xref: /netbsd-src/sys/kern/kern_malloc.c (revision 5aefcfdc06931dd97e76246d2fe0302f7b3fe094)
1 /*	$NetBSD: kern_malloc.c,v 1.55 2000/11/24 00:34:32 chs Exp $	*/
2 
3 /*
4  * Copyright (c) 1996 Christopher G. Demetriou.  All rights reserved.
5  * Copyright (c) 1987, 1991, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	@(#)kern_malloc.c	8.4 (Berkeley) 5/20/95
37  */
38 
39 #include "opt_lockdebug.h"
40 
41 #include <sys/param.h>
42 #include <sys/proc.h>
43 #include <sys/map.h>
44 #include <sys/kernel.h>
45 #include <sys/malloc.h>
46 #include <sys/systm.h>
47 
48 #include <uvm/uvm_extern.h>
49 
50 static struct vm_map_intrsafe kmem_map_store;
51 vm_map_t kmem_map = NULL;
52 
53 #include "opt_kmempages.h"
54 
55 #ifdef NKMEMCLUSTERS
56 #error NKMEMCLUSTERS is obsolete; remove it from your kernel config file and use NKMEMPAGES instead or let the kernel auto-size
57 #endif
58 
59 /*
60  * Default number of pages in kmem_map.  We attempt to calculate this
61  * at run-time, but allow it to be either patched or set in the kernel
62  * config file.
63  */
64 #ifndef NKMEMPAGES
65 #define	NKMEMPAGES	0
66 #endif
67 int	nkmempages = NKMEMPAGES;
68 
69 /*
70  * Defaults for lower- and upper-bounds for the kmem_map page count.
71  * Can be overridden by kernel config options.
72  */
73 #ifndef	NKMEMPAGES_MIN
74 #define	NKMEMPAGES_MIN	NKMEMPAGES_MIN_DEFAULT
75 #endif
76 
77 #ifndef NKMEMPAGES_MAX
78 #define	NKMEMPAGES_MAX	NKMEMPAGES_MAX_DEFAULT
79 #endif
80 
81 #include "opt_kmemstats.h"
82 #include "opt_malloclog.h"
83 
84 struct kmembuckets bucket[MINBUCKET + 16];
85 struct kmemstats kmemstats[M_LAST];
86 struct kmemusage *kmemusage;
87 char *kmembase, *kmemlimit;
88 const char *memname[] = INITKMEMNAMES;
89 
90 #ifdef MALLOCLOG
91 #ifndef MALLOCLOGSIZE
92 #define	MALLOCLOGSIZE	100000
93 #endif
94 
95 struct malloclog {
96 	void *addr;
97 	long size;
98 	int type;
99 	int action;
100 	const char *file;
101 	long line;
102 } malloclog[MALLOCLOGSIZE];
103 
104 long	malloclogptr;
105 
106 static void domlog __P((void *a, long size, int type, int action,
107 	const char *file, long line));
108 static void hitmlog __P((void *a));
109 
110 static void
111 domlog(a, size, type, action, file, line)
112 	void *a;
113 	long size;
114 	int type;
115 	int action;
116 	const char *file;
117 	long line;
118 {
119 
120 	malloclog[malloclogptr].addr = a;
121 	malloclog[malloclogptr].size = size;
122 	malloclog[malloclogptr].type = type;
123 	malloclog[malloclogptr].action = action;
124 	malloclog[malloclogptr].file = file;
125 	malloclog[malloclogptr].line = line;
126 	malloclogptr++;
127 	if (malloclogptr >= MALLOCLOGSIZE)
128 		malloclogptr = 0;
129 }
130 
131 static void
132 hitmlog(a)
133 	void *a;
134 {
135 	struct malloclog *lp;
136 	long l;
137 
138 #define	PRT \
139 	if (malloclog[l].addr == a && malloclog[l].action) { \
140 		lp = &malloclog[l]; \
141 		printf("malloc log entry %ld:\n", l); \
142 		printf("\taddr = %p\n", lp->addr); \
143 		printf("\tsize = %ld\n", lp->size); \
144 		printf("\ttype = %s\n", memname[lp->type]); \
145 		printf("\taction = %s\n", lp->action == 1 ? "alloc" : "free"); \
146 		printf("\tfile = %s\n", lp->file); \
147 		printf("\tline = %ld\n", lp->line); \
148 	}
149 
150 	for (l = malloclogptr; l < MALLOCLOGSIZE; l++)
151 		PRT
152 
153 	for (l = 0; l < malloclogptr; l++)
154 		PRT
155 }
156 #endif /* MALLOCLOG */
157 
158 #ifdef DIAGNOSTIC
159 /*
160  * This structure provides a set of masks to catch unaligned frees.
161  */
162 long addrmask[] = { 0,
163 	0x00000001, 0x00000003, 0x00000007, 0x0000000f,
164 	0x0000001f, 0x0000003f, 0x0000007f, 0x000000ff,
165 	0x000001ff, 0x000003ff, 0x000007ff, 0x00000fff,
166 	0x00001fff, 0x00003fff, 0x00007fff, 0x0000ffff,
167 };
168 
169 /*
170  * The WEIRD_ADDR is used as known text to copy into free objects so
171  * that modifications after frees can be detected.
172  */
173 #define WEIRD_ADDR	((unsigned) 0xdeadbeef)
174 #ifdef DEBUG
175 #define MAX_COPY	PAGE_SIZE
176 #else
177 #define MAX_COPY	32
178 #endif
179 
180 /*
181  * Normally the freelist structure is used only to hold the list pointer
182  * for free objects.  However, when running with diagnostics, the first
183  * 8 bytes of the structure is unused except for diagnostic information,
184  * and the free list pointer is at offst 8 in the structure.  Since the
185  * first 8 bytes is the portion of the structure most often modified, this
186  * helps to detect memory reuse problems and avoid free list corruption.
187  */
188 struct freelist {
189 	int32_t	spare0;
190 	int16_t	type;
191 	int16_t	spare1;
192 	caddr_t	next;
193 };
194 #else /* !DIAGNOSTIC */
195 struct freelist {
196 	caddr_t	next;
197 };
198 #endif /* DIAGNOSTIC */
199 
200 /*
201  * Allocate a block of memory
202  */
203 #ifdef MALLOCLOG
204 void *
205 _malloc(size, type, flags, file, line)
206 	unsigned long size;
207 	int type, flags;
208 	const char *file;
209 	long line;
210 #else
211 void *
212 malloc(size, type, flags)
213 	unsigned long size;
214 	int type, flags;
215 #endif /* MALLOCLOG */
216 {
217 	struct kmembuckets *kbp;
218 	struct kmemusage *kup;
219 	struct freelist *freep;
220 	long indx, npg, allocsize;
221 	int s;
222 	caddr_t va, cp, savedlist;
223 #ifdef DIAGNOSTIC
224 	int32_t *end, *lp;
225 	int copysize;
226 	const char *savedtype;
227 #endif
228 #ifdef KMEMSTATS
229 	struct kmemstats *ksp = &kmemstats[type];
230 
231 	if (__predict_false(((unsigned long)type) > M_LAST))
232 		panic("malloc - bogus type");
233 #endif
234 	indx = BUCKETINDX(size);
235 	kbp = &bucket[indx];
236 	s = splmem();
237 #ifdef KMEMSTATS
238 	while (ksp->ks_memuse >= ksp->ks_limit) {
239 		if (flags & M_NOWAIT) {
240 			splx(s);
241 			return ((void *) NULL);
242 		}
243 		if (ksp->ks_limblocks < 65535)
244 			ksp->ks_limblocks++;
245 		tsleep((caddr_t)ksp, PSWP+2, memname[type], 0);
246 	}
247 	ksp->ks_size |= 1 << indx;
248 #endif
249 #ifdef DIAGNOSTIC
250 	copysize = 1 << indx < MAX_COPY ? 1 << indx : MAX_COPY;
251 #endif
252 	if (kbp->kb_next == NULL) {
253 		kbp->kb_last = NULL;
254 		if (size > MAXALLOCSAVE)
255 			allocsize = roundup(size, PAGE_SIZE);
256 		else
257 			allocsize = 1 << indx;
258 		npg = btoc(allocsize);
259 		va = (caddr_t) uvm_km_kmemalloc(kmem_map, uvmexp.kmem_object,
260 				(vsize_t)ctob(npg),
261 				(flags & M_NOWAIT) ? UVM_KMF_NOWAIT : 0);
262 		if (__predict_false(va == NULL)) {
263 			/*
264 			 * Kmem_malloc() can return NULL, even if it can
265 			 * wait, if there is no map space avaiable, because
266 			 * it can't fix that problem.  Neither can we,
267 			 * right now.  (We should release pages which
268 			 * are completely free and which are in buckets
269 			 * with too many free elements.)
270 			 */
271 			if ((flags & M_NOWAIT) == 0)
272 				panic("malloc: out of space in kmem_map");
273 			splx(s);
274 			return ((void *) NULL);
275 		}
276 #ifdef KMEMSTATS
277 		kbp->kb_total += kbp->kb_elmpercl;
278 #endif
279 		kup = btokup(va);
280 		kup->ku_indx = indx;
281 		if (allocsize > MAXALLOCSAVE) {
282 			if (npg > 65535)
283 				panic("malloc: allocation too large");
284 			kup->ku_pagecnt = npg;
285 #ifdef KMEMSTATS
286 			ksp->ks_memuse += allocsize;
287 #endif
288 			goto out;
289 		}
290 #ifdef KMEMSTATS
291 		kup->ku_freecnt = kbp->kb_elmpercl;
292 		kbp->kb_totalfree += kbp->kb_elmpercl;
293 #endif
294 		/*
295 		 * Just in case we blocked while allocating memory,
296 		 * and someone else also allocated memory for this
297 		 * bucket, don't assume the list is still empty.
298 		 */
299 		savedlist = kbp->kb_next;
300 		kbp->kb_next = cp = va + (npg << PAGE_SHIFT) - allocsize;
301 		for (;;) {
302 			freep = (struct freelist *)cp;
303 #ifdef DIAGNOSTIC
304 			/*
305 			 * Copy in known text to detect modification
306 			 * after freeing.
307 			 */
308 			end = (int32_t *)&cp[copysize];
309 			for (lp = (int32_t *)cp; lp < end; lp++)
310 				*lp = WEIRD_ADDR;
311 			freep->type = M_FREE;
312 #endif /* DIAGNOSTIC */
313 			if (cp <= va)
314 				break;
315 			cp -= allocsize;
316 			freep->next = cp;
317 		}
318 		freep->next = savedlist;
319 		if (kbp->kb_last == NULL)
320 			kbp->kb_last = (caddr_t)freep;
321 	}
322 	va = kbp->kb_next;
323 	kbp->kb_next = ((struct freelist *)va)->next;
324 #ifdef DIAGNOSTIC
325 	freep = (struct freelist *)va;
326 	savedtype = (unsigned)freep->type < M_LAST ?
327 		memname[freep->type] : "???";
328 	if (kbp->kb_next) {
329 		int rv;
330 		vaddr_t addr = (vaddr_t)kbp->kb_next;
331 
332 		vm_map_lock(kmem_map);
333 		rv = uvm_map_checkprot(kmem_map, addr,
334 				       addr + sizeof(struct freelist),
335 				       VM_PROT_WRITE);
336 		vm_map_unlock(kmem_map);
337 
338 		if (__predict_false(rv == 0)) {
339 			printf(
340 		    "%s %ld of object %p size %ld %s %s (invalid addr %p)\n",
341 			    "Data modified on freelist: word",
342 			    (long)((int32_t *)&kbp->kb_next - (int32_t *)kbp),
343 			    va, size, "previous type", savedtype, kbp->kb_next);
344 #ifdef MALLOCLOG
345 			hitmlog(va);
346 #endif
347 			kbp->kb_next = NULL;
348 		}
349 	}
350 
351 	/* Fill the fields that we've used with WEIRD_ADDR */
352 #if BYTE_ORDER == BIG_ENDIAN
353 	freep->type = WEIRD_ADDR >> 16;
354 #endif
355 #if BYTE_ORDER == LITTLE_ENDIAN
356 	freep->type = (short)WEIRD_ADDR;
357 #endif
358 	end = (int32_t *)&freep->next +
359 	    (sizeof(freep->next) / sizeof(int32_t));
360 	for (lp = (int32_t *)&freep->next; lp < end; lp++)
361 		*lp = WEIRD_ADDR;
362 
363 	/* and check that the data hasn't been modified. */
364 	end = (int32_t *)&va[copysize];
365 	for (lp = (int32_t *)va; lp < end; lp++) {
366 		if (__predict_true(*lp == WEIRD_ADDR))
367 			continue;
368 		printf("%s %ld of object %p size %ld %s %s (0x%x != 0x%x)\n",
369 		    "Data modified on freelist: word",
370 		    (long)(lp - (int32_t *)va), va, size, "previous type",
371 		    savedtype, *lp, WEIRD_ADDR);
372 #ifdef MALLOCLOG
373 		hitmlog(va);
374 #endif
375 		break;
376 	}
377 
378 	freep->spare0 = 0;
379 #endif /* DIAGNOSTIC */
380 #ifdef KMEMSTATS
381 	kup = btokup(va);
382 	if (kup->ku_indx != indx)
383 		panic("malloc: wrong bucket");
384 	if (kup->ku_freecnt == 0)
385 		panic("malloc: lost data");
386 	kup->ku_freecnt--;
387 	kbp->kb_totalfree--;
388 	ksp->ks_memuse += 1 << indx;
389 out:
390 	kbp->kb_calls++;
391 	ksp->ks_inuse++;
392 	ksp->ks_calls++;
393 	if (ksp->ks_memuse > ksp->ks_maxused)
394 		ksp->ks_maxused = ksp->ks_memuse;
395 #else
396 out:
397 #endif
398 #ifdef MALLOCLOG
399 	domlog(va, size, type, 1, file, line);
400 #endif
401 	splx(s);
402 	return ((void *) va);
403 }
404 
405 /*
406  * Free a block of memory allocated by malloc.
407  */
408 #ifdef MALLOCLOG
409 void
410 _free(addr, type, file, line)
411 	void *addr;
412 	int type;
413 	const char *file;
414 	long line;
415 #else
416 void
417 free(addr, type)
418 	void *addr;
419 	int type;
420 #endif /* MALLOCLOG */
421 {
422 	struct kmembuckets *kbp;
423 	struct kmemusage *kup;
424 	struct freelist *freep;
425 	long size;
426 	int s;
427 #ifdef DIAGNOSTIC
428 	caddr_t cp;
429 	int32_t *end, *lp;
430 	long alloc, copysize;
431 #endif
432 #ifdef KMEMSTATS
433 	struct kmemstats *ksp = &kmemstats[type];
434 #endif
435 
436 #ifdef DIAGNOSTIC
437 	/*
438 	 * Ensure that we're free'ing something that we could
439 	 * have allocated in the first place.  That is, check
440 	 * to see that the address is within kmem_map.
441 	 */
442 	if (__predict_false((vaddr_t)addr < kmem_map->header.start ||
443 			    (vaddr_t)addr >= kmem_map->header.end))
444 		panic("free: addr %p not within kmem_map", addr);
445 #endif
446 
447 	kup = btokup(addr);
448 	size = 1 << kup->ku_indx;
449 	kbp = &bucket[kup->ku_indx];
450 	s = splmem();
451 #ifdef MALLOCLOG
452 	domlog(addr, 0, type, 2, file, line);
453 #endif
454 #ifdef DIAGNOSTIC
455 	/*
456 	 * Check for returns of data that do not point to the
457 	 * beginning of the allocation.
458 	 */
459 	if (size > PAGE_SIZE)
460 		alloc = addrmask[BUCKETINDX(PAGE_SIZE)];
461 	else
462 		alloc = addrmask[kup->ku_indx];
463 	if (((u_long)addr & alloc) != 0)
464 		panic("free: unaligned addr %p, size %ld, type %s, mask %ld\n",
465 			addr, size, memname[type], alloc);
466 #endif /* DIAGNOSTIC */
467 	if (size > MAXALLOCSAVE) {
468 		uvm_km_free(kmem_map, (vaddr_t)addr, ctob(kup->ku_pagecnt));
469 #ifdef KMEMSTATS
470 		size = kup->ku_pagecnt << PGSHIFT;
471 		ksp->ks_memuse -= size;
472 		kup->ku_indx = 0;
473 		kup->ku_pagecnt = 0;
474 		if (ksp->ks_memuse + size >= ksp->ks_limit &&
475 		    ksp->ks_memuse < ksp->ks_limit)
476 			wakeup((caddr_t)ksp);
477 		ksp->ks_inuse--;
478 		kbp->kb_total -= 1;
479 #endif
480 		splx(s);
481 		return;
482 	}
483 	freep = (struct freelist *)addr;
484 #ifdef DIAGNOSTIC
485 	/*
486 	 * Check for multiple frees. Use a quick check to see if
487 	 * it looks free before laboriously searching the freelist.
488 	 */
489 	if (__predict_false(freep->spare0 == WEIRD_ADDR)) {
490 		for (cp = kbp->kb_next; cp;
491 		    cp = ((struct freelist *)cp)->next) {
492 			if (addr != cp)
493 				continue;
494 			printf("multiply freed item %p\n", addr);
495 #ifdef MALLOCLOG
496 			hitmlog(addr);
497 #endif
498 			panic("free: duplicated free");
499 		}
500 	}
501 #ifdef LOCKDEBUG
502 	/*
503 	 * Check if we're freeing a locked simple lock.
504 	 */
505 	simple_lock_freecheck(addr, (char *)addr + size);
506 #endif
507 	/*
508 	 * Copy in known text to detect modification after freeing
509 	 * and to make it look free. Also, save the type being freed
510 	 * so we can list likely culprit if modification is detected
511 	 * when the object is reallocated.
512 	 */
513 	copysize = size < MAX_COPY ? size : MAX_COPY;
514 	end = (int32_t *)&((caddr_t)addr)[copysize];
515 	for (lp = (int32_t *)addr; lp < end; lp++)
516 		*lp = WEIRD_ADDR;
517 	freep->type = type;
518 #endif /* DIAGNOSTIC */
519 #ifdef KMEMSTATS
520 	kup->ku_freecnt++;
521 	if (kup->ku_freecnt >= kbp->kb_elmpercl) {
522 		if (kup->ku_freecnt > kbp->kb_elmpercl)
523 			panic("free: multiple frees");
524 		else if (kbp->kb_totalfree > kbp->kb_highwat)
525 			kbp->kb_couldfree++;
526 	}
527 	kbp->kb_totalfree++;
528 	ksp->ks_memuse -= size;
529 	if (ksp->ks_memuse + size >= ksp->ks_limit &&
530 	    ksp->ks_memuse < ksp->ks_limit)
531 		wakeup((caddr_t)ksp);
532 	ksp->ks_inuse--;
533 #endif
534 	if (kbp->kb_next == NULL)
535 		kbp->kb_next = addr;
536 	else
537 		((struct freelist *)kbp->kb_last)->next = addr;
538 	freep->next = NULL;
539 	kbp->kb_last = addr;
540 	splx(s);
541 }
542 
543 /*
544  * Change the size of a block of memory.
545  */
546 void *
547 realloc(curaddr, newsize, type, flags)
548 	void *curaddr;
549 	unsigned long newsize;
550 	int type, flags;
551 {
552 	struct kmemusage *kup;
553 	long cursize;
554 	void *newaddr;
555 #ifdef DIAGNOSTIC
556 	long alloc;
557 #endif
558 
559 	/*
560 	 * Realloc() with a NULL pointer is the same as malloc().
561 	 */
562 	if (curaddr == NULL)
563 		return (malloc(newsize, type, flags));
564 
565 	/*
566 	 * Realloc() with zero size is the same as free().
567 	 */
568 	if (newsize == 0) {
569 		free(curaddr, type);
570 		return (NULL);
571 	}
572 
573 	/*
574 	 * Find out how large the old allocation was (and do some
575 	 * sanity checking).
576 	 */
577 	kup = btokup(curaddr);
578 	cursize = 1 << kup->ku_indx;
579 
580 #ifdef DIAGNOSTIC
581 	/*
582 	 * Check for returns of data that do not point to the
583 	 * beginning of the allocation.
584 	 */
585 	if (cursize > PAGE_SIZE)
586 		alloc = addrmask[BUCKETINDX(PAGE_SIZE)];
587 	else
588 		alloc = addrmask[kup->ku_indx];
589 	if (((u_long)curaddr & alloc) != 0)
590 		panic("realloc: unaligned addr %p, size %ld, type %s, mask %ld\n",
591 			curaddr, cursize, memname[type], alloc);
592 #endif /* DIAGNOSTIC */
593 
594 	if (cursize > MAXALLOCSAVE)
595 		cursize = ctob(kup->ku_pagecnt);
596 
597 	/*
598 	 * If we already actually have as much as they want, we're done.
599 	 */
600 	if (newsize <= cursize)
601 		return (curaddr);
602 
603 	/*
604 	 * Can't satisfy the allocation with the existing block.
605 	 * Allocate a new one and copy the data.
606 	 */
607 	newaddr = malloc(newsize, type, flags);
608 	if (__predict_false(newaddr == NULL)) {
609 		/*
610 		 * Malloc() failed, because flags included M_NOWAIT.
611 		 * Return NULL to indicate that failure.  The old
612 		 * pointer is still valid.
613 		 */
614 		return NULL;
615 	}
616 	memcpy(newaddr, curaddr, cursize);
617 
618 	/*
619 	 * We were successful: free the old allocation and return
620 	 * the new one.
621 	 */
622 	free(curaddr, type);
623 	return (newaddr);
624 }
625 
626 /*
627  * Compute the number of pages that kmem_map will map, that is,
628  * the size of the kernel malloc arena.
629  */
630 void
631 kmeminit_nkmempages()
632 {
633 	int npages;
634 
635 	if (nkmempages != 0) {
636 		/*
637 		 * It's already been set (by us being here before, or
638 		 * by patching or kernel config options), bail out now.
639 		 */
640 		return;
641 	}
642 
643 	/*
644 	 * We use the following (simple) formula:
645 	 *
646 	 *	- Starting point is physical memory / 4.
647 	 *
648 	 *	- Clamp it down to NKMEMPAGES_MAX.
649 	 *
650 	 *	- Round it up to NKMEMPAGES_MIN.
651 	 */
652 	npages = physmem / 4;
653 
654 	if (npages > NKMEMPAGES_MAX)
655 		npages = NKMEMPAGES_MAX;
656 
657 	if (npages < NKMEMPAGES_MIN)
658 		npages = NKMEMPAGES_MIN;
659 
660 	nkmempages = npages;
661 }
662 
663 /*
664  * Initialize the kernel memory allocator
665  */
666 void
667 kmeminit()
668 {
669 #ifdef KMEMSTATS
670 	long indx;
671 #endif
672 
673 #if	((MAXALLOCSAVE & (MAXALLOCSAVE - 1)) != 0)
674 		ERROR!_kmeminit:_MAXALLOCSAVE_not_power_of_2
675 #endif
676 #if	(MAXALLOCSAVE > MINALLOCSIZE * 32768)
677 		ERROR!_kmeminit:_MAXALLOCSAVE_too_big
678 #endif
679 #if	(MAXALLOCSAVE < NBPG)
680 		ERROR!_kmeminit:_MAXALLOCSAVE_too_small
681 #endif
682 
683 	if (sizeof(struct freelist) > (1 << MINBUCKET))
684 		panic("minbucket too small/struct freelist too big");
685 
686 	/*
687 	 * Compute the number of kmem_map pages, if we have not
688 	 * done so already.
689 	 */
690 	kmeminit_nkmempages();
691 
692 	kmemusage = (struct kmemusage *) uvm_km_zalloc(kernel_map,
693 		(vsize_t)(nkmempages * sizeof(struct kmemusage)));
694 	kmem_map = uvm_km_suballoc(kernel_map, (vaddr_t *)&kmembase,
695 		(vaddr_t *)&kmemlimit, (vsize_t)(nkmempages << PAGE_SHIFT),
696 			VM_MAP_INTRSAFE, FALSE, &kmem_map_store.vmi_map);
697 #ifdef KMEMSTATS
698 	for (indx = 0; indx < MINBUCKET + 16; indx++) {
699 		if (1 << indx >= PAGE_SIZE)
700 			bucket[indx].kb_elmpercl = 1;
701 		else
702 			bucket[indx].kb_elmpercl = PAGE_SIZE / (1 << indx);
703 		bucket[indx].kb_highwat = 5 * bucket[indx].kb_elmpercl;
704 	}
705 	for (indx = 0; indx < M_LAST; indx++)
706 		kmemstats[indx].ks_limit = (nkmempages << PAGE_SHIFT) * 6 / 10;
707 #endif
708 }
709 
710 #ifdef DDB
711 #include <ddb/db_output.h>
712 
713 /*
714  * Dump kmem statistics from ddb.
715  *
716  * usage: call dump_kmemstats
717  */
718 void	dump_kmemstats __P((void));
719 
720 void
721 dump_kmemstats()
722 {
723 #ifdef KMEMSTATS
724 	const char *name;
725 	int i;
726 
727 	for (i = 0; i < M_LAST; i++) {
728 		name = memname[i] ? memname[i] : "";
729 
730 		db_printf("%2d %s%.*s %ld\n", i, name,
731 		    (int)(20 - strlen(name)), "                    ",
732 		    kmemstats[i].ks_memuse);
733 	}
734 #else
735 	db_printf("Kmem stats are not being collected.\n");
736 #endif /* KMEMSTATS */
737 }
738 #endif /* DDB */
739