xref: /dragonfly/sys/vm/vm_zone.c (revision 1de703da) 
1 /*
2  * Copyright (c) 1997, 1998 John S. Dyson
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *	notice immediately at the beginning of the file, without modification,
10  *	this list of conditions, and the following disclaimer.
11  * 2. Absolutely no warranty of function or purpose is made by the author
12  *	John S. Dyson.
13  *
14  * $FreeBSD: src/sys/vm/vm_zone.c,v 1.30.2.6 2002/10/10 19:50:16 dillon Exp $
15  * $DragonFly: src/sys/vm/vm_zone.c,v 1.2 2003/06/17 04:29:00 dillon Exp $
16  */
17 
18 #include <sys/param.h>
19 #include <sys/systm.h>
20 #include <sys/kernel.h>
21 #include <sys/lock.h>
22 #include <sys/malloc.h>
23 #include <sys/sysctl.h>
24 #include <sys/vmmeter.h>
25 
26 #include <vm/vm.h>
27 #include <vm/vm_object.h>
28 #include <vm/vm_page.h>
29 #include <vm/vm_map.h>
30 #include <vm/vm_kern.h>
31 #include <vm/vm_extern.h>
32 #include <vm/vm_zone.h>
33 
34 static MALLOC_DEFINE(M_ZONE, "ZONE", "Zone header");
35 
36 #define ZONE_ERROR_INVALID 0
37 #define ZONE_ERROR_NOTFREE 1
38 #define ZONE_ERROR_ALREADYFREE 2
39 
40 #define ZONE_ROUNDING	32
41 
42 #define ZENTRY_FREE	0x12342378
43 /*
44  * void *zalloc(vm_zone_t zone) --
45  *	Returns an item from a specified zone.
46  *
47  * void zfree(vm_zone_t zone, void *item) --
48  *  Frees an item back to a specified zone.
49  */
50 static __inline__ void *
51 _zalloc(vm_zone_t z)
52 {
53 	void *item;
54 
55 #ifdef INVARIANTS
56 	if (z == 0)
57 		zerror(ZONE_ERROR_INVALID);
58 #endif
59 
60 	if (z->zfreecnt <= z->zfreemin) {
61 		item = _zget(z);
62 		/*
63 		 * PANICFAIL allows the caller to assume that the zalloc()
64 		 * will always succeed.  If it doesn't, we panic here.
65 		 */
66 		if (item == NULL && (z->zflags & ZONE_PANICFAIL))
67 			panic("zalloc(%s) failed", z->zname);
68 		return(item);
69 	}
70 
71 	item = z->zitems;
72 	z->zitems = ((void **) item)[0];
73 #ifdef INVARIANTS
74 	KASSERT(item != NULL, ("zitems unexpectedly NULL"));
75 	if (((void **) item)[1] != (void *) ZENTRY_FREE)
76 		zerror(ZONE_ERROR_NOTFREE);
77 	((void **) item)[1] = 0;
78 #endif
79 
80 	z->zfreecnt--;
81 	z->znalloc++;
82 	return item;
83 }
84 
85 static __inline__ void
86 _zfree(vm_zone_t z, void *item)
87 {
88 	((void **) item)[0] = z->zitems;
89 #ifdef INVARIANTS
90 	if (((void **) item)[1] == (void *) ZENTRY_FREE)
91 		zerror(ZONE_ERROR_ALREADYFREE);
92 	((void **) item)[1] = (void *) ZENTRY_FREE;
93 #endif
94 	z->zitems = item;
95 	z->zfreecnt++;
96 }
97 
98 /*
99  * This file comprises a very simple zone allocator.  This is used
100  * in lieu of the malloc allocator, where needed or more optimal.
101  *
102  * Note that the initial implementation of this had coloring, and
103  * absolutely no improvement (actually perf degradation) occurred.
104  *
105  * Note also that the zones are type stable.  The only restriction is
106  * that the first two longwords of a data structure can be changed
107  * between allocations.  Any data that must be stable between allocations
108  * must reside in areas after the first two longwords.
109  *
110  * zinitna, zinit, zbootinit are the initialization routines.
111  * zalloc, zfree, are the interrupt/lock unsafe allocation/free routines.
112  * zalloci, zfreei, are the interrupt/lock safe allocation/free routines.
113  */
114 
115 static struct vm_zone *zlist;
116 static int sysctl_vm_zone(SYSCTL_HANDLER_ARGS);
117 static int zone_kmem_pages, zone_kern_pages, zone_kmem_kvaspace;
118 
119 /*
120  * Create a zone, but don't allocate the zone structure.  If the
121  * zone had been previously created by the zone boot code, initialize
122  * various parts of the zone code.
123  *
124  * If waits are not allowed during allocation (e.g. during interrupt
125  * code), a-priori allocate the kernel virtual space, and allocate
126  * only pages when needed.
127  *
128  * Arguments:
129  * z		pointer to zone structure.
130  * obj		pointer to VM object (opt).
131  * name		name of zone.
132  * size		size of zone entries.
133  * nentries	number of zone entries allocated (only ZONE_INTERRUPT.)
134  * flags	ZONE_INTERRUPT -- items can be allocated at interrupt time.
135  * zalloc	number of pages allocated when memory is needed.
136  *
137  * Note that when using ZONE_INTERRUPT, the size of the zone is limited
138  * by the nentries argument.  The size of the memory allocatable is
139  * unlimited if ZONE_INTERRUPT is not set.
140  *
141  */
142 int
143 zinitna(vm_zone_t z, vm_object_t obj, char *name, int size,
144 	int nentries, int flags, int zalloc)
145 {
146 	int totsize;
147 
148 	if ((z->zflags & ZONE_BOOT) == 0) {
149 		z->zsize = (size + ZONE_ROUNDING - 1) & ~(ZONE_ROUNDING - 1);
150 		simple_lock_init(&z->zlock);
151 		z->zfreecnt = 0;
152 		z->ztotal = 0;
153 		z->zmax = 0;
154 		z->zname = name;
155 		z->znalloc = 0;
156 		z->zitems = NULL;
157 
158 		z->znext = zlist;
159 		zlist = z;
160 	}
161 
162 	z->zflags |= flags;
163 
164 	/*
165 	 * If we cannot wait, allocate KVA space up front, and we will fill
166 	 * in pages as needed.
167 	 */
168 	if (z->zflags & ZONE_INTERRUPT) {
169 
170 		totsize = round_page(z->zsize * nentries);
171 		zone_kmem_kvaspace += totsize;
172 
173 		z->zkva = kmem_alloc_pageable(kernel_map, totsize);
174 		if (z->zkva == 0) {
175 			zlist = z->znext;
176 			return 0;
177 		}
178 
179 		z->zpagemax = totsize / PAGE_SIZE;
180 		if (obj == NULL) {
181 			z->zobj = vm_object_allocate(OBJT_DEFAULT, z->zpagemax);
182 		} else {
183 			z->zobj = obj;
184 			_vm_object_allocate(OBJT_DEFAULT, z->zpagemax, obj);
185 		}
186 		z->zallocflag = VM_ALLOC_INTERRUPT;
187 		z->zmax += nentries;
188 	} else {
189 		z->zallocflag = VM_ALLOC_SYSTEM;
190 		z->zmax = 0;
191 	}
192 
193 
194 	if (z->zsize > PAGE_SIZE)
195 		z->zfreemin = 1;
196 	else
197 		z->zfreemin = PAGE_SIZE / z->zsize;
198 
199 	z->zpagecount = 0;
200 	if (zalloc)
201 		z->zalloc = zalloc;
202 	else
203 		z->zalloc = 1;
204 
205 	return 1;
206 }
207 
208 /*
209  * Subroutine same as zinitna, except zone data structure is allocated
210  * automatically by malloc.  This routine should normally be used, except
211  * in certain tricky startup conditions in the VM system -- then
212  * zbootinit and zinitna can be used.  Zinit is the standard zone
213  * initialization call.
214  */
215 vm_zone_t
216 zinit(char *name, int size, int nentries, int flags, int zalloc)
217 {
218 	vm_zone_t z;
219 
220 	z = (vm_zone_t) malloc(sizeof (struct vm_zone), M_ZONE, M_NOWAIT);
221 	if (z == NULL)
222 		return NULL;
223 
224 	z->zflags = 0;
225 	if (zinitna(z, NULL, name, size, nentries, flags, zalloc) == 0) {
226 		free(z, M_ZONE);
227 		return NULL;
228 	}
229 
230 	return z;
231 }
232 
233 /*
234  * Initialize a zone before the system is fully up.  This routine should
235  * only be called before full VM startup.
236  */
237 void
238 zbootinit(vm_zone_t z, char *name, int size, void *item, int nitems)
239 {
240 	int i;
241 
242 	z->zname = name;
243 	z->zsize = size;
244 	z->zpagemax = 0;
245 	z->zobj = NULL;
246 	z->zflags = ZONE_BOOT;
247 	z->zfreemin = 0;
248 	z->zallocflag = 0;
249 	z->zpagecount = 0;
250 	z->zalloc = 0;
251 	z->znalloc = 0;
252 	simple_lock_init(&z->zlock);
253 
254 	bzero(item, nitems * z->zsize);
255 	z->zitems = NULL;
256 	for (i = 0; i < nitems; i++) {
257 		((void **) item)[0] = z->zitems;
258 #ifdef INVARIANTS
259 		((void **) item)[1] = (void *) ZENTRY_FREE;
260 #endif
261 		z->zitems = item;
262 		(char *) item += z->zsize;
263 	}
264 	z->zfreecnt = nitems;
265 	z->zmax = nitems;
266 	z->ztotal = nitems;
267 
268 	if (zlist == 0) {
269 		zlist = z;
270 	} else {
271 		z->znext = zlist;
272 		zlist = z;
273 	}
274 }
275 
276 /*
277  * Zone critical region locks.
278  */
279 static __inline int
280 zlock(vm_zone_t z)
281 {
282 	int s;
283 
284 	s = splhigh();
285 	simple_lock(&z->zlock);
286 	return s;
287 }
288 
289 static __inline void
290 zunlock(vm_zone_t z, int s)
291 {
292 	simple_unlock(&z->zlock);
293 	splx(s);
294 }
295 
296 /*
297  * void *zalloc(vm_zone_t zone) --
298  *	Returns an item from a specified zone.
299  *
300  * void zfree(vm_zone_t zone, void *item) --
301  *  Frees an item back to a specified zone.
302  *
303  * void *zalloci(vm_zone_t zone) --
304  *	Returns an item from a specified zone, interrupt safe.
305  *
306  * void zfreei(vm_zone_t zone, void *item) --
307  *  Frees an item back to a specified zone, interrupt safe.
308  *
309  */
310 
311 void *
312 zalloc(vm_zone_t z)
313 {
314 #if defined(SMP)
315 	return zalloci(z);
316 #else
317 	return _zalloc(z);
318 #endif
319 }
320 
321 void
322 zfree(vm_zone_t z, void *item)
323 {
324 #ifdef SMP
325 	zfreei(z, item);
326 #else
327 	_zfree(z, item);
328 #endif
329 }
330 
331 /*
332  * Zone allocator/deallocator.  These are interrupt / (or potentially SMP)
333  * safe.  The raw zalloc/zfree routines are not interrupt safe, but are fast.
334  */
335 void *
336 zalloci(vm_zone_t z)
337 {
338 	int s;
339 	void *item;
340 
341 	s = zlock(z);
342 	item = _zalloc(z);
343 	zunlock(z, s);
344 	return item;
345 }
346 
347 void
348 zfreei(vm_zone_t z, void *item)
349 {
350 	int s;
351 
352 	s = zlock(z);
353 	_zfree(z, item);
354 	zunlock(z, s);
355 	return;
356 }
357 
358 /*
359  * Internal zone routine.  Not to be called from external (non vm_zone) code.
360  */
361 void *
362 _zget(vm_zone_t z)
363 {
364 	int i;
365 	vm_page_t m;
366 	int nitems, nbytes;
367 	void *item;
368 
369 	if (z == NULL)
370 		panic("zget: null zone");
371 
372 	if (z->zflags & ZONE_INTERRUPT) {
373 		nbytes = z->zpagecount * PAGE_SIZE;
374 		nbytes -= nbytes % z->zsize;
375 		item = (char *) z->zkva + nbytes;
376 		for (i = 0; ((i < z->zalloc) && (z->zpagecount < z->zpagemax));
377 		     i++) {
378 			vm_offset_t zkva;
379 
380 			m = vm_page_alloc(z->zobj, z->zpagecount,
381 					  z->zallocflag);
382 			if (m == NULL)
383 				break;
384 
385 			zkva = z->zkva + z->zpagecount * PAGE_SIZE;
386 			pmap_kenter(zkva, VM_PAGE_TO_PHYS(m));
387 			bzero((caddr_t) zkva, PAGE_SIZE);
388 			z->zpagecount++;
389 			zone_kmem_pages++;
390 			cnt.v_wire_count++;
391 		}
392 		nitems = ((z->zpagecount * PAGE_SIZE) - nbytes) / z->zsize;
393 	} else {
394 		nbytes = z->zalloc * PAGE_SIZE;
395 
396 		/*
397 		 * Check to see if the kernel map is already locked.  We could allow
398 		 * for recursive locks, but that eliminates a valuable debugging
399 		 * mechanism, and opens up the kernel map for potential corruption
400 		 * by inconsistent data structure manipulation.  We could also use
401 		 * the interrupt allocation mechanism, but that has size limitations.
402 		 * Luckily, we have kmem_map that is a submap of kernel map available
403 		 * for memory allocation, and manipulation of that map doesn't affect
404 		 * the kernel map structures themselves.
405 		 *
406 		 * We can wait, so just do normal map allocation in the appropriate
407 		 * map.
408 		 */
409 		if (lockstatus(&kernel_map->lock, NULL)) {
410 			int s;
411 			s = splvm();
412 #ifdef SMP
413 			simple_unlock(&z->zlock);
414 #endif
415 			item = (void *) kmem_malloc(kmem_map, nbytes, M_WAITOK);
416 #ifdef SMP
417 			simple_lock(&z->zlock);
418 #endif
419 			if (item != NULL)
420 				zone_kmem_pages += z->zalloc;
421 			splx(s);
422 		} else {
423 #ifdef SMP
424 			simple_unlock(&z->zlock);
425 #endif
426 			item = (void *) kmem_alloc(kernel_map, nbytes);
427 #ifdef SMP
428 			simple_lock(&z->zlock);
429 #endif
430 			if (item != NULL)
431 				zone_kern_pages += z->zalloc;
432 		}
433 		if (item != NULL) {
434 			bzero(item, nbytes);
435 		} else {
436 			nbytes = 0;
437 		}
438 		nitems = nbytes / z->zsize;
439 	}
440 	z->ztotal += nitems;
441 
442 	/*
443 	 * Save one for immediate allocation
444 	 */
445 	if (nitems != 0) {
446 		nitems -= 1;
447 		for (i = 0; i < nitems; i++) {
448 			((void **) item)[0] = z->zitems;
449 #ifdef INVARIANTS
450 			((void **) item)[1] = (void *) ZENTRY_FREE;
451 #endif
452 			z->zitems = item;
453 			(char *) item += z->zsize;
454 		}
455 		z->zfreecnt += nitems;
456 		z->znalloc++;
457 	} else if (z->zfreecnt > 0) {
458 		item = z->zitems;
459 		z->zitems = ((void **) item)[0];
460 #ifdef INVARIANTS
461 		if (((void **) item)[1] != (void *) ZENTRY_FREE)
462 			zerror(ZONE_ERROR_NOTFREE);
463 		((void **) item)[1] = 0;
464 #endif
465 		z->zfreecnt--;
466 		z->znalloc++;
467 	} else {
468 		item = NULL;
469 	}
470 
471 	return item;
472 }
473 
474 static int
475 sysctl_vm_zone(SYSCTL_HANDLER_ARGS)
476 {
477 	int error=0;
478 	vm_zone_t curzone, nextzone;
479 	char tmpbuf[128];
480 	char tmpname[14];
481 
482 	snprintf(tmpbuf, sizeof(tmpbuf),
483 	    "\nITEM            SIZE     LIMIT    USED    FREE  REQUESTS\n");
484 	error = SYSCTL_OUT(req, tmpbuf, strlen(tmpbuf));
485 	if (error)
486 		return (error);
487 
488 	for (curzone = zlist; curzone; curzone = nextzone) {
489 		int i;
490 		int len;
491 		int offset;
492 
493 		nextzone = curzone->znext;
494 		len = strlen(curzone->zname);
495 		if (len >= (sizeof(tmpname) - 1))
496 			len = (sizeof(tmpname) - 1);
497 		for(i = 0; i < sizeof(tmpname) - 1; i++)
498 			tmpname[i] = ' ';
499 		tmpname[i] = 0;
500 		memcpy(tmpname, curzone->zname, len);
501 		tmpname[len] = ':';
502 		offset = 0;
503 		if (curzone == zlist) {
504 			offset = 1;
505 			tmpbuf[0] = '\n';
506 		}
507 
508 		snprintf(tmpbuf + offset, sizeof(tmpbuf) - offset,
509 			"%s %6.6u, %8.8u, %6.6u, %6.6u, %8.8u\n",
510 			tmpname, curzone->zsize, curzone->zmax,
511 			(curzone->ztotal - curzone->zfreecnt),
512 			curzone->zfreecnt, curzone->znalloc);
513 
514 		len = strlen((char *)tmpbuf);
515 		if (nextzone == NULL)
516 			tmpbuf[len - 1] = 0;
517 
518 		error = SYSCTL_OUT(req, tmpbuf, len);
519 
520 		if (error)
521 			return (error);
522 	}
523 	return (0);
524 }
525 
526 #ifdef INVARIANT_SUPPORT
527 void
528 zerror(int error)
529 {
530 	char *msg;
531 
532 	switch (error) {
533 	case ZONE_ERROR_INVALID:
534 		msg = "zone: invalid zone";
535 		break;
536 	case ZONE_ERROR_NOTFREE:
537 		msg = "zone: entry not free";
538 		break;
539 	case ZONE_ERROR_ALREADYFREE:
540 		msg = "zone: freeing free entry";
541 		break;
542 	default:
543 		msg = "zone: invalid error";
544 		break;
545 	}
546 	panic(msg);
547 }
548 #endif
549 
550 SYSCTL_OID(_vm, OID_AUTO, zone, CTLTYPE_STRING|CTLFLAG_RD, \
551 	NULL, 0, sysctl_vm_zone, "A", "Zone Info");
552 
553 SYSCTL_INT(_vm, OID_AUTO, zone_kmem_pages,
554 	CTLFLAG_RD, &zone_kmem_pages, 0, "Number of interrupt safe pages allocated by zone");
555 SYSCTL_INT(_vm, OID_AUTO, zone_kmem_kvaspace,
556 	CTLFLAG_RD, &zone_kmem_kvaspace, 0, "KVA space allocated by zone");
557 SYSCTL_INT(_vm, OID_AUTO, zone_kern_pages,
558 	CTLFLAG_RD, &zone_kern_pages, 0, "Number of non-interrupt safe pages allocated by zone");
559