
455 		 * Cache a pointer to the malloc_type that most recently freed
456 		 * this memory here.  This way we know who is most likely to
457 		 * have stepped on it later.
458 		 *
459 		 * This code assumes that size is a multiple of 8 bytes for
460 		 * 64 bit machines
461 		 */
462 		mtpp = (struct malloc_type **)
463 		    ((unsigned long)mtpp & ~UMA_ALIGN_PTR);
464 		mtpp += (size - sizeof(struct malloc_type *)) /
465 		    sizeof(struct malloc_type *);
466 		*mtpp = mtp;
467 #endif
468 		uma_zfree_arg(LIST_FIRST(&slab->us_keg->uk_zones), addr, slab);
469 	} else {
470 		size = slab->us_size;
471 		uma_large_free(slab);
472 	}
473 	malloc_type_freed(mtp, size);
474 }
475 
476 /*
477  *	realloc: change the size of a memory block
478  */
479 void *
480 realloc(void *addr, unsigned long size, struct malloc_type *mtp, int flags)
481 {
482 	uma_slab_t slab;
483 	unsigned long alloc;
484 	void *newaddr;
485 
486 	KASSERT(mtp->ks_magic == M_MAGIC,
487 	    ("realloc: bad malloc type magic"));
488 
489 	/* realloc(NULL, ...) is equivalent to malloc(...) */
490 	if (addr == NULL)
491 		return (malloc(size, mtp, flags));
492 
493 	/*
494 	 * XXX: Should report free of old memory and alloc of new memory to
495 	 * per-CPU stats.
496 	 */
497 
498 #ifdef DEBUG_MEMGUARD
499 if (memguard_cmp(mtp)) {
500 	slab = NULL;
501 	alloc = size;
502 } else {
503 #endif
504 
505 #ifdef DEBUG_REDZONE
506 	slab = NULL;
507 	alloc = redzone_get_size(addr);
508 #else
509 	slab = vtoslab((vm_offset_t)addr & ~(UMA_SLAB_MASK));
510 
511 	/* Sanity check */
512 	KASSERT(slab != NULL,
513 	    ("realloc: address %p out of range", (void *)addr));
514 
515 	/* Get the size of the original block */
516 	if (!(slab->us_flags & UMA_SLAB_MALLOC))
517 		alloc = slab->us_keg->uk_size;
518 	else
519 		alloc = slab->us_size;
520 
521 	/* Reuse the original block if appropriate */
522 	if (size <= alloc
523 	    && (size > (alloc >> REALLOC_FRACTION) || alloc == MINALLOCSIZE))
524 		return (addr);
525 #endif /* !DEBUG_REDZONE */
526 
527 #ifdef DEBUG_MEMGUARD
528 }
529 #endif
530 
531 	/* Allocate a new, bigger (or smaller) block */
532 	if ((newaddr = malloc(size, mtp, flags)) == NULL)
533 		return (NULL);
534 
535 	/* Copy over original contents */
536 	bcopy(addr, newaddr, min(size, alloc));
537 	free(addr, mtp);
538 	return (newaddr);
539 }
540 
541 /*
542  *	reallocf: same as realloc() but free memory on failure.
543  */
544 void *
545 reallocf(void *addr, unsigned long size, struct malloc_type *mtp, int flags)
546 {
547 	void *mem;
548 
549 	if ((mem = realloc(addr, size, mtp, flags)) == NULL)
550 		free(addr, mtp);
551 	return (mem);
552 }
553 
554 /*
555  * Initialize the kernel memory allocator
556  */
557 /* ARGSUSED*/
558 static void
559 kmeminit(void *dummy)
560 {
561 	u_int8_t indx;
562 	u_long mem_size;
563 	int i;
564 
565 	mtx_init(&malloc_mtx, "malloc", NULL, MTX_DEF);
566 
567 	/*
568 	 * Try to auto-tune the kernel memory size, so that it is
569 	 * more applicable for a wider range of machine sizes.
570 	 * On an X86, a VM_KMEM_SIZE_SCALE value of 4 is good, while
571 	 * a VM_KMEM_SIZE of 12MB is a fair compromise.  The
572 	 * VM_KMEM_SIZE_MAX is dependent on the maximum KVA space
573 	 * available, and on an X86 with a total KVA space of 256MB,
574 	 * try to keep VM_KMEM_SIZE_MAX at 80MB or below.
575 	 *
576 	 * Note that the kmem_map is also used by the zone allocator,
577 	 * so make sure that there is enough space.
578 	 */
579 	vm_kmem_size = VM_KMEM_SIZE + nmbclusters * PAGE_SIZE;
580 	mem_size = cnt.v_page_count;
581 
582 #if defined(VM_KMEM_SIZE_SCALE)
583 	vm_kmem_size_scale = VM_KMEM_SIZE_SCALE;
584 #endif
585 	TUNABLE_INT_FETCH("vm.kmem_size_scale", &vm_kmem_size_scale);
586 	if (vm_kmem_size_scale > 0 &&
587 	    (mem_size / vm_kmem_size_scale) > (vm_kmem_size / PAGE_SIZE))
588 		vm_kmem_size = (mem_size / vm_kmem_size_scale) * PAGE_SIZE;
589 
590 #if defined(VM_KMEM_SIZE_MIN)
591 	vm_kmem_size_min = VM_KMEM_SIZE_MIN;
592 #endif
593 	TUNABLE_ULONG_FETCH("vm.kmem_size_min", &vm_kmem_size_min);
594 	if (vm_kmem_size_min > 0 && vm_kmem_size < vm_kmem_size_min) {
595 		vm_kmem_size = vm_kmem_size_min;
596 	}
597 
598 #if defined(VM_KMEM_SIZE_MAX)
599 	vm_kmem_size_max = VM_KMEM_SIZE_MAX;
600 #endif
601 	TUNABLE_ULONG_FETCH("vm.kmem_size_max", &vm_kmem_size_max);
602 	if (vm_kmem_size_max > 0 && vm_kmem_size >= vm_kmem_size_max)
603 		vm_kmem_size = vm_kmem_size_max;
604 
605 	/* Allow final override from the kernel environment */
606 	TUNABLE_ULONG_FETCH("vm.kmem_size", &vm_kmem_size);
607 
608 	/*
609 	 * Limit kmem virtual size to twice the physical memory.
610 	 * This allows for kmem map sparseness, but limits the size
611 	 * to something sane. Be careful to not overflow the 32bit
612 	 * ints while doing the check.
613 	 */
614 	if (((vm_kmem_size / 2) / PAGE_SIZE) > cnt.v_page_count)
615 		vm_kmem_size = 2 * cnt.v_page_count * PAGE_SIZE;
616 
617 	/*
618 	 * Tune settings based on the kmem map's size at this time.
619 	 */
620 	init_param3(vm_kmem_size / PAGE_SIZE);
621 
622 	kmem_map = kmem_suballoc(kernel_map, &kmembase, &kmemlimit,
623 	    vm_kmem_size, TRUE);
624 	kmem_map->system_map = 1;
625 
626 #ifdef DEBUG_MEMGUARD
627 	/*
628 	 * Initialize MemGuard if support compiled in.  MemGuard is a
629 	 * replacement allocator used for detecting tamper-after-free
630 	 * scenarios as they occur.  It is only used for debugging.
631 	 */
632 	vm_memguard_divisor = 10;
633 	TUNABLE_INT_FETCH("vm.memguard.divisor", &vm_memguard_divisor);
634 
635 	/* Pick a conservative value if provided value sucks. */
636 	if ((vm_memguard_divisor <= 0) ||
637 	    ((vm_kmem_size / vm_memguard_divisor) == 0))
638 		vm_memguard_divisor = 10;
639 	memguard_init(kmem_map, vm_kmem_size / vm_memguard_divisor);
640 #endif
641 
642 	uma_startup2();
643 
644 	mt_zone = uma_zcreate("mt_zone", sizeof(struct malloc_type_internal),
645 #ifdef INVARIANTS
646 	    mtrash_ctor, mtrash_dtor, mtrash_init, mtrash_fini,
647 #else
648 	    NULL, NULL, NULL, NULL,
649 #endif
650 	    UMA_ALIGN_PTR, UMA_ZONE_MALLOC);
651 	for (i = 0, indx = 0; kmemzones[indx].kz_size != 0; indx++) {
652 		int size = kmemzones[indx].kz_size;
653 		char *name = kmemzones[indx].kz_name;
654 
655 		kmemzones[indx].kz_zone = uma_zcreate(name, size,
656 #ifdef INVARIANTS
657 		    mtrash_ctor, mtrash_dtor, mtrash_init, mtrash_fini,
658 #else
659 		    NULL, NULL, NULL, NULL,
660 #endif
661 		    UMA_ALIGN_PTR, UMA_ZONE_MALLOC);
662 
663 		for (;i <= size; i+= KMEM_ZBASE)
664 			kmemsize[i >> KMEM_ZSHIFT] = indx;
665 
666 	}
667 }
668 
669 void
670 malloc_init(void *data)
671 {
672 	struct malloc_type_internal *mtip;
673 	struct malloc_type *mtp;
674 
675 	KASSERT(cnt.v_page_count != 0, ("malloc_register before vm_init"));
676 
677 	mtp = data;
678 	if (mtp->ks_magic != M_MAGIC)
679 		panic("malloc_init: bad malloc type magic");
680 
681 	mtip = uma_zalloc(mt_zone, M_WAITOK | M_ZERO);
682 	mtp->ks_handle = mtip;
683 
684 	mtx_lock(&malloc_mtx);
685 	mtp->ks_next = kmemstatistics;
686 	kmemstatistics = mtp;
687 	kmemcount++;
688 	mtx_unlock(&malloc_mtx);
689 }
690 
691 void
692 malloc_uninit(void *data)
693 {
694 	struct malloc_type_internal *mtip;
695 	struct malloc_type_stats *mtsp;
696 	struct malloc_type *mtp, *temp;
697 	uma_slab_t slab;
698 	long temp_allocs, temp_bytes;
699 	int i;
700 
701 	mtp = data;
702 	KASSERT(mtp->ks_magic == M_MAGIC,
703 	    ("malloc_uninit: bad malloc type magic"));
704 	KASSERT(mtp->ks_handle != NULL, ("malloc_deregister: cookie NULL"));
705 
706 	mtx_lock(&malloc_mtx);
707 	mtip = mtp->ks_handle;
708 	mtp->ks_handle = NULL;
709 	if (mtp != kmemstatistics) {
710 		for (temp = kmemstatistics; temp != NULL;
711 		    temp = temp->ks_next) {
712 			if (temp->ks_next == mtp) {
713 				temp->ks_next = mtp->ks_next;
714 				break;
715 			}
716 		}
717 		KASSERT(temp,
718 		    ("malloc_uninit: type '%s' not found", mtp->ks_shortdesc));
719 	} else
720 		kmemstatistics = mtp->ks_next;
721 	kmemcount--;
722 	mtx_unlock(&malloc_mtx);
723 
724 	/*
725 	 * Look for memory leaks.
726 	 */
727 	temp_allocs = temp_bytes = 0;
728 	for (i = 0; i < MAXCPU; i++) {
729 		mtsp = &mtip->mti_stats[i];
730 		temp_allocs += mtsp->mts_numallocs;
731 		temp_allocs -= mtsp->mts_numfrees;
732 		temp_bytes += mtsp->mts_memalloced;
733 		temp_bytes -= mtsp->mts_memfreed;
734 	}
735 	if (temp_allocs > 0 || temp_bytes > 0) {
736 		printf("Warning: memory type %s leaked memory on destroy "
737 		    "(%ld allocations, %ld bytes leaked).\n", mtp->ks_shortdesc,
738 		    temp_allocs, temp_bytes);
739 	}
740 
741 	slab = vtoslab((vm_offset_t) mtip & (~UMA_SLAB_MASK));
742 	uma_zfree_arg(mt_zone, mtip, slab);
743 }
744 
745 struct malloc_type *
746 malloc_desc2type(const char *desc)
747 {
748 	struct malloc_type *mtp;
749 
750 	mtx_assert(&malloc_mtx, MA_OWNED);
751 	for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
752 		if (strcmp(mtp->ks_shortdesc, desc) == 0)
753 			return (mtp);
754 	}
755 	return (NULL);
756 }
757 
758 static int
759 sysctl_kern_malloc_stats(SYSCTL_HANDLER_ARGS)
760 {
761 	struct malloc_type_stream_header mtsh;
762 	struct malloc_type_internal *mtip;
763 	struct malloc_type_header mth;
764 	struct malloc_type *mtp;
765 	int buflen, count, error, i;
766 	struct sbuf sbuf;
767 	char *buffer;
768 
769 	mtx_lock(&malloc_mtx);
770 restart:
771 	mtx_assert(&malloc_mtx, MA_OWNED);
772 	count = kmemcount;
773 	mtx_unlock(&malloc_mtx);
774 	buflen = sizeof(mtsh) + count * (sizeof(mth) +
775 	    sizeof(struct malloc_type_stats) * MAXCPU) + 1;
776 	buffer = malloc(buflen, M_TEMP, M_WAITOK | M_ZERO);
777 	mtx_lock(&malloc_mtx);
778 	if (count < kmemcount) {
779 		free(buffer, M_TEMP);
780 		goto restart;
781 	}
782 
783 	sbuf_new(&sbuf, buffer, buflen, SBUF_FIXEDLEN);
784 
785 	/*
786 	 * Insert stream header.
787 	 */
788 	bzero(&mtsh, sizeof(mtsh));
789 	mtsh.mtsh_version = MALLOC_TYPE_STREAM_VERSION;
790 	mtsh.mtsh_maxcpus = MAXCPU;
791 	mtsh.mtsh_count = kmemcount;
792 	if (sbuf_bcat(&sbuf, &mtsh, sizeof(mtsh)) < 0) {
793 		mtx_unlock(&malloc_mtx);
794 		error = ENOMEM;
795 		goto out;
796 	}
797 
798 	/*
799 	 * Insert alternating sequence of type headers and type statistics.
800 	 */
801 	for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
802 		mtip = (struct malloc_type_internal *)mtp->ks_handle;
803 
804 		/*
805 		 * Insert type header.
806 		 */
807 		bzero(&mth, sizeof(mth));
808 		strlcpy(mth.mth_name, mtp->ks_shortdesc, MALLOC_MAX_NAME);
809 		if (sbuf_bcat(&sbuf, &mth, sizeof(mth)) < 0) {
810 			mtx_unlock(&malloc_mtx);
811 			error = ENOMEM;
812 			goto out;
813 		}
814 
815 		/*
816 		 * Insert type statistics for each CPU.
817 		 */
818 		for (i = 0; i < MAXCPU; i++) {
819 			if (sbuf_bcat(&sbuf, &mtip->mti_stats[i],
820 			    sizeof(mtip->mti_stats[i])) < 0) {
821 				mtx_unlock(&malloc_mtx);
822 				error = ENOMEM;
823 				goto out;
824 			}
825 		}
826 	}
827 	mtx_unlock(&malloc_mtx);
828 	sbuf_finish(&sbuf);
829 	error = SYSCTL_OUT(req, sbuf_data(&sbuf), sbuf_len(&sbuf));
830 out:
831 	sbuf_delete(&sbuf);
832 	free(buffer, M_TEMP);
833 	return (error);
834 }
835 
836 SYSCTL_PROC(_kern, OID_AUTO, malloc_stats, CTLFLAG_RD|CTLTYPE_STRUCT,
837     0, 0, sysctl_kern_malloc_stats, "s,malloc_type_ustats",
838     "Return malloc types");
839 
840 SYSCTL_INT(_kern, OID_AUTO, malloc_count, CTLFLAG_RD, &kmemcount, 0,
841     "Count of kernel malloc types");
842 
843 void
844 malloc_type_list(malloc_type_list_func_t *func, void *arg)
845 {
846 	struct malloc_type *mtp, **bufmtp;
847 	int count, i;
848 	size_t buflen;
849 
850 	mtx_lock(&malloc_mtx);
851 restart:
852 	mtx_assert(&malloc_mtx, MA_OWNED);
853 	count = kmemcount;
854 	mtx_unlock(&malloc_mtx);
855 
856 	buflen = sizeof(struct malloc_type *) * count;
857 	bufmtp = malloc(buflen, M_TEMP, M_WAITOK);
858 
859 	mtx_lock(&malloc_mtx);
860 
861 	if (count < kmemcount) {
862 		free(bufmtp, M_TEMP);
863 		goto restart;
864 	}
865 
866 	for (mtp = kmemstatistics, i = 0; mtp != NULL; mtp = mtp->ks_next, i++)
867 		bufmtp[i] = mtp;
868 
869 	mtx_unlock(&malloc_mtx);
870 
871 	for (i = 0; i < count; i++)
872 		(func)(bufmtp[i], arg);
873 
874 	free(bufmtp, M_TEMP);
875 }
876 
877 #ifdef DDB
878 DB_SHOW_COMMAND(malloc, db_show_malloc)
879 {
880 	struct malloc_type_internal *mtip;
881 	struct malloc_type *mtp;
882 	u_int64_t allocs, frees;
883 	u_int64_t alloced, freed;
884 	int i;
885 
886 	db_printf("%18s %12s  %12s %12s\n", "Type", "InUse", "MemUse",
887 	    "Requests");
888 	for (mtp = kmemstatistics; mtp != NULL; mtp = mtp->ks_next) {
889 		mtip = (struct malloc_type_internal *)mtp->ks_handle;
890 		allocs = 0;
891 		frees = 0;
892 		alloced = 0;
893 		freed = 0;
894 		for (i = 0; i < MAXCPU; i++) {
895 			allocs += mtip->mti_stats[i].mts_numallocs;
896 			frees += mtip->mti_stats[i].mts_numfrees;
897 			alloced += mtip->mti_stats[i].mts_memalloced;
898 			freed += mtip->mti_stats[i].mts_memfreed;
899 		}
900 		db_printf("%18s %12ju %12juK %12ju\n",
901 		    mtp->ks_shortdesc, allocs - frees,
902 		    (alloced - freed + 1023) / 1024, allocs);
903 	}
904 }
905 #endif
906 
907 #ifdef MALLOC_PROFILE
908 
909 static int
910 sysctl_kern_mprof(SYSCTL_HANDLER_ARGS)
911 {
912 	int linesize = 64;
913 	struct sbuf sbuf;
914 	uint64_t count;
915 	uint64_t waste;
916 	uint64_t mem;
917 	int bufsize;
918 	int error;
919 	char *buf;
920 	int rsize;
921 	int size;
922 	int i;
923 
924 	bufsize = linesize * (KMEM_ZSIZE + 1);
925 	bufsize += 128; 	/* For the stats line */
926 	bufsize += 128; 	/* For the banner line */
927 	waste = 0;
928 	mem = 0;
929 
930 	buf = malloc(bufsize, M_TEMP, M_WAITOK|M_ZERO);
931 	sbuf_new(&sbuf, buf, bufsize, SBUF_FIXEDLEN);
932 	sbuf_printf(&sbuf,
933 	    "\n  Size                    Requests  Real Size\n");
934 	for (i = 0; i < KMEM_ZSIZE; i++) {
935 		size = i << KMEM_ZSHIFT;
936 		rsize = kmemzones[kmemsize[i]].kz_size;
937 		count = (long long unsigned)krequests[i];
938 
939 		sbuf_printf(&sbuf, "%6d%28llu%11d\n", size,
940 		    (unsigned long long)count, rsize);
941 
942 		if ((rsize * count) > (size * count))
943 			waste += (rsize * count) - (size * count);
944 		mem += (rsize * count);
945 	}
946 	sbuf_printf(&sbuf,
947 	    "\nTotal memory used:\t%30llu\nTotal Memory wasted:\t%30llu\n",
948 	    (unsigned long long)mem, (unsigned long long)waste);
949 	sbuf_finish(&sbuf);
950 
951 	error = SYSCTL_OUT(req, sbuf_data(&sbuf), sbuf_len(&sbuf));
952 
953 	sbuf_delete(&sbuf);
954 	free(buf, M_TEMP);
955 	return (error);
956 }
957 
958 SYSCTL_OID(_kern, OID_AUTO, mprof, CTLTYPE_STRING|CTLFLAG_RD,
959     NULL, 0, sysctl_kern_mprof, "A", "Malloc Profiling");
960 #endif /* MALLOC_PROFILE */
961