Get rid of VPLACEMARKER and retool vmntvnodescan() to use a secondary
[dragonfly.git] / sys / kern / kern_slaballoc.c
CommitLineData
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1/*
2 * KERN_SLABALLOC.C - Kernel SLAB memory allocator
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3 *
4 * Copyright (c) 2003,2004 The DragonFly Project. All rights reserved.
5 *
6 * This code is derived from software contributed to The DragonFly Project
7 * by Matthew Dillon <dillon@backplane.com>
8 *
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9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
8c10bfcf 12 *
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13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
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16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
18 * distribution.
19 * 3. Neither the name of The DragonFly Project nor the names of its
20 * contributors may be used to endorse or promote products derived
21 * from this software without specific, prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
26 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
27 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
28 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
29 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
30 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
31 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
32 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
33 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
a108bf71 34 * SUCH DAMAGE.
8c10bfcf 35 *
4c9f5a7f 36 * $DragonFly: src/sys/kern/kern_slaballoc.c,v 1.29 2005/04/13 04:00:50 dillon Exp $
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37 *
38 * This module implements a slab allocator drop-in replacement for the
39 * kernel malloc().
40 *
41 * A slab allocator reserves a ZONE for each chunk size, then lays the
42 * chunks out in an array within the zone. Allocation and deallocation
43 * is nearly instantanious, and fragmentation/overhead losses are limited
44 * to a fixed worst-case amount.
45 *
46 * The downside of this slab implementation is in the chunk size
47 * multiplied by the number of zones. ~80 zones * 128K = 10MB of VM per cpu.
48 * In a kernel implementation all this memory will be physical so
49 * the zone size is adjusted downward on machines with less physical
50 * memory. The upside is that overhead is bounded... this is the *worst*
51 * case overhead.
52 *
53 * Slab management is done on a per-cpu basis and no locking or mutexes
54 * are required, only a critical section. When one cpu frees memory
55 * belonging to another cpu's slab manager an asynchronous IPI message
56 * will be queued to execute the operation. In addition, both the
57 * high level slab allocator and the low level zone allocator optimize
58 * M_ZERO requests, and the slab allocator does not have to pre initialize
59 * the linked list of chunks.
60 *
61 * XXX Balancing is needed between cpus. Balance will be handled through
62 * asynchronous IPIs primarily by reassigning the z_Cpu ownership of chunks.
63 *
64 * XXX If we have to allocate a new zone and M_USE_RESERVE is set, use of
65 * the new zone should be restricted to M_USE_RESERVE requests only.
66 *
67 * Alloc Size Chunking Number of zones
68 * 0-127 8 16
69 * 128-255 16 8
70 * 256-511 32 8
71 * 512-1023 64 8
72 * 1024-2047 128 8
73 * 2048-4095 256 8
74 * 4096-8191 512 8
75 * 8192-16383 1024 8
76 * 16384-32767 2048 8
77 * (if PAGE_SIZE is 4K the maximum zone allocation is 16383)
78 *
46a3f46d 79 * Allocations >= ZoneLimit go directly to kmem.
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80 *
81 * API REQUIREMENTS AND SIDE EFFECTS
82 *
83 * To operate as a drop-in replacement to the FreeBSD-4.x malloc() we
84 * have remained compatible with the following API requirements:
85 *
86 * + small power-of-2 sized allocations are power-of-2 aligned (kern_tty)
3d177b31 87 * + all power-of-2 sized allocations are power-of-2 aligned (twe)
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88 * + malloc(0) is allowed and returns non-NULL (ahc driver)
89 * + ability to allocate arbitrarily large chunks of memory
90 */
91
92#include "opt_vm.h"
93
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94#include <sys/param.h>
95#include <sys/systm.h>
96#include <sys/kernel.h>
97#include <sys/slaballoc.h>
98#include <sys/mbuf.h>
99#include <sys/vmmeter.h>
100#include <sys/lock.h>
101#include <sys/thread.h>
102#include <sys/globaldata.h>
103
104#include <vm/vm.h>
105#include <vm/vm_param.h>
106#include <vm/vm_kern.h>
107#include <vm/vm_extern.h>
108#include <vm/vm_object.h>
109#include <vm/pmap.h>
110#include <vm/vm_map.h>
111#include <vm/vm_page.h>
112#include <vm/vm_pageout.h>
113
114#include <machine/cpu.h>
115
116#include <sys/thread2.h>
117
118#define arysize(ary) (sizeof(ary)/sizeof((ary)[0]))
119
120/*
121 * Fixed globals (not per-cpu)
122 */
123static int ZoneSize;
46a3f46d 124static int ZoneLimit;
a108bf71 125static int ZonePageCount;
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126static int ZoneMask;
127static struct malloc_type *kmemstatistics;
128static struct kmemusage *kmemusage;
129static int32_t weirdary[16];
130
131static void *kmem_slab_alloc(vm_size_t bytes, vm_offset_t align, int flags);
132static void kmem_slab_free(void *ptr, vm_size_t bytes);
133
134/*
135 * Misc constants. Note that allocations that are exact multiples of
136 * PAGE_SIZE, or exceed the zone limit, fall through to the kmem module.
137 * IN_SAME_PAGE_MASK is used to sanity-check the per-page free lists.
138 */
139#define MIN_CHUNK_SIZE 8 /* in bytes */
140#define MIN_CHUNK_MASK (MIN_CHUNK_SIZE - 1)
141#define ZONE_RELS_THRESH 2 /* threshold number of zones */
142#define IN_SAME_PAGE_MASK (~(intptr_t)PAGE_MASK | MIN_CHUNK_MASK)
143
144/*
145 * The WEIRD_ADDR is used as known text to copy into free objects to
146 * try to create deterministic failure cases if the data is accessed after
147 * free.
148 */
149#define WEIRD_ADDR 0xdeadc0de
150#define MAX_COPY sizeof(weirdary)
151#define ZERO_LENGTH_PTR ((void *)-8)
152
153/*
154 * Misc global malloc buckets
155 */
156
157MALLOC_DEFINE(M_CACHE, "cache", "Various Dynamically allocated caches");
158MALLOC_DEFINE(M_DEVBUF, "devbuf", "device driver memory");
159MALLOC_DEFINE(M_TEMP, "temp", "misc temporary data buffers");
160
161MALLOC_DEFINE(M_IP6OPT, "ip6opt", "IPv6 options");
162MALLOC_DEFINE(M_IP6NDP, "ip6ndp", "IPv6 Neighbor Discovery");
163
164/*
165 * Initialize the slab memory allocator. We have to choose a zone size based
166 * on available physical memory. We choose a zone side which is approximately
167 * 1/1024th of our memory, so if we have 128MB of ram we have a zone size of
168 * 128K. The zone size is limited to the bounds set in slaballoc.h
169 * (typically 32K min, 128K max).
170 */
171static void kmeminit(void *dummy);
172
173SYSINIT(kmem, SI_SUB_KMEM, SI_ORDER_FIRST, kmeminit, NULL)
174
175static void
176kmeminit(void *dummy)
177{
178 vm_poff_t limsize;
179 int usesize;
180 int i;
181 vm_pindex_t npg;
182
183 limsize = (vm_poff_t)vmstats.v_page_count * PAGE_SIZE;
184 if (limsize > VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS)
185 limsize = VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS;
186
187 usesize = (int)(limsize / 1024); /* convert to KB */
188
189 ZoneSize = ZALLOC_MIN_ZONE_SIZE;
190 while (ZoneSize < ZALLOC_MAX_ZONE_SIZE && (ZoneSize << 1) < usesize)
191 ZoneSize <<= 1;
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192 ZoneLimit = ZoneSize / 4;
193 if (ZoneLimit > ZALLOC_ZONE_LIMIT)
194 ZoneLimit = ZALLOC_ZONE_LIMIT;
a108bf71 195 ZoneMask = ZoneSize - 1;
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196 ZonePageCount = ZoneSize / PAGE_SIZE;
197
198 npg = (VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS) / PAGE_SIZE;
dc1fd4b3 199 kmemusage = kmem_slab_alloc(npg * sizeof(struct kmemusage), PAGE_SIZE, M_WAITOK|M_ZERO);
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200
201 for (i = 0; i < arysize(weirdary); ++i)
202 weirdary[i] = WEIRD_ADDR;
203
204 if (bootverbose)
205 printf("Slab ZoneSize set to %dKB\n", ZoneSize / 1024);
206}
207
208/*
bba6a44d 209 * Initialize a malloc type tracking structure.
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210 */
211void
212malloc_init(void *data)
213{
214 struct malloc_type *type = data;
215 vm_poff_t limsize;
216
217 if (type->ks_magic != M_MAGIC)
218 panic("malloc type lacks magic");
219
220 if (type->ks_limit != 0)
221 return;
222
223 if (vmstats.v_page_count == 0)
224 panic("malloc_init not allowed before vm init");
225
226 limsize = (vm_poff_t)vmstats.v_page_count * PAGE_SIZE;
227 if (limsize > VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS)
228 limsize = VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS;
229 type->ks_limit = limsize / 10;
230
231 type->ks_next = kmemstatistics;
232 kmemstatistics = type;
233}
234
235void
236malloc_uninit(void *data)
237{
238 struct malloc_type *type = data;
239 struct malloc_type *t;
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240#ifdef INVARIANTS
241 int i;
1d712609 242 long ttl;
bba6a44d 243#endif
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244
245 if (type->ks_magic != M_MAGIC)
246 panic("malloc type lacks magic");
247
248 if (vmstats.v_page_count == 0)
249 panic("malloc_uninit not allowed before vm init");
250
251 if (type->ks_limit == 0)
252 panic("malloc_uninit on uninitialized type");
253
254#ifdef INVARIANTS
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255 /*
256 * memuse is only correct in aggregation. Due to memory being allocated
257 * on one cpu and freed on another individual array entries may be
258 * negative or positive (canceling each other out).
259 */
260 for (i = ttl = 0; i < ncpus; ++i)
261 ttl += type->ks_memuse[i];
262 if (ttl) {
263 printf("malloc_uninit: %ld bytes of '%s' still allocated on cpu %d\n",
264 ttl, type->ks_shortdesc, i);
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265 }
266#endif
267 if (type == kmemstatistics) {
268 kmemstatistics = type->ks_next;
269 } else {
270 for (t = kmemstatistics; t->ks_next != NULL; t = t->ks_next) {
271 if (t->ks_next == type) {
272 t->ks_next = type->ks_next;
273 break;
274 }
275 }
276 }
277 type->ks_next = NULL;
278 type->ks_limit = 0;
279}
280
281/*
282 * Calculate the zone index for the allocation request size and set the
283 * allocation request size to that particular zone's chunk size.
284 */
285static __inline int
286zoneindex(unsigned long *bytes)
287{
288 unsigned int n = (unsigned int)*bytes; /* unsigned for shift opt */
289 if (n < 128) {
290 *bytes = n = (n + 7) & ~7;
291 return(n / 8 - 1); /* 8 byte chunks, 16 zones */
292 }
293 if (n < 256) {
294 *bytes = n = (n + 15) & ~15;
295 return(n / 16 + 7);
296 }
297 if (n < 8192) {
298 if (n < 512) {
299 *bytes = n = (n + 31) & ~31;
300 return(n / 32 + 15);
301 }
302 if (n < 1024) {
303 *bytes = n = (n + 63) & ~63;
304 return(n / 64 + 23);
305 }
306 if (n < 2048) {
307 *bytes = n = (n + 127) & ~127;
308 return(n / 128 + 31);
309 }
310 if (n < 4096) {
311 *bytes = n = (n + 255) & ~255;
312 return(n / 256 + 39);
313 }
314 *bytes = n = (n + 511) & ~511;
315 return(n / 512 + 47);
316 }
317#if ZALLOC_ZONE_LIMIT > 8192
318 if (n < 16384) {
319 *bytes = n = (n + 1023) & ~1023;
320 return(n / 1024 + 55);
321 }
322#endif
323#if ZALLOC_ZONE_LIMIT > 16384
324 if (n < 32768) {
325 *bytes = n = (n + 2047) & ~2047;
326 return(n / 2048 + 63);
327 }
328#endif
329 panic("Unexpected byte count %d", n);
330 return(0);
331}
332
333/*
334 * malloc() (SLAB ALLOCATOR)
335 *
336 * Allocate memory via the slab allocator. If the request is too large,
337 * or if it page-aligned beyond a certain size, we fall back to the
338 * KMEM subsystem. A SLAB tracking descriptor must be specified, use
339 * &SlabMisc if you don't care.
340 *
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341 * M_RNOWAIT - don't block.
342 * M_NULLOK - return NULL instead of blocking.
a108bf71 343 * M_ZERO - zero the returned memory.
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344 * M_USE_RESERVE - allow greater drawdown of the free list
345 * M_USE_INTERRUPT_RESERVE - allow the freelist to be exhausted
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346 */
347void *
348malloc(unsigned long size, struct malloc_type *type, int flags)
349{
350 SLZone *z;
351 SLChunk *chunk;
352 SLGlobalData *slgd;
bba6a44d 353 struct globaldata *gd;
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354 int zi;
355
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356 gd = mycpu;
357 slgd = &gd->gd_slab;
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358
359 /*
360 * XXX silly to have this in the critical path.
361 */
362 if (type->ks_limit == 0) {
363 crit_enter();
364 if (type->ks_limit == 0)
365 malloc_init(type);
366 crit_exit();
367 }
368 ++type->ks_calls;
369
370 /*
371 * Handle the case where the limit is reached. Panic if can't return
372 * NULL. XXX the original malloc code looped, but this tended to
373 * simply deadlock the computer.
374 */
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375 while (type->ks_loosememuse >= type->ks_limit) {
376 int i;
377 long ttl;
378
379 for (i = ttl = 0; i < ncpus; ++i)
380 ttl += type->ks_memuse[i];
381 type->ks_loosememuse = ttl;
382 if (ttl >= type->ks_limit) {
8cb2bf45 383 if (flags & M_NULLOK)
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384 return(NULL);
385 panic("%s: malloc limit exceeded", type->ks_shortdesc);
386 }
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387 }
388
389 /*
390 * Handle the degenerate size == 0 case. Yes, this does happen.
391 * Return a special pointer. This is to maintain compatibility with
392 * the original malloc implementation. Certain devices, such as the
393 * adaptec driver, not only allocate 0 bytes, they check for NULL and
394 * also realloc() later on. Joy.
395 */
396 if (size == 0)
397 return(ZERO_LENGTH_PTR);
398
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399 /*
400 * Handle hysteresis from prior frees here in malloc(). We cannot
401 * safely manipulate the kernel_map in free() due to free() possibly
402 * being called via an IPI message or from sensitive interrupt code.
403 */
dc1fd4b3 404 while (slgd->NFreeZones > ZONE_RELS_THRESH && (flags & M_RNOWAIT) == 0) {
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405 crit_enter();
406 if (slgd->NFreeZones > ZONE_RELS_THRESH) { /* crit sect race */
407 z = slgd->FreeZones;
408 slgd->FreeZones = z->z_Next;
409 --slgd->NFreeZones;
410 kmem_slab_free(z, ZoneSize); /* may block */
411 }
412 crit_exit();
413 }
414 /*
415 * XXX handle oversized frees that were queued from free().
416 */
dc1fd4b3 417 while (slgd->FreeOvZones && (flags & M_RNOWAIT) == 0) {
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418 crit_enter();
419 if ((z = slgd->FreeOvZones) != NULL) {
420 KKASSERT(z->z_Magic == ZALLOC_OVSZ_MAGIC);
421 slgd->FreeOvZones = z->z_Next;
422 kmem_slab_free(z, z->z_ChunkSize); /* may block */
423 }
424 crit_exit();
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425 }
426
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427 /*
428 * Handle large allocations directly. There should not be very many of
429 * these so performance is not a big issue.
430 *
431 * Guarentee page alignment for allocations in multiples of PAGE_SIZE
432 */
46a3f46d 433 if (size >= ZoneLimit || (size & PAGE_MASK) == 0) {
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434 struct kmemusage *kup;
435
436 size = round_page(size);
437 chunk = kmem_slab_alloc(size, PAGE_SIZE, flags);
438 if (chunk == NULL)
439 return(NULL);
440 flags &= ~M_ZERO; /* result already zero'd if M_ZERO was set */
8f1d5415 441 flags |= M_PASSIVE_ZERO;
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442 kup = btokup(chunk);
443 kup->ku_pagecnt = size / PAGE_SIZE;
bba6a44d 444 kup->ku_cpu = gd->gd_cpuid;
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445 crit_enter();
446 goto done;
447 }
448
449 /*
450 * Attempt to allocate out of an existing zone. First try the free list,
451 * then allocate out of unallocated space. If we find a good zone move
452 * it to the head of the list so later allocations find it quickly
453 * (we might have thousands of zones in the list).
454 *
455 * Note: zoneindex() will panic of size is too large.
456 */
457 zi = zoneindex(&size);
458 KKASSERT(zi < NZONES);
459 crit_enter();
460 if ((z = slgd->ZoneAry[zi]) != NULL) {
461 KKASSERT(z->z_NFree > 0);
462
463 /*
464 * Remove us from the ZoneAry[] when we become empty
465 */
466 if (--z->z_NFree == 0) {
467 slgd->ZoneAry[zi] = z->z_Next;
468 z->z_Next = NULL;
469 }
470
471 /*
472 * Locate a chunk in a free page. This attempts to localize
473 * reallocations into earlier pages without us having to sort
474 * the chunk list. A chunk may still overlap a page boundary.
475 */
476 while (z->z_FirstFreePg < ZonePageCount) {
477 if ((chunk = z->z_PageAry[z->z_FirstFreePg]) != NULL) {
478#ifdef DIAGNOSTIC
479 /*
480 * Diagnostic: c_Next is not total garbage.
481 */
482 KKASSERT(chunk->c_Next == NULL ||
483 ((intptr_t)chunk->c_Next & IN_SAME_PAGE_MASK) ==
484 ((intptr_t)chunk & IN_SAME_PAGE_MASK));
485#endif
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486#ifdef INVARIANTS
487 if ((uintptr_t)chunk < VM_MIN_KERNEL_ADDRESS)
a108bf71 488 panic("chunk %p FFPG %d/%d", chunk, z->z_FirstFreePg, ZonePageCount);
6ab8e1da 489 if (chunk->c_Next && (uintptr_t)chunk->c_Next < VM_MIN_KERNEL_ADDRESS)
a108bf71 490 panic("chunkNEXT %p %p FFPG %d/%d", chunk, chunk->c_Next, z->z_FirstFreePg, ZonePageCount);
6ab8e1da 491#endif
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492 z->z_PageAry[z->z_FirstFreePg] = chunk->c_Next;
493 goto done;
494 }
495 ++z->z_FirstFreePg;
496 }
497
498 /*
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499 * No chunks are available but NFree said we had some memory, so
500 * it must be available in the never-before-used-memory area
501 * governed by UIndex. The consequences are very serious if our zone
502 * got corrupted so we use an explicit panic rather then a KASSERT.
a108bf71 503 */
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504 if (z->z_UIndex + 1 != z->z_NMax)
505 z->z_UIndex = z->z_UIndex + 1;
506 else
507 z->z_UIndex = 0;
508 if (z->z_UIndex == z->z_UEndIndex)
509 panic("slaballoc: corrupted zone");
510 chunk = (SLChunk *)(z->z_BasePtr + z->z_UIndex * size);
8f1d5415 511 if ((z->z_Flags & SLZF_UNOTZEROD) == 0) {
6ab8e1da 512 flags &= ~M_ZERO;
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MD
513 flags |= M_PASSIVE_ZERO;
514 }
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515 goto done;
516 }
517
518 /*
519 * If all zones are exhausted we need to allocate a new zone for this
520 * index. Use M_ZERO to take advantage of pre-zerod pages. Also see
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521 * UAlloc use above in regards to M_ZERO. Note that when we are reusing
522 * a zone from the FreeZones list UAlloc'd data will not be zero'd, and
523 * we do not pre-zero it because we do not want to mess up the L1 cache.
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524 *
525 * At least one subsystem, the tty code (see CROUND) expects power-of-2
526 * allocations to be power-of-2 aligned. We maintain compatibility by
527 * adjusting the base offset below.
528 */
529 {
530 int off;
531
532 if ((z = slgd->FreeZones) != NULL) {
533 slgd->FreeZones = z->z_Next;
534 --slgd->NFreeZones;
535 bzero(z, sizeof(SLZone));
6ab8e1da 536 z->z_Flags |= SLZF_UNOTZEROD;
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537 } else {
538 z = kmem_slab_alloc(ZoneSize, ZoneSize, flags|M_ZERO);
539 if (z == NULL)
540 goto fail;
541 }
542
543 /*
544 * Guarentee power-of-2 alignment for power-of-2-sized chunks.
545 * Otherwise just 8-byte align the data.
546 */
547 if ((size | (size - 1)) + 1 == (size << 1))
548 off = (sizeof(SLZone) + size - 1) & ~(size - 1);
549 else
550 off = (sizeof(SLZone) + MIN_CHUNK_MASK) & ~MIN_CHUNK_MASK;
551 z->z_Magic = ZALLOC_SLAB_MAGIC;
552 z->z_ZoneIndex = zi;
553 z->z_NMax = (ZoneSize - off) / size;
554 z->z_NFree = z->z_NMax - 1;
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555 z->z_BasePtr = (char *)z + off;
556 z->z_UIndex = z->z_UEndIndex = slgd->JunkIndex % z->z_NMax;
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557 z->z_ChunkSize = size;
558 z->z_FirstFreePg = ZonePageCount;
2db3b277 559 z->z_CpuGd = gd;
bba6a44d 560 z->z_Cpu = gd->gd_cpuid;
1c5ca4f3 561 chunk = (SLChunk *)(z->z_BasePtr + z->z_UIndex * size);
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562 z->z_Next = slgd->ZoneAry[zi];
563 slgd->ZoneAry[zi] = z;
8f1d5415 564 if ((z->z_Flags & SLZF_UNOTZEROD) == 0) {
6ab8e1da 565 flags &= ~M_ZERO; /* already zero'd */
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566 flags |= M_PASSIVE_ZERO;
567 }
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568
569 /*
570 * Slide the base index for initial allocations out of the next
571 * zone we create so we do not over-weight the lower part of the
572 * cpu memory caches.
573 */
574 slgd->JunkIndex = (slgd->JunkIndex + ZALLOC_SLAB_SLIDE)
575 & (ZALLOC_MAX_ZONE_SIZE - 1);
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576 }
577done:
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578 ++type->ks_inuse[gd->gd_cpuid];
579 type->ks_memuse[gd->gd_cpuid] += size;
580 type->ks_loosememuse += size;
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581 crit_exit();
582 if (flags & M_ZERO)
583 bzero(chunk, size);
bba6a44d 584#ifdef INVARIANTS
8f1d5415 585 else if ((flags & (M_ZERO|M_PASSIVE_ZERO)) == 0)
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586 chunk->c_Next = (void *)-1; /* avoid accidental double-free check */
587#endif
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588 return(chunk);
589fail:
590 crit_exit();
591 return(NULL);
592}
593
594void *
595realloc(void *ptr, unsigned long size, struct malloc_type *type, int flags)
596{
597 SLZone *z;
598 void *nptr;
599 unsigned long osize;
600
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601 KKASSERT((flags & M_ZERO) == 0); /* not supported */
602
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603 if (ptr == NULL || ptr == ZERO_LENGTH_PTR)
604 return(malloc(size, type, flags));
605 if (size == 0) {
606 free(ptr, type);
607 return(NULL);
608 }
609
610 /*
611 * Handle oversized allocations. XXX we really should require that a
612 * size be passed to free() instead of this nonsense.
613 */
614 {
615 struct kmemusage *kup;
616
617 kup = btokup(ptr);
618 if (kup->ku_pagecnt) {
619 osize = kup->ku_pagecnt << PAGE_SHIFT;
620 if (osize == round_page(size))
621 return(ptr);
622 if ((nptr = malloc(size, type, flags)) == NULL)
623 return(NULL);
624 bcopy(ptr, nptr, min(size, osize));
625 free(ptr, type);
626 return(nptr);
627 }
628 }
629
630 /*
631 * Get the original allocation's zone. If the new request winds up
632 * using the same chunk size we do not have to do anything.
633 */
634 z = (SLZone *)((uintptr_t)ptr & ~(uintptr_t)ZoneMask);
635 KKASSERT(z->z_Magic == ZALLOC_SLAB_MAGIC);
636
637 zoneindex(&size);
638 if (z->z_ChunkSize == size)
639 return(ptr);
640
641 /*
642 * Allocate memory for the new request size. Note that zoneindex has
643 * already adjusted the request size to the appropriate chunk size, which
644 * should optimize our bcopy(). Then copy and return the new pointer.
645 */
646 if ((nptr = malloc(size, type, flags)) == NULL)
647 return(NULL);
648 bcopy(ptr, nptr, min(size, z->z_ChunkSize));
649 free(ptr, type);
650 return(nptr);
651}
652
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653char *
654strdup(const char *str, struct malloc_type *type)
655{
656 int zlen; /* length inclusive of terminating NUL */
657 char *nstr;
658
659 if (str == NULL)
660 return(NULL);
661 zlen = strlen(str) + 1;
662 nstr = malloc(zlen, type, M_WAITOK);
663 bcopy(str, nstr, zlen);
664 return(nstr);
665}
666
1d712609 667#ifdef SMP
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668/*
669 * free() (SLAB ALLOCATOR)
670 *
bba6a44d 671 * Free the specified chunk of memory.
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672 */
673static
674void
675free_remote(void *ptr)
676{
677 free(ptr, *(struct malloc_type **)ptr);
678}
679
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680#endif
681
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682void
683free(void *ptr, struct malloc_type *type)
684{
685 SLZone *z;
686 SLChunk *chunk;
687 SLGlobalData *slgd;
bba6a44d 688 struct globaldata *gd;
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689 int pgno;
690
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691 gd = mycpu;
692 slgd = &gd->gd_slab;
a108bf71 693
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694 if (ptr == NULL)
695 panic("trying to free NULL pointer");
696
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697 /*
698 * Handle special 0-byte allocations
699 */
700 if (ptr == ZERO_LENGTH_PTR)
701 return;
702
703 /*
704 * Handle oversized allocations. XXX we really should require that a
705 * size be passed to free() instead of this nonsense.
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706 *
707 * This code is never called via an ipi.
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708 */
709 {
710 struct kmemusage *kup;
711 unsigned long size;
712
713 kup = btokup(ptr);
714 if (kup->ku_pagecnt) {
715 size = kup->ku_pagecnt << PAGE_SHIFT;
716 kup->ku_pagecnt = 0;
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717#ifdef INVARIANTS
718 KKASSERT(sizeof(weirdary) <= size);
719 bcopy(weirdary, ptr, sizeof(weirdary));
720#endif
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721 /*
722 * note: we always adjust our cpu's slot, not the originating
723 * cpu (kup->ku_cpuid). The statistics are in aggregate.
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724 *
725 * note: XXX we have still inherited the interrupts-can't-block
726 * assumption. An interrupt thread does not bump
727 * gd_intr_nesting_level so check TDF_INTTHREAD. This is
728 * primarily until we can fix softupdate's assumptions about free().
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729 */
730 crit_enter();
731 --type->ks_inuse[gd->gd_cpuid];
732 type->ks_memuse[gd->gd_cpuid] -= size;
81f5fc99 733 if (mycpu->gd_intr_nesting_level || (gd->gd_curthread->td_flags & TDF_INTTHREAD)) {
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734 z = (SLZone *)ptr;
735 z->z_Magic = ZALLOC_OVSZ_MAGIC;
736 z->z_Next = slgd->FreeOvZones;
737 z->z_ChunkSize = size;
738 slgd->FreeOvZones = z;
739 crit_exit();
740 } else {
bba6a44d 741 crit_exit();
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742 kmem_slab_free(ptr, size); /* may block */
743 }
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744 return;
745 }
746 }
747
748 /*
749 * Zone case. Figure out the zone based on the fact that it is
750 * ZoneSize aligned.
751 */
752 z = (SLZone *)((uintptr_t)ptr & ~(uintptr_t)ZoneMask);
753 KKASSERT(z->z_Magic == ZALLOC_SLAB_MAGIC);
754
755 /*
756 * If we do not own the zone then forward the request to the
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757 * cpu that does. Since the timing is non-critical, a passive
758 * message is sent.
a108bf71 759 */
2db3b277 760 if (z->z_CpuGd != gd) {
a108bf71 761 *(struct malloc_type **)ptr = type;
75c7ffea 762#ifdef SMP
4c9f5a7f 763 lwkt_send_ipiq_passive(z->z_CpuGd, free_remote, ptr);
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764#else
765 panic("Corrupt SLZone");
766#endif
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767 return;
768 }
769
770 if (type->ks_magic != M_MAGIC)
771 panic("free: malloc type lacks magic");
772
773 crit_enter();
774 pgno = ((char *)ptr - (char *)z) >> PAGE_SHIFT;
775 chunk = ptr;
776
bba6a44d 777#ifdef INVARIANTS
a108bf71 778 /*
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779 * Attempt to detect a double-free. To reduce overhead we only check
780 * if there appears to be link pointer at the base of the data.
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781 */
782 if (((intptr_t)chunk->c_Next - (intptr_t)z) >> PAGE_SHIFT == pgno) {
783 SLChunk *scan;
784 for (scan = z->z_PageAry[pgno]; scan; scan = scan->c_Next) {
785 if (scan == chunk)
786 panic("Double free at %p", chunk);
787 }
788 }
789#endif
790
791 /*
792 * Put weird data into the memory to detect modifications after freeing,
793 * illegal pointer use after freeing (we should fault on the odd address),
794 * and so forth. XXX needs more work, see the old malloc code.
795 */
796#ifdef INVARIANTS
797 if (z->z_ChunkSize < sizeof(weirdary))
798 bcopy(weirdary, chunk, z->z_ChunkSize);
799 else
800 bcopy(weirdary, chunk, sizeof(weirdary));
801#endif
802
803 /*
804 * Add this free non-zero'd chunk to a linked list for reuse, adjust
805 * z_FirstFreePg.
806 */
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807#ifdef INVARIANTS
808 if ((uintptr_t)chunk < VM_MIN_KERNEL_ADDRESS)
fc92d4aa 809 panic("BADFREE %p", chunk);
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810#endif
811 chunk->c_Next = z->z_PageAry[pgno];
812 z->z_PageAry[pgno] = chunk;
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813#ifdef INVARIANTS
814 if (chunk->c_Next && (uintptr_t)chunk->c_Next < VM_MIN_KERNEL_ADDRESS)
a108bf71 815 panic("BADFREE2");
6ab8e1da 816#endif
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817 if (z->z_FirstFreePg > pgno)
818 z->z_FirstFreePg = pgno;
819
820 /*
821 * Bump the number of free chunks. If it becomes non-zero the zone
822 * must be added back onto the appropriate list.
823 */
824 if (z->z_NFree++ == 0) {
825 z->z_Next = slgd->ZoneAry[z->z_ZoneIndex];
826 slgd->ZoneAry[z->z_ZoneIndex] = z;
827 }
828
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829 --type->ks_inuse[z->z_Cpu];
830 type->ks_memuse[z->z_Cpu] -= z->z_ChunkSize;
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831
832 /*
833 * If the zone becomes totally free, and there are other zones we
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834 * can allocate from, move this zone to the FreeZones list. Since
835 * this code can be called from an IPI callback, do *NOT* try to mess
836 * with kernel_map here. Hysteresis will be performed at malloc() time.
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837 */
838 if (z->z_NFree == z->z_NMax &&
839 (z->z_Next || slgd->ZoneAry[z->z_ZoneIndex] != z)
840 ) {
841 SLZone **pz;
842
843 for (pz = &slgd->ZoneAry[z->z_ZoneIndex]; z != *pz; pz = &(*pz)->z_Next)
844 ;
845 *pz = z->z_Next;
846 z->z_Magic = -1;
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847 z->z_Next = slgd->FreeZones;
848 slgd->FreeZones = z;
849 ++slgd->NFreeZones;
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850 }
851 crit_exit();
852}
853
854/*
855 * kmem_slab_alloc()
856 *
857 * Directly allocate and wire kernel memory in PAGE_SIZE chunks with the
858 * specified alignment. M_* flags are expected in the flags field.
859 *
860 * Alignment must be a multiple of PAGE_SIZE.
861 *
862 * NOTE! XXX For the moment we use vm_map_entry_reserve/release(),
863 * but when we move zalloc() over to use this function as its backend
864 * we will have to switch to kreserve/krelease and call reserve(0)
865 * after the new space is made available.
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866 *
867 * Interrupt code which has preempted other code is not allowed to
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868 * use PQ_CACHE pages. However, if an interrupt thread is run
869 * non-preemptively or blocks and then runs non-preemptively, then
870 * it is free to use PQ_CACHE pages.
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871 */
872static void *
873kmem_slab_alloc(vm_size_t size, vm_offset_t align, int flags)
874{
875 vm_size_t i;
876 vm_offset_t addr;
877 vm_offset_t offset;
1de1e800 878 int count, vmflags, base_vmflags;
dc1fd4b3 879 thread_t td;
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880 vm_map_t map = kernel_map;
881
882 size = round_page(size);
883 addr = vm_map_min(map);
884
885 /*
886 * Reserve properly aligned space from kernel_map
887 */
888 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
889 crit_enter();
890 vm_map_lock(map);
891 if (vm_map_findspace(map, vm_map_min(map), size, align, &addr)) {
892 vm_map_unlock(map);
8cb2bf45 893 if ((flags & M_NULLOK) == 0)
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894 panic("kmem_slab_alloc(): kernel_map ran out of space!");
895 crit_exit();
896 vm_map_entry_release(count);
897 return(NULL);
898 }
899 offset = addr - VM_MIN_KERNEL_ADDRESS;
900 vm_object_reference(kernel_object);
901 vm_map_insert(map, &count,
902 kernel_object, offset, addr, addr + size,
903 VM_PROT_ALL, VM_PROT_ALL, 0);
904
dc1fd4b3 905 td = curthread;
dc1fd4b3 906
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907 base_vmflags = 0;
908 if (flags & M_ZERO)
909 base_vmflags |= VM_ALLOC_ZERO;
910 if (flags & M_USE_RESERVE)
911 base_vmflags |= VM_ALLOC_SYSTEM;
912 if (flags & M_USE_INTERRUPT_RESERVE)
913 base_vmflags |= VM_ALLOC_INTERRUPT;
914 if ((flags & (M_RNOWAIT|M_WAITOK)) == 0)
915 panic("kmem_slab_alloc: bad flags %08x (%p)", flags, ((int **)&size)[-1]);
916
917
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918 /*
919 * Allocate the pages. Do not mess with the PG_ZERO flag yet.
920 */
921 for (i = 0; i < size; i += PAGE_SIZE) {
922 vm_page_t m;
923 vm_pindex_t idx = OFF_TO_IDX(offset + i);
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924
925 /*
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926 * VM_ALLOC_NORMAL can only be set if we are not preempting.
927 *
928 * VM_ALLOC_SYSTEM is automatically set if we are preempting and
929 * M_WAITOK was specified as an alternative (i.e. M_USE_RESERVE is
930 * implied in this case), though I'm sure if we really need to do
931 * that.
fe1e98d0 932 */
1de1e800 933 vmflags = base_vmflags;
c397c465 934 if (flags & M_WAITOK) {
1de1e800 935 if (td->td_preempted)
fe1e98d0 936 vmflags |= VM_ALLOC_SYSTEM;
1de1e800 937 else
dc1fd4b3 938 vmflags |= VM_ALLOC_NORMAL;
dc1fd4b3 939 }
a108bf71 940
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941 m = vm_page_alloc(kernel_object, idx, vmflags);
942
943 /*
944 * If the allocation failed we either return NULL or we retry.
945 *
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946 * If M_WAITOK is specified we wait for more memory and retry.
947 * If M_WAITOK is specified from a preemption we yield instead of
948 * wait. Livelock will not occur because the interrupt thread
949 * will not be preempting anyone the second time around after the
950 * yield.
dc1fd4b3 951 */
a108bf71 952 if (m == NULL) {
c397c465 953 if (flags & M_WAITOK) {
fe1e98d0 954 if (td->td_preempted) {
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955 vm_map_unlock(map);
956 lwkt_yield();
957 vm_map_lock(map);
958 } else {
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959 vm_map_unlock(map);
960 vm_wait();
961 vm_map_lock(map);
962 }
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963 i -= PAGE_SIZE; /* retry */
964 continue;
965 }
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966
967 /*
968 * We were unable to recover, cleanup and return NULL
969 */
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970 while (i != 0) {
971 i -= PAGE_SIZE;
972 m = vm_page_lookup(kernel_object, OFF_TO_IDX(offset + i));
973 vm_page_free(m);
974 }
975 vm_map_delete(map, addr, addr + size, &count);
976 vm_map_unlock(map);
977 crit_exit();
978 vm_map_entry_release(count);
979 return(NULL);
980 }
981 }
982
983 /*
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984 * Success!
985 *
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986 * Mark the map entry as non-pageable using a routine that allows us to
987 * populate the underlying pages.
988 */
989 vm_map_set_wired_quick(map, addr, size, &count);
990 crit_exit();
991
992 /*
993 * Enter the pages into the pmap and deal with PG_ZERO and M_ZERO.
994 */
995 for (i = 0; i < size; i += PAGE_SIZE) {
996 vm_page_t m;
997
998 m = vm_page_lookup(kernel_object, OFF_TO_IDX(offset + i));
999 m->valid = VM_PAGE_BITS_ALL;
1000 vm_page_wire(m);
1001 vm_page_wakeup(m);
1002 pmap_enter(kernel_pmap, addr + i, m, VM_PROT_ALL, 1);
1003 if ((m->flags & PG_ZERO) == 0 && (flags & M_ZERO))
1004 bzero((char *)addr + i, PAGE_SIZE);
1005 vm_page_flag_clear(m, PG_ZERO);
1006 vm_page_flag_set(m, PG_MAPPED | PG_WRITEABLE | PG_REFERENCED);
1007 }
1008 vm_map_unlock(map);
1009 vm_map_entry_release(count);
1010 return((void *)addr);
1011}
1012
1013static void
1014kmem_slab_free(void *ptr, vm_size_t size)
1015{
1016 crit_enter();
1017 vm_map_remove(kernel_map, (vm_offset_t)ptr, (vm_offset_t)ptr + size);
1018 crit_exit();
1019}
1020